# coding=utf-8
# Copyright 2023 Mistral AI and the HuggingFace Inc. team. All rights reserved.
#
# This code is based on EleutherAI's GPT-NeoX library and the GPT-NeoX
# and OPT implementations in this library. It has been modified from its
# original forms to accommodate minor architectural differences compared
# to GPT-NeoX and OPT used by the Meta AI team that trained the model.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
""" PyTorch Mistral model."""
from termcolor import colored
from tqdm import tqdm
import pandas as pd
import seaborn as sns
import matplotlib.pyplot as plt
import inspect
import math
import copy
import time
import warnings
from typing import List, Optional, Tuple, Union
import gc
import os
import tempfile
import random
import numpy as np
import warnings
import torch
import torch.nn.functional as F
import torch.utils.checkpoint
from matplotlib.colors import LinearSegmentedColormap, LogNorm
from torch import nn
from torch.nn import BCEWithLogitsLoss, CrossEntropyLoss, MSELoss
from configuration_mistral_advanced import VisionEncoderDecoderConfig
from configuration_mistral_advanced import EncoderDecoderConfig
from transformers.auto.configuration_auto import AutoConfig
from transformers.auto.modeling_auto import AutoModel, AutoModelForCausalLM
from collections import defaultdict
from transformers.activations import ACT2FN
from transformers.cache_utils import Cache, DynamicCache
from transformers.modeling_attn_mask_utils import _prepare_4d_causal_attention_mask, _prepare_4d_causal_attention_mask_for_sdpa
from transformers.modeling_outputs import BaseModelOutputWithPast, CausalLMOutputWithPast, SequenceClassifierOutputWithPast
from transformers.modeling_utils import PreTrainedModel
from transformers.utils import (
add_start_docstrings,
add_start_docstrings_to_model_forward,
is_flash_attn_2_available,
is_flash_attn_greater_or_equal_2_10,
logging,
replace_return_docstrings,
)
from configuration_mistral_advanced import MistralConfig
if is_flash_attn_2_available():
from flash_attn import flash_attn_func, flash_attn_varlen_func
from flash_attn.bert_padding import index_first_axis, pad_input, unpad_input # noqa
_flash_supports_window_size = "window_size" in list(inspect.signature(flash_attn_func).parameters)
logger = logging.get_logger(__name__)
_CONFIG_FOR_DOC = "MistralConfig"
# Copied from transformers.models.llama.modeling_llama._get_unpad_data
def _get_unpad_data(attention_mask):
seqlens_in_batch = attention_mask.sum(dim=-1, dtype=torch.int32)
indices = torch.nonzero(attention_mask.flatten(), as_tuple=False).flatten()
max_seqlen_in_batch = seqlens_in_batch.max().item()
cu_seqlens = F.pad(torch.cumsum(seqlens_in_batch, dim=0, dtype=torch.int32), (1, 0))
return (
indices,
cu_seqlens,
max_seqlen_in_batch,
)
# Copied from transformers.models.bart.modeling_bart._make_causal_mask
def _make_causal_mask(
input_ids_shape: torch.Size, dtype: torch.dtype, device: torch.device, past_key_values_length: int = 0
):
"""
Make causal mask used for bi-directional self-attention.
"""
bsz, tgt_len = input_ids_shape
mask = torch.full((tgt_len, tgt_len), torch.finfo(dtype).min, device=device)
mask_cond = torch.arange(mask.size(-1), device=device)
mask.masked_fill_(mask_cond < (mask_cond + 1).view(mask.size(-1), 1), 0)
mask = mask.to(dtype)
if past_key_values_length > 0:
mask = torch.cat([torch.zeros(tgt_len, past_key_values_length, dtype=dtype, device=device), mask], dim=-1)
return mask[None, None, :, :].expand(bsz, 1, tgt_len, tgt_len + past_key_values_length)
def _make_sliding_window_causal_mask(
input_ids_shape: torch.Size,
dtype: torch.dtype,
device: torch.device,
past_key_values_length: int = 0,
sliding_window: int = 4096,
):
"""
Make causal mask used for sliding window attention
"""
bsz, tgt_len = input_ids_shape
tensor = torch.full(
(tgt_len, tgt_len),
fill_value=1,
device=device,
)
mask = torch.tril(tensor, diagonal=0)
# make the mask banded to account for sliding window
mask = torch.triu(mask, diagonal=-sliding_window)
mask = torch.log(mask).to(dtype)
if past_key_values_length > 0:
mask = torch.cat([torch.zeros(tgt_len, past_key_values_length, dtype=dtype, device=device), mask], dim=-1)
return mask[None, None, :, :].expand(bsz, 1, tgt_len, tgt_len + past_key_values_length)
# Copied from transformers.models.bart.modeling_bart._expand_mask
def _expand_mask(mask: torch.Tensor, dtype: torch.dtype, tgt_len: Optional[int] = None):
"""
Expands attention_mask from `[bsz, seq_len]` to `[bsz, 1, tgt_seq_len, src_seq_len]`.
"""
bsz, src_len = mask.size()
tgt_len = tgt_len if tgt_len is not None else src_len
expanded_mask = mask[:, None, None, :].expand(bsz, 1, tgt_len, src_len).to(dtype)
inverted_mask = 1.0 - expanded_mask
return inverted_mask.masked_fill(inverted_mask.to(torch.bool), torch.finfo(dtype).min)
# Inverse dim formula to find dim based on number of rotations
def _yarn_find_correction_dim(num_rotations, dim, base=10000, max_position_embeddings=2048):
return (dim * math.log(max_position_embeddings/(num_rotations * 2 * math.pi)))/(2 * math.log(base))
# Find dim range bounds based on rotations
def _yarn_find_correction_range(low_rot, high_rot, dim, base=10000, max_position_embeddings=2048):
low = math.floor(_yarn_find_correction_dim(
low_rot, dim, base, max_position_embeddings))
high = math.ceil(_yarn_find_correction_dim(
high_rot, dim, base, max_position_embeddings))
return max(low, 0), min(high, dim-1) # Clamp values just in case
def _yarn_linear_ramp_mask(min, max, dim):
if min == max:
max += 0.001 # Prevent singularity
linear_func = (torch.arange(dim, dtype=torch.float32) - min) / (max - min)
ramp_func = torch.clamp(linear_func, 0, 1)
return ramp_func
def _yarn_get_mscale(scale=1):
if scale <= 1:
return 1.0
return 0.07 * math.log(scale) + 1.0
# Copied from transformers.models.llama.modeling_llama.LlamaRMSNorm with Llama->Mistral
class MistralRMSNorm(nn.Module):
def __init__(self, hidden_size, eps=1e-6):
"""
MistralRMSNorm is equivalent to T5LayerNorm
"""
super().__init__()
self.weight = nn.Parameter(torch.ones(hidden_size))
self.variance_epsilon = eps
def forward(self, hidden_states):
input_dtype = hidden_states.dtype
hidden_states = hidden_states.to(torch.float32)
variance = hidden_states.pow(2).mean(-1, keepdim=True)
hidden_states = hidden_states * torch.rsqrt(variance + self.variance_epsilon)
return self.weight * hidden_states.to(input_dtype)
# copied from transformers.models.llama.modeling_llama.LlamaRotaryEmbedding with Llama->Mistral
# TODO @Arthur no longer copied from LLama after static cache
class MistralRotaryEmbedding(nn.Module):
def __init__(self, dim, max_position_embeddings=2048, base=10000, device=None):
super().__init__()
self.dim = dim
self.max_position_embeddings = max_position_embeddings
self.base = base
inv_freq = 1.0 / (self.base ** (torch.arange(0, self.dim, 2, dtype=torch.int64).float().to(device) / self.dim))
self.register_buffer("inv_freq", inv_freq, persistent=False)
# Build here to make `torch.jit.trace` work.
self._set_cos_sin_cache(
seq_len=max_position_embeddings, device=self.inv_freq.device, dtype=torch.get_default_dtype()
)
def _set_cos_sin_cache(self, seq_len, device, dtype):
self.max_seq_len_cached = seq_len
t = torch.arange(self.max_seq_len_cached, device=device, dtype=torch.int64).type_as(self.inv_freq)
freqs = torch.outer(t, self.inv_freq)
# Different from paper, but it uses a different permutation in order to obtain the same calculation
emb = torch.cat((freqs, freqs), dim=-1)
self.register_buffer("cos_cached", emb.cos().to(dtype), persistent=False)
self.register_buffer("sin_cached", emb.sin().to(dtype), persistent=False)
def forward(self, x, seq_len=None):
# x: [bs, num_attention_heads, seq_len, head_size]
if seq_len > self.max_seq_len_cached:
self._set_cos_sin_cache(seq_len=seq_len, device=x.device, dtype=x.dtype)
return (
self.cos_cached[:seq_len].to(dtype=x.dtype),
self.sin_cached[:seq_len].to(dtype=x.dtype),
)
### YARN ADDITIONS
class MistralDynamicNTKScalingRotaryEmbedding(MistralRotaryEmbedding):
"""MistralRotaryEmbedding extended with Dynamic NTK scaling. Credits to the Reddit users /u/bloc97 and /u/emozilla"""
def __init__(self, dim, max_position_embeddings=2048, base=10000, device=None, scaling_factor=1.0):
self.scaling_factor = scaling_factor
super().__init__(dim, max_position_embeddings, base, device)
def _set_cos_sin_cache(self, seq_len, device, dtype):
self.max_seq_len_cached = seq_len
if seq_len > self.max_position_embeddings:
base = self.base * (
(self.scaling_factor * seq_len / self.max_position_embeddings) - (self.scaling_factor - 1)
) ** (self.dim / (self.dim - 2))
inv_freq = 1.0 / (base ** (torch.arange(0, self.dim, 2).float().to(device) / self.dim))
self.register_buffer("inv_freq", inv_freq, persistent=False)
t = torch.arange(self.max_seq_len_cached, device=device, dtype=self.inv_freq.dtype)
freqs = torch.einsum("i,j->ij", t, self.inv_freq)
# Different from paper, but it uses a different permutation in order to obtain the same calculation
emb = torch.cat((freqs, freqs), dim=-1)
self.register_buffer("cos_cached", emb.cos().to(dtype), persistent=False)
self.register_buffer("sin_cached", emb.sin().to(dtype), persistent=False)
class MistralLinearScalingRotaryEmbedding(MistralRotaryEmbedding):
"""MistralRotaryEmbedding extended with linear scaling. Credits to the Reddit user /u/kaiokendev"""
def __init__(self, dim, max_position_embeddings=2048, base=10000, device=None, scaling_factor=1.0):
self.scaling_factor = scaling_factor
super().__init__(dim, max_position_embeddings, base, device)
def _set_cos_sin_cache(self, seq_len, device, dtype):
self.max_seq_len_cached = seq_len
t = torch.arange(self.max_seq_len_cached, device=device, dtype=self.inv_freq.dtype)
t = t / self.scaling_factor
freqs = torch.einsum("i,j->ij", t, self.inv_freq)
# Different from paper, but it uses a different permutation in order to obtain the same calculation
emb = torch.cat((freqs, freqs), dim=-1)
self.register_buffer("cos_cached", emb.cos().to(dtype), persistent=False)
self.register_buffer("sin_cached", emb.cos().to(dtype), persistent=False)
class MistralYaRNScaledRotaryEmbedding(torch.nn.Module):
"""MistralRotaryEmbedding extended with YaRN. See: https://arxiv.org/abs/2309.00071"""
def __init__(self, dim, max_position_embeddings=2048, base=10000, scale=1, original_max_position_embeddings=2048,
extrapolation_factor=1, attn_factor=1, beta_fast=128, beta_slow=2, finetuned=False, device=None):
super().__init__()
self.dim = dim
self.max_position_embeddings = max_position_embeddings
self.base = base
self.scale = scale
self.original_max_position_embeddings = original_max_position_embeddings
self.extrapolation_factor = extrapolation_factor
self.attn_factor = attn_factor
self.beta_fast = beta_fast
self.beta_slow = beta_slow
self.yarn(device)
# Build here to make `torch.jit.trace` work.
self.max_seq_len_cached = max_position_embeddings
t = torch.arange(self.max_seq_len_cached, device=self.inv_freq.device, dtype=self.inv_freq.dtype)
freqs = torch.einsum("i,j->ij", t, self.inv_freq)
# Different from paper, but it uses a different permutation in order to obtain the same calculation
emb = torch.cat((freqs, freqs), dim=-1)
dtype = torch.get_default_dtype()
self.register_buffer("cos_cached", (emb.cos() * self.mscale).to(dtype), persistent=False)
self.register_buffer("sin_cached", (emb.sin() * self.mscale).to(dtype), persistent=False)
def forward(self, x, seq_len=None):
# x: [bs, num_attention_heads, seq_len, head_size]
# This `if` block is unlikely to be run after we build sin/cos in `__init__`. Keep the logic here just in case.
if seq_len > self.max_seq_len_cached:
self.max_seq_len_cached = seq_len
t = torch.arange(self.max_seq_len_cached, device=x.device, dtype=self.inv_freq.dtype)
freqs = torch.einsum("i,j->ij", t, self.inv_freq)
# Different from paper, but it uses a different permutation in order to obtain the same calculation
emb = torch.cat((freqs, freqs), dim=-1).to(x.device)
self.register_buffer("cos_cached", (emb.cos() * self.mscale).to(x.dtype), persistent=False)
self.register_buffer("sin_cached", (emb.sin() * self.mscale).to(x.dtype), persistent=False)
return (
self.cos_cached[:seq_len].to(dtype=x.dtype),
self.sin_cached[:seq_len].to(dtype=x.dtype),
)
def yarn(self, device):
pos_freqs = self.base ** (torch.arange(0, self.dim, 2).float().to(device) / self.dim)
inv_freq_extrapolation = 1.0 / pos_freqs
inv_freq_interpolation = 1.0 / (self.scale * pos_freqs)
low, high = _yarn_find_correction_range(self.beta_fast, self.beta_slow, self.dim, self.base, self.original_max_position_embeddings)
inv_freq_mask = (1 - _yarn_linear_ramp_mask(low, high, self.dim // 2).float().to(device)) * self.extrapolation_factor # Get n-d rotational scaling corrected for extrapolation
inv_freq = inv_freq_interpolation * (1 - inv_freq_mask) + inv_freq_extrapolation * inv_freq_mask
self.register_buffer("inv_freq", inv_freq, persistent=False)
self.mscale = float(_yarn_get_mscale(self.scale) * self.attn_factor) # Get n-d magnitude scaling corrected for interpolation
class MistralDynamicYaRNScaledRotaryEmbedding(torch.nn.Module):
"""MistralRotaryEmbedding extended with Dynamic YaRN. See: https://arxiv.org/abs/2309.00071"""
def __init__(self, dim, max_position_embeddings=2048, base=10000, original_max_position_embeddings=2048,
extrapolation_factor=1, attn_factor=1, beta_fast=128, beta_slow=2, finetuned=False, device=None):
super().__init__()
self.dim = dim
self.max_position_embeddings = max_position_embeddings
self.base = base
self.original_max_position_embeddings = original_max_position_embeddings
self.extrapolation_factor = extrapolation_factor
self.attn_factor = attn_factor
self.beta_fast = beta_fast
self.beta_slow = beta_slow
if finetuned:
self.yarn(self.max_position_embeddings / self.original_max_position_embeddings, device)
else:
inv_freq = 1.0 / \
(base ** (torch.arange(0, dim, 2).float().to(device) / dim))
self.register_buffer("inv_freq", inv_freq, persistent=False)
self.mscale = 1
# Build here to make `torch.jit.trace` work.
self.max_seq_len_cached = max_position_embeddings
t = torch.arange(self.max_seq_len_cached, device=self.inv_freq.device, dtype=torch.float32)
freqs = torch.einsum("i,j->ij", t, self.inv_freq)
# Different from paper, but it uses a different permutation in order to obtain the same calculation
emb = torch.cat((freqs, freqs), dim=-1)
dtype = torch.get_default_dtype()
self.register_buffer("cos_cached", (emb.cos() * self.mscale).to(dtype), persistent=False)
self.register_buffer("sin_cached", (emb.sin() * self.mscale).to(dtype), persistent=False)
def forward(self, x, seq_len=None):
# x: [bs, num_attention_heads, seq_len, head_size]
# This `if` block is unlikely to be run after we build sin/cos in `__init__`. Keep the logic here just in case.
if seq_len > self.max_seq_len_cached:
self.max_seq_len_cached = seq_len
self.yarn(seq_len / self.max_position_embeddings, x.device)
t = torch.arange(self.max_seq_len_cached, device=x.device, dtype=self.inv_freq.dtype)
freqs = torch.einsum("i,j->ij", t, self.inv_freq)
# Different from paper, but it uses a different permutation in order to obtain the same calculation
emb = torch.cat((freqs, freqs), dim=-1).to(x.device)
self.register_buffer("cos_cached", (emb.cos() * self.mscale).to(x.dtype), persistent=False)
self.register_buffer("sin_cached", (emb.sin() * self.mscale).to(x.dtype), persistent=False)
return (
self.cos_cached[:seq_len].to(dtype=x.dtype),
self.sin_cached[:seq_len].to(dtype=x.dtype),
)
def yarn(self, scale, device):
pos_freqs = self.base ** (torch.arange(0, self.dim, 2).float().to(device) / self.dim)
inv_freq_extrapolation = 1.0 / pos_freqs
inv_freq_interpolation = 1.0 / (scale * pos_freqs)
low, high = _yarn_find_correction_range(self.beta_fast, self.beta_slow, self.dim, self.base, self.original_max_position_embeddings)
inv_freq_mask = (1 - _yarn_linear_ramp_mask(low, high, self.dim // 2).float().to(device)) * self.extrapolation_factor # Get n-d rotational scaling corrected for extrapolation
inv_freq = inv_freq_interpolation * (1 - inv_freq_mask) + inv_freq_extrapolation * inv_freq_mask
self.register_buffer("inv_freq", inv_freq, persistent=False)
self.mscale = float(_yarn_get_mscale(scale) * self.attn_factor) # Get n-d magnitude scaling corrected for interpolation
###################
# Copied from transformers.models.llama.modeling_llama.rotate_half
def rotate_half(x):
"""Rotates half the hidden dims of the input."""
x1 = x[..., : x.shape[-1] // 2]
x2 = x[..., x.shape[-1] // 2 :]
return torch.cat((-x2, x1), dim=-1)
# copied from transformers.models.llama.modeling_llama.apply_rotary_pos_emb
# TODO @Arthur no longer copied from LLama after static cache
def apply_rotary_pos_emb(q, k, cos, sin, position_ids, unsqueeze_dim=1):
"""Applies Rotary Position Embedding to the query and key tensors.
Args:
q (`torch.Tensor`): The query tensor.
k (`torch.Tensor`): The key tensor.
cos (`torch.Tensor`): The cosine part of the rotary embedding.
sin (`torch.Tensor`): The sine part of the rotary embedding.
position_ids (`torch.Tensor`):
The position indices of the tokens corresponding to the query and key tensors. For example, this can be
used to pass offsetted position ids when working with a KV-cache.
unsqueeze_dim (`int`, *optional*, defaults to 1):
The 'unsqueeze_dim' argument specifies the dimension along which to unsqueeze cos[position_ids] and
sin[position_ids] so that they can be properly broadcasted to the dimensions of q and k. For example, note
that cos[position_ids] and sin[position_ids] have the shape [batch_size, seq_len, head_dim]. Then, if q and
k have the shape [batch_size, heads, seq_len, head_dim], then setting unsqueeze_dim=1 makes
cos[position_ids] and sin[position_ids] broadcastable to the shapes of q and k. Similarly, if q and k have
the shape [batch_size, seq_len, heads, head_dim], then set unsqueeze_dim=2.
Returns:
`tuple(torch.Tensor)` comprising of the query and key tensors rotated using the Rotary Position Embedding.
"""
cos = cos[position_ids].unsqueeze(unsqueeze_dim)
sin = sin[position_ids].unsqueeze(unsqueeze_dim)
q_embed = (q * cos) + (rotate_half(q) * sin)
k_embed = (k * cos) + (rotate_half(k) * sin)
return q_embed, k_embed
class MistralMLP(nn.Module):
def __init__(self, config):
super().__init__()
self.config = config
self.hidden_size = config.hidden_size
self.intermediate_size = config.intermediate_size
self.gate_proj = nn.Linear(self.hidden_size, self.intermediate_size, bias=False)
self.up_proj = nn.Linear(self.hidden_size, self.intermediate_size, bias=False)
self.down_proj = nn.Linear(self.intermediate_size, self.hidden_size, bias=False)
self.act_fn = ACT2FN[config.hidden_act]
def forward(self, x):
return self.down_proj(self.act_fn(self.gate_proj(x)) * self.up_proj(x))
# Copied from transformers.models.llama.modeling_llama.repeat_kv
def repeat_kv(hidden_states: torch.Tensor, n_rep: int) -> torch.Tensor:
"""
This is the equivalent of torch.repeat_interleave(x, dim=1, repeats=n_rep). The hidden states go from (batch,
num_key_value_heads, seqlen, head_dim) to (batch, num_attention_heads, seqlen, head_dim)
"""
batch, num_key_value_heads, slen, head_dim = hidden_states.shape
if n_rep == 1:
return hidden_states
hidden_states = hidden_states[:, :, None, :, :].expand(batch, num_key_value_heads, n_rep, slen, head_dim)
return hidden_states.reshape(batch, num_key_value_heads * n_rep, slen, head_dim)
class MistralAttention(nn.Module):
"""
Multi-headed attention from 'Attention Is All You Need' paper. Modified to use sliding window attention: Longformer
and "Generating Long Sequences with Sparse Transformers".
