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langgraph/libs/checkpoint/tests/test_memory.py
T

666 lines
24 KiB
Python

import logging
from typing import Any
import pytest
from langchain_core.runnables import RunnableConfig
from pydantic import BaseModel
from langgraph.checkpoint.base import (
DELTA_SENTINEL,
Checkpoint,
CheckpointMetadata,
create_checkpoint,
empty_checkpoint,
)
from langgraph.checkpoint.memory import InMemorySaver
from langgraph.checkpoint.serde.jsonplus import (
JsonPlusSerializer,
_warned_blocked_types,
_warned_unregistered_types,
)
class MemoryPydantic(BaseModel):
foo: str
@pytest.fixture(autouse=True)
def _reset_warned_types() -> None:
# Warning dedup state is process-global; reset per-test so each case sees
# a fresh slate and assertions about warning emission are stable.
_warned_unregistered_types.clear()
_warned_blocked_types.clear()
class TestMemorySaver:
@pytest.fixture(autouse=True)
def setup(self) -> None:
self.memory_saver = InMemorySaver()
# objects for test setup
self.config_1: RunnableConfig = {
"configurable": {
"thread_id": "thread-1",
"checkpoint_ns": "",
"checkpoint_id": "1",
}
}
self.config_2: RunnableConfig = {
"configurable": {
"thread_id": "thread-2",
"checkpoint_ns": "",
"checkpoint_id": "2",
}
}
self.config_3: RunnableConfig = {
"configurable": {
"thread_id": "thread-2",
"checkpoint_id": "2-inner",
"checkpoint_ns": "inner",
}
}
self.chkpnt_1: Checkpoint = empty_checkpoint()
self.chkpnt_2: Checkpoint = create_checkpoint(self.chkpnt_1, {}, 1)
self.chkpnt_3: Checkpoint = empty_checkpoint()
self.metadata_1: CheckpointMetadata = {
"source": "input",
"step": 2,
"writes": {},
"score": 1,
}
self.metadata_2: CheckpointMetadata = {
"source": "loop",
"step": 1,
"writes": {"foo": "bar"},
"score": None,
}
self.metadata_3: CheckpointMetadata = {}
def test_combined_metadata(self) -> None:
config: RunnableConfig = {
"configurable": {
"thread_id": "thread-2",
"checkpoint_ns": "",
"__super_private_key": "super_private_value",
},
"metadata": {"run_id": "my_run_id"},
}
self.memory_saver.put(
config, self.chkpnt_2, self.metadata_2, self.chkpnt_2["channel_versions"]
)
checkpoint = self.memory_saver.get_tuple(config)
assert checkpoint is not None
assert checkpoint.metadata == {
**self.metadata_2,
"run_id": "my_run_id",
}
async def test_search(self) -> None:
# set up test
# save checkpoints
self.memory_saver.put(
self.config_1,
self.chkpnt_1,
self.metadata_1,
self.chkpnt_1["channel_versions"],
)
self.memory_saver.put(
self.config_2,
self.chkpnt_2,
self.metadata_2,
self.chkpnt_2["channel_versions"],
)
self.memory_saver.put(
self.config_3,
self.chkpnt_3,
self.metadata_3,
self.chkpnt_3["channel_versions"],
)
# call method / assertions
query_1 = {"source": "input"} # search by 1 key
query_2 = {
"step": 1,
"writes": {"foo": "bar"},
} # search by multiple keys
query_3: dict[str, Any] = {} # search by no keys, return all checkpoints
query_4 = {"source": "update", "step": 1} # no match
search_results_1 = list(self.memory_saver.list(None, filter=query_1))
assert len(search_results_1) == 1
assert search_results_1[0].metadata == self.metadata_1
search_results_2 = list(self.memory_saver.list(None, filter=query_2))
assert len(search_results_2) == 1
assert search_results_2[0].metadata == self.metadata_2
search_results_3 = list(self.memory_saver.list(None, filter=query_3))
assert len(search_results_3) == 3
search_results_4 = list(self.memory_saver.list(None, filter=query_4))
assert len(search_results_4) == 0
# search by config (defaults to checkpoints across all namespaces)
search_results_5 = list(
self.memory_saver.list({"configurable": {"thread_id": "thread-2"}})
)
assert len(search_results_5) == 2
assert {
search_results_5[0].config["configurable"]["checkpoint_ns"],
search_results_5[1].config["configurable"]["checkpoint_ns"],
} == {"", "inner"}
# TODO: test before and limit params
async def test_asearch(self) -> None:
# set up test
# save checkpoints
self.memory_saver.put(
self.config_1,
self.chkpnt_1,
self.metadata_1,
self.chkpnt_1["channel_versions"],
)
self.memory_saver.put(
self.config_2,
self.chkpnt_2,
self.metadata_2,
self.chkpnt_2["channel_versions"],
)
self.memory_saver.put(
self.config_3,
self.chkpnt_3,
self.metadata_3,
self.chkpnt_3["channel_versions"],
)
# call method / assertions
query_1 = {"source": "input"} # search by 1 key
query_2 = {
"step": 1,
"writes": {"foo": "bar"},
} # search by multiple keys
