import sqlite3
import warnings
from dataclasses import dataclass, field
from tempfile import NamedTemporaryFile
from typing import (
Iterable,
Dict,
Optional,
TYPE_CHECKING,
Union,
)
from .helper import initialize_table
from ..base.backend import BaseBackendMixin
from ....helper import random_identity, dataclass_from_dict
if TYPE_CHECKING:
from ....typing import DocumentArraySourceType
def _sanitize_table_name(table_name: str) -> str:
ret = ''.join(c for c in table_name if c.isalnum() or c == '_')
if ret != table_name:
warnings.warn(f'The table name is changed to {ret} due to illegal characters')
return ret
[docs]@dataclass
class SqliteConfig:
connection: Optional[Union[str, 'sqlite3.Connection']] = None
table_name: Optional[str] = None
serialize_config: Dict = field(default_factory=dict)
conn_config: Dict = field(default_factory=dict)
journal_mode: str = 'DELETE'
synchronous: str = 'OFF'
[docs]class BackendMixin(BaseBackendMixin):
"""Provide necessary functions to enable this storage backend."""
schema_version = '0'
def _sql(self, *args, **kwargs) -> 'sqlite3.Cursor':
return self._cursor.execute(*args, **kwargs)
def _commit(self):
self._connection.commit()
@property
def _cursor(self) -> 'sqlite3.Cursor':
return self._connection.cursor()
def _init_storage(
self,
_docs: Optional['DocumentArraySourceType'] = None,
config: Optional[Union[SqliteConfig, Dict]] = None,
**kwargs,
):
if not config:
config = SqliteConfig()
if isinstance(config, dict):
config = dataclass_from_dict(SqliteConfig, config)
from docarray import Document
sqlite3.register_adapter(
Document, lambda d: d.to_bytes(**config.serialize_config)
)
sqlite3.register_converter(
'Document', lambda x: Document.from_bytes(x, **config.serialize_config)
)
_conn_kwargs = dict()
_conn_kwargs.update(config.conn_config)
if config.connection is None:
config.connection = NamedTemporaryFile().name
if isinstance(config.connection, str):
self._connection = sqlite3.connect(
config.connection,
detect_types=sqlite3.PARSE_DECLTYPES,
check_same_thread=False,
**_conn_kwargs,
)
elif isinstance(config.connection, sqlite3.Connection):
self._connection = config.connection
else:
raise TypeError(
f'connection argument must be None or a string or a sqlite3.Connection, not `{type(config.connection)}`'
)
self._connection.execute(f'PRAGMA synchronous={config.synchronous}')
self._connection.execute(f'PRAGMA journal_mode={config.journal_mode}')
self._table_name = (
_sanitize_table_name(self.__class__.__name__ + random_identity())
if config.table_name is None
else _sanitize_table_name(config.table_name)
)
self._persist = bool(config.table_name)
config.table_name = self._table_name
initialize_table(
self._table_name, self.__class__.__name__, self.schema_version, self._cursor
)
self._connection.commit()
self._config = config
super()._init_storage()
if _docs is None:
return
elif isinstance(_docs, Iterable):
self.clear()
self.extend(_docs)
else:
self.clear()
if isinstance(_docs, Document):
self.append(_docs)
def __getstate__(self):
d = dict(self.__dict__)
del d['_connection']
return d
def __setstate__(self, state):
self.__dict__ = state
_conn_kwargs = dict()
_conn_kwargs.update(state['_config'].conn_config)
self._connection = sqlite3.connect(
state['_config'].connection,
detect_types=sqlite3.PARSE_DECLTYPES,
check_same_thread=False,
**_conn_kwargs,
)