"""
def __init__(self, config: MistralConfig, layer_idx: Optional[int] = None):
super().__init__()
self.config = config
self.layer_idx = layer_idx
if layer_idx is None:
logger.warning_once(
f"Instantiating {self.__class__.__name__} without passing a `layer_idx` is not recommended and will "
"lead to errors during the forward call if caching is used. Please make sure to provide a `layer_idx` "
"when creating this class."
)
self.hidden_size = config.hidden_size
self.num_heads = config.num_attention_heads
self.head_dim = self.hidden_size // self.num_heads
self.num_key_value_heads = config.num_key_value_heads
self.num_key_value_groups = self.num_heads // self.num_key_value_heads
self.max_position_embeddings = config.max_position_embeddings
self.rope_theta = config.rope_theta
self.is_causal = True
self.attention_dropout = config.attention_dropout
if (self.head_dim * self.num_heads) != self.hidden_size:
raise ValueError(
f"hidden_size must be divisible by num_heads (got `hidden_size`: {self.hidden_size}"
f" and `num_heads`: {self.num_heads})."
)
self.q_proj = nn.Linear(self.hidden_size, self.num_heads * self.head_dim, bias=False)
self.k_proj = nn.Linear(self.hidden_size, self.num_key_value_heads * self.head_dim, bias=False)
self.v_proj = nn.Linear(self.hidden_size, self.num_key_value_heads * self.head_dim, bias=False)
self.o_proj = nn.Linear(self.num_heads * self.head_dim, self.hidden_size, bias=False)
self.rotary_emb = MistralRotaryEmbedding(
self.head_dim,
max_position_embeddings=self.max_position_embeddings,
base=self.rope_theta,
)
def _shape(self, tensor: torch.Tensor, seq_len: int, bsz: int):
return tensor.view(bsz, seq_len, self.num_heads, self.head_dim).transpose(1, 2).contiguous()
def forward(
self,
hidden_states: torch.Tensor,
attention_mask: Optional[torch.Tensor] = None,
position_ids: Optional[torch.LongTensor] = None,
past_key_value: Optional[Cache] = None,
output_attentions: bool = False,
use_cache: bool = False,
**kwargs,
) -> Tuple[torch.Tensor, Optional[torch.Tensor], Optional[Tuple[torch.Tensor]]]:
if "padding_mask" in kwargs:
warnings.warn(
"Passing `padding_mask` is deprecated and will be removed in v4.37. Please make sure use `attention_mask` instead.`"
)
bsz, q_len, _ = hidden_states.size()
query_states = self.q_proj(hidden_states)
key_states = self.k_proj(hidden_states)
value_states = self.v_proj(hidden_states)
query_states = query_states.view(bsz, q_len, self.num_heads, self.head_dim).transpose(1, 2)
key_states = key_states.view(bsz, q_len, self.num_key_value_heads, self.head_dim).transpose(1, 2)
value_states = value_states.view(bsz, q_len, self.num_key_value_heads, self.head_dim).transpose(1, 2)
kv_seq_len = key_states.shape[-2]
if past_key_value is not None:
if self.layer_idx is None:
raise ValueError(
f"The cache structure has changed since version v4.36. If you are using {self.__class__.__name__} "
"for auto-regressive decoding with k/v caching, please make sure to initialize the attention class "
"with a layer index."
)
kv_seq_len += past_key_value.get_usable_length(kv_seq_len, self.layer_idx)
cos, sin = self.rotary_emb(value_states, seq_len=kv_seq_len)
query_states, key_states = apply_rotary_pos_emb(query_states, key_states, cos, sin, position_ids)
if past_key_value is not None:
cache_kwargs = {"sin": sin, "cos": cos} # Specific to RoPE models
key_states, value_states = past_key_value.update(key_states, value_states, self.layer_idx, cache_kwargs)
# repeat k/v heads if n_kv_heads < n_heads
key_states = repeat_kv(key_states, self.num_key_value_groups)
value_states = repeat_kv(value_states, self.num_key_value_groups)
attn_weights = torch.matmul(query_states, key_states.transpose(2, 3)) / math.sqrt(self.head_dim)
if attn_weights.size() != (bsz, self.num_heads, q_len, kv_seq_len):
raise ValueError(
f"Attention weights should be of size {(bsz, self.num_heads, q_len, kv_seq_len)}, but is"
f" {attn_weights.size()}"
)
if attention_mask is not None:
if attention_mask.size() != (bsz, 1, q_len, kv_seq_len):
raise ValueError(
f"Attention mask should be of size {(bsz, 1, q_len, kv_seq_len)}, but is {attention_mask.size()}"
)
attn_weights = attn_weights + attention_mask
# upcast attention to fp32
attn_weights = nn.functional.softmax(attn_weights, dim=-1, dtype=torch.float32).to(query_states.dtype)
attn_weights = nn.functional.dropout(attn_weights, p=self.attention_dropout, training=self.training)
attn_output = torch.matmul(attn_weights, value_states)
if attn_output.size() != (bsz, self.num_heads, q_len, self.head_dim):
raise ValueError(
f"`attn_output` should be of size {(bsz, self.num_heads, q_len, self.head_dim)}, but is"
f" {attn_output.size()}"
)
attn_output = attn_output.transpose(1, 2).contiguous()
attn_output = attn_output.reshape(bsz, q_len, self.hidden_size)
attn_output = self.o_proj(attn_output)
if not output_attentions:
attn_weights = None
return attn_output, attn_weights, past_key_value
class MistralFlashAttention2(MistralAttention):
"""
Mistral flash attention module. This module inherits from `MistralAttention` as the weights of the module stays
untouched. The only required change would be on the forward pass where it needs to correctly call the public API of
flash attention and deal with padding tokens in case the input contains any of them.
"""
# Copied from transformers.models.llama.modeling_llama.LlamaFlashAttention2.__init__
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
# TODO: Should be removed once Flash Attention for RoCm is bumped to 2.1.
# flash_attn<2.1 generates top-left aligned causal mask, while what is needed here is bottom-right alignement, that was made default for flash_attn>=2.1. This attribute is used to handle this difference. Reference: https://github.com/Dao-AILab/flash-attention/releases/tag/v2.1.0.
# Beware that with flash_attn<2.1, using q_seqlen != k_seqlen (except for the case q_seqlen == 1) produces a wrong mask (top-left).
self._flash_attn_uses_top_left_mask = not is_flash_attn_greater_or_equal_2_10()
def forward(
self,
hidden_states: torch.Tensor,
attention_mask: Optional[torch.Tensor] = None,
position_ids: Optional[torch.LongTensor] = None,
past_key_value: Optional[Cache] = None,
output_attentions: bool = False,
use_cache: bool = False,
**kwargs,
):
if "padding_mask" in kwargs:
warnings.warn(
"Passing `padding_mask` is deprecated and will be removed in v4.37. Please make sure use `attention_mask` instead.`"
)
# overwrite attention_mask with padding_mask
attention_mask = kwargs.pop("padding_mask")
bsz, q_len, _ = hidden_states.size()
query_states = self.q_proj(hidden_states)
key_states = self.k_proj(hidden_states)
value_states = self.v_proj(hidden_states)
query_states = query_states.view(bsz, q_len, self.num_heads, self.head_dim).transpose(1, 2)
key_states = key_states.view(bsz, q_len, self.num_key_value_heads, self.head_dim).transpose(1, 2)
value_states = value_states.view(bsz, q_len, self.num_key_value_heads, self.head_dim).transpose(1, 2)
kv_seq_len = key_states.shape[-2]
if past_key_value is not None:
if self.layer_idx is None:
raise ValueError(
f"The cache structure has changed since version v4.36. If you are using {self.__class__.__name__} "
"for auto-regressive decoding with k/v caching, please make sure to initialize the attention class "
"with a layer index."
)
kv_seq_len += past_key_value.get_usable_length(kv_seq_len, self.layer_idx)
# Because the input can be padded, the absolute sequence length depends on the max position id.
rotary_seq_len = max(kv_seq_len, position_ids[:, -1].max().item()) + 1
cos, sin = self.rotary_emb(value_states, seq_len=rotary_seq_len)
query_states, key_states = apply_rotary_pos_emb(query_states, key_states, cos, sin, position_ids)
use_sliding_windows = (
_flash_supports_window_size
and getattr(self.config, "sliding_window", None) is not None
and kv_seq_len > self.config.sliding_window
)
if not _flash_supports_window_size:
logger.warning_once(
"The current flash attention version does not support sliding window attention, for a more memory efficient implementation"
" make sure to upgrade flash-attn library."
)
if past_key_value is not None:
# Activate slicing cache only if the config has a value `sliding_windows` attribute
cache_has_contents = past_key_value.get_seq_length(self.layer_idx) > 0
if (
getattr(self.config, "sliding_window", None) is not None
and kv_seq_len > self.config.sliding_window
and cache_has_contents
):
slicing_tokens = 1 - self.config.sliding_window
past_key = past_key_value[self.layer_idx][0]
past_value = past_key_value[self.layer_idx][1]
past_key = past_key[:, :, slicing_tokens:, :].contiguous()
past_value = past_value[:, :, slicing_tokens:, :].contiguous()
if past_key.shape[-2] != self.config.sliding_window - 1:
raise ValueError(
f"past key must have a shape of (`batch_size, num_heads, self.config.sliding_window-1, head_dim`), got"
f" {past_key.shape}"
)
if attention_mask is not None:
attention_mask = attention_mask[:, slicing_tokens:]
attention_mask = torch.cat([attention_mask, torch.ones_like(attention_mask[:, -1:])], dim=-1)
cache_kwargs = {"sin": sin, "cos": cos} # Specific to RoPE models
key_states, value_states = past_key_value.update(key_states, value_states, self.layer_idx, cache_kwargs)
# repeat k/v heads if n_kv_heads < n_heads
key_states = repeat_kv(key_states, self.num_key_value_groups)
value_states = repeat_kv(value_states, self.num_key_value_groups)
dropout_rate = 0.0 if not self.training else self.attention_dropout
# In PEFT, usually we cast the layer norms in float32 for training stability reasons
# therefore the input hidden states gets silently casted in float32. Hence, we need
# cast them back in float16 just to be sure everything works as expected.
input_dtype = query_states.dtype
if input_dtype == torch.float32:
if torch.is_autocast_enabled():
target_dtype = torch.get_autocast_gpu_dtype()
# Handle the case where the model is quantized
elif hasattr(self.config, "_pre_quantization_dtype"):
target_dtype = self.config._pre_quantization_dtype
else:
target_dtype = self.q_proj.weight.dtype
logger.warning_once(
f"The input hidden states seems to be silently casted in float32, this might be related to"
f" the fact you have upcasted embedding or layer norm layers in float32. We will cast back the input in"
f" {target_dtype}."
)
query_states = query_states.to(target_dtype)
key_states = key_states.to(target_dtype)
value_states = value_states.to(target_dtype)
# Reashape to the expected shape for Flash Attention
query_states = query_states.transpose(1, 2)
key_states = key_states.transpose(1, 2)
value_states = value_states.transpose(1, 2)
attn_output = self._flash_attention_forward(
query_states,
key_states,
value_states,
attention_mask,
q_len,
dropout=dropout_rate,
use_sliding_windows=use_sliding_windows,
)
attn_output = attn_output.reshape(bsz, q_len, self.hidden_size).contiguous()
attn_output = self.o_proj(attn_output)
if not output_attentions:
attn_weights = None
return attn_output, attn_weights, past_key_value
def _flash_attention_forward(
self,
query_states,
key_states,
value_states,
attention_mask,
query_length,
dropout=0.0,
softmax_scale=None,
use_sliding_windows=False,
):
"""
Calls the forward method of Flash Attention - if the input hidden states contain at least one padding token
first unpad the input, then computes the attention scores and pad the final attention scores.
Args:
query_states (`torch.Tensor`):
Input query states to be passed to Flash Attention API
key_states (`torch.Tensor`):
Input key states to be passed to Flash Attention API
value_states (`torch.Tensor`):
Input value states to be passed to Flash Attention API
attention_mask (`torch.Tensor`):
The padding mask - corresponds to a tensor of size `(batch_size, seq_len)` where 0 stands for the
position of padding tokens and 1 for the position of non-padding tokens.
dropout (`float`):
Attention dropout
softmax_scale (`float`, *optional*):
The scaling of QK^T before applying softmax. Default to 1 / sqrt(head_dim)
use_sliding_windows (`bool`, *optional*):
Whether to activate sliding window attention.
"""
if not self._flash_attn_uses_top_left_mask:
causal = self.is_causal
else:
# TODO: Remove the `query_length != 1` check once Flash Attention for RoCm is bumped to 2.1. For details, please see the comment in LlamaFlashAttention2 __init__.
causal = self.is_causal and query_length != 1
# Contains at least one padding token in the sequence
if attention_mask is not None:
batch_size = query_states.shape[0]
query_states, key_states, value_states, indices_q, cu_seq_lens, max_seq_lens = self._upad_input(
query_states, key_states, value_states, attention_mask, query_length
)
cu_seqlens_q, cu_seqlens_k = cu_seq_lens
max_seqlen_in_batch_q, max_seqlen_in_batch_k = max_seq_lens
if not use_sliding_windows:
attn_output_unpad = flash_attn_varlen_func(
query_states,
key_states,
value_states,
cu_seqlens_q=cu_seqlens_q,
cu_seqlens_k=cu_seqlens_k,
max_seqlen_q=max_seqlen_in_batch_q,
max_seqlen_k=max_seqlen_in_batch_k,
dropout_p=dropout,
softmax_scale=softmax_scale,
causal=causal,
)
else:
attn_output_unpad = flash_attn_varlen_func(
query_states,
key_states,
value_states,
cu_seqlens_q=cu_seqlens_q,
cu_seqlens_k=cu_seqlens_k,
max_seqlen_q=max_seqlen_in_batch_q,
max_seqlen_k=max_seqlen_in_batch_k,
dropout_p=dropout,
softmax_scale=softmax_scale,
causal=causal,
window_size=(self.config.sliding_window, self.config.sliding_window),
)
attn_output = pad_input(attn_output_unpad, indices_q, batch_size, query_length)
else:
if not use_sliding_windows:
attn_output = flash_attn_func(
query_states,
key_states,
value_states,
dropout,
softmax_scale=softmax_scale,
causal=causal,
)
else:
attn_output = flash_attn_func(
query_states,
key_states,
value_states,
dropout,
softmax_scale=softmax_scale,
causal=causal,
window_size=(self.config.sliding_window, self.config.sliding_window),
)
return attn_output
def _upad_input(self, query_layer, key_layer, value_layer, attention_mask, query_length):
batch_size, kv_seq_len, num_heads, head_dim = key_layer.shape
# On the first iteration we need to properly re-create the padding mask
# by slicing it on the proper place
if kv_seq_len != attention_mask.shape[-1]:
attention_mask_num_tokens = attention_mask.shape[-1]
attention_mask = attention_mask[:, attention_mask_num_tokens - kv_seq_len :]
indices_k, cu_seqlens_k, max_seqlen_in_batch_k = _get_unpad_data(attention_mask)
key_layer = index_first_axis(key_layer.reshape(batch_size * kv_seq_len, num_heads, head_dim), indices_k)
value_layer = index_first_axis(value_layer.reshape(batch_size * kv_seq_len, num_heads, head_dim), indices_k)
if query_length == kv_seq_len:
query_layer = index_first_axis(
query_layer.reshape(batch_size * kv_seq_len, num_heads, head_dim), indices_k
)
cu_seqlens_q = cu_seqlens_k
max_seqlen_in_batch_q = max_seqlen_in_batch_k
indices_q = indices_k
elif query_length == 1:
max_seqlen_in_batch_q = 1
cu_seqlens_q = torch.arange(
batch_size + 1, dtype=torch.int32, device=query_layer.device
) # There is a memcpy here, that is very bad.
indices_q = cu_seqlens_q[:-1]
query_layer = query_layer.squeeze(1)
else:
# The -q_len: slice assumes left padding.
attention_mask = attention_mask[:, -query_length:]
query_layer, indices_q, cu_seqlens_q, max_seqlen_in_batch_q = unpad_input(query_layer, attention_mask)
return (
query_layer,
key_layer,
value_layer,
indices_q,
(cu_seqlens_q, cu_seqlens_k),
(max_seqlen_in_batch_q, max_seqlen_in_batch_k),
)
# copied from transformers.models.llama.modeling_llama.LlamaSdpaAttention with Llama->Mistral
# TODO @Arthur no longer copied from LLama after static cache
class MistralSdpaAttention(MistralAttention):
"""
Mistral attention module using torch.nn.functional.scaled_dot_product_attention. This module inherits from
`MistralAttention` as the weights of the module stays untouched. The only changes are on the forward pass to adapt to
SDPA API.
"""
# Adapted from MistralAttention.forward
def forward(
self,
hidden_states: torch.Tensor,
attention_mask: Optional[torch.Tensor] = None,
position_ids: Optional[torch.LongTensor] = None,
past_key_value: Optional[Cache] = None,
output_attentions: bool = False,
use_cache: bool = False,
) -> Tuple[torch.Tensor, Optional[torch.Tensor], Optional[Tuple[torch.Tensor]]]:
if output_attentions:
# TODO: Improve this warning with e.g. `model.config.attn_implementation = "manual"` once this is implemented.
logger.warning_once(
"MistralModel is using MistralSdpaAttention, but `torch.nn.functional.scaled_dot_product_attention` does not support `output_attentions=True`. Falling back to the manual attention implementation, "
'but specifying the manual implementation will be required from Transformers version v5.0.0 onwards. This warning can be removed using the argument `attn_implementation="eager"` when loading the model.'
)
return super().forward(
hidden_states=hidden_states,
attention_mask=attention_mask,
position_ids=position_ids,
past_key_value=past_key_value,
output_attentions=output_attentions,
use_cache=use_cache,
)
bsz, q_len, _ = hidden_states.size()
query_states = self.q_proj(hidden_states)
key_states = self.k_proj(hidden_states)
value_states = self.v_proj(hidden_states)
query_states = query_states.view(bsz, q_len, self.num_heads, self.head_dim).transpose(1, 2)
key_states = key_states.view(bsz, q_len, self.num_key_value_heads, self.head_dim).transpose(1, 2)
value_states = value_states.view(bsz, q_len, self.num_key_value_heads, self.head_dim).transpose(1, 2)
kv_seq_len = key_states.shape[-2]
if past_key_value is not None:
kv_seq_len += past_key_value.get_usable_length(kv_seq_len, self.layer_idx)
cos, sin = self.rotary_emb(value_states, seq_len=kv_seq_len)
query_states, key_states = apply_rotary_pos_emb(query_states, key_states, cos, sin, position_ids)
if past_key_value is not None:
cache_kwargs = {"sin": sin, "cos": cos} # Specific to RoPE models
key_states, value_states = past_key_value.update(key_states, value_states, self.layer_idx, cache_kwargs)
key_states = repeat_kv(key_states, self.num_key_value_groups)
value_states = repeat_kv(value_states, self.num_key_value_groups)
if attention_mask is not None:
if attention_mask.size() != (bsz, 1, q_len, kv_seq_len):
raise ValueError(
f"Attention mask should be of size {(bsz, 1, q_len, kv_seq_len)}, but is {attention_mask.size()}"
)
# SDPA with memory-efficient backend is currently (torch==2.1.2) bugged with non-contiguous inputs with custom attn_mask,
# Reference: https://github.com/pytorch/pytorch/issues/112577.
if query_states.device.type == "cuda" and attention_mask is not None:
query_states = query_states.contiguous()
key_states = key_states.contiguous()
value_states = value_states.contiguous()
attn_output = torch.nn.functional.scaled_dot_product_attention(
query_states,
key_states,
value_states,
attn_mask=attention_mask,
dropout_p=self.attention_dropout if self.training else 0.0,
# The q_len > 1 is necessary to match with AttentionMaskConverter.to_causal_4d that does not create a causal mask in case q_len == 1.
is_causal=self.is_causal and attention_mask is None and q_len > 1,
)
attn_output = attn_output.transpose(1, 2).contiguous()
attn_output = attn_output.view(bsz, q_len, self.hidden_size)
attn_output = self.o_proj(attn_output)
return attn_output, None, past_key_value
MISTRAL_ATTENTION_CLASSES = {
"eager": MistralAttention,
"flash_attention_2": MistralFlashAttention2,
"sdpa": MistralSdpaAttention,
}
class MistralDecoderLayer(nn.Module):
def __init__(self, config: MistralConfig, layer_idx: int):
super().__init__()
self.hidden_size = config.hidden_size
self.self_attn = MISTRAL_ATTENTION_CLASSES[config._attn_implementation](config, layer_idx)
self.mlp = MistralMLP(config)
self.input_layernorm = MistralRMSNorm(config.hidden_size, eps=config.rms_norm_eps)
self.post_attention_layernorm = MistralRMSNorm(config.hidden_size, eps=config.rms_norm_eps)
def forward(
self,
hidden_states: torch.Tensor,
attention_mask: Optional[torch.Tensor] = None,
position_ids: Optional[torch.LongTensor] = None,
past_key_value: Optional[Tuple[torch.Tensor]] = None,
output_attentions: Optional[bool] = False,
use_cache: Optional[bool] = False,
**kwargs,
) -> Tuple[torch.FloatTensor, Optional[Tuple[torch.FloatTensor, torch.FloatTensor]]]:
if "padding_mask" in kwargs:
warnings.warn(
"Passing `padding_mask` is deprecated and will be removed in v4.37. Please make sure use `attention_mask` instead.`"
)
"""
Args:
hidden_states (`torch.FloatTensor`): input to the layer of shape `(batch, seq_len, embed_dim)`
attention_mask (`torch.FloatTensor`, *optional*): attention mask of size
`(batch, sequence_length)` where padding elements are indicated by 0.
output_attentions (`bool`, *optional*):
Whether or not to return the attentions tensors of all attention layers. See `attentions` under
returned tensors for more detail.
use_cache (`bool`, *optional*):
If set to `True`, `past_key_values` key value states are returned and can be used to speed up decoding
(see `past_key_values`).
past_key_value (`Tuple(torch.FloatTensor)`, *optional*): cached past key and value projection states
"""
residual = hidden_states
hidden_states = self.input_layernorm(hidden_states)
# Self Attention
hidden_states, self_attn_weights, present_key_value = self.self_attn(
hidden_states=hidden_states,
attention_mask=attention_mask,
position_ids=position_ids,
past_key_value=past_key_value,
output_attentions=output_attentions,
use_cache=use_cache,
)
hidden_states = residual + hidden_states
# Fully Connected
residual = hidden_states
hidden_states = self.post_attention_layernorm(hidden_states)
hidden_states = self.mlp(hidden_states)
hidden_states = residual + hidden_states
outputs = (hidden_states,)
if output_attentions:
outputs += (self_attn_weights,)
if use_cache:
outputs += (present_key_value,)
return outputs
MISTRAL_START_DOCSTRING = r"""
This model inherits from [`PreTrainedModel`]. Check the superclass documentation for the generic methods the
library implements for all its model (such as downloading or saving, resizing the input embeddings, pruning heads
etc.)
