text: # Copyright 2021 The Feast Authors
  #
  # 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
  #
  #     https://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.
  import itertools
  import os
  import sqlite3
  from datetime import datetime
  from pathlib import Path
  from typing import Any, Callable, Dict, List, Optional, Sequence, Tuple
  
  from pydantic import StrictStr
  from pydantic.schema import Literal
  
  from feast import Entity
  from feast.feature_view import FeatureView
  from feast.infra.infra_object import SQLITE_INFRA_OBJECT_CLASS_TYPE, InfraObject
  from feast.infra.key_encoding_utils import serialize_entity_key
  from feast.infra.online_stores.online_store import OnlineStore
  from feast.protos.feast.core.InfraObject_pb2 import InfraObject as InfraObjectProto
  from feast.protos.feast.core.Registry_pb2 import Registry as RegistryProto
  from feast.protos.feast.core.SqliteTable_pb2 import SqliteTable as SqliteTableProto
  from feast.protos.feast.types.EntityKey_pb2 import EntityKey as EntityKeyProto
  from feast.protos.feast.types.Value_pb2 import Value as ValueProto
  from feast.repo_config import FeastConfigBaseModel, RepoConfig
  from feast.usage import log_exceptions_and_usage, tracing_span
  from feast.utils import to_naive_utc
  
  
  class SqliteOnlineStoreConfig(FeastConfigBaseModel):
      """Online store config for local (SQLite-based) store"""
  
      type: Literal[
          "sqlite", "feast.infra.online_stores.sqlite.SqliteOnlineStore"
      ] = "sqlite"
      """ Online store type selector"""
  
      path: StrictStr = "data/online.db"
      """ (optional) Path to sqlite db """
  
  
  class SqliteOnlineStore(OnlineStore):
      """
      OnlineStore is an object used for all interaction between Feast and the service used for offline storage of
      features.
  
      Attributes:
          _conn: SQLite connection.
      """
  
      _conn: Optional[sqlite3.Connection] = None
  
      @staticmethod
      def _get_db_path(config: RepoConfig) -> str:
          assert (
              config.online_store.type == "sqlite"
              or config.online_store.type.endswith("SqliteOnlineStore")
          )
  
          if config.repo_path and not Path(config.online_store.path).is_absolute():
              db_path = str(config.repo_path / config.online_store.path)
          else:
              db_path = config.online_store.path
          return db_path
  
      def _get_conn(self, config: RepoConfig):
          if not self._conn:
              db_path = self._get_db_path(config)
              self._conn = _initialize_conn(db_path)
          return self._conn
  
      @log_exceptions_and_usage(online_store="sqlite")
      def online_write_batch(
          self,
          config: RepoConfig,
          table: FeatureView,
          data: List[
              Tuple[EntityKeyProto, Dict[str, ValueProto], datetime, Optional[datetime]]
          ],
          progress: Optional[Callable[[int], Any]],
      ) -> None:
  
          conn = self._get_conn(config)
  
          project = config.project
  
          with conn:
              for entity_key, values, timestamp, created_ts in data:
                  entity_key_bin = serialize_entity_key(entity_key)
                  timestamp = to_naive_utc(timestamp)
                  if created_ts is not None:
                      created_ts = to_naive_utc(created_ts)
  
                  for feature_name, val in values.items():
                      conn.execute(
                          f"""
                              UPDATE {_table_id(project, table)}
                              SET value = ?, event_ts = ?, created_ts = ?
                              WHERE (entity_key = ? AND feature_name = ?)
                          """,
                          (
                              # SET
                              val.SerializeToString(),
                              timestamp,
                              created_ts,
                              # WHERE
                              entity_key_bin,
                              feature_name,
                          ),
                      )
  
                      conn.execute(
                          f"""INSERT OR IGNORE INTO {_table_id(project, table)}
                              (entity_key, feature_name, value, event_ts, created_ts)
                              VALUES (?, ?, ?, ?, ?)""",
                          (
                              entity_key_bin,
                              feature_name,
                              val.SerializeToString(),
                              timestamp,
                              created_ts,
                          ),
                      )
                  if progress:
                      progress(1)
  
      @log_exceptions_and_usage(online_store="sqlite")
      def online_read(
          self,
          config: RepoConfig,
          table: FeatureView,
          entity_keys: List[EntityKeyProto],
          requested_features: Optional[List[str]] = None,
      ) -> List[Tuple[Optional[datetime], Optional[Dict[str, ValueProto]]]]:
          conn = self._get_conn(config)
          cur = conn.cursor()
  
          result: List[Tuple[Optional[datetime], Optional[Dict[str, ValueProto]]]] = []
  
