code: def _copy_offsets_buffer_if_needed(
      buf: "pyarrow.Buffer",
      arr_type: "pyarrow.DataType",
      offset: int,
      length: int,
  ) -> Tuple["pyarrow.Buffer", int, int]:
      """Copy the provided offsets buffer, returning the copied buffer and the
      offset + length of the underlying data.
      """
      import pyarrow as pa
      import pyarrow.compute as pac
  
      if (
          pa.types.is_large_list(arr_type)
          or pa.types.is_large_string(arr_type)
          or pa.types.is_large_binary(arr_type)
          or pa.types.is_large_unicode(arr_type)
      ):
          offset_type = pa.int64()
      else:
          offset_type = pa.int32()
      # Copy offset buffer, if needed.
      buf = _copy_buffer_if_needed(buf, offset_type, offset, length + 1)
      # Reconstruct the offset array so we can determine the offset and length
      # of the child array.
      offsets = pa.Array.from_buffers(
          offset_type, length + 1, [None, buf]
      )
      child_offset = offsets[0].as_py()
      child_length = offsets[-1].as_py() - child_offset
      # Create new offsets aligned to 0 for the copied data buffer slice.
      offsets = pac.subtract(offsets, child_offset)
      if pa.types.is_int32(offset_type):
          # We need to cast the resulting Int64Array back down to an Int32Array.
          offsets = offsets.cast(offset_type, safe=False)
      buf = offsets.buffers()[1]
      return buf, child_offset, child_length
  
imports: from dataclasses import dataclass
  import logging
  import os
  import sys
  from typing import List, Tuple, Optional, TYPE_CHECKING
label_desc: Use image node_id 27 for calling a global function with example usage: _copy_offsets_buffer_if_needed(buf, arr_type, offset, length) and returns: buf,  child_offset,  child_length