This model is also a PyTorch [torch.nn.Module](https://pytorch.org/docs/stable/nn.html#torch.nn.Module) subclass.
Use it as a regular PyTorch Module and refer to the PyTorch documentation for all matter related to general usage
and behavior.
Parameters:
config ([`MistralConfig`]):
Model configuration class with all the parameters of the model. Initializing with a config file does not
load the weights associated with the model, only the configuration. Check out the
[`~PreTrainedModel.from_pretrained`] method to load the model weights.
"""
@add_start_docstrings(
"The bare Mistral Model outputting raw hidden-states without any specific head on top.",
MISTRAL_START_DOCSTRING,
)
class MistralPreTrainedModel(PreTrainedModel):
config_class = MistralConfig
base_model_prefix = "model"
supports_gradient_checkpointing = True
_no_split_modules = ["MistralDecoderLayer"]
_skip_keys_device_placement = "past_key_values"
_supports_flash_attn_2 = True
_supports_sdpa = True
_supports_cache_class = True
def _init_weights(self, module):
std = self.config.initializer_range
if isinstance(module, nn.Linear):
module.weight.data.normal_(mean=0.0, std=std)
if module.bias is not None:
module.bias.data.zero_()
elif isinstance(module, nn.Embedding):
module.weight.data.normal_(mean=0.0, std=std)
if module.padding_idx is not None:
module.weight.data[module.padding_idx].zero_()
MISTRAL_INPUTS_DOCSTRING = r"""
Args:
input_ids (`torch.LongTensor` of shape `(batch_size, sequence_length)`):
Indices of input sequence tokens in the vocabulary. Padding will be ignored by default should you provide
it.
Indices can be obtained using [`AutoTokenizer`]. See [`PreTrainedTokenizer.encode`] and
[`PreTrainedTokenizer.__call__`] for details.
[What are input IDs?](../glossary#input-ids)
attention_mask (`torch.Tensor` of shape `(batch_size, sequence_length)`, *optional*):
Mask to avoid performing attention on padding token indices. Mask values selected in `[0, 1]`:
- 1 for tokens that are **not masked**,
- 0 for tokens that are **masked**.
[What are attention masks?](../glossary#attention-mask)
Indices can be obtained using [`AutoTokenizer`]. See [`PreTrainedTokenizer.encode`] and
[`PreTrainedTokenizer.__call__`] for details.
If `past_key_values` is used, optionally only the last `decoder_input_ids` have to be input (see
`past_key_values`).
If you want to change padding behavior, you should read [`modeling_opt._prepare_decoder_attention_mask`]
and modify to your needs. See diagram 1 in [the paper](https://arxiv.org/abs/1910.13461) for more
information on the default strategy.
- 1 indicates the head is **not masked**,
- 0 indicates the head is **masked**.
position_ids (`torch.LongTensor` of shape `(batch_size, sequence_length)`, *optional*):
Indices of positions of each input sequence tokens in the position embeddings. Selected in the range `[0,
config.n_positions - 1]`.
[What are position IDs?](../glossary#position-ids)
past_key_values (`Cache` or `tuple(tuple(torch.FloatTensor))`, *optional*):
Pre-computed hidden-states (key and values in the self-attention blocks and in the cross-attention
blocks) that can be used to speed up sequential decoding. This typically consists in the `past_key_values`
returned by the model at a previous stage of decoding, when `use_cache=True` or `config.use_cache=True`.
Two formats are allowed:
- a [`~cache_utils.Cache`] instance;
- Tuple of `tuple(torch.FloatTensor)` of length `config.n_layers`, with each tuple having 2 tensors of
shape `(batch_size, num_heads, sequence_length, embed_size_per_head)`). This is also known as the legacy
cache format.
The model will output the same cache format that is fed as input. If no `past_key_values` are passed, the
legacy cache format will be returned.
If `past_key_values` are used, the user can optionally input only the last `input_ids` (those that don't
have their past key value states given to this model) of shape `(batch_size, 1)` instead of all `input_ids`
of shape `(batch_size, sequence_length)`.
inputs_embeds (`torch.FloatTensor` of shape `(batch_size, sequence_length, hidden_size)`, *optional*):
Optionally, instead of passing `input_ids` you can choose to directly pass an embedded representation. This
is useful if you want more control over how to convert `input_ids` indices into associated vectors than the
model's internal embedding lookup matrix.
use_cache (`bool`, *optional*):
If set to `True`, `past_key_values` key value states are returned and can be used to speed up decoding (see
`past_key_values`).
output_attentions (`bool`, *optional*):
Whether or not to return the attentions tensors of all attention layers. See `attentions` under returned
tensors for more detail.
output_hidden_states (`bool`, *optional*):
Whether or not to return the hidden states of all layers. See `hidden_states` under returned tensors for
more detail.
return_dict (`bool`, *optional*):
Whether or not to return a [`~utils.ModelOutput`] instead of a plain tuple.
"""
""" Classes to support Vision-Encoder-Text-Decoder architectures"""
VISION_ENCODER_DECODER_START_DOCSTRING = r"""
This class can be used to initialize an image-to-text-sequence model with any pretrained vision autoencoding model
as the encoder and any pretrained text autoregressive model as the decoder. The encoder is loaded via
[`~AutoModel.from_pretrained`] function and the decoder is loaded via [`~AutoModelForCausalLM.from_pretrained`]
function. Cross-attention layers are automatically added to the decoder and should be fine-tuned on a downstream
generative task, like image captioning.
The effectiveness of initializing sequence-to-sequence models with pretrained checkpoints for sequence generation
tasks was shown in [Leveraging Pre-trained Checkpoints for Sequence Generation
Tasks](https://arxiv.org/abs/1907.12461) by Sascha Rothe, Shashi Narayan, Aliaksei Severyn. Michael Matena, Yanqi
Zhou, Wei Li, Peter J. Liu.
Additionally, in [TrOCR: Transformer-based Optical Character Recognition with Pre-trained
Models](https://arxiv.org/abs/2109.10282) it is shown how leveraging large pretrained vision models for optical
character recognition (OCR) yields a significant performance improvement.
After such a Vision-Encoder-Text-Decoder model has been trained/fine-tuned, it can be saved/loaded just like any
other models (see the examples for more information).
This model inherits from [`PreTrainedModel`]. Check the superclass documentation for the generic methods the
library implements for all its model (such as downloading or saving, resizing the input embeddings, pruning heads
etc.)
This model is also a PyTorch [torch.nn.Module](https://pytorch.org/docs/stable/nn.html#torch.nn.Module) subclass.
Use it as a regular PyTorch Module and refer to the PyTorch documentation for all matter related to general usage
and behavior.
Parameters:
config ([`VisionEncoderDecoderConfig`]): Model configuration class with all the parameters of the model.
Initializing with a config file does not load the weights associated with the model, only the
configuration. Check out the [`~PreTrainedModel.from_pretrained`] method to load the model weights.
"""
VISION_ENCODER_DECODER_INPUTS_DOCSTRING = r"""
Args:
pixel_values (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)`):
Pixel values. Pixel values can be obtained using an image processor (e.g. if you use ViT as the encoder,
you should use [`AutoImageProcessor`]). See [`ViTImageProcessor.__call__`] for details.
decoder_input_ids (`torch.LongTensor` of shape `(batch_size, target_sequence_length)`, *optional*):
Indices of decoder input sequence tokens in the vocabulary.
Indices can be obtained using [`PreTrainedTokenizer`]. See [`PreTrainedTokenizer.encode`] and
[`PreTrainedTokenizer.__call__`] for details.
[What are input IDs?](../glossary#input-ids)
If `past_key_values` is used, optionally only the last `decoder_input_ids` have to be input (see
`past_key_values`).
For training, `decoder_input_ids` are automatically created by the model by shifting the `labels` to the
right, replacing -100 by the `pad_token_id` and prepending them with the `decoder_start_token_id`.
decoder_attention_mask (`torch.BoolTensor` of shape `(batch_size, target_sequence_length)`, *optional*):
Default behavior: generate a tensor that ignores pad tokens in `decoder_input_ids`. Causal mask will also
be used by default.
encoder_outputs (`tuple(torch.FloatTensor)`, *optional*):
This tuple must consist of (`last_hidden_state`, *optional*: `hidden_states`, *optional*: `attentions`)
`last_hidden_state` (`torch.FloatTensor` of shape `(batch_size, sequence_length, hidden_size)`) is a tensor
of hidden-states at the output of the last layer of the encoder. Used in the cross-attention of the
decoder.
past_key_values (`tuple(tuple(torch.FloatTensor))` of length `config.n_layers` with each tuple having 4 tensors of shape `(batch_size, num_heads, sequence_length - 1, embed_size_per_head)`):
Contains precomputed key and value hidden states of the attention blocks. Can be used to speed up decoding.
If `past_key_values` are used, the user can optionally input only the last `decoder_input_ids` (those that
don't have their past key value states given to this model) of shape `(batch_size, 1)` instead of all
`decoder_input_ids` of shape `(batch_size, sequence_length)`.
decoder_inputs_embeds (`torch.FloatTensor` of shape `(batch_size, target_sequence_length, hidden_size)`, *optional*):
Optionally, instead of passing `decoder_input_ids` you can choose to directly pass an embedded
representation. This is useful if you want more control over how to convert `decoder_input_ids` indices
into associated vectors than the model's internal embedding lookup matrix.
labels (`torch.LongTensor` of shape `(batch_size, sequence_length)`, *optional*):
Labels for computing the masked language modeling loss for the decoder. Indices should be in `[-100, 0,
..., config.vocab_size]` (see `input_ids` docstring) Tokens with indices set to `-100` are ignored
(masked), the loss is only computed for the tokens with labels in `[0, ..., config.vocab_size]`
use_cache (`bool`, *optional*):
If set to `True`, `past_key_values` key value states are returned and can be used to speed up decoding (see
`past_key_values`).
output_attentions (`bool`, *optional*):
Whether or not to return the attentions tensors of all attention layers. See `attentions` under returned
tensors for more detail.
output_hidden_states (`bool`, *optional*):
Whether or not to return the hidden states of all layers. See `hidden_states` under returned tensors for
more detail.
return_dict (`bool`, *optional*):
If set to `True`, the model will return a [`~utils.Seq2SeqLMOutput`] instead of a plain tuple.
kwargs (*optional*): Remaining dictionary of keyword arguments. Keyword arguments come in two flavors:
- Without a prefix which will be input as `**encoder_kwargs` for the encoder forward function.
- With a *decoder_* prefix which will be input as `**decoder_kwargs` for the decoder forward function.
"""
DEPRECATION_WARNING = (
"Version v4.12.0 introduces a better way to train encoder-decoder models by computing the loss inside the"
" encoder-decoder framework rather than in the decoder itself. You may observe training discrepancies if"
" fine-tuning a model trained with versions anterior to 4.12.0. The decoder_input_ids are now created based on the"
" labels, no need to pass them yourself anymore."
)
ENCODER_DECODER_START_DOCSTRING = r"""
This class can be used to initialize a sequence-to-sequence model with any pretrained autoencoding model as the
encoder and any pretrained autoregressive model as the decoder. The encoder is loaded via
[`~AutoModel.from_pretrained`] function and the decoder is loaded via [`~AutoModelForCausalLM.from_pretrained`]
function. Cross-attention layers are automatically added to the decoder and should be fine-tuned on a downstream
generative task, like summarization.
The effectiveness of initializing sequence-to-sequence models with pretrained checkpoints for sequence generation
tasks was shown in [Leveraging Pre-trained Checkpoints for Sequence Generation
Tasks](https://arxiv.org/abs/1907.12461) by Sascha Rothe, Shashi Narayan, Aliaksei Severyn. Michael Matena, Yanqi
Zhou, Wei Li, Peter J. Liu.
After such an Encoder Decoder model has been trained/fine-tuned, it can be saved/loaded just like any other models
(see the examples for more information).
This model inherits from [`PreTrainedModel`]. Check the superclass documentation for the generic methods the
library implements for all its model (such as downloading or saving, resizing the input embeddings, pruning heads
etc.)
This model is also a PyTorch [torch.nn.Module](https://pytorch.org/docs/stable/nn.html#torch.nn.Module) subclass.
Use it as a regular PyTorch Module and refer to the PyTorch documentation for all matter related to general usage
and behavior.
Parameters:
config ([`EncoderDecoderConfig`]): Model configuration class with all the parameters of the model.
Initializing with a config file does not load the weights associated with the model, only the
configuration. Check out the [`~PreTrainedModel.from_pretrained`] method to load the model weights.
"""
ENCODER_DECODER_INPUTS_DOCSTRING = r"""
Args:
input_ids (`torch.LongTensor` of shape `(batch_size, sequence_length)`):
Indices of input sequence tokens in the vocabulary.
Indices can be obtained using [`PreTrainedTokenizer`]. See [`PreTrainedTokenizer.encode`] and
[`PreTrainedTokenizer.__call__`] for details.
[What are input IDs?](../glossary#input-ids)
attention_mask (`torch.FloatTensor` of shape `(batch_size, sequence_length)`, *optional*):
Mask to avoid performing attention on padding token indices. Mask values selected in `[0, 1]`:
- 1 for tokens that are **not masked**,
- 0 for tokens that are **masked**.
[What are attention masks?](../glossary#attention-mask)
decoder_input_ids (`torch.LongTensor` of shape `(batch_size, target_sequence_length)`, *optional*):
Indices of decoder input sequence tokens in the vocabulary.
Indices can be obtained using [`PreTrainedTokenizer`]. See [`PreTrainedTokenizer.encode`] and
[`PreTrainedTokenizer.__call__`] for details.
[What are input IDs?](../glossary#input-ids)
If `past_key_values` is used, optionally only the last `decoder_input_ids` have to be input (see
`past_key_values`).
For training, `decoder_input_ids` are automatically created by the model by shifting the `labels` to the
right, replacing -100 by the `pad_token_id` and prepending them with the `decoder_start_token_id`.
decoder_attention_mask (`torch.BoolTensor` of shape `(batch_size, target_sequence_length)`, *optional*):
Default behavior: generate a tensor that ignores pad tokens in `decoder_input_ids`. Causal mask will also
be used by default.
encoder_outputs (`tuple(torch.FloatTensor)`, *optional*):
This tuple must consist of (`last_hidden_state`, *optional*: `hidden_states`, *optional*: `attentions`)
`last_hidden_state` (`torch.FloatTensor` of shape `(batch_size, sequence_length, hidden_size)`) is a tensor
of hidden-states at the output of the last layer of the encoder. Used in the cross-attention of the
decoder.
past_key_values (`tuple(tuple(torch.FloatTensor))` of length `config.n_layers` with each tuple having 4 tensors of shape `(batch_size, num_heads, sequence_length - 1, embed_size_per_head)`):
Contains precomputed key and value hidden states of the attention blocks. Can be used to speed up decoding.
If `past_key_values` are used, the user can optionally input only the last `decoder_input_ids` (those that
don't have their past key value states given to this model) of shape `(batch_size, 1)` instead of all
`decoder_input_ids` of shape `(batch_size, sequence_length)`.
inputs_embeds (`torch.FloatTensor` of shape `(batch_size, sequence_length, hidden_size)`, *optional*):
Optionally, instead of passing `input_ids` you can choose to directly pass an embedded representation. This
is useful if you want more control over how to convert `input_ids` indices into associated vectors than the
model's internal embedding lookup matrix.
decoder_inputs_embeds (`torch.FloatTensor` of shape `(batch_size, target_sequence_length, hidden_size)`, *optional*):
Optionally, instead of passing `decoder_input_ids` you can choose to directly pass an embedded
representation. This is useful if you want more control over how to convert `decoder_input_ids` indices
into associated vectors than the model's internal embedding lookup matrix.
labels (`torch.LongTensor` of shape `(batch_size, sequence_length)`, *optional*):
Labels for computing the masked language modeling loss for the decoder. Indices should be in `[-100, 0,
..., config.vocab_size]` (see `input_ids` docstring) Tokens with indices set to `-100` are ignored
(masked), the loss is only computed for the tokens with labels in `[0, ..., config.vocab_size]`
use_cache (`bool`, *optional*):
If set to `True`, `past_key_values` key value states are returned and can be used to speed up decoding (see
`past_key_values`).
output_attentions (`bool`, *optional*):
Whether or not to return the attentions tensors of all attention layers. See `attentions` under returned
tensors for more detail.
output_hidden_states (`bool`, *optional*):
Whether or not to return the hidden states of all layers. See `hidden_states` under returned tensors for
more detail.
return_dict (`bool`, *optional*):
If set to `True`, the model will return a [`~utils.Seq2SeqLMOutput`] instead of a plain tuple.
kwargs (*optional*): Remaining dictionary of keyword arguments. Keyword arguments come in two flavors:
- Without a prefix which will be input as `**encoder_kwargs` for the encoder forward function.
- With a *decoder_* prefix which will be input as `**decoder_kwargs` for the decoder forward function.
"""
@add_start_docstrings(
"The bare Mistral Model outputting raw hidden-states without any specific head on top.",
MISTRAL_START_DOCSTRING,
)
class MistralModel(MistralPreTrainedModel):
"""
Transformer decoder consisting of *config.num_hidden_layers* layers. Each layer is a [`MistralDecoderLayer`]
Args:
config: MistralConfig
"""
def __init__(self, config: MistralConfig):
super().__init__(config)
self.padding_idx = config.pad_token_id
self.vocab_size = config.vocab_size
self.embed_tokens = nn.Embedding(config.vocab_size, config.hidden_size, self.padding_idx)
self.layers = nn.ModuleList(
[MistralDecoderLayer(config, layer_idx) for layer_idx in range(config.num_hidden_layers)]
)
self._attn_implementation = config._attn_implementation
self.norm = MistralRMSNorm(config.hidden_size, eps=config.rms_norm_eps)
self.gradient_checkpointing = False
# Initialize weights and apply final processing
self.post_init()
def get_input_embeddings(self):
return self.embed_tokens
def set_input_embeddings(self, value):
self.embed_tokens = value
@add_start_docstrings_to_model_forward(MISTRAL_INPUTS_DOCSTRING)
def forward(
self,
input_ids: torch.LongTensor = None,
attention_mask: Optional[torch.Tensor] = None,
position_ids: Optional[torch.LongTensor] = None,
past_key_values: Optional[List[torch.FloatTensor]] = None,
inputs_embeds: Optional[torch.FloatTensor] = None,
use_cache: Optional[bool] = None,
output_attentions: Optional[bool] = None,
output_hidden_states: Optional[bool] = None,
return_dict: Optional[bool] = None,
) -> Union[Tuple, BaseModelOutputWithPast]:
output_attentions = output_attentions if output_attentions is not None else self.config.output_attentions
output_hidden_states = (
output_hidden_states if output_hidden_states is not None else self.config.output_hidden_states
)
use_cache = use_cache if use_cache is not None else self.config.use_cache
return_dict = return_dict if return_dict is not None else self.config.use_return_dict
# retrieve input_ids and inputs_embeds
if input_ids is not None and inputs_embeds is not None:
raise ValueError("You cannot specify both decoder_input_ids and decoder_inputs_embeds at the same time")
elif input_ids is not None:
batch_size, seq_length = input_ids.shape
elif inputs_embeds is not None:
batch_size, seq_length, _ = inputs_embeds.shape
else:
raise ValueError("You have to specify either decoder_input_ids or decoder_inputs_embeds")
if self.gradient_checkpointing and self.training:
if use_cache:
logger.warning_once(
"`use_cache=True` is incompatible with gradient checkpointing. Setting `use_cache=False`..."