query_3: dict[str, Any] = {} # search by no keys, return all checkpoints
query_4 = {"source": "update", "step": 1} # no match
search_results_1 = [
c async for c in self.memory_saver.alist(None, filter=query_1)
]
assert len(search_results_1) == 1
assert search_results_1[0].metadata == self.metadata_1
search_results_2 = [
c async for c in self.memory_saver.alist(None, filter=query_2)
]
assert len(search_results_2) == 1
assert search_results_2[0].metadata == self.metadata_2
search_results_3 = [
c async for c in self.memory_saver.alist(None, filter=query_3)
]
assert len(search_results_3) == 3
search_results_4 = [
c async for c in self.memory_saver.alist(None, filter=query_4)
]
assert len(search_results_4) == 0
async def test_memory_saver() -> None:
memory_saver = InMemorySaver()
assert isinstance(memory_saver, InMemorySaver)
async with memory_saver as async_memory_saver:
assert async_memory_saver is memory_saver
with memory_saver as sync_memory_saver:
assert sync_memory_saver is memory_saver
def test_memory_saver_warns_on_unregistered_msgpack(
caplog: pytest.LogCaptureFixture,
) -> None:
serde = JsonPlusSerializer()
memory_saver = InMemorySaver(serde=serde)
obj = MemoryPydantic(foo="bar")
checkpoint = empty_checkpoint()
checkpoint["channel_values"] = {"foo": obj}
checkpoint["channel_versions"] = {"foo": 1}
config: RunnableConfig = {
"configurable": {"thread_id": "thread-1", "checkpoint_ns": ""}
}
caplog.set_level(logging.WARNING, logger="langgraph.checkpoint.serde.jsonplus")
new_config = memory_saver.put(config, checkpoint, {}, {"foo": 1})
result = memory_saver.get_tuple(new_config)
assert result is not None
assert "unregistered type" in caplog.text.lower()
assert result.checkpoint["channel_values"]["foo"] == obj
def test_memory_saver_allowlist_silences_warning(
caplog: pytest.LogCaptureFixture,
) -> None:
serde = JsonPlusSerializer(
allowed_msgpack_modules=[("tests.test_memory", "MemoryPydantic")]
)
memory_saver = InMemorySaver(serde=serde)
obj = MemoryPydantic(foo="bar")
checkpoint = empty_checkpoint()
checkpoint["channel_values"] = {"foo": obj}
checkpoint["channel_versions"] = {"foo": 1}
config: RunnableConfig = {
"configurable": {"thread_id": "thread-1", "checkpoint_ns": ""}
}
caplog.set_level(logging.WARNING, logger="langgraph.checkpoint.serde.jsonplus")
new_config = memory_saver.put(config, checkpoint, {}, {"foo": 1})
result = memory_saver.get_tuple(new_config)
assert result is not None
assert "unregistered type" not in caplog.text.lower()
assert result.checkpoint["channel_values"]["foo"] == obj
def test_memory_saver_strict_blocks_unregistered(
caplog: pytest.LogCaptureFixture,
) -> None:
serde = JsonPlusSerializer(allowed_msgpack_modules=None)
memory_saver = InMemorySaver(serde=serde)
obj = MemoryPydantic(foo="bar")
checkpoint = empty_checkpoint()
checkpoint["channel_values"] = {"foo": obj}
checkpoint["channel_versions"] = {"foo": 1}
config: RunnableConfig = {
"configurable": {"thread_id": "thread-1", "checkpoint_ns": ""}
}
caplog.set_level(logging.WARNING, logger="langgraph.checkpoint.serde.jsonplus")
new_config = memory_saver.put(config, checkpoint, {}, {"foo": 1})
result = memory_saver.get_tuple(new_config)
assert result is not None
assert "blocked" in caplog.text.lower()
expected = obj.model_dump() if hasattr(obj, "model_dump") else obj.dict()
assert result.checkpoint["channel_values"]["foo"] == expected
def test_memory_saver_with_allowlist_proxy_isolated() -> None:
serde = JsonPlusSerializer(allowed_msgpack_modules=None)
memory_saver = InMemorySaver(serde=serde)
proxy = memory_saver.with_allowlist([("tests.test_memory", "MemoryPydantic")])
obj = MemoryPydantic(foo="bar")
checkpoint = empty_checkpoint()
checkpoint["channel_values"] = {"foo": obj}
checkpoint["channel_versions"] = {"foo": 1}
config: RunnableConfig = {
"configurable": {"thread_id": "thread-1", "checkpoint_ns": ""}
}
new_config = proxy.put(config, checkpoint, {}, {"foo": 1})
proxied = proxy.get_tuple(new_config)
assert proxied is not None
assert proxied.checkpoint["channel_values"]["foo"] == obj
direct = memory_saver.get_tuple(new_config)
assert direct is not None
expected = obj.model_dump() if hasattr(obj, "model_dump") else obj.dict()
assert direct.checkpoint["channel_values"]["foo"] == expected
class TestInMemorySaverDeltaChannel:
def test_load_blobs_returns_sentinel_for_delta_channel(self) -> None:
"""_load_blobs returns DELTA_SENTINEL for delta channels (reconstruction deferred)."""
