254 lines
7.1 KiB
Python

from __future__ import annotations
import dataclasses
import logging
import sys
import types
from collections import deque
from enum import Enum
from typing import (
Annotated,
Any,
Literal,
Union,
get_args,
get_origin,
get_type_hints,
)
from langchain_core import messages as lc_messages
from langgraph.checkpoint.base import BaseCheckpointSaver
from pydantic import BaseModel
from typing_extensions import NotRequired, Required, is_typeddict
try:
from langgraph.checkpoint.serde._msgpack import ( # noqa: F401
STRICT_MSGPACK_ENABLED,
)
except ImportError:
STRICT_MSGPACK_ENABLED = False
_warned_allowlist_unsupported = False
logger = logging.getLogger(__name__)
def _supports_checkpointer_allowlist() -> bool:
return hasattr(BaseCheckpointSaver, "with_allowlist")
_SUPPORTS_ALLOWLIST = _supports_checkpointer_allowlist()
def apply_checkpointer_allowlist(
checkpointer: Any, allowlist: set[tuple[str, ...]] | None
) -> Any:
if not checkpointer or allowlist is None or checkpointer in (True, False):
return checkpointer
if not _SUPPORTS_ALLOWLIST:
global _warned_allowlist_unsupported
if not _warned_allowlist_unsupported:
logger.warning(
"Checkpointer does not support with_allowlist; strict msgpack "
"allowlist will be skipped."
)
_warned_allowlist_unsupported = True
return checkpointer
return checkpointer.with_allowlist(allowlist)
def curated_core_allowlist() -> set[tuple[str, ...]]:
allowlist: set[tuple[str, ...]] = set()
for name in (
"BaseMessage",
"BaseMessageChunk",
"HumanMessage",
"HumanMessageChunk",
"AIMessage",
"AIMessageChunk",
"SystemMessage",
"SystemMessageChunk",
"ChatMessage",
"ChatMessageChunk",
"ToolMessage",
"ToolMessageChunk",
"FunctionMessage",
"FunctionMessageChunk",
"RemoveMessage",
):
cls = getattr(lc_messages, name, None)
if cls is None:
continue
allowlist.add((cls.__module__, cls.__name__))
return allowlist
def build_serde_allowlist(
*,
schemas: list[type[Any]] | None = None,
channels: dict[str, Any] | None = None,
) -> set[tuple[str, ...]]:
allowlist = curated_core_allowlist()
if schemas:
schemas = [schema for schema in schemas if schema is not None]
return allowlist | collect_allowlist_from_schemas(
schemas=schemas,
channels=channels,
)
def collect_allowlist_from_schemas(
*,
schemas: list[type[Any]] | None = None,
channels: dict[str, Any] | None = None,
) -> set[tuple[str, ...]]:
allowlist: set[tuple[str, ...]] = set()
seen: set[Any] = set()
seen_ids: set[int] = set()
if schemas:
for schema in schemas:
_collect_from_type(schema, allowlist, seen, seen_ids)
if channels:
for channel in channels.values():
value_type = getattr(channel, "ValueType", None)
if value_type is not None:
_collect_from_type(value_type, allowlist, seen, seen_ids)
update_type = getattr(channel, "UpdateType", None)
if update_type is not None:
_collect_from_type(update_type, allowlist, seen, seen_ids)
return allowlist
def _collect_from_type(
typ: Any,
allowlist: set[tuple[str, ...]],
seen: set[Any],
seen_ids: set[int],
) -> None:
if _already_seen(typ, seen, seen_ids):
return
if typ is Any or typ is None:
return
if typ is Literal:
return
if isinstance(typ, types.UnionType):
for arg in typ.__args__:
_collect_from_type(arg, allowlist, seen, seen_ids)
return
origin = get_origin(typ)
if origin is Union:
for arg in get_args(typ):
_collect_from_type(arg, allowlist, seen, seen_ids)
return
if origin is Annotated or origin in (Required, NotRequired):
args = get_args(typ)
if args:
_collect_from_type(args[0], allowlist, seen, seen_ids)
return
if origin is Literal:
return
if origin in (list, set, tuple, dict, deque, frozenset):
for arg in get_args(typ):
_collect_from_type(arg, allowlist, seen, seen_ids)
return
if hasattr(typ, "__supertype__"):
_collect_from_type(typ.__supertype__, allowlist, seen, seen_ids)
return
if is_typeddict(typ):
for field_type in _safe_get_type_hints(typ).values():
_collect_from_type(field_type, allowlist, seen, seen_ids)
return
if _is_pydantic_model(typ):
allowlist.add((typ.__module__, typ.__name__))
field_types = _safe_get_type_hints(typ)
if field_types:
for field_type in field_types.values():
_collect_from_type(field_type, allowlist, seen, seen_ids)
else:
for field_type in _pydantic_field_types(typ):
_collect_from_type(field_type, allowlist, seen, seen_ids)
return
if dataclasses.is_dataclass(typ):
if typ_name := getattr(typ, "__name__", None):
allowlist.add((typ.__module__, typ_name))
field_types = _safe_get_type_hints(typ)
if field_types:
for field_type in field_types.values():
_collect_from_type(field_type, allowlist, seen, seen_ids)
else:
for field in dataclasses.fields(typ):
_collect_from_type(field.type, allowlist, seen, seen_ids)
return
if isinstance(typ, type) and issubclass(typ, Enum):
allowlist.add((typ.__module__, typ.__name__))
return
def _already_seen(typ: Any, seen: set[Any], seen_ids: set[int]) -> bool:
try:
if typ in seen:
return True
seen.add(typ)
return False
except TypeError:
typ_id = id(typ)
if typ_id in seen_ids:
return True
seen_ids.add(typ_id)
return False
def _safe_get_type_hints(typ: Any) -> dict[str, Any]:
try:
module = sys.modules.get(getattr(typ, "__module__", ""))
globalns = module.__dict__ if module else None
localns = dict(vars(typ)) if hasattr(typ, "__dict__") else None
return get_type_hints(
typ, globalns=globalns, localns=localns, include_extras=True
)
except Exception:
return {}
def _is_pydantic_model(typ: Any) -> bool:
if not isinstance(typ, type):
return False
if issubclass(typ, BaseModel):
return True
try:
from pydantic.v1 import BaseModel as BaseModelV1
except Exception:
return False
return issubclass(typ, BaseModelV1)
def _pydantic_field_types(typ: type[Any]) -> list[Any]:
if hasattr(typ, "model_fields"):
return [
field.annotation
for field in typ.model_fields.values()
if getattr(field, "annotation", None) is not None
]
if hasattr(typ, "__fields__"):
return [
field.outer_type_
for field in typ.__fields__.values()
if getattr(field, "outer_type_", None) is not None
]
return []