)
use_cache = False
past_key_values_length = 0
if use_cache:
use_legacy_cache = not isinstance(past_key_values, Cache)
if use_legacy_cache:
past_key_values = DynamicCache.from_legacy_cache(past_key_values)
past_key_values_length = past_key_values.get_usable_length(seq_length)
if position_ids is None:
device = input_ids.device if input_ids is not None else inputs_embeds.device
position_ids = torch.arange(
past_key_values_length, seq_length + past_key_values_length, dtype=torch.long, device=device
)
position_ids = position_ids.unsqueeze(0).view(-1, seq_length)
else:
position_ids = position_ids.view(-1, seq_length).long()
if inputs_embeds is None:
inputs_embeds = self.embed_tokens(input_ids)
if attention_mask is not None and self._attn_implementation == "flash_attention_2" and use_cache:
is_padding_right = attention_mask[:, -1].sum().item() != batch_size
if is_padding_right:
raise ValueError(
"You are attempting to perform batched generation with padding_side='right'"
" this may lead to unexpected behaviour for Flash Attention version of Mistral. Make sure to "
" call `tokenizer.padding_side = 'left'` before tokenizing the input. "
)
if self._attn_implementation == "flash_attention_2":
# 2d mask is passed through the layers
attention_mask = attention_mask if (attention_mask is not None and 0 in attention_mask) else None
elif self._attn_implementation == "sdpa" and not output_attentions:
# output_attentions=True can not be supported when using SDPA, and we fall back on
# the manual implementation that requires a 4D causal mask in all cases.
attention_mask = _prepare_4d_causal_attention_mask_for_sdpa(
attention_mask,
(batch_size, seq_length),
inputs_embeds,
past_key_values_length,
)
else:
# 4d mask is passed through the layers
attention_mask = _prepare_4d_causal_attention_mask(
attention_mask,
(batch_size, seq_length),
inputs_embeds,
past_key_values_length,
sliding_window=self.config.sliding_window,
)
hidden_states = inputs_embeds
# decoder layers
all_hidden_states = () if output_hidden_states else None
all_self_attns = () if output_attentions else None
next_decoder_cache = None
for decoder_layer in self.layers:
if output_hidden_states:
all_hidden_states += (hidden_states,)
if self.gradient_checkpointing and self.training:
layer_outputs = self._gradient_checkpointing_func(
decoder_layer.__call__,
hidden_states,
attention_mask,
position_ids,
past_key_values,
output_attentions,
use_cache,
)
else:
layer_outputs = decoder_layer(
hidden_states,
attention_mask=attention_mask,
position_ids=position_ids,
past_key_value=past_key_values,
output_attentions=output_attentions,
use_cache=use_cache,
)
hidden_states = layer_outputs[0]
if use_cache:
next_decoder_cache = layer_outputs[2 if output_attentions else 1]
if output_attentions:
all_self_attns += (layer_outputs[1],)
hidden_states = self.norm(hidden_states)
# add hidden states from the last decoder layer
if output_hidden_states:
all_hidden_states += (hidden_states,)
next_cache = None
if use_cache:
next_cache = next_decoder_cache.to_legacy_cache() if use_legacy_cache else next_decoder_cache
if not return_dict:
return tuple(v for v in [hidden_states, next_cache, all_hidden_states, all_self_attns] if v is not None)
return BaseModelOutputWithPast(
last_hidden_state=hidden_states,
past_key_values=next_cache,
hidden_states=all_hidden_states,
attentions=all_self_attns,
)
class MistralForCausalLM(MistralPreTrainedModel):
_tied_weights_keys = ["lm_head.weight"]
def __init__(self, config):
super().__init__(config)
self.model = MistralModel(config)
self.vocab_size = config.vocab_size
self.lm_head = nn.Linear(config.hidden_size, config.vocab_size, bias=False)
# Initialize weights and apply final processing
self.post_init()
def get_input_embeddings(self):
return self.model.embed_tokens
def set_input_embeddings(self, value):
self.model.embed_tokens = value
def get_output_embeddings(self):
return self.lm_head
def set_output_embeddings(self, new_embeddings):
self.lm_head = new_embeddings
def set_decoder(self, decoder):
self.model = decoder
def get_decoder(self):
return self.model
@add_start_docstrings_to_model_forward(MISTRAL_INPUTS_DOCSTRING)
@replace_return_docstrings(output_type=CausalLMOutputWithPast, config_class=_CONFIG_FOR_DOC)
def forward(
self,
input_ids: torch.LongTensor = None,
attention_mask: Optional[torch.Tensor] = None,
position_ids: Optional[torch.LongTensor] = None,
past_key_values: Optional[List[torch.FloatTensor]] = None,
inputs_embeds: Optional[torch.FloatTensor] = None,
labels: Optional[torch.LongTensor] = None,
use_cache: Optional[bool] = None,
output_attentions: Optional[bool] = None,
output_hidden_states: Optional[bool] = None,
return_dict: Optional[bool] = None,
) -> Union[Tuple, CausalLMOutputWithPast]:
r"""
Args:
labels (`torch.LongTensor` of shape `(batch_size, sequence_length)`, *optional*):
Labels for computing the masked language modeling loss. Indices should either be in `[0, ...,
config.vocab_size]` or -100 (see `input_ids` docstring). Tokens with indices set to `-100` are ignored
(masked), the loss is only computed for the tokens with labels in `[0, ..., config.vocab_size]`.
Returns:
Example:
```python
>>> from transformers import AutoTokenizer, MistralForCausalLM
>>> model = MistralForCausalLM.from_pretrained("mistralai/Mistral-7B-v0.1")
>>> tokenizer = AutoTokenizer.from_pretrained("mistralai/Mistral-7B-v0.1")
>>> prompt = "Hey, are you conscious? Can you talk to me?"
>>> inputs = tokenizer(prompt, return_tensors="pt")
>>> # Generate
>>> generate_ids = model.generate(inputs.input_ids, max_length=30)
>>> tokenizer.batch_decode(generate_ids, skip_special_tokens=True, clean_up_tokenization_spaces=False)[0]
"Hey, are you conscious? Can you talk to me?\nI'm not conscious, but I can talk to you."
```"""
output_attentions = output_attentions if output_attentions is not None else self.config.output_attentions
output_hidden_states = (
output_hidden_states if output_hidden_states is not None else self.config.output_hidden_states
)
return_dict = return_dict if return_dict is not None else self.config.use_return_dict
# decoder outputs consists of (dec_features, layer_state, dec_hidden, dec_attn)
outputs = self.model(
input_ids=input_ids,
attention_mask=attention_mask,
position_ids=position_ids,
past_key_values=past_key_values,
inputs_embeds=inputs_embeds,
use_cache=use_cache,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
return_dict=return_dict,
)
hidden_states = outputs[0]
logits = self.lm_head(hidden_states)
logits = logits.float()
loss = None
if labels is not None:
# Shift so that tokens < n predict n
shift_logits = logits[..., :-1, :].contiguous()
shift_labels = labels[..., 1:].contiguous()
# Flatten the tokens
shift_logits = shift_logits.view(-1, self.config.vocab_size)
shift_labels = shift_labels.view(-1)
# Ensure tensors are on the same device
shift_labels = shift_labels.to(shift_logits.device)
loss_fct = CrossEntropyLoss()
loss = loss_fct(shift_logits, shift_labels)
if not return_dict:
output = (logits,) + outputs[1:]
return (loss,) + output if loss is not None else output
return CausalLMOutputWithPast(
loss=loss,
logits=logits,
past_key_values=outputs.past_key_values,
hidden_states=outputs.hidden_states,
attentions=outputs.attentions,
)
def prepare_inputs_for_generation(
self, input_ids, past_key_values=None, attention_mask=None, inputs_embeds=None, **kwargs
):
# Omit tokens covered by past_key_values
if past_key_values is not None:
if isinstance(past_key_values, Cache):
cache_length = past_key_values.get_seq_length()
past_length = past_key_values.seen_tokens
max_cache_length = past_key_values.get_max_length()
else:
cache_length = past_length = past_key_values[0][0].shape[2]
max_cache_length = None
# Keep only the unprocessed tokens:
# 1 - If the length of the attention_mask exceeds the length of input_ids, then we are in a setting where
# some of the inputs are exclusively passed as part of the cache (e.g. when passing input_embeds as
# input)
if attention_mask is not None and attention_mask.shape[1] > input_ids.shape[1]:
input_ids = input_ids[:, -(attention_mask.shape[1] - past_length) :]
# 2 - If the past_length is smaller than input_ids', then input_ids holds all input tokens. We can discard
# input_ids based on the past_length.
elif past_length < input_ids.shape[1]:
input_ids = input_ids[:, past_length:]
# 3 - Otherwise (past_length >= input_ids.shape[1]), let's assume input_ids only has unprocessed tokens.
# If we are about to go beyond the maximum cache length, we need to crop the input attention mask.
if (
max_cache_length is not None
and attention_mask is not None
and cache_length + input_ids.shape[1] > max_cache_length
):
attention_mask = attention_mask[:, -max_cache_length:]
position_ids = kwargs.get("position_ids", None)
if attention_mask is not None and position_ids is None:
# create position_ids on the fly for batch generation
position_ids = attention_mask.long().cumsum(-1) - 1
position_ids.masked_fill_(attention_mask == 0, 1)
if past_key_values:
position_ids = position_ids[:, -input_ids.shape[1] :]
# if `inputs_embeds` are passed, we only want to use them in the 1st generation step
if inputs_embeds is not None and past_key_values is None:
model_inputs = {"inputs_embeds": inputs_embeds}
else:
model_inputs = {"input_ids": input_ids}
model_inputs.update(
{
"position_ids": position_ids,
"past_key_values": past_key_values,
"use_cache": kwargs.get("use_cache"),
"attention_mask": attention_mask,
}
)
return model_inputs
@staticmethod
def _reorder_cache(past_key_values, beam_idx):
reordered_past = ()
for layer_past in past_key_values:
reordered_past += (
tuple(past_state.index_select(0, beam_idx.to(past_state.device)) for past_state in layer_past),
)
return reordered_past
@add_start_docstrings(
"""
The Mistral Model transformer with a sequence classification head on top (linear layer).
[`MistralForSequenceClassification`] uses the last token in order to do the classification, as other causal models
(e.g. GPT-2) do.
Since it does classification on the last token, it requires to know the position of the last token. If a
`pad_token_id` is defined in the configuration, it finds the last token that is not a padding token in each row. If
no `pad_token_id` is defined, it simply takes the last value in each row of the batch. Since it cannot guess the
padding tokens when `inputs_embeds` are passed instead of `input_ids`, it does the same (take the last value in
each row of the batch).
""",
MISTRAL_START_DOCSTRING,
)
# Copied from transformers.models.llama.modeling_llama.LlamaForSequenceClassification with Llama->Mistral, LLAMA->MISTRAL
class MistralForSequenceClassification(MistralPreTrainedModel):
def __init__(self, config):
super().__init__(config)
self.num_labels = config.num_labels
self.model = MistralModel(config)
self.score = nn.Linear(config.hidden_size, self.num_labels, bias=False)
# Initialize weights and apply final processing
self.post_init()
def get_input_embeddings(self):
return self.model.embed_tokens
def set_input_embeddings(self, value):
self.model.embed_tokens = value
@add_start_docstrings_to_model_forward(MISTRAL_INPUTS_DOCSTRING)
def forward(
self,
input_ids: torch.LongTensor = None,
attention_mask: Optional[torch.Tensor] = None,
position_ids: Optional[torch.LongTensor] = None,
past_key_values: Optional[List[torch.FloatTensor]] = None,
inputs_embeds: Optional[torch.FloatTensor] = None,
labels: Optional[torch.LongTensor] = None,
use_cache: Optional[bool] = None,
output_attentions: Optional[bool] = None,
output_hidden_states: Optional[bool] = None,
return_dict: Optional[bool] = None,
) -> Union[Tuple, SequenceClassifierOutputWithPast]:
r"""
labels (`torch.LongTensor` of shape `(batch_size,)`, *optional*):
Labels for computing the sequence classification/regression loss. Indices should be in `[0, ...,
config.num_labels - 1]`. If `config.num_labels == 1` a regression loss is computed (Mean-Square loss), If
`config.num_labels > 1` a classification loss is computed (Cross-Entropy).
"""
return_dict = return_dict if return_dict is not None else self.config.use_return_dict
transformer_outputs = self.model(
input_ids,
attention_mask=attention_mask,
position_ids=position_ids,
past_key_values=past_key_values,
inputs_embeds=inputs_embeds,
use_cache=use_cache,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
return_dict=return_dict,
)
hidden_states = transformer_outputs[0]
logits = self.score(hidden_states)
if input_ids is not None:
batch_size = input_ids.shape[0]
else:
batch_size = inputs_embeds.shape[0]
if self.config.pad_token_id is None and batch_size != 1:
raise ValueError("Cannot handle batch sizes > 1 if no padding token is defined.")
if self.config.pad_token_id is None:
sequence_lengths = -1
else:
if input_ids is not None:
sequence_lengths = (torch.eq(input_ids, self.config.pad_token_id).long().argmax(-1) - 1).to(
logits.device
)
else:
sequence_lengths = -1
pooled_logits = logits[torch.arange(batch_size, device=logits.device), sequence_lengths]
loss = None
if labels is not None:
labels = labels.to(logits.device)
if self.config.problem_type is None:
if self.num_labels == 1:
self.config.problem_type = "regression"
elif self.num_labels > 1 and (labels.dtype == torch.long or labels.dtype == torch.int):
self.config.problem_type = "single_label_classification"
else:
self.config.problem_type = "multi_label_classification"
if self.config.problem_type == "regression":
loss_fct = MSELoss()
if self.num_labels == 1:
loss = loss_fct(pooled_logits.squeeze(), labels.squeeze())
else:
loss = loss_fct(pooled_logits, labels)
elif self.config.problem_type == "single_label_classification":
loss_fct = CrossEntropyLoss()
loss = loss_fct(pooled_logits.view(-1, self.num_labels), labels.view(-1))
elif self.config.problem_type == "multi_label_classification":
loss_fct = BCEWithLogitsLoss()
loss = loss_fct(pooled_logits, labels)
if not return_dict:
output = (pooled_logits,) + transformer_outputs[1:]
return ((loss,) + output) if loss is not None else output
return SequenceClassifierOutputWithPast(
loss=loss,
logits=pooled_logits,
past_key_values=transformer_outputs.past_key_values,
hidden_states=transformer_outputs.hidden_states,
attentions=transformer_outputs.attentions,
)
@add_start_docstrings(VISION_ENCODER_DECODER_START_DOCSTRING)
class VisionEncoderDecoderModel(PreTrainedModel):
r"""
[`VisionEncoderDecoderModel`] is a generic model class that will be instantiated as a transformer architecture with
one of the base vision model classes of the library as encoder and another one as decoder when created with the
:meth*~transformers.AutoModel.from_pretrained* class method for the encoder and
:meth*~transformers.AutoModelForCausalLM.from_pretrained* class method for the decoder.
"""
config_class = VisionEncoderDecoderConfig
base_model_prefix = "vision_encoder_decoder"
main_input_name = "pixel_values"
supports_gradient_checkpointing = True
def __init__(
self,
config: Optional[PretrainedConfig] = None,
encoder: Optional[PreTrainedModel] = None,
decoder: Optional[PreTrainedModel] = None,
):
if config is None and (encoder is None or decoder is None):
raise ValueError("Either a configuration or an encoder and a decoder has to be provided.")
if config is None:
config = VisionEncoderDecoderConfig.from_encoder_decoder_configs(encoder.config, decoder.config)
else:
if not isinstance(config, self.config_class):
raise ValueError(f"Config: {config} has to be of type {self.config_class}")
if config.decoder.cross_attention_hidden_size is not None:
if config.decoder.cross_attention_hidden_size != config.encoder.hidden_size:
raise ValueError(
"If `cross_attention_hidden_size` is specified in the decoder's configuration, it has to be equal"
f" to the encoder's `hidden_size`. Got {config.decoder.cross_attention_hidden_size} for"
f" `config.decoder.cross_attention_hidden_size` and {config.encoder.hidden_size} for"
" `config.encoder.hidden_size`."
)
# initialize with config
# make sure input & output embeddings is not tied
config.tie_word_embeddings = False
super().__init__(config)
if encoder is None:
encoder = AutoModel.from_config(config.encoder)
if decoder is None:
decoder = AutoModelForCausalLM.from_config(config.decoder)
self.encoder = encoder
self.decoder = decoder
if self.encoder.config.to_dict() != self.config.encoder.to_dict():
logger.warning(
f"Config of the encoder: {self.encoder.__class__} is overwritten by shared encoder config:"
f" {self.config.encoder}"
)
if self.decoder.config.to_dict() != self.config.decoder.to_dict():
logger.warning(
f"Config of the decoder: {self.decoder.__class__} is overwritten by shared decoder config:"
f" {self.config.decoder}"
)
# make sure that the individual model's config refers to the shared config
# so that the updates to the config will be synced
self.encoder.config = self.config.encoder
self.decoder.config = self.config.decoder
# encoder outputs might need to be projected to different dimension for decoder
if (
self.encoder.config.hidden_size != self.decoder.config.hidden_size
and self.decoder.config.cross_attention_hidden_size is None
):
self.enc_to_dec_proj = nn.Linear(self.encoder.config.hidden_size, self.decoder.config.hidden_size)
if self.encoder.get_output_embeddings() is not None:
raise ValueError(
f"The encoder {self.encoder} should not have a LM Head. Please use a model without LM Head"
)
def get_encoder(self):
return self.encoder
def get_decoder(self):
return self.decoder
def get_output_embeddings(self):
return self.decoder.get_output_embeddings()
def set_output_embeddings(self, new_embeddings):
return self.decoder.set_output_embeddings(new_embeddings)
@classmethod
def from_pretrained(cls, pretrained_model_name_or_path, *model_args, **kwargs):
r"""
Example:
```python
>>> from transformers import VisionEncoderDecoderModel, AutoImageProcessor, AutoTokenizer
>>> from PIL import Image
>>> import requests
>>> image_processor = AutoImageProcessor.from_pretrained("ydshieh/vit-gpt2-coco-en")
>>> decoder_tokenizer = AutoTokenizer.from_pretrained("ydshieh/vit-gpt2-coco-en")
>>> model = VisionEncoderDecoderModel.from_pretrained("ydshieh/vit-gpt2-coco-en")
>>> url = "http://images.cocodataset.org/val2017/000000039769.jpg"
>>> img = Image.open(requests.get(url, stream=True).raw)
>>> pixel_values = image_processor(images=img, return_tensors="pt").pixel_values # Batch size 1
>>> output_ids = model.generate(
... pixel_values, max_length=16, num_beams=4, return_dict_in_generate=True
... ).sequences
>>> preds = decoder_tokenizer.batch_decode(output_ids, skip_special_tokens=True)
>>> preds = [pred.strip() for pred in preds]
>>> assert preds == ["a cat laying on top of a couch next to another cat"]
```"""
from_tf = kwargs.pop("from_tf", False)
if from_tf:
from transformers import TFVisionEncoderDecoderModel
# a workaround to load from tensorflow checkpoint
# Using `_tf_model` won't work, because the weight names in the encoder/decoder of `_tf_model` get
# extended before saving those components. For example, The name of `_tf_model.encoder.vit` is
# `[top model name]/encoder/vit`, but the name of `tf_model.encoder.vit` is `[top model name]/vit`. The
# [top model name] is handled (stripped) by the conversion method, and the former case gets extra `encoder`,
# which should not occur when we want to save the components alone.
# There was a (very) ugly potential fix, which wasn't integrated to `transformers`: see
# https://github.com/huggingface/transformers/pull/13222/commits/dbb3c9de76eee235791d2064094654637c99f36d#r697304245
# (the change in `src/transformers/modeling_tf_utils.py`)
_tf_model = TFVisionEncoderDecoderModel.from_pretrained(
pretrained_model_name_or_path, *model_args, **kwargs
)
config = _tf_model.config
# Using `tf_model` instead
encoder = _tf_model.encoder.__class__(_tf_model.config.encoder)
decoder = _tf_model.decoder.__class__(_tf_model.config.decoder)
# Make sure models are built
encoder(encoder.dummy_inputs)
decoder(decoder.dummy_inputs)
# Get the variable correspondence between `_tf_model` and `encoder` and `decoder`
encoder_variables = {}
for v in encoder.trainable_variables + encoder.non_trainable_variables:
encoder_variables["/".join(v.name.split("/")[1:])] = v
decoder_variables = {}
for v in decoder.trainable_variables + decoder.non_trainable_variables:
decoder_variables["/".join(v.name.split("/")[1:])] = v
_encoder_variables = {}
for v in _tf_model.encoder.trainable_variables + _tf_model.encoder.non_trainable_variables:
_encoder_variables["/".join(v.name.split("/")[2:])] = v
_decoder_variables = {}
for v in _tf_model.decoder.trainable_variables + _tf_model.decoder.non_trainable_variables:
_decoder_variables["/".join(v.name.split("/")[2:])] = v
# assign weight values to `encoder` and `decoder` from `_tf_model`
for name, v in encoder_variables.items():
v.assign(_encoder_variables[name])
for name, v in decoder_variables.items():
v.assign(_decoder_variables[name])
tf_model = TFVisionEncoderDecoderModel(encoder=encoder, decoder=decoder)
# Deal with `enc_to_dec_proj`
if hasattr(_tf_model, "enc_to_dec_proj"):
tf_model(tf_model.dummy_inputs)
tf_model.enc_to_dec_proj.kernel.assign(_tf_model.enc_to_dec_proj.kernel)
tf_model.enc_to_dec_proj.bias.assign(_tf_model.enc_to_dec_proj.bias)
with tempfile.TemporaryDirectory() as tmpdirname:
encoder_dir = os.path.join(tmpdirname, "encoder")
decoder_dir = os.path.join(tmpdirname, "decoder")
tf_model.encoder.save_pretrained(encoder_dir)
tf_model.decoder.save_pretrained(decoder_dir)
if hasattr(tf_model, "enc_to_dec_proj"):
enc_to_dec_proj_weight = torch.transpose(
torch.from_numpy(tf_model.enc_to_dec_proj.kernel.numpy()), 1, 0
)
enc_to_dec_proj_bias = torch.from_numpy(tf_model.enc_to_dec_proj.bias.numpy())
del _tf_model
del tf_model
gc.collect()
model = VisionEncoderDecoderModel.from_encoder_decoder_pretrained(
encoder_dir, decoder_dir, encoder_from_tf=True, decoder_from_tf=True
)
# This is only for copying some specific attributes of this particular model.
model.config = config
if hasattr(model, "enc_to_dec_proj"):
model.enc_to_dec_proj.weight.data = enc_to_dec_proj_weight.contiguous()
model.enc_to_dec_proj.bias.data = enc_to_dec_proj_bias.contiguous()
return model
# At the moment fast initialization is not supported for composite models
if kwargs.get("_fast_init", False):
logger.warning(
"Fast initialization is currently not supported for VisionEncoderDecoderModel. "
"Falling back to slow initialization..."