saver = InMemorySaver()
serde = JsonPlusSerializer()
thread_id, ns, channel = "t1", "", "messages"
v1 = "00000000000000000000000000000001.0000000000000000"
saver.blobs[(thread_id, ns, channel, v1)] = serde.dumps_typed(DELTA_SENTINEL)
cp1 = empty_checkpoint()
cp1["id"] = "cp1"
cp1["channel_versions"][channel] = v1
saver.storage[thread_id][ns] = {
"cp1": (serde.dumps_typed(cp1), serde.dumps_typed({}), None),
}
result = saver._load_blobs(thread_id, ns, {channel: v1})
assert channel in result
assert result[channel] is DELTA_SENTINEL
def test_get_channel_writes_collects_ancestor_writes_only(self) -> None:
"""_get_channel_writes_history collects ancestor writes oldest→newest,
and excludes writes stored at the target checkpoint itself (those are
pending writes for the next step, applied separately by pregel)."""
saver = InMemorySaver()
serde = JsonPlusSerializer()
thread_id, ns, channel = "t1", "", "messages"
cp1 = empty_checkpoint()
cp1["id"] = "cp1"
cp2 = empty_checkpoint()
cp2["id"] = "cp2"
saver.storage[thread_id][ns] = {
"cp1": (serde.dumps_typed(cp1), serde.dumps_typed({}), None),
"cp2": (serde.dumps_typed(cp2), serde.dumps_typed({}), "cp1"),
}
# Writes stored at cp1 produced the cp1 snapshot; part of history.
saver.writes[(thread_id, ns, "cp1")][("task1", 0)] = (
"task1",
channel,
serde.dumps_typed({"content": "hi"}),
"",
)
# Writes stored at cp2 are pending — they will produce cp3 when the
# step that loaded cp2 completes. They MUST NOT appear in the
# reconstructed snapshot value at cp2.
saver.writes[(thread_id, ns, "cp2")][("task2", 0)] = (
"task2",
channel,
serde.dumps_typed({"content": "pending"}),
"",
)
config: RunnableConfig = {
"configurable": {
"thread_id": thread_id,
"checkpoint_ns": ns,
"checkpoint_id": "cp2",
}
}
result = saver._get_channel_writes_history(config, channel)
assert result.seed is DELTA_SENTINEL
values = [v for _, _, v in result.writes]
assert values == [{"content": "hi"}]
def test_get_channel_writes_at_root_returns_empty(self) -> None:
"""Reconstructing the root checkpoint's state: no ancestors → []."""
saver = InMemorySaver()
serde = JsonPlusSerializer()
thread_id, ns, channel = "t1", "", "messages"
cp1 = empty_checkpoint()
cp1["id"] = "cp1"
saver.storage[thread_id][ns] = {
"cp1": (serde.dumps_typed(cp1), serde.dumps_typed({}), None),
}
saver.writes[(thread_id, ns, "cp1")][("task1", 0)] = (
"task1",
channel,
serde.dumps_typed({"content": "pending"}),
"",
)
config: RunnableConfig = {
"configurable": {
"thread_id": thread_id,
"checkpoint_ns": ns,
"checkpoint_id": "cp1",
}
}
result = saver._get_channel_writes_history(config, channel)
assert result.seed is DELTA_SENTINEL
assert result.writes == []
class TestBaseFallbackGetChannelWrites:
"""Exercises the `BaseCheckpointSaver._get_channel_writes_history` default
implementation — the path third-party savers inherit when they don't
override `_get_channel_writes_history` themselves.