          with tracing_span(name="remote_call"):
              # Fetch all entities in one go
              cur.execute(
                  f"SELECT entity_key, feature_name, value, event_ts "
                  f"FROM {_table_id(config.project, table)} "
                  f"WHERE entity_key IN ({','.join('?' * len(entity_keys))}) "
                  f"ORDER BY entity_key",
                  [serialize_entity_key(entity_key) for entity_key in entity_keys],
              )
              rows = cur.fetchall()
  
          rows = {
              k: list(group) for k, group in itertools.groupby(rows, key=lambda r: r[0])
          }
          for entity_key in entity_keys:
              entity_key_bin = serialize_entity_key(entity_key)
              res = {}
              res_ts = None
              for _, feature_name, val_bin, ts in rows.get(entity_key_bin, []):
                  val = ValueProto()
                  val.ParseFromString(val_bin)
                  res[feature_name] = val
                  res_ts = ts
  
              if not res:
                  result.append((None, None))
              else:
                  result.append((res_ts, res))
          return result
  
      @log_exceptions_and_usage(online_store="sqlite")
      def update(
          self,
          config: RepoConfig,
          tables_to_delete: Sequence[FeatureView],
          tables_to_keep: Sequence[FeatureView],
          entities_to_delete: Sequence[Entity],
          entities_to_keep: Sequence[Entity],
          partial: bool,
      ):
          conn = self._get_conn(config)
          project = config.project
  
          for table in tables_to_keep:
              conn.execute(
                  f"CREATE TABLE IF NOT EXISTS {_table_id(project, table)} (entity_key BLOB, feature_name TEXT, value BLOB, event_ts timestamp, created_ts timestamp,  PRIMARY KEY(entity_key, feature_name))"
              )
              conn.execute(
                  f"CREATE INDEX IF NOT EXISTS {_table_id(project, table)}_ek ON {_table_id(project, table)} (entity_key);"
              )
  
          for table in tables_to_delete:
              conn.execute(f"DROP TABLE IF EXISTS {_table_id(project, table)}")
  
      @log_exceptions_and_usage(online_store="sqlite")
      def plan(
          self, config: RepoConfig, desired_registry_proto: RegistryProto
      ) -> List[InfraObject]:
          project = config.project
  
          infra_objects: List[InfraObject] = [
              SqliteTable(
                  path=self._get_db_path(config),
                  name=_table_id(project, FeatureView.from_proto(view)),
              )
              for view in desired_registry_proto.feature_views
          ]
          return infra_objects
  
      def teardown(
          self,
          config: RepoConfig,
          tables: Sequence[FeatureView],
          entities: Sequence[Entity],
      ):
          try:
              os.unlink(self._get_db_path(config))
          except FileNotFoundError:
              pass
  
  
  def _initialize_conn(db_path: str):
      Path(db_path).parent.mkdir(exist_ok=True)
      return sqlite3.connect(
          db_path,
          detect_types=sqlite3.PARSE_DECLTYPES | sqlite3.PARSE_COLNAMES,
          check_same_thread=False,
      )
  
  
  def _table_id(project: str, table: FeatureView) -> str:
      return f"{project}_{table.name}"
  
  
  class SqliteTable(InfraObject):
      """
      A Sqlite table managed by Feast.
  
      Attributes:
          path: The absolute path of the Sqlite file.
          name: The name of the table.
          conn: SQLite connection.
      """
  
      path: str
      conn: sqlite3.Connection
  
      def __init__(self, path: str, name: str):
          super().__init__(name)
          self.path = path
          self.conn = _initialize_conn(path)
  
      def to_infra_object_proto(self) -> InfraObjectProto:
          sqlite_table_proto = self.to_proto()
          return InfraObjectProto(
              infra_object_class_type=SQLITE_INFRA_OBJECT_CLASS_TYPE,
              sqlite_table=sqlite_table_proto,
          )
  
      def to_proto(self) -> Any:
          sqlite_table_proto = SqliteTableProto()
          sqlite_table_proto.path = self.path
          sqlite_table_proto.name = self.name
          return sqlite_table_proto
  
      @staticmethod
      def from_infra_object_proto(infra_object_proto: InfraObjectProto) -> Any:
          return SqliteTable(
              path=infra_object_proto.sqlite_table.path,
              name=infra_object_proto.sqlite_table.name,
          )
  
      @staticmethod
      def from_proto(sqlite_table_proto: SqliteTableProto) -> Any:
          return SqliteTable(path=sqlite_table_proto.path, name=sqlite_table_proto.name,)
  
      def update(self):
          self.conn.execute(
              f"CREATE TABLE IF NOT EXISTS {self.name} (entity_key BLOB, feature_name TEXT, value BLOB, event_ts timestamp, created_ts timestamp,  PRIMARY KEY(entity_key, feature_name))"
          )
          self.conn.execute(
              f"CREATE INDEX IF NOT EXISTS {self.name}_ek ON {self.name} (entity_key);"
          )
  
      def teardown(self):
          self.conn.execute(f"DROP TABLE IF EXISTS {self.name}")
  