)
kwargs["_fast_init"] = False
return super().from_pretrained(pretrained_model_name_or_path, *model_args, **kwargs)
@classmethod
def from_encoder_decoder_pretrained(
cls,
encoder_pretrained_model_name_or_path: str = None,
decoder_pretrained_model_name_or_path: str = None,
*model_args,
**kwargs,
) -> PreTrainedModel:
r"""
Instantiate an encoder and a decoder from one or two base classes of the library from pretrained model
checkpoints.
The model is set in evaluation mode by default using `model.eval()` (Dropout modules are deactivated). To train
the model, you need to first set it back in training mode with `model.train()`.
Params:
encoder_pretrained_model_name_or_path (`str`, *optional*):
Information necessary to initiate the image encoder. Can be either:
- A string, the *model id* of a pretrained model hosted inside a model repo on huggingface.co. An
example is `google/vit-base-patch16-224-in21k`.
- A path to a *directory* containing model weights saved using
[`~PreTrainedModel.save_pretrained`], e.g., `./my_model_directory/`.
- A path or url to a *tensorflow index checkpoint file* (e.g, `./tf_model/model.ckpt.index`). In
this case, `from_tf` should be set to `True` and a configuration object should be provided as
`config` argument. This loading path is slower than converting the TensorFlow checkpoint in a
PyTorch model using the provided conversion scripts and loading the PyTorch model afterwards.
decoder_pretrained_model_name_or_path (`str`, *optional*, defaults to `None`):
Information necessary to initiate the text decoder. Can be either:
- A string, the *model id* of a pretrained model hosted inside a model repo on huggingface.co.
- A path to a *directory* containing model weights saved using
[`~PreTrainedModel.save_pretrained`], e.g., `./my_model_directory/`.
- A path or url to a *tensorflow index checkpoint file* (e.g, `./tf_model/model.ckpt.index`). In
this case, `from_tf` should be set to `True` and a configuration object should be provided as
`config` argument. This loading path is slower than converting the TensorFlow checkpoint in a
PyTorch model using the provided conversion scripts and loading the PyTorch model afterwards.
model_args (remaining positional arguments, *optional*):
All remaning positional arguments will be passed to the underlying model's `__init__` method.
kwargs (remaining dictionary of keyword arguments, *optional*):
Can be used to update the configuration object (after it being loaded) and initiate the model (e.g.,
`output_attentions=True`).
- To update the encoder configuration, use the prefix *encoder_* for each configuration parameter.
- To update the decoder configuration, use the prefix *decoder_* for each configuration parameter.
- To update the parent model configuration, do not use a prefix for each configuration parameter.
Behaves differently depending on whether a `config` is provided or automatically loaded.
Example:
```python
>>> from transformers import VisionEncoderDecoderModel
>>> # initialize a vit-bert from a pretrained ViT and a pretrained BERT model. Note that the cross-attention layers will be randomly initialized
>>> model = VisionEncoderDecoderModel.from_encoder_decoder_pretrained(
... "google/vit-base-patch16-224-in21k", "google-bert/bert-base-uncased"
... )
>>> # saving model after fine-tuning
>>> model.save_pretrained("./vit-bert")
>>> # load fine-tuned model
>>> model = VisionEncoderDecoderModel.from_pretrained("./vit-bert")
```"""
kwargs_encoder = {
argument[len("encoder_") :]: value for argument, value in kwargs.items() if argument.startswith("encoder_")
}
kwargs_decoder = {
argument[len("decoder_") :]: value for argument, value in kwargs.items() if argument.startswith("decoder_")
}
# remove encoder, decoder kwargs from kwargs
for key in kwargs_encoder.keys():
del kwargs["encoder_" + key]
for key in kwargs_decoder.keys():
del kwargs["decoder_" + key]
# Load and initialize the encoder and decoder
# The distinction between encoder and decoder at the model level is made
# by the value of the flag `is_decoder` that we need to set correctly.
encoder = kwargs_encoder.pop("model", None)
if encoder is None:
if encoder_pretrained_model_name_or_path is None:
raise ValueError(
"If `encoder_model` is not defined as an argument, a `encoder_pretrained_model_name_or_path` has "
"to be defined."
)
if "config" not in kwargs_encoder:
encoder_config, kwargs_encoder = AutoConfig.from_pretrained(
encoder_pretrained_model_name_or_path, **kwargs_encoder, return_unused_kwargs=True
)
if encoder_config.is_decoder is True or encoder_config.add_cross_attention is True:
logger.info(
f"Initializing {encoder_pretrained_model_name_or_path} as a encoder model "
"from a decoder model. Cross-attention and casual mask are disabled."
)
encoder_config.is_decoder = False
encoder_config.add_cross_attention = False
kwargs_encoder["config"] = encoder_config
encoder = AutoModel.from_pretrained(encoder_pretrained_model_name_or_path, *model_args, **kwargs_encoder)
decoder = kwargs_decoder.pop("model", None)
if decoder is None:
if decoder_pretrained_model_name_or_path is None:
raise ValueError(
"If `decoder_model` is not defined as an argument, a `decoder_pretrained_model_name_or_path` has "
"to be defined."
)
if "config" not in kwargs_decoder:
decoder_config, kwargs_decoder = AutoConfig.from_pretrained(
decoder_pretrained_model_name_or_path, **kwargs_decoder, return_unused_kwargs=True
)
if decoder_config.is_decoder is False or decoder_config.add_cross_attention is False:
logger.info(
f"Initializing {decoder_pretrained_model_name_or_path} as a decoder model. Cross attention"
f" layers are added to {decoder_pretrained_model_name_or_path} and randomly initialized if"
f" {decoder_pretrained_model_name_or_path}'s architecture allows for cross attention layers."
)
decoder_config.is_decoder = True
decoder_config.add_cross_attention = True
kwargs_decoder["config"] = decoder_config
if kwargs_decoder["config"].is_decoder is False or kwargs_decoder["config"].add_cross_attention is False:
logger.warning(
f"Decoder model {decoder_pretrained_model_name_or_path} is not initialized as a decoder. "
f"In order to initialize {decoder_pretrained_model_name_or_path} as a decoder, "
"make sure that the attributes `is_decoder` and `add_cross_attention` of `decoder_config` "
"passed to `.from_encoder_decoder_pretrained(...)` are set to `True` or do not pass a "
"`decoder_config` to `.from_encoder_decoder_pretrained(...)`"
)
decoder = AutoModelForCausalLM.from_pretrained(decoder_pretrained_model_name_or_path, **kwargs_decoder)
# instantiate config with corresponding kwargs
config = VisionEncoderDecoderConfig.from_encoder_decoder_configs(encoder.config, decoder.config, **kwargs)
# make sure input & output embeddings is not tied
config.tie_word_embeddings = False
return cls(encoder=encoder, decoder=decoder, config=config)
@add_start_docstrings_to_model_forward(VISION_ENCODER_DECODER_INPUTS_DOCSTRING)
@replace_return_docstrings(output_type=Seq2SeqLMOutput, config_class=_CONFIG_FOR_DOC)
def forward(
self,
pixel_values: Optional[torch.FloatTensor] = None,
decoder_input_ids: Optional[torch.LongTensor] = None,
decoder_attention_mask: Optional[torch.BoolTensor] = None,
encoder_outputs: Optional[Tuple[torch.FloatTensor]] = None,
past_key_values: Optional[Tuple[Tuple[torch.FloatTensor]]] = None,
decoder_inputs_embeds: Optional[torch.FloatTensor] = None,
labels: Optional[torch.LongTensor] = None,
use_cache: Optional[bool] = None,
output_attentions: Optional[bool] = None,
output_hidden_states: Optional[bool] = None,
return_dict: Optional[bool] = None,
**kwargs,
) -> Union[Tuple[torch.FloatTensor], Seq2SeqLMOutput]:
r"""
Returns:
Examples:
```python
>>> from transformers import AutoProcessor, VisionEncoderDecoderModel
>>> import requests
>>> from PIL import Image
>>> import torch
>>> processor = AutoProcessor.from_pretrained("microsoft/trocr-base-handwritten")
>>> model = VisionEncoderDecoderModel.from_pretrained("microsoft/trocr-base-handwritten")
>>> # load image from the IAM dataset
>>> url = "https://fki.tic.heia-fr.ch/static/img/a01-122-02.jpg"
>>> image = Image.open(requests.get(url, stream=True).raw).convert("RGB")
>>> # training
>>> model.config.decoder_start_token_id = processor.tokenizer.eos_token_id
>>> model.config.pad_token_id = processor.tokenizer.pad_token_id
>>> model.config.vocab_size = model.config.decoder.vocab_size
>>> pixel_values = processor(image, return_tensors="pt").pixel_values
>>> text = "hello world"
>>> labels = processor.tokenizer(text, return_tensors="pt").input_ids
>>> outputs = model(pixel_values=pixel_values, labels=labels)
>>> loss = outputs.loss
>>> # inference (generation)
>>> generated_ids = model.generate(pixel_values)
>>> generated_text = processor.batch_decode(generated_ids, skip_special_tokens=True)[0]
```"""
return_dict = return_dict if return_dict is not None else self.config.use_return_dict
kwargs_encoder = {argument: value for argument, value in kwargs.items() if not argument.startswith("decoder_")}
kwargs_decoder = {
argument[len("decoder_") :]: value for argument, value in kwargs.items() if argument.startswith("decoder_")
}
if encoder_outputs is None:
if pixel_values is None:
raise ValueError("You have to specify pixel_values")
encoder_outputs = self.encoder(
pixel_values=pixel_values,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
return_dict=return_dict,
**kwargs_encoder,
)
elif isinstance(encoder_outputs, tuple):
encoder_outputs = BaseModelOutput(*encoder_outputs)
encoder_hidden_states = encoder_outputs[0]
# optionally project encoder_hidden_states
if (
self.encoder.config.hidden_size != self.decoder.config.hidden_size
and self.decoder.config.cross_attention_hidden_size is None
):
encoder_hidden_states = self.enc_to_dec_proj(encoder_hidden_states)
# else:
encoder_attention_mask = None
if (labels is not None) and (decoder_input_ids is None and decoder_inputs_embeds is None):
decoder_input_ids = shift_tokens_right(
labels, self.config.pad_token_id, self.config.decoder_start_token_id
)
# Decode
decoder_outputs = self.decoder(
input_ids=decoder_input_ids,
attention_mask=decoder_attention_mask,
encoder_hidden_states=encoder_hidden_states,
encoder_attention_mask=encoder_attention_mask,
inputs_embeds=decoder_inputs_embeds,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
use_cache=use_cache,
past_key_values=past_key_values,
return_dict=return_dict,
**kwargs_decoder,
)
# Compute loss independent from decoder (as some shift the logits inside them)
loss = None
if labels is not None:
logits = decoder_outputs.logits if return_dict else decoder_outputs[0]
loss_fct = CrossEntropyLoss()
loss = loss_fct(logits.reshape(-1, self.decoder.config.vocab_size), labels.reshape(-1))
if not return_dict:
if loss is not None:
return (loss,) + decoder_outputs + encoder_outputs
else:
return decoder_outputs + encoder_outputs
return Seq2SeqLMOutput(
loss=loss,
logits=decoder_outputs.logits,
past_key_values=decoder_outputs.past_key_values,
decoder_hidden_states=decoder_outputs.hidden_states,
decoder_attentions=decoder_outputs.attentions,
cross_attentions=decoder_outputs.cross_attentions,
encoder_last_hidden_state=encoder_outputs.last_hidden_state,
encoder_hidden_states=encoder_outputs.hidden_states,
encoder_attentions=encoder_outputs.attentions,
)
def prepare_decoder_input_ids_from_labels(self, labels: torch.Tensor):
return shift_tokens_right(labels, self.config.pad_token_id, self.config.decoder_start_token_id)
def prepare_inputs_for_generation(
self, input_ids, past_key_values=None, attention_mask=None, use_cache=None, encoder_outputs=None, **kwargs
):
decoder_inputs = self.decoder.prepare_inputs_for_generation(input_ids, past_key_values=past_key_values)
decoder_attention_mask = decoder_inputs["attention_mask"] if "attention_mask" in decoder_inputs else None
input_dict = {
"attention_mask": attention_mask,
"decoder_attention_mask": decoder_attention_mask,
"decoder_input_ids": decoder_inputs["input_ids"],
"encoder_outputs": encoder_outputs,
"past_key_values": decoder_inputs["past_key_values"],
"use_cache": use_cache,
}
return input_dict
def resize_token_embeddings(self, *args, **kwargs):
raise NotImplementedError(
"Resizing the embedding layers via the VisionEncoderDecoderModel directly is not supported.Please use the"
" respective methods of the wrapped decoder object (model.decoder.resize_token_embeddings(...))"
)
def _reorder_cache(self, past_key_values, beam_idx):
# apply decoder cache reordering here
return self.decoder._reorder_cache(past_key_values, beam_idx)
@add_start_docstrings(ENCODER_DECODER_START_DOCSTRING)
class EncoderDecoderModel(PreTrainedModel):
r"""
[`EncoderDecoderModel`] is a generic model class that will be instantiated as a transformer architecture with one
of the base model classes of the library as encoder and another one as decoder when created with the
:meth*~transformers.AutoModel.from_pretrained* class method for the encoder and
:meth*~transformers.AutoModelForCausalLM.from_pretrained* class method for the decoder.
"""
config_class = EncoderDecoderConfig
base_model_prefix = "encoder_decoder"
main_input_name = "input_ids"
supports_gradient_checkpointing = True
def __init__(
self,
config: Optional[PretrainedConfig] = None,
encoder: Optional[PreTrainedModel] = None,
decoder: Optional[PreTrainedModel] = None,
):
if config is None and (encoder is None or decoder is None):
raise ValueError("Either a configuration or an encoder and a decoder has to be provided.")
if config is None:
config = EncoderDecoderConfig.from_encoder_decoder_configs(encoder.config, decoder.config)
else:
if not isinstance(config, self.config_class):
raise ValueError(f"Config: {config} has to be of type {self.config_class}")
if config.decoder.cross_attention_hidden_size is not None:
if config.decoder.cross_attention_hidden_size != config.encoder.hidden_size:
raise ValueError(
"If `cross_attention_hidden_size` is specified in the decoder's configuration, it has to be equal"
f" to the encoder's `hidden_size`. Got {config.decoder.cross_attention_hidden_size} for"
f" `config.decoder.cross_attention_hidden_size` and {config.encoder.hidden_size} for"
" `config.encoder.hidden_size`."
)
# initialize with config
super().__init__(config)
if encoder is None:
from ..auto.modeling_auto import AutoModel
encoder = AutoModel.from_config(config.encoder)
if decoder is None:
from ..auto.modeling_auto import AutoModelForCausalLM
decoder = AutoModelForCausalLM.from_config(config.decoder)
self.encoder = encoder
self.decoder = decoder
if self.encoder.config.to_dict() != self.config.encoder.to_dict():
logger.warning(
f"Config of the encoder: {self.encoder.__class__} is overwritten by shared encoder config:"
f" {self.config.encoder}"
)
if self.decoder.config.to_dict() != self.config.decoder.to_dict():
logger.warning(
f"Config of the decoder: {self.decoder.__class__} is overwritten by shared decoder config:"
f" {self.config.decoder}"
)
# make sure that the individual model's config refers to the shared config
# so that the updates to the config will be synced
self.encoder.config = self.config.encoder
self.decoder.config = self.config.decoder
# encoder outputs might need to be projected to different dimension for decoder
if (
self.encoder.config.hidden_size != self.decoder.config.hidden_size
and self.decoder.config.cross_attention_hidden_size is None
):
self.enc_to_dec_proj = nn.Linear(self.encoder.config.hidden_size, self.decoder.config.hidden_size)
if self.encoder.get_output_embeddings() is not None:
raise ValueError(
f"The encoder {self.encoder} should not have a LM Head. Please use a model without LM Head"
)
decoder_signature = set(inspect.signature(self.decoder.forward).parameters.keys())
if "encoder_hidden_states" not in decoder_signature:
raise ValueError(
"The selected decoder is not prepared for the encoder hidden states to be passed. Please see the "
"following discussion on GitHub: https://github.com/huggingface/transformers/issues/23350"
)
# tie encoder, decoder weights if config set accordingly
self.tie_weights()
def tie_weights(self):
# tie encoder & decoder if needed
if self.config.tie_encoder_decoder:
# tie encoder and decoder base model
decoder_base_model_prefix = self.decoder.base_model_prefix
tied_weights = self._tie_encoder_decoder_weights(
self.encoder,
self.decoder._modules[decoder_base_model_prefix],
self.decoder.base_model_prefix,
"encoder",
)
# Setting a dynamic variable instead of `_tied_weights_keys` because it's a class
# attributed not an instance member, therefore modifying it will modify the entire class
# Leading to issues on subsequent calls by different tests or subsequent calls.
self._dynamic_tied_weights_keys = tied_weights
def get_encoder(self):
return self.encoder
def get_decoder(self):
return self.decoder
def get_input_embeddings(self):
return self.encoder.get_input_embeddings()
def get_output_embeddings(self):
return self.decoder.get_output_embeddings()
def set_output_embeddings(self, new_embeddings):
return self.decoder.set_output_embeddings(new_embeddings)
@classmethod
def from_pretrained(cls, pretrained_model_name_or_path, *model_args, **kwargs):
r"""
Example:
```python
>>> from transformers import EncoderDecoderModel
>>> model = EncoderDecoderModel.from_pretrained("patrickvonplaten/bert2bert-cnn_dailymail-fp16")
```"""
from_tf = kwargs.pop("from_tf", False)
if from_tf:
from transformers import TFEncoderDecoderModel
# a workaround to load from tensorflow checkpoint
# Using `_tf_model` won't work, because the weight names in the encoder/decoder of `_tf_model` get
# extended before saving those components. For example, The name of `_tf_model.encoder.vit` is
# `[top model name]/encoder/vit`, but the name of `tf_model.encoder.vit` is `[top model name]/vit`. The
# [top model name] is handled (stripped) by the conversion method, and the former case gets extra `encoder`,
# which should not occur when we want to save the components alone.
# There was a (very) ugly potential fix, which wasn't integrated to `transformers`: see
# https://github.com/huggingface/transformers/pull/13222/commits/dbb3c9de76eee235791d2064094654637c99f36d#r697304245
# (the change in `src/transformers/modeling_tf_utils.py`)
_tf_model = TFEncoderDecoderModel.from_pretrained(pretrained_model_name_or_path, *model_args, **kwargs)
config = _tf_model.config
# Using `tf_model` instead
encoder = _tf_model.encoder.__class__(_tf_model.config.encoder)
decoder = _tf_model.decoder.__class__(_tf_model.config.decoder)
# Make sure models are built
encoder(encoder.dummy_inputs)
decoder(decoder.dummy_inputs)
# Get the variable correspondence between `_tf_model` and `encoder` and `decoder`
encoder_variables = {}
for v in encoder.trainable_variables + encoder.non_trainable_variables:
encoder_variables["/".join(v.name.split("/")[1:])] = v
decoder_variables = {}
for v in decoder.trainable_variables + decoder.non_trainable_variables:
decoder_variables["/".join(v.name.split("/")[1:])] = v
_encoder_variables = {}
for v in _tf_model.encoder.trainable_variables + _tf_model.encoder.non_trainable_variables:
_encoder_variables["/".join(v.name.split("/")[2:])] = v
_decoder_variables = {}
for v in _tf_model.decoder.trainable_variables + _tf_model.decoder.non_trainable_variables:
_decoder_variables["/".join(v.name.split("/")[2:])] = v
# assign weight values to `encoder` and `decoder` from `_tf_model`
for name, v in encoder_variables.items():
v.assign(_encoder_variables[name])
for name, v in decoder_variables.items():
v.assign(_decoder_variables[name])
tf_model = TFEncoderDecoderModel(encoder=encoder, decoder=decoder)
# Deal with `enc_to_dec_proj`
if hasattr(_tf_model, "enc_to_dec_proj"):
tf_model(tf_model.dummy_inputs)
tf_model.enc_to_dec_proj.kernel.assign(_tf_model.enc_to_dec_proj.kernel)
tf_model.enc_to_dec_proj.bias.assign(_tf_model.enc_to_dec_proj.bias)
with tempfile.TemporaryDirectory() as tmpdirname:
encoder_dir = os.path.join(tmpdirname, "encoder")
decoder_dir = os.path.join(tmpdirname, "decoder")
tf_model.encoder.save_pretrained(encoder_dir)
tf_model.decoder.save_pretrained(decoder_dir)
if hasattr(tf_model, "enc_to_dec_proj"):
enc_to_dec_proj_weight = torch.transpose(
torch.from_numpy(tf_model.enc_to_dec_proj.kernel.numpy()), 1, 0
)
enc_to_dec_proj_bias = torch.from_numpy(tf_model.enc_to_dec_proj.bias.numpy())
del _tf_model
del tf_model
gc.collect()
model = EncoderDecoderModel.from_encoder_decoder_pretrained(
encoder_dir, decoder_dir, encoder_from_tf=True, decoder_from_tf=True
)
# This is only for copying some specific attributes of this particular model.
model.config = config
if hasattr(model, "enc_to_dec_proj"):
model.enc_to_dec_proj.weight.data = enc_to_dec_proj_weight.contiguous()
model.enc_to_dec_proj.bias.data = enc_to_dec_proj_bias.contiguous()
return model
# At the moment fast initialization is not supported for composite models
if kwargs.get("_fast_init", False):
logger.warning(
"Fast initialization is currently not supported for EncoderDecoderModel. "
"Falling back to slow initialization..."