Regression guard for a bug where the fallback passed the caller's config
(with `checkpoint_id`) straight to `self.list()`, which most savers
collapse to a single row — causing the fallback to return `[]`.
"""
def _build_saver_with_chain(self) -> tuple[InMemorySaver, str, str]:
"""Build an InMemorySaver with a 3-checkpoint chain and per-step writes
for a `messages` channel.
Returns `(saver, thread_id, namespace)`. The saver subclass deletes the
InMemorySaver override so the base class fallback is exercised.
"""
class _ThirdPartyStyleSaver(InMemorySaver):
_get_channel_writes_history = (
InMemorySaver.__mro__[1]._get_channel_writes_history # type: ignore[attr-defined]
)
_aget_channel_writes_history = (
InMemorySaver.__mro__[1]._aget_channel_writes_history # type: ignore[attr-defined]
)
saver = _ThirdPartyStyleSaver()
serde = JsonPlusSerializer()
thread_id, ns, channel = "t1", "", "messages"
cp0 = empty_checkpoint()
cp0["id"] = "00000000000000000000000000000001.0000000000000000"
cp1 = empty_checkpoint()
cp1["id"] = "00000000000000000000000000000002.0000000000000000"
cp2 = empty_checkpoint()
cp2["id"] = "00000000000000000000000000000003.0000000000000000"
saver.storage[thread_id][ns] = {
cp0["id"]: (serde.dumps_typed(cp0), serde.dumps_typed({}), None),
cp1["id"]: (serde.dumps_typed(cp1), serde.dumps_typed({}), cp0["id"]),
cp2["id"]: (serde.dumps_typed(cp2), serde.dumps_typed({}), cp1["id"]),
}
# Writes under cp0 produced cp1's state; writes under cp1 produced cp2's.
saver.writes[(thread_id, ns, cp0["id"])][("task1", 0)] = (
"task1",
channel,
serde.dumps_typed({"content": "first"}),
"",
)
saver.writes[(thread_id, ns, cp1["id"])][("task2", 0)] = (
"task2",
channel,
serde.dumps_typed({"content": "second"}),
"",
)
return saver, thread_id, ns
def test_fallback_returns_ancestor_writes_oldest_first(self) -> None:
saver, thread_id, ns = self._build_saver_with_chain()
target_id = "00000000000000000000000000000003.0000000000000000"
config: RunnableConfig = {
"configurable": {
"thread_id": thread_id,
"checkpoint_ns": ns,
"checkpoint_id": target_id,
}
}
result = saver._get_channel_writes_history(config, "messages")
assert result.seed is DELTA_SENTINEL
values = [v for _, _, v in result.writes]
assert values == [{"content": "first"}, {"content": "second"}]
async def test_async_fallback_returns_ancestor_writes_oldest_first(self) -> None:
saver, thread_id, ns = self._build_saver_with_chain()
target_id = "00000000000000000000000000000003.0000000000000000"
config: RunnableConfig = {
"configurable": {
"thread_id": thread_id,
"checkpoint_ns": ns,
"checkpoint_id": target_id,
}
}
result = await saver._aget_channel_writes_history(config, "messages")
assert result.seed is DELTA_SENTINEL
values = [v for _, _, v in result.writes]
assert values == [{"content": "first"}, {"content": "second"}]
async def test_async_fallback_concurrent_tasks_do_not_interfere(self) -> None:
"""Regression: the re-entrancy guard must be task-local, not thread-local.
Two concurrent `_aget_channel_writes_history` calls on the same
event-loop thread must each see their full reconstructed writes. A
`threading.local()` guard would let whichever task set it first
short-circuit the other to `writes=[]`.
"""
import asyncio
saver, thread_id, ns = self._build_saver_with_chain()
# Force the two tasks to interleave across the `set(True)` boundary:
# each `aget_tuple` yields control, so if the guard were thread-local
# the second task would observe `active=True` set by the first.
orig_aget_tuple = saver.aget_tuple
async def slow_aget_tuple(config: RunnableConfig) -> Any:
await asyncio.sleep(0)
return await orig_aget_tuple(config)
saver.aget_tuple = slow_aget_tuple # type: ignore[method-assign]
target_id = "00000000000000000000000000000003.0000000000000000"
config: RunnableConfig = {
"configurable": {
"thread_id": thread_id,
"checkpoint_ns": ns,
"checkpoint_id": target_id,
}
}
results = await asyncio.gather(
saver._aget_channel_writes_history(config, "messages"),
saver._aget_channel_writes_history(config, "messages"),
)
expected_values = [{"content": "first"}, {"content": "second"}]
for result in results:
assert result.seed is DELTA_SENTINEL
values = [v for _, _, v in result.writes]
assert values == expected_values
class TestPreDeltaBlobTerminator:
"""Verify the pre-delta blob terminator: when the ancestor walk hits a
checkpoint whose blob for the channel is a real value (not
DELTA_SENTINEL), reconstruction seeds from it and stops. This guards
* back-compat: a thread written by pre-delta code, then extended under
delta — reconstruction must return the correct value without walking
past the last pre-delta ancestor;
* perf: without the terminator, every reconstruct-after-migration would
walk all the way to the thread root.