)
kwargs["_fast_init"] = False
return super().from_pretrained(pretrained_model_name_or_path, *model_args, **kwargs)
@classmethod
def from_encoder_decoder_pretrained(
cls,
encoder_pretrained_model_name_or_path: str = None,
decoder_pretrained_model_name_or_path: str = None,
*model_args,
**kwargs,
) -> PreTrainedModel:
r"""
Instantiate an encoder and a decoder from one or two base classes of the library from pretrained model
checkpoints.
The model is set in evaluation mode by default using `model.eval()` (Dropout modules are deactivated). To train
the model, you need to first set it back in training mode with `model.train()`.
Params:
encoder_pretrained_model_name_or_path (`str`, *optional*):
Information necessary to initiate the encoder. Can be either:
- A string, the *model id* of a pretrained model hosted inside a model repo on huggingface.co.
- A path to a *directory* containing model weights saved using
[`~PreTrainedModel.save_pretrained`], e.g., `./my_model_directory/`.
- A path or url to a *tensorflow index checkpoint file* (e.g, `./tf_model/model.ckpt.index`). In
this case, `from_tf` should be set to `True` and a configuration object should be provided as
`config` argument. This loading path is slower than converting the TensorFlow checkpoint in a
PyTorch model using the provided conversion scripts and loading the PyTorch model afterwards.
decoder_pretrained_model_name_or_path (`str`, *optional*, defaults to `None`):
Information necessary to initiate the decoder. Can be either:
- A string, the *model id* of a pretrained model hosted inside a model repo on huggingface.co.
- A path to a *directory* containing model weights saved using
[`~PreTrainedModel.save_pretrained`], e.g., `./my_model_directory/`.
- A path or url to a *tensorflow index checkpoint file* (e.g, `./tf_model/model.ckpt.index`). In
this case, `from_tf` should be set to `True` and a configuration object should be provided as
`config` argument. This loading path is slower than converting the TensorFlow checkpoint in a
PyTorch model using the provided conversion scripts and loading the PyTorch model afterwards.
model_args (remaining positional arguments, *optional*):
All remaining positional arguments will be passed to the underlying model's `__init__` method.
kwargs (remaining dictionary of keyword arguments, *optional*):
Can be used to update the configuration object (after it being loaded) and initiate the model (e.g.,
`output_attentions=True`).
- To update the encoder configuration, use the prefix *encoder_* for each configuration parameter.
- To update the decoder configuration, use the prefix *decoder_* for each configuration parameter.
- To update the parent model configuration, do not use a prefix for each configuration parameter.
Behaves differently depending on whether a `config` is provided or automatically loaded.
Example:
```python
>>> from transformers import EncoderDecoderModel
>>> # initialize a bert2bert from two pretrained BERT models. Note that the cross-attention layers will be randomly initialized
>>> model = EncoderDecoderModel.from_encoder_decoder_pretrained("google-bert/bert-base-uncased", "google-bert/bert-base-uncased")
>>> # saving model after fine-tuning
>>> model.save_pretrained("./bert2bert")
>>> # load fine-tuned model
>>> model = EncoderDecoderModel.from_pretrained("./bert2bert")
```"""
kwargs_encoder = {
argument[len("encoder_") :]: value for argument, value in kwargs.items() if argument.startswith("encoder_")
}
kwargs_decoder = {
argument[len("decoder_") :]: value for argument, value in kwargs.items() if argument.startswith("decoder_")
}
# remove encoder, decoder kwargs from kwargs
for key in kwargs_encoder.keys():
del kwargs["encoder_" + key]
for key in kwargs_decoder.keys():
del kwargs["decoder_" + key]
# Load and initialize the encoder and decoder
# The distinction between encoder and decoder at the model level is made
# by the value of the flag `is_decoder` that we need to set correctly.
encoder = kwargs_encoder.pop("model", None)
if encoder is None:
if encoder_pretrained_model_name_or_path is None:
raise ValueError(
"If `encoder_model` is not defined as an argument, a `encoder_pretrained_model_name_or_path` has "
"to be defined."
)
if "config" not in kwargs_encoder:
encoder_config, kwargs_encoder = AutoConfig.from_pretrained(
encoder_pretrained_model_name_or_path, **kwargs_encoder, return_unused_kwargs=True
)
if encoder_config.is_decoder is True or encoder_config.add_cross_attention is True:
logger.info(
f"Initializing {encoder_pretrained_model_name_or_path} as a encoder model "
"from a decoder model. Cross-attention and casual mask are disabled."
)
encoder_config.is_decoder = False
encoder_config.add_cross_attention = False
kwargs_encoder["config"] = encoder_config
encoder = AutoModel.from_pretrained(encoder_pretrained_model_name_or_path, *model_args, **kwargs_encoder)
decoder = kwargs_decoder.pop("model", None)
if decoder is None:
if decoder_pretrained_model_name_or_path is None:
raise ValueError(
"If `decoder_model` is not defined as an argument, a `decoder_pretrained_model_name_or_path` has "
"to be defined."
)
if "config" not in kwargs_decoder:
decoder_config, kwargs_decoder = AutoConfig.from_pretrained(
decoder_pretrained_model_name_or_path, **kwargs_decoder, return_unused_kwargs=True
)
if decoder_config.is_decoder is False or decoder_config.add_cross_attention is False:
logger.info(
f"Initializing {decoder_pretrained_model_name_or_path} as a decoder model. Cross attention"
f" layers are added to {decoder_pretrained_model_name_or_path} and randomly initialized if"
f" {decoder_pretrained_model_name_or_path}'s architecture allows for cross attention layers."
)
decoder_config.is_decoder = True
decoder_config.add_cross_attention = True
kwargs_decoder["config"] = decoder_config
if kwargs_decoder["config"].is_decoder is False or kwargs_decoder["config"].add_cross_attention is False:
logger.warning(
f"Decoder model {decoder_pretrained_model_name_or_path} is not initialized as a decoder. "
f"In order to initialize {decoder_pretrained_model_name_or_path} as a decoder, "
"make sure that the attributes `is_decoder` and `add_cross_attention` of `decoder_config` "
"passed to `.from_encoder_decoder_pretrained(...)` are set to `True` or do not pass a "
"`decoder_config` to `.from_encoder_decoder_pretrained(...)`"
)
decoder = AutoModelForCausalLM.from_pretrained(decoder_pretrained_model_name_or_path, **kwargs_decoder)
# instantiate config with corresponding kwargs
config = EncoderDecoderConfig.from_encoder_decoder_configs(encoder.config, decoder.config, **kwargs)
return cls(encoder=encoder, decoder=decoder, config=config)
@add_start_docstrings_to_model_forward(ENCODER_DECODER_INPUTS_DOCSTRING)
@replace_return_docstrings(output_type=Seq2SeqLMOutput, config_class=_CONFIG_FOR_DOC)
def forward(
self,
input_ids: Optional[torch.LongTensor] = None,
attention_mask: Optional[torch.FloatTensor] = None,
decoder_input_ids: Optional[torch.LongTensor] = None,
decoder_attention_mask: Optional[torch.BoolTensor] = None,
encoder_outputs: Optional[Tuple[torch.FloatTensor]] = None,
past_key_values: Tuple[Tuple[torch.FloatTensor]] = None,
inputs_embeds: Optional[torch.FloatTensor] = None,
decoder_inputs_embeds: Optional[torch.FloatTensor] = None,
labels: Optional[torch.LongTensor] = None,
use_cache: Optional[bool] = None,
output_attentions: Optional[bool] = None,
output_hidden_states: Optional[bool] = None,
return_dict: Optional[bool] = None,
**kwargs,
) -> Union[Tuple, Seq2SeqLMOutput]:
r"""
Returns:
Examples:
```python
>>> from transformers import EncoderDecoderModel, BertTokenizer
>>> import torch
>>> tokenizer = BertTokenizer.from_pretrained("google-bert/bert-base-uncased")
>>> model = EncoderDecoderModel.from_encoder_decoder_pretrained(
... "google-bert/bert-base-uncased", "google-bert/bert-base-uncased"
... ) # initialize Bert2Bert from pre-trained checkpoints
>>> # training
>>> model.config.decoder_start_token_id = tokenizer.cls_token_id
>>> model.config.pad_token_id = tokenizer.pad_token_id
>>> model.config.vocab_size = model.config.decoder.vocab_size
>>> input_ids = tokenizer("This is a really long text", return_tensors="pt").input_ids
>>> labels = tokenizer("This is the corresponding summary", return_tensors="pt").input_ids
>>> outputs = model(input_ids=input_ids, labels=labels)
>>> loss, logits = outputs.loss, outputs.logits
>>> # save and load from pretrained
>>> model.save_pretrained("bert2bert")
>>> model = EncoderDecoderModel.from_pretrained("bert2bert")
>>> # generation
>>> generated = model.generate(input_ids)
```"""
return_dict = return_dict if return_dict is not None else self.config.use_return_dict
kwargs_encoder = {argument: value for argument, value in kwargs.items() if not argument.startswith("decoder_")}
kwargs_decoder = {
argument[len("decoder_") :]: value for argument, value in kwargs.items() if argument.startswith("decoder_")
}
if encoder_outputs is None:
encoder_outputs = self.encoder(
input_ids=input_ids,
attention_mask=attention_mask,
inputs_embeds=inputs_embeds,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
return_dict=return_dict,
**kwargs_encoder,
)
elif isinstance(encoder_outputs, tuple):
encoder_outputs = BaseModelOutput(*encoder_outputs)
encoder_hidden_states = encoder_outputs[0]
# optionally project encoder_hidden_states
if (
self.encoder.config.hidden_size != self.decoder.config.hidden_size
and self.decoder.config.cross_attention_hidden_size is None
):
encoder_hidden_states = self.enc_to_dec_proj(encoder_hidden_states)
if (labels is not None) and (decoder_input_ids is None and decoder_inputs_embeds is None):
decoder_input_ids = shift_tokens_right(
labels, self.config.pad_token_id, self.config.decoder_start_token_id
)
if decoder_attention_mask is None:
decoder_attention_mask = decoder_input_ids.new_tensor(decoder_input_ids != self.config.pad_token_id)
# Decode
decoder_outputs = self.decoder(
input_ids=decoder_input_ids,
attention_mask=decoder_attention_mask,
encoder_hidden_states=encoder_hidden_states,
encoder_attention_mask=attention_mask,
inputs_embeds=decoder_inputs_embeds,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
use_cache=use_cache,
past_key_values=past_key_values,
return_dict=return_dict,
**kwargs_decoder,
)
# Compute loss independent from decoder (as some shift the logits inside them)
loss = None
if labels is not None:
warnings.warn(DEPRECATION_WARNING, FutureWarning)
logits = decoder_outputs.logits if return_dict else decoder_outputs[0]
loss_fct = CrossEntropyLoss()
loss = loss_fct(logits.reshape(-1, self.decoder.config.vocab_size), labels.view(-1))
if not return_dict:
if loss is not None:
return (loss,) + decoder_outputs + encoder_outputs
else:
return decoder_outputs + encoder_outputs
return Seq2SeqLMOutput(
loss=loss,
logits=decoder_outputs.logits,
past_key_values=decoder_outputs.past_key_values,
decoder_hidden_states=decoder_outputs.hidden_states,
decoder_attentions=decoder_outputs.attentions,
cross_attentions=decoder_outputs.cross_attentions,
encoder_last_hidden_state=encoder_outputs.last_hidden_state,
encoder_hidden_states=encoder_outputs.hidden_states,
encoder_attentions=encoder_outputs.attentions,
)
def prepare_decoder_input_ids_from_labels(self, labels: torch.Tensor):
return shift_tokens_right(labels, self.config.pad_token_id, self.config.decoder_start_token_id)
def prepare_inputs_for_generation(
self, input_ids, past_key_values=None, attention_mask=None, use_cache=None, encoder_outputs=None, **kwargs
):
decoder_inputs = self.decoder.prepare_inputs_for_generation(input_ids, past_key_values=past_key_values)
decoder_attention_mask = decoder_inputs["attention_mask"] if "attention_mask" in decoder_inputs else None
input_dict = {
"attention_mask": attention_mask,
"decoder_attention_mask": decoder_attention_mask,
"decoder_input_ids": decoder_inputs["input_ids"],
"encoder_outputs": encoder_outputs,
"past_key_values": decoder_inputs["past_key_values"],
"use_cache": use_cache,
}
return input_dict
def resize_token_embeddings(self, *args, **kwargs):
raise NotImplementedError(
"Resizing the embedding layers via the EncoderDecoderModel directly is not supported. Please use the"
" respective methods of the wrapped objects (model.encoder.resize_token_embeddings(...) or"
" model.decoder.resize_token_embeddings(...))"
)
def _reorder_cache(self, past_key_values, beam_idx):
# apply decoder cache reordering here
return self.decoder._reorder_cache(past_key_values, beam_idx)
class MistralForCausalThoughtLM(MistralPreTrainedModel):
_tied_weights_keys = ["lm_head.weight"]
def save_tokens_with_rewards_to_pdf(input_ids, token_rewards, tokenizer, output_file="text.pdf", eps=0.2, eps2=0.5):
c = canvas.Canvas(output_file, pagesize=letter)
c.setFont("Courier", 8)
x, y = 50, 750
previous_text = ""
current_text = ""
for token_idx, reward in enumerate(token_rewards):
current_text = tokenizer.decode(input_ids[: token_idx + 1])
if current_text != previous_text:
diff_text = current_text[len(previous_text) :]
if "\n" in diff_text:
lines = diff_text.split("\n")
for line_idx, line in enumerate(lines):
if line_idx > 0:
x = 50
y -= 12
if abs(reward) < eps:
opacity = 0
elif abs(reward) > eps2:
opacity = 0.8
else:
opacity = 0.8 * (abs(reward) - eps) / (eps2 - eps)
text_width = c.stringWidth(line)
if reward > 0:
highlight_color = HexColor("#4CCD99")
else:
highlight_color = HexColor("#FFC700")
highlight_color.alpha = opacity
c.setFillColor(highlight_color)
c.rect(x, y - 2, text_width, 10, fill=True, stroke=False)
c.setFillColor(HexColor("#000000"))
c.drawString(x, y, line)
x += text_width
else:
if abs(reward) < eps:
opacity = 0
elif abs(reward) > eps2:
opacity = 0.8
else:
opacity = 0.8 * (abs(reward) - eps) / (eps2 - eps)
text_width = c.stringWidth(diff_text)
if reward > 0:
highlight_color = HexColor("#4CCD99")
else:
highlight_color = HexColor("#FFC700")
highlight_color.alpha = opacity
c.setFillColor(highlight_color)
c.rect(x, y - 2, text_width, 10, fill=True, stroke=False)
c.setFillColor(HexColor("#000000"))
c.drawString(x, y, diff_text)
x += text_width
if x > 550:
x = 50
y -= 12
if y < 50:
c.showPage()
y = 750
x = 50
previous_text = current_text
c.showPage()
c.save()
def __init__(self, config):
super().__init__(config)
self.model = MistralModel(config)
self.vocab_size = config.vocab_size
self.lm_head = nn.Linear(config.hidden_size, config.vocab_size, bias=False)
self.max_thoughts = config.max_thoughts
self.merged_lm_and_talk_heads = config.merged_lm_and_talk_heads
self.use_concat_talk_head = config.use_concat_talk_head
self.use_shallow_talk = config.use_shallow_talk
self.use_complex_talk_head = config.use_complex_talk_head
self.use_weighted_talk_head = config.use_weighted_talk_head
# the weighted head will output a single value, so it can't be passed to the lm head
assert not (self.use_weighted_talk_head and self.use_shallow_talk)
self.n_ahead = 1
self.n_ahead_talk = 1
self.n_passes = 1
self.n_tokens_print = 1
self.gradient_accumulation_steps = 1
self.training_steps = 0
self.tokenizer = None
self.start_token_id = None
self.end_token_id = None
self.rm_initialized = False
self.residual_talk_head = True
self.thought_init_std_scale = 1e-2
self.final_only_mode = False
self.first_and_last_mode = True
self.first_only = False
self.original_loss_weight = 0.5
self.cumulative_residual = False
self.clever_residual = False
self.skip_residual = False
self.no_residual = True
self.optimize_lm_head_only_at_start = False
self.optimize_model_only_at_start = False
if self.optimize_model_only_at_start:
raise NotImplementedError
self.train_only_thinking_embedding = False
self.weighted_embeddings = False
self.use_start_thought_token = True
self.use_end_thought_token = True
self.initialize_thought_embedding_to_normal = False
self.initial_start_token = "---"
self.initial_end_token = "---"
self.output_logits_at_the_end = True
self.gumbel_temperature = 0.001
self.use_policy_loss = True
self.include_policy_loss = True
self.trice_mode = True
self.remove_negative_rewards = True
self.use_policy_loss_for_end_thought = True
self.base_original_mode = False
self.original_mode = False
self.thought_prefix = "(Let's think step by step"
self.tokenized_thought_prefix = None
self.log_dict = defaultdict(int)
self.eval_log_dict = defaultdict(int)
self.print_final_only = True
self.loss_mean = loss_mean
self.all_rewards = []
self.all_unreduced_losses = []
self.kill_after = 100
self.start_embedding = nn.Parameter(torch.zeros(2, self.model.config.hidden_size))
self.end_embedding = nn.Parameter(torch.zeros(2, self.model.config.hidden_size))
self.policy_loss_beta = 1e6
self.embedding_scale = 1e2
self.reinforce_temperature = 3
self.base_loss_beta = 1
# Not used in the paper:
self.use_thought_prefix = False
self.use_reparam_for_thought_embeddings = False
self.use_upper_triangular = False
self.subtract_mean_reward = False
self.comparison_mode = False
self.gumbel_detach = True
# For visualization
self.eval_mode = False
num_talk = 1
talk_input_dim = config.hidden_size if not self.use_concat_talk_head else config.hidden_size * 2
if self.use_weighted_talk_head:
talk_output_dim = 1
else:
talk_output_dim = config.hidden_size if self.use_shallow_talk else config.vocab_size
if not self.merged_lm_and_talk_heads:
if self.use_complex_talk_head:
self.talk_head = nn.ModuleList([nn.Sequential(
nn.Linear(talk_input_dim, config.hidden_size),
nn.ReLU(),
nn.Linear(config.hidden_size, config.hidden_size),
nn.ReLU(),
nn.Linear(config.hidden_size, talk_output_dim, bias=False)
)])
else:
self.talk_head = nn.ModuleList([nn.Sequential(
nn.Linear(talk_input_dim, talk_output_dim, bias=False)
)])
# Initialize weights and apply final processing
self.post_init()
def get_input_embeddings(self):
return self.model.embed_tokens
def set_input_embeddings(self, value):
self.model.embed_tokens = value
def get_output_embeddings(self):
return self.lm_head
def set_output_embeddings(self, new_embeddings):
self.lm_head = new_embeddings
def set_decoder(self, decoder):
self.model = decoder
def get_decoder(self):
return self.model
@torch.no_grad()
def infer(
self,
input_ids: torch.LongTensor,
attention_mask: Optional[torch.Tensor] = None,
position_ids: Optional[torch.LongTensor] = None,
past_key_values: Optional[List[torch.FloatTensor]] = None,
inputs_embeds: Optional[torch.FloatTensor] = None,
use_cache: Optional[bool] = None,
output_attentions: Optional[bool] = None,
output_hidden_states: Optional[bool] = None,
return_dict: Optional[bool] = None,
):
batch_size, seq_len = input_ids.shape
# Save the original input_ids and attention_mask for later use
original_input_ids = input_ids.clone()
original_attention_mask = attention_mask.clone() if attention_mask is not None else None
# Append the start thought token to the input sequence
start_thought_token_id = self.tokenizer.convert_tokens_to_ids("<|startthought|>")
input_ids = torch.cat([input_ids, torch.tensor([[start_thought_token_id]] * batch_size).to(input_ids.device)], dim=-1)
seq_len += 1
# Update the attention mask
if attention_mask is not None:
attention_mask = torch.cat([attention_mask, torch.ones((batch_size, 1)).to(attention_mask.device)], dim=-1)
# Generate the continuation
continuation_length = self.n_ahead - 2
new_key_values = past_key_values
start_time = time.time()
for continuation_idx in range(continuation_length):
outputs = self.model(
input_ids=input_ids if continuation_idx == 0 else next_token_id.unsqueeze(-1).to(input_ids.device),
attention_mask=attention_mask,
position_ids=position_ids,
past_key_values=new_key_values,
inputs_embeds=inputs_embeds,
use_cache=True,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
return_dict=return_dict,
)
new_key_values = outputs.past_key_values
hidden_states = outputs[0]
logits = self.lm_head(hidden_states)
logits = logits[:, -1, :] # Only consider the last token
# Apply Gumbel-Softmax to the logits
next_token_logits = F.gumbel_softmax(logits, tau=self.gumbel_temperature, hard=True, dim=-1)
next_token_id = torch.argmax(next_token_logits, dim=-1)
# Append the generated token to the input sequence
input_ids = torch.cat([input_ids, next_token_id.unsqueeze(-1).to(input_ids.device)], dim=-1)
seq_len += 1
# Update the attention mask
if attention_mask is not None:
attention_mask = torch.cat([attention_mask, torch.ones((batch_size, 1)).to(attention_mask.device)], dim=-1)
# Append the end thought token to the input sequence
end_thought_token_id = self.tokenizer.convert_tokens_to_ids("<|endthought|>")
input_ids = torch.cat([input_ids, torch.tensor([[end_thought_token_id]] * batch_size).to(input_ids.device)], dim=-1)
seq_len += 1
# Update the attention mask
if attention_mask is not None:
attention_mask = torch.cat([attention_mask, torch.ones((batch_size, 1)).to(attention_mask.device)], dim=-1)
# Get the hidden states before and after the thought
outputs_before = self.model(
input_ids=original_input_ids,
attention_mask=original_attention_mask,
position_ids=position_ids,
past_key_values=past_key_values,
inputs_embeds=inputs_embeds,
use_cache=use_cache,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
return_dict=return_dict,
)
hidden_states_before = outputs_before[0][:, -1:, :]
# two new tokens: last continuation token and end thought token
outputs_after = self.model(
input_ids=torch.cat([next_token_id.unsqueeze(-1).to(input_ids.device), torch.tensor(end_thought_token_id).unsqueeze(-1).unsqueeze(-1).to(input_ids.device)], dim=-1),
attention_mask=attention_mask,
position_ids=position_ids,
past_key_values=new_key_values,
inputs_embeds=inputs_embeds,
use_cache=use_cache,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
return_dict=return_dict,
)
hidden_states_after = outputs_after[0][:, -1:, :]
# Apply the talk head to get the mixing weight
mixing_weight = self.talk_head[0](torch.cat([hidden_states_before, hidden_states_after], dim=-1))
# Apply the mixing weight to the hidden states
mixed_hidden_states = (1 - mixing_weight) * hidden_states_before + mixing_weight * hidden_states_after
# Apply the language model head to get the final logits
logits = self.lm_head(mixed_hidden_states)
return logits
@add_start_docstrings_to_model_forward(MISTRAL_INPUTS_DOCSTRING)
@replace_return_docstrings(output_type=CausalLMOutputWithPast, config_class=_CONFIG_FOR_DOC)
def forward(
self,
input_ids: torch.LongTensor = None,
attention_mask: Optional[torch.Tensor] = None,
position_ids: Optional[torch.LongTensor] = None,
past_key_values: Optional[List[torch.FloatTensor]] = None,
inputs_embeds: Optional[torch.FloatTensor] = None,
labels: Optional[torch.LongTensor] = None,
use_cache: Optional[bool] = None,
output_attentions: Optional[bool] = None,
output_hidden_states: Optional[bool] = None,
return_dict: Optional[bool] = None,
) -> Union[Tuple, CausalLMOutputWithPast]:
r"""
Args:
labels (`torch.LongTensor` of shape `(batch_size, sequence_length)`, *optional*):
Labels for computing the masked language modeling loss. Indices should either be in `[0, ...,
config.vocab_size]` or -100 (see `input_ids` docstring). Tokens with indices set to `-100` are ignored
(masked), the loss is only computed for the tokens with labels in `[0, ..., config.vocab_size]`.
Returns:
Example:
```python
>>> from transformers import AutoTokenizer, MistralForCausalLM
>>> model = MistralForCausalLM.from_pretrained("mistralai/Mistral-7B-v0.1")
>>> tokenizer = AutoTokenizer.from_pretrained("mistralai/Mistral-7B-v0.1")
>>> prompt = "Hey, are you conscious? Can you talk to me?"
>>> inputs = tokenizer(prompt, return_tensors="pt")
>>> # Generate
>>> generate_ids = model.generate(inputs.input_ids, max_length=30)
>>> tokenizer.batch_decode(generate_ids, skip_special_tokens=True, clean_up_tokenization_spaces=False)[0]
"Hey, are you conscious? Can you talk to me?\nI'm not conscious, but I can talk to you."
```"""
log_dict = self.log_dict if self.training else self.eval_log_dict
if self.training and self.kill_after is not None and self.training_steps // self.gradient_accumulation_steps > self.kill_after:
raise ValueError("Killed after")
if not self.training:
n_ahead_talk_to_restore = self.n_ahead_talk
n_passes_to_restore = self.n_passes
self.n_ahead_talk = 1
self.n_passes = 1
output_attentions = output_attentions if output_attentions is not None else self.config.output_attentions
output_hidden_states = (
output_hidden_states if output_hidden_states is not None else self.config.output_hidden_states
)
return_dict = return_dict if return_dict is not None else self.config.use_return_dict
assert self.cumulative_residual or self.clever_residual or self.skip_residual or self.no_residual
assert not (self.skip_residual and self.use_policy_loss)
if self.tokenized_thought_prefix is None and self.use_thought_prefix:
self.tokenized_thought_prefix = self.tokenizer(self.thought_prefix, return_tensors="pt", add_special_tokens=False)["input_ids"]
def apply_head(head, states, detach=False):
if detach:
head_weight = head.weight.detach()
else:
head_weight = head.weight
head_weight = head_weight.to(states.device)
return (head_weight @ states.transpose(-1, -2)).transpose(-1, -2).contiguous()
def idx_if_sequential(head, idx=0):
if isinstance(head, nn.Sequential) or isinstance(head, nn.ModuleList):
return idx_if_sequential(head[idx], idx=idx)
return head
def none_repeat_interleave(x, n):
if x is None:
return x
return x.repeat_interleave(n, dim=0)
if self.n_passes > 1:
input_ids = none_repeat_interleave(input_ids, self.n_passes)
attention_mask = none_repeat_interleave(attention_mask, self.n_passes)
position_ids = none_repeat_interleave(position_ids, self.n_passes)
inputs_embeds = none_repeat_interleave(inputs_embeds, self.n_passes)
labels = none_repeat_interleave(labels, self.n_passes)
if past_key_values is not None:
past_key_values = [none_repeat_interleave(p, self.n_passes) for p in past_key_values]
cur_token_indices = torch.arange(input_ids.shape[1], device=input_ids.device)
self.tokenizer_has_start_thought_token = True
self.tokenizer_has_end_thought_token = True
if self.start_token_id is None:
self.start_token_id = self.tokenizer.convert_tokens_to_ids("<|startthought|>")
if self.start_token_id == 0:
self.start_token_id = self.tokenizer.bos_token_id
self.tokenizer_has_start_thought_token = False
elif self.use_start_thought_token:
# base_start_id = self.tokenizer.convert_tokens_to_ids(self.initial_start_token)
base_start_id = self.tokenizer.encode(self.initial_start_token, add_special_tokens=False)[0]
if self.initialize_thought_embedding_to_normal:
self.start_embedding.data = torch.zeros_like(self.start_embedding.data)
else:
self.start_embedding.data[0] = self.model.embed_tokens.weight.data[base_start_id].clone().detach() / self.embedding_scale
self.start_embedding.data[1] = torch.log(self.model.embed_tokens.weight.data.std(dim=0) * self.thought_init_std_scale / self.embedding_scale)
if self.end_token_id is None:
self.end_token_id = self.tokenizer.convert_tokens_to_ids("<|endthought|>")
if self.end_token_id == 0:
self.end_token_id = self.tokenizer.eos_token_id
self.tokenizer_has_end_thought_token = False
elif self.use_end_thought_token:
# base_end_id = self.tokenizer.convert_tokens_to_ids(self.initial_end_token)
base_end_id = self.tokenizer.encode(self.initial_end_token, add_special_tokens=False)[0]
if self.initialize_thought_embedding_to_normal:
self.end_embedding.data = torch.zeros_like(self.end_embedding.data)
else:
self.end_embedding.data[0] = self.model.embed_tokens.weight.data[base_end_id].clone().detach() / self.embedding_scale
self.end_embedding.data[1] = torch.log(self.model.embed_tokens.weight.data.std(dim=0) * self.thought_init_std_scale / self.embedding_scale)
if not self.rm_initialized and (self.n_ahead > 1 or not self.base_original_mode):
self.rm_initialized = True
if not self.use_shallow_talk:
head = self.talk_head[0]
cur_head = head[-1] if isinstance(head, nn.Sequential) else head
talk_input_dim = cur_head.weight.data.shape[1]
talk_output_dim = 1 if self.use_weighted_talk_head else self.lm_head.weight.data.shape[0]
cur_head.weight.data = torch.zeros(talk_output_dim, talk_input_dim, device=cur_head.weight.device, dtype=cur_head.weight.dtype)
else:
# convert to identity transform
def lambda_transform(cur_head):
if cur_head.weight.data.shape[0] != cur_head.weight.data.shape[1]:
return torch.cat([
torch.eye(
cur_head.weight.data.shape[0],
device=cur_head.weight.device,
dtype=cur_head.weight.dtype
),
torch.zeros(
cur_head.weight.data.shape[0],
cur_head.weight.data.shape[1] - cur_head.weight.data.shape[0],
device=cur_head.weight.device,
dtype=cur_head.weight.dtype
)], dim=1)
return torch.eye(
cur_head.weight.data.shape[0],
device=cur_head.weight.device,
dtype=cur_head.weight.dtype
)
if isinstance(self.talk_head[0], nn.Sequential):
for cur_head in self.talk_head[0]:
# if it has weights
if hasattr(cur_head, "weight"):
cur_head.weight.data = lambda_transform(cur_head)
else:
self.talk_head[-1].weight.data = lambda_transform(self.talk_head[0])
loss = None
prev_rm_tokens = None
cur_rm_tokens = None
prev_rm_logits = None
prev_sample_probs = None
did_skip_sampling = None
skip_sampling = None
sample_probs = None
hidden_states = None
logits = None
talk_kl_penalty = None
rm_logits = None
residual_logits = None
probabilities_2d = None
prev_probabilities_2d = None
policy_reward = None
logits_to_output = None
batch_size, seq_len = input_ids.shape
base_input_ids = input_ids.clone()
loss_list = []
dqn_loss_list = []
sampled_token_history = []
sample_probs_history = []
action_loglikelihoods_list = []
if self.use_end_thought_token or self.use_start_thought_token:
if not self.use_reparam_for_thought_embeddings:
start_embedding = self.start_embedding[0].unsqueeze(0) * self.embedding_scale
end_embedding = self.end_embedding[0].unsqueeze(0) * self.embedding_scale
else:
start_embedding = self.start_embedding * self.embedding_scale
end_embedding = self.end_embedding * self.embedding_scale
base_embeddings = self.model.embed_tokens.weight
if self.train_only_thinking_embedding:
base_embeddings = base_embeddings.detach()
# # decoder outputs consists of (dec_features, layer_state, dec_hidden, dec_attn)
fwd_iters = 1 if self.original_mode else self.n_ahead + self.n_ahead_talk - 1
for ahead_idx in range(fwd_iters):
past_key_values_length = 0
if past_key_values is not None:
use_legacy_cache = not isinstance(past_key_values, Cache)
if use_legacy_cache:
past_key_values = DynamicCache.from_legacy_cache(past_key_values)
past_key_values_length = past_key_values.get_usable_length(seq_len)
if position_ids is None:
device = input_ids.device if input_ids is not None else inputs_embeds.device
position_ids = torch.arange(
past_key_values_length, seq_len + past_key_values_length, dtype=torch.long, device=device
)
position_ids = position_ids.unsqueeze(0).view(-1, seq_len)
else:
position_ids = position_ids.view(-1, seq_len).long()
if inputs_embeds is None:
contains_start = self.use_start_thought_token and (input_ids == self.start_token_id).any()
contains_end = self.use_end_thought_token and (input_ids == self.end_token_id).any()
contains_thought = contains_start or contains_end
if contains_thought:
thought_id = self.start_token_id if contains_start else self.end_token_id
cur_thought_embedding = start_embedding if contains_start else end_embedding
if self.use_reparam_for_thought_embeddings:
inputs_embeds = torch.randn(batch_size, seq_len, self.model.config.hidden_size, device=input_ids.device, dtype=cur_thought_embedding.dtype)
inputs_embeds = inputs_embeds.detach() * torch.exp(cur_thought_embedding[1]) + cur_thought_embedding[0]
if contains_start:
sampled_start = inputs_embeds.clone().detach()
if contains_end:
sampled_end = inputs_embeds.clone().detach()
else:
inputs_embeds = cur_thought_embedding.unsqueeze(0).repeat(batch_size, seq_len, 1)
else:
with torch.set_grad_enabled(not self.train_only_thinking_embedding):
inputs_embeds = self.model.embed_tokens(input_ids)
if self.n_ahead != 1 or self.n_ahead_talk != 1 or self.comparison_mode:
if attention_mask is None:
base_attention_mask = torch.triu(torch.ones(seq_len, seq_len), diagonal=0).to(input_ids.device)
base_attention_mask = base_attention_mask.view(1, 1, seq_len, seq_len)
base_attention_mask = base_attention_mask.repeat(input_ids.shape[0], 1, 1, 1)
attention_mask = base_attention_mask
breakpoint()
elif attention_mask.dim() == 2:
if seq_len + past_key_values_length != attention_mask.shape[-1]:
breakpoint()
attention_mask = torch.cat(
[torch.ones((attention_mask.shape[0], past_key_values_length), dtype=attention_mask.dtype, device=attention_mask.device), attention_mask],
dim=-1
)
# # if the attention mask
attention_mask = _prepare_4d_causal_attention_mask(
attention_mask,
(batch_size, seq_len),
inputs_embeds,
past_key_values_length,
sliding_window=self.config.sliding_window,
)
outputs = self.model(
# input_ids=input_ids,
attention_mask=attention_mask,
position_ids=position_ids,
past_key_values=past_key_values,
inputs_embeds=inputs_embeds,
use_cache=use_cache,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
return_dict=return_dict,
)
prev_hidden_states = hidden_states
hidden_states = outputs[0]
prev_rm_logits = rm_logits # for policy gradient
prev_rm_tokens = cur_rm_tokens # for policy gradient
if ahead_idx == 0:
hidden_states_lm = hidden_states
logits = self.lm_head(hidden_states_lm)
base_hidden_states = hidden_states.clone()
initial_loss_logits = logits.clone()
if self.optimize_lm_head_only_at_start or self.optimize_model_only_at_start:
logits = logits.detach()
base_hidden_states = base_hidden_states.detach()
if self.optimize_model_only_at_start:
hidden_states = hidden_states.detach()
base_logits = logits.clone()
else:
talk_hidden_states = hidden_states
if self.merged_lm_and_talk_heads:
assert self.no_residual
residual_logits = self.lm_head(hidden_states)
talk_hidden_states = hidden_states
else:
if ahead_idx > self.n_ahead - 1:
cur_base_hidden = torch.cat([
base_hidden_states[..., ahead_idx - self.n_ahead + 1:, :],
base_hidden_states[..., :ahead_idx - self.n_ahead + 1, :]
], dim=-2)
else:
cur_base_hidden = base_hidden_states
if self.use_concat_talk_head:
# concatenate the hidden states with the original hidden states
head_input_hidden_states = torch.cat([cur_base_hidden, talk_hidden_states], dim=-1)
else:
head_input_hidden_states = talk_hidden_states
residual_logits = self.talk_head[0](head_input_hidden_states)
if self.use_shallow_talk:
residual_logits = apply_head(self.lm_head, residual_logits, detach=self.optimize_lm_head_only_at_start)
residual_logits = residual_logits.to(logits.device)
if self.use_weighted_talk_head:
# combine the cur_base_hidden with the talk_hidden_states according to the weighted head
residual_logits = cur_base_hidden * (1 - residual_logits) + talk_hidden_states * residual_logits
residual_logits = apply_head(self.lm_head, residual_logits, detach=self.optimize_lm_head_only_at_start)
assert sum([self.cumulative_residual, self.clever_residual, self.skip_residual, self.no_residual]) == 1
if self.clever_residual:
if ahead_idx >= self.n_ahead - 1:
# get the logits shifted according to the current talk ahead
cur_base_logits = torch.cat([
base_logits[..., ahead_idx - self.n_ahead + 1:, :],
base_logits[..., :ahead_idx - self.n_ahead + 1, :]
], dim=-2)
if self.optimize_lm_head_only_at_start:
cur_base_logits = cur_base_logits.detach()
logits = cur_base_logits + residual_logits
else:
logits += residual_logits / self.n_ahead
elif self.cumulative_residual:
if self.residual_talk_head:
if ahead_idx < self.n_ahead:
logits += residual_logits
else:
# get the logits shifted according to the current talk ahead
cur_base_logits = torch.cat([
base_logits[..., ahead_idx - self.n_ahead + 1:, :],
base_logits[..., :ahead_idx - self.n_ahead + 1, :]
], dim=-2)
if self.optimize_lm_head_only_at_start:
cur_base_logits = cur_base_logits.detach()
logits = cur_base_logits + residual_logits
else:
if ahead_idx < self.n_ahead:
logits += residual_logits
else:
logits = residual_logits
elif self.skip_residual:
if ahead_idx >= self.n_ahead:
# get the logits shifted according to the current talk ahead
cur_base_logits = torch.cat([
base_logits[..., ahead_idx - self.n_ahead + 1:, :],
base_logits[..., :ahead_idx - self.n_ahead + 1, :]
], dim=-2)
if self.optimize_lm_head_only_at_start:
cur_base_logits = cur_base_logits.detach()
logits = cur_base_logits
elif self.no_residual:
logits = residual_logits
else:
logits = base_logits + residual_logits
attempted = False
talk_loss_list = []
if self.original_mode or (self.n_ahead == 1) or (self.comparison_mode and ahead_idx == 0):# or (self.optimize_lm_head_only_at_start and ahead_idx == 0):
loss = None
attempted = True
if labels is not None:
for shift_amount in range(self.n_ahead_talk):
# Shift so that tokens < n predict n
# ab[cde]f
# abc[def]
if ahead_idx == 0 and self.optimize_lm_head_only_at_start:
loss_logits = initial_loss_logits
else:
loss_logits = logits
shift_logits = loss_logits[..., shift_amount:-1, :].contiguous()
shift_labels = labels[..., 1 + shift_amount:].contiguous()
# Flatten the tokens
loss_fct = CrossEntropyLoss(reduction="none")
shift_logits = shift_logits.view(-1, self.config.vocab_size)
shift_labels = shift_labels.view(-1).clone()
# Enable model parallelism
shift_labels[shift_labels == self.tokenizer.pad_token_id] = -100
shift_labels = shift_labels.to(shift_logits.device)
loss = loss_fct(shift_logits, shift_labels)
if not self.comparison_mode and not (self.optimize_lm_head_only_at_start and (self.n_ahead + self.n_ahead_talk > 2)) or self.original_mode:
loss_list.append(loss)
talk_loss_list.append(nonzero_mean(loss).detach())
if not attempted or self.comparison_mode:
rm_hidden_states = hidden_states
# print("Magnitude of RM hidden states before RM head", rm_hidden_states.norm())
rm_logits = apply_head(self.lm_head, rm_hidden_states, detach=self.optimize_lm_head_only_at_start)
# don't allow it to predict the thinking token
if self.tokenizer_has_start_thought_token:
rm_logits[..., self.start_token_id] = -1e10
if self.tokenizer_has_end_thought_token:
rm_logits[..., self.end_token_id] = -1e10
probabilities = rm_logits
if probabilities_2d is not None:
prev_probabilities_2d = probabilities_2d.clone()
probabilities_2d = probabilities.view(-1, probabilities.size(-1))
did_skip_sampling = skip_sampling
skip_sampling = False
if ahead_idx == 0 and self.use_start_thought_token:
override_token = self.start_token_id
elif self.use_thought_prefix and ahead_idx < self.tokenized_thought_prefix.shape[-1]:
override_token = self.tokenized_thought_prefix[..., ahead_idx]
elif ahead_idx == self.n_ahead - 2 and self.use_end_thought_token:
override_token = self.end_token_id
else:
override_token = None
if override_token is not None and self.n_ahead > 1:
# always start with the start token
probabilities_2d = torch.zeros_like(probabilities_2d)
probabilities_2d[:, override_token] = 1.0
skip_sampling = True
elif ahead_idx >= self.n_ahead - 1:
if labels is not None: # we're in the talk phase
cur_talk_n = ahead_idx - (self.n_ahead - 1) + 1
# print("Setting rm to labels", cur_talk_n, "during", ahead_idx)
shift_labels = labels[..., cur_talk_n:].contiguous().to(probabilities_2d.device)
padding = torch.full_like(
labels[..., :cur_talk_n],
self.tokenizer.pad_token_id,
dtype=torch.long,
device=shift_labels.device
)
new_rm_tokens = torch.cat(
[shift_labels, padding],
dim=-1
)
# convert rm tokens to one-hot
probabilities_2d = F.one_hot(new_rm_tokens, num_classes=self.vocab_size).reshape(-1, self.vocab_size).to(probabilities_2d.dtype)
skip_sampling = True
else:
continue
temperature = self.gumbel_temperature if self.training else 0.001
prev_sample_probs = sample_probs
sample_probs = probabilities_2d
if ahead_idx < self.n_ahead - 1 and not skip_sampling:
probabilities_2d = F.gumbel_softmax(sample_probs, tau=temperature, hard=True, dim=-1)
if self.gumbel_detach:
probabilities_2d = probabilities_2d.detach()
sampled_token_history.append(probabilities_2d.argmax(dim=-1).detach().cpu())
# convert rm logits directly to embeddings
contains_start = self.use_start_thought_token and (probabilities_2d[..., self.start_token_id].sum() > 0)
contains_end = self.use_end_thought_token and (probabilities_2d[..., self.end_token_id].sum() > 0)
contains_thought = contains_start or contains_end
if not contains_thought:
with torch.set_grad_enabled(not self.train_only_thinking_embedding):
inputs_embeds = probabilities_2d @ (self.model.embed_tokens.weight.to(probabilities.device).to(probabilities.dtype))
else:
thought_id = self.start_token_id if contains_start else self.end_token_id
cur_thought_embedding = start_embedding if contains_start else end_embedding
if self.use_reparam_for_thought_embeddings:
inputs_embeds = torch.randn(batch_size, seq_len, self.model.config.hidden_size, device=input_ids.device, dtype=cur_thought_embedding.dtype)
inputs_embeds = inputs_embeds * torch.exp(cur_thought_embedding[1]) + cur_thought_embedding[0]
if contains_start:
sampled_start = inputs_embeds.clone().detach()
else:
sampled_end = inputs_embeds.clone().detach()
else:
inputs_embeds = cur_thought_embedding.unsqueeze(0).repeat(batch_size, seq_len, 1)
inputs_embeds = inputs_embeds.view(probabilities.size(0), probabilities.size(1), -1).to(self.model.embed_tokens.weight.dtype)
inputs_embeds = inputs_embeds.view(probabilities.size(0), probabilities.size(1), -1).to(self.model.embed_tokens.weight.dtype)
if len(attention_mask.shape) == 2:
breakpoint()
else:
original_attention = attention_mask[..., :attention_mask.shape[-2]]
if self.use_upper_triangular:
new_attention = original_attention
else:
original_attention = original_attention == attention_mask.max()
# because eye isn't implemented for BF16, we need to handle the case
if not attention_mask.dtype == torch.bfloat16:
new_attention = torch.eye(
seq_len, dtype=attention_mask.dtype, device=attention_mask.device
)
else:
new_attention = torch.eye(
seq_len, dtype=torch.float32, device=attention_mask.device
).to(attention_mask.dtype)
new_attention = new_attention.view(1, 1, seq_len, seq_len).repeat(input_ids.shape[0], 1, 1, 1)
new_attention = new_attention * original_attention
new_attention[new_attention == 0] = attention_mask.min()
new_attention[new_attention == 1] = attention_mask.max()
attention_mask = torch.cat([attention_mask, new_attention], dim=-1)
past_key_values = outputs.past_key_values
position_ids = position_ids + 1
if labels is not None and (self.n_ahead > 1 or not self.base_original_mode):