"""
def _build_mixed_thread(self) -> tuple[InMemorySaver, str, str, str, str]:
"""Three-checkpoint chain: cp1 (pre-delta, blob=[A]), cp2 (delta,
write=B), cp3 (delta, write=C). Reconstructing at cp3 must yield
seed=[A] + writes=[B, C].
Returns `(saver, thread_id, ns, channel, cp3_id)`.
"""
saver = InMemorySaver()
serde = JsonPlusSerializer()
thread_id, ns, channel = "t1", "", "messages"
v1 = "00000000000000000000000000000001.0"
v2 = "00000000000000000000000000000002.0"
v3 = "00000000000000000000000000000003.0"
# Pre-delta: cp1 stored a real blob for the channel.
saver.blobs[(thread_id, ns, channel, v1)] = serde.dumps_typed(["A"])
# Delta-era: cp2 and cp3 store sentinels; real writes in checkpoint_writes.
saver.blobs[(thread_id, ns, channel, v2)] = serde.dumps_typed(DELTA_SENTINEL)
saver.blobs[(thread_id, ns, channel, v3)] = serde.dumps_typed(DELTA_SENTINEL)
cp1 = empty_checkpoint()
cp1["id"] = "cp1"
cp1["channel_versions"][channel] = v1
cp2 = empty_checkpoint()
cp2["id"] = "cp2"
cp2["channel_versions"][channel] = v2
cp3 = empty_checkpoint()
cp3["id"] = "cp3"
cp3["channel_versions"][channel] = v3
saver.storage[thread_id][ns] = {
"cp1": (serde.dumps_typed(cp1), serde.dumps_typed({}), None),
"cp2": (serde.dumps_typed(cp2), serde.dumps_typed({}), "cp1"),
"cp3": (serde.dumps_typed(cp3), serde.dumps_typed({}), "cp2"),
}
# Write under cp1 would be from the pre-delta era and MUST be ignored
# (the blob already captures it). We add one and assert it is not
# folded into the reconstructed result.
saver.writes[(thread_id, ns, "cp1")][("task0", 0)] = (
"task0",
channel,
serde.dumps_typed("PRE-DELTA-WRITE"),
"",
)
saver.writes[(thread_id, ns, "cp2")][("task2", 0)] = (
"task2",
channel,
serde.dumps_typed("B"),
"",
)
saver.writes[(thread_id, ns, "cp3")][("task3", 0)] = (
"task3",
channel,
serde.dumps_typed("PENDING-AT-TARGET"),
"",
)
return saver, thread_id, ns, channel, "cp3"
def test_seed_from_pre_delta_ancestor_blob(self) -> None:
saver, thread_id, ns, channel, target = self._build_mixed_thread()
config: RunnableConfig = {
"configurable": {
"thread_id": thread_id,
"checkpoint_ns": ns,
"checkpoint_id": target,
}
}
result = saver._get_channel_writes_history(config, channel)
# Seed came from the pre-delta blob at cp1.
assert result.seed == ["A"]
# Delta-era writes from cp2 replay through the reducer on top of seed.
# cp3 is the target — its own write is pending for the NEXT step and
# must be excluded.
values = [v for _, _, v in result.writes]
assert values == ["B"]
def test_pre_delta_blob_terminates_walk_before_older_writes(self) -> None:
"""Writes stored at the pre-delta ancestor itself must not be replayed
(the blob subsumes them)."""
saver, thread_id, ns, channel, target = self._build_mixed_thread()
config: RunnableConfig = {
"configurable": {
"thread_id": thread_id,
"checkpoint_ns": ns,
"checkpoint_id": target,
}
}
result = saver._get_channel_writes_history(config, channel)
values = [v for _, _, v in result.writes]
# The pre-delta write under cp1 must not appear (the blob subsumes it).
assert "PRE-DELTA-WRITE" not in values
# And the pending write at the target is never folded in.
assert "PENDING-AT-TARGET" not in values