# Shift so that tokens < n predict n
# logits: abcdef -> bcdef? -> cdef??
# labels: abcdef -> ?bcdef -> ??cdef
if ahead_idx == 0 and self.optimize_lm_head_only_at_start:
loss_logits = initial_loss_logits
else:
loss_logits = logits
shift_idx = 1 + max(0, ahead_idx - (self.n_ahead - 1))
shift_logits = loss_logits[..., :-shift_idx, :].contiguous()
shift_labels = labels[..., shift_idx:].contiguous()
# Flatten the tokens
loss_fct = CrossEntropyLoss(reduction="none")
shift_logits = shift_logits.view(-1, self.config.vocab_size)
shift_labels = shift_labels.view(-1)
# Enable model parallelism
shift_labels = shift_labels.to(shift_logits.device)
# if shift_labels.min() == self.tokenizer.pad_token_id:
shift_labels = torch.where(shift_labels == self.tokenizer.pad_token_id, -100, shift_labels)
unreduced_loss = loss_fct(shift_logits, shift_labels)
if torch.any(unreduced_loss != unreduced_loss):
raise ValueError("NaN loss")
unreduced_loss = unreduced_loss.reshape(logits.shape[0], -1)
loss_list.append(unreduced_loss)
if self.use_policy_loss and ahead_idx > 0 and (ahead_idx > 1 or not self.use_start_thought_token):
# we treat the change in loss as the reward
previous_loss = loss_list[-2]
# for example, suppose n_ahead = 3 and n_ahead_talk = 2
# note that we end at self.n_ahead + self.n_ahead_talk - 2
# in this case, 5 - 2 = 3, so we end at ahead_idx = 3
# we also predict the next token at ahead_idx = 2
# when we get to ahead_idx = 2, we predict ahead
# so we shift by 1
# note that this is ahead_idx = n_ahead - 1
# when we get to ahead_idx = 3, we predict ahead
# so we shift by 2
# note that this is ahead_idx = n_ahead
if ahead_idx < self.n_ahead - 1:
shift_amount = 0
original_dqn_reward = (previous_loss - unreduced_loss).detach()
if self.first_and_last_mode:
original_dqn_reward = original_dqn_reward * 0.0
else:
# logits vs cur_policy_shift_logits
# let's look at rm_logits and prev_rm_logits
shift_amount = max(0, ahead_idx - (self.n_ahead - 1))
# let's say shift_amount = 2
# abcdefg -> bcdefg? -> cdefg??
# logits = [a b]c d e f[g]
# labels = [a b c]d e f g
cur_policy_shift_logits = initial_loss_logits[..., shift_amount:-1, :].contiguous().detach()
cur_policy_shift_labels = labels[..., 1 + shift_amount:].contiguous()
# Flatten the tokens
cur_policy_loss_fct = CrossEntropyLoss(reduction="none")
cur_policy_shift_logits = cur_policy_shift_logits.view(-1, self.config.vocab_size)
cur_policy_shift_labels = cur_policy_shift_labels.view(-1).clone()
# Enable model parallelism
cur_policy_shift_labels[cur_policy_shift_labels == self.tokenizer.pad_token_id] = -100
cur_policy_shift_labels = cur_policy_shift_labels.to(cur_policy_shift_labels.device)
cur_policy_reward_base_loss = loss_fct(
cur_policy_shift_logits, cur_policy_shift_labels.to(cur_policy_shift_logits.device)
).reshape(logits.shape[0], -1)
original_dqn_reward = cur_policy_reward_base_loss.detach() - unreduced_loss
if not did_skip_sampling:
nonzero_indices = prev_probabilities_2d.nonzero()
action_loglikelihoods = F.log_softmax(prev_sample_probs / self.reinforce_temperature, dim=-1)[nonzero_indices[:, 0], nonzero_indices[:, 1]]
action_loglikelihoods_2d = action_loglikelihoods.reshape(batch_size, -1)[:, :-1 - shift_amount]
action_loglikelihoods_list.append(action_loglikelihoods_2d)
if policy_reward is None:
policy_reward = original_dqn_reward[:, :-(self.n_ahead_talk - shift_amount)]
else:
if self.n_ahead_talk > shift_amount:
added_reward = original_dqn_reward[:, :-(self.n_ahead_talk - shift_amount)]
else:
added_reward = original_dqn_reward
policy_reward += added_reward
if self.use_policy_loss and ahead_idx == self.n_ahead + self.n_ahead_talk - 2:
# only compute during the thinking phase
if self.use_reparam_for_thought_embeddings and (self.use_start_thought_token or self.use_end_thought_token):
# sampled_start, sampled_end
# calculate the log likelihood of the start and end embeddings sampled from a multivariate normal distribution
# with mean start_embedding[0] and standard deviation start_embedding[1]
if self.use_start_thought_token:
exp_start_std = torch.exp(start_embedding[1])
start_loglikelihood = -0.5 * (sampled_start.detach() - start_embedding[0]) ** 2 / exp_start_std ** 2 - start_embedding[1] - 0.5 * math.log(2 * math.pi)
start_loglikelihood = start_loglikelihood.mean(dim=-1)
if self.use_end_thought_token:
exp_end_std = torch.exp(end_embedding[1])
end_loglikelihood = -0.5 * (sampled_end.detach() - end_embedding[0]) ** 2 / exp_end_std ** 2 - end_embedding[1] - 0.5 * math.log(2 * math.pi)
end_loglikelihood = end_loglikelihood.mean(dim=-1)
# we use the mean instead of the sum to prevent dependence on the dimensionality of the embeddings
if self.use_end_thought_token and self.use_policy_loss_for_end_thought:
action_loglikelihoods_list.append(end_loglikelihood)
if self.use_start_thought_token:
action_loglikelihoods_list.append(start_loglikelihood)
if ahead_idx == self.n_ahead + self.n_ahead_talk - 2 and self.eval_mode:
with torch.no_grad():
# calculate the 0.75 quantile of the rewards
filtered_tokens = input_ids[:, :policy_reward.shape[-1]].cpu().detach().numpy().flatten()
filtered_tokens_mask = filtered_tokens != self.tokenizer.pad_token_id
filtered_tokens = filtered_tokens[filtered_tokens_mask]
filtered_rewards = policy_reward.float().cpu().detach().numpy()[:, :seq_len - self.n_ahead_talk].flatten()
filtered_rewards = filtered_rewards[filtered_tokens_mask]
abs_reward_list = np.abs(policy_reward.float().cpu().detach().numpy()[:, :seq_len - self.n_ahead_talk].flatten())
abs_reward_list = abs_reward_list[filtered_tokens_mask]
medium_quantile = np.quantile(abs_reward_list, 0.5)
upper_quantile = np.quantile(abs_reward_list, 0.95)
save_tokens_with_rewards_to_pdf(
filtered_tokens,
[0] + filtered_rewards.tolist(),
self.tokenizer,
output_file=f"texts/rewards_talk_{self.n_ahead_talk}_{self.training_steps}.pdf",
eps=medium_quantile,
eps2=upper_quantile,
)
def plot_kde(data, losses):
sns.set(style="whitegrid")
# Create the KDE plot
sns.kdeplot(data, fill=True)
# Set the plot title and labels
plt.title("KDE Plot")
plt.xlabel("Value")
plt.ylabel("Density")
# Save the plot
plt.savefig(f"texts/kde_talk_{self.n_ahead_talk}_{self.training_steps}.pdf")
# Close the plot
plt.close()
# Step 1: Create a base color palette
base_colors = sns.color_palette("light:#5A9", n_colors=256) # More colors for a smoother gradient
base_cmap = LinearSegmentedColormap.from_list("log_light", base_colors)
log_norm = LogNorm(vmin=1e-3, vmax=10)
sns.kdeplot(x=data, y=losses, fill=True, levels=20, norm=log_norm, cut=0, linewidths=0)
# limit y to 0 to 25 and x to -1 to 1
plt.xlim(-1, 1)
plt.ylim(0, 25)
plt.savefig(f"texts/jointer_talk_{self.n_ahead_talk}_{self.training_steps}.pdf")
plt.close()
self.all_rewards.extend(filtered_rewards)
self.all_unreduced_losses.extend(unreduced_loss[:, :-1].flatten()[filtered_tokens_mask].float().flatten().cpu().detach().numpy())
plot_kde(self.all_rewards, self.all_unreduced_losses)
for action_loglikelihoods_2d in action_loglikelihoods_list:
train_policy_reward = policy_reward
# discard rewards below the mean
if self.trice_mode and self.n_passes > 1:
batched_policy_reward = train_policy_reward.reshape(-1, self.n_passes, train_policy_reward.shape[-1])
# average over the passes
train_policy_reward = batched_policy_reward - batched_policy_reward.mean(dim=1, keepdim=True)
train_policy_reward = train_policy_reward.reshape(-1, train_policy_reward.shape[-1])
if self.subtract_mean_reward:
train_policy_reward = train_policy_reward - train_policy_reward.mean()
if self.remove_negative_rewards:
fixed_policy_reward = train_policy_reward.detach().clamp(min=0)
else:
fixed_policy_reward = train_policy_reward.detach()
actor_loss = -fixed_policy_reward * action_loglikelihoods_2d[:, :policy_reward.shape[-1]].to(policy_reward.device)
if action_loglikelihoods_2d.mean() < -1e4 and not self.use_policy_loss_just_for_thoughts:
# This will only happen when we force the next token to be the end of thought token
break
dqn_loss_list.append(actor_loss.mean())
if loss_list:
if self.first_and_last_mode:
loss = sum(
self.loss_mean(loss_list[-(i + 1)]) for i in range(self.n_ahead_talk)
) * (1 - self.original_loss_weight) / self.n_ahead_talk
loss = loss + self.loss_mean(loss_list[0]) * self.original_loss_weight
# Let's NaN out the others
# e.g. if n_ahead_talk = 2 and the list is 5 long, we want to NaN out 1, 2 but keep 0, 3, 4
for i in range(1, len(loss_list) - self.n_ahead_talk):
loss_list[i] = loss_list[i] * math.nan
elif self.first_only:
loss = self.loss_mean(loss_list[0])
elif self.final_only_mode:
loss = sum(
self.loss_mean(loss_list[-i]) for i in range(1, self.n_ahead_talk + 1)
) / self.n_ahead_talk
else:
loss = None
for i in range(len(loss_list)):
cur_loss = self.loss_mean(loss_list[i])
if loss is not None:
loss = loss + cur_loss.to(loss.device)
else:
loss = cur_loss
loss = loss / len(loss_list)
loss = loss * self.base_loss_beta
if dqn_loss_list:
dqn_loss = sum(dqn_loss_list) / len(dqn_loss_list)
if self.include_policy_loss:
if loss is not None:
loss += dqn_loss * self.policy_loss_beta
else:
loss = dqn_loss * self.policy_loss_beta
if not return_dict:
output = (logits,) + outputs[1:]
return (loss,) + output if loss is not None else output
base_log_dict = {
f"loss_{i}": nonzero_mean(loss_list[i]) for i in range(len(loss_list))
}
if loss is not None:
base_log_dict["loss_train"] = loss.item()
for loss_key, loss_val in base_log_dict.items():
log_dict[loss_key] += loss_val / self.n_tokens_print
if self.use_policy_loss and policy_reward is not None:
log_dict["policy_loss"] += dqn_loss / self.n_tokens_print
log_dict["policy_reward"] += policy_reward.mean() / self.n_tokens_print
if not loss_list:
if loss is not None:
log_dict["loss_0"] += loss / self.n_tokens_print
else:
log_dict["loss_final"] += nonzero_mean(loss_list[-1]) / self.n_tokens_print
log_dict["loss_talk"] += sum(nonzero_mean(cur_loss_item) for cur_loss_item in loss_list[-self.n_ahead_talk:]) / self.n_ahead_talk / self.n_tokens_print
# also log relative losses to loss_0
if loss_list:
for i in range(len(loss_list)):
talk_idx = min(max(i - (self.n_ahead - 1), 0), len(talk_loss_list) - 1)
if not talk_loss_list:
cur_talk_loss = nonzero_mean(loss_list[0])
else:
cur_talk_loss = talk_loss_list[talk_idx]
log_dict[f"rel_loss_{i}"] += (nonzero_mean(loss_list[i]) - cur_talk_loss) / self.n_tokens_print
if self.training:
self.training_steps += 1
try:
# if self.training_steps % (self.gradient_accumulation_steps * 256) == 0:
if self.wandb_enabled:
if self.training_steps % (self.n_tokens_print) == 0 or not self.training:# and "0" in str(loss.device):
if not self.training:
new_log_dict = {}
for key in list(log_dict.keys()):
new_log_dict["eval_" + key] = log_dict[key]
log_dict = new_log_dict
log_dict["training_steps"] = self.training_steps
log_dict["batch_size"] = batch_size
log_dict["example_steps"] = self.training_steps * batch_size * self.gradient_accumulation_steps
if self.n_ahead > 1:
log_dict["compute_steps"] = self.training_steps * batch_size * (self.n_ahead + self.n_ahead_talk - 1) * self.gradient_accumulation_steps
else: # There's no overhead for talk tokens if there's no thinking
log_dict["compute_steps"] = self.training_steps * batch_size * self.gradient_accumulation_steps
# remove all nans
for key in list(log_dict.keys()):
if log_dict[key] != log_dict[key]:
del log_dict[key]
if self.training:
wandb.log(log_dict)
if self.training:
self.log_dict = defaultdict(int)
else:
self.eval_log_dict = defaultdict(int)
except Exception as e:
pass
if not self.training:
self.n_ahead_talk = n_ahead_talk_to_restore
self.n_passes = n_passes_to_restore
return CausalLMOutputWithPast(
loss=loss if loss is not None else None,
logits=(rm_logits if self.n_ahead > 1 else logits) if not self.output_logits_at_the_end else logits,
past_key_values=outputs.past_key_values,
hidden_states=outputs.hidden_states,
attentions=outputs.attentions,
)
def prepare_inputs_for_generation(
self, input_ids, past_key_values=None, attention_mask=None, inputs_embeds=None, **kwargs
):
# Omit tokens covered by past_key_values
if past_key_values is not None:
if isinstance(past_key_values, Cache):
cache_length = past_key_values.get_seq_length()
past_length = past_key_values.seen_tokens
max_cache_length = past_key_values.get_max_length()
else:
cache_length = past_length = past_key_values[0][0].shape[2]
max_cache_length = None
# Keep only the unprocessed tokens:
# 1 - If the length of the attention_mask exceeds the length of input_ids, then we are in a setting where
# some of the inputs are exclusively passed as part of the cache (e.g. when passing inputs_embeds as
# input)
if attention_mask is not None and attention_mask.shape[1] > input_ids.shape[1]:
input_ids = input_ids[:, -(attention_mask.shape[1] - past_length) :]
# 2 - If the past_length is smaller than input_ids', then input_ids holds all input tokens. We can discard
# input_ids based on the past_length.
elif past_length < input_ids.shape[1]:
input_ids = input_ids[:, past_length:]
# 3 - Otherwise (past_length >= input_ids.shape[1]), let's assume input_ids only has unprocessed tokens.
# If we are about to go beyond the maximum cache length, we need to crop the input attention mask.
if (
max_cache_length is not None
and attention_mask is not None
and cache_length + input_ids.shape[1] > max_cache_length
):
attention_mask = attention_mask[:, -max_cache_length:]
position_ids = kwargs.get("position_ids", None)
if attention_mask is not None and position_ids is None:
# create position_ids on the fly for batch generation
position_ids = attention_mask.long().cumsum(-1) - 1
position_ids.masked_fill_(attention_mask == 0, 1)
if past_key_values:
position_ids = position_ids[:, -input_ids.shape[1] :]
# if `inputs_embeds` are passed, we only want to use them in the 1st generation step
if inputs_embeds is not None and past_key_values is None:
model_inputs = {"inputs_embeds": inputs_embeds}
else:
model_inputs = {"input_ids": input_ids}
model_inputs.update(
{
"position_ids": position_ids,
"past_key_values": past_key_values,
"use_cache": kwargs.get("use_cache"),
"attention_mask": attention_mask,
}
)
return model_inputs
@staticmethod
def _reorder_cache(past_key_values, beam_idx):
reordered_past = ()
for layer_past in past_key_values:
reordered_past += (
tuple(past_state.index_select(0, beam_idx.to(past_state.device)) for past_state in layer_past),
)
return reordered_past