Files
langgraph/libs/checkpoint-postgres/tests/test_async_store.py
T
William FHandGitHub d767af421b feat: Add vector search (#2535)
- Initializing the store with an 'embedding config' -> this contains the
'dims' (used to create the table) and the encoder object (rn langchain
embeddings object, though that is ......)
- Call setup() -> creates the vector table.

Each document has 1 or more vectors associated with it for each json
path in the embedding config.

Would welcome critique and requests! 

Leaving the params as the defaults for pgvector but open to feedback if
you think it's important to be able to more transparently configure that
in setup()

```python
from typing import TypedDict, List, Dict, Any, Optional

from langchain_openai import OpenAIEmbeddings
from langgraph.graph import StateGraph
from langgraph.store.postgres import PostgresStore

emb_config = {
    "dims": 1536,  # OpenAI embedding dimensions
    "embed": OpenAIEmbeddings(model="text-embedding-3-small"),
    "distance_type": "cosine",
}
with PostgresStore.from_conn_string(
    "postgres://postgres:postgres@localhost:5441",
    embedding=emb_config,
) as store:
    store.setup()


# Define the state type for our graph
class State(TypedDict):
    query: str
    results: Optional[List[Dict[str, Any]]]


def put_stuff(state: State) -> State:
    docs = [
        ("doc1", {"text": "red apple in kitchen"}),
        ("doc2", {"text": "blue car in garage"}),
        ("doc3", {"text": "green apple on table"}),
    ]
    for key, value in docs:
        store.put(("docs",), key, value)


def search_stuff(state: State) -> State:
    """Search for documents using vector similarity."""
    results = store.search(("docs",), query=state["query"])

    return {"results": results}


builder = StateGraph(State)
builder.add_node(put_stuff)
builder.add_node(search_stuff)
builder.add_edge("__start__", "put_stuff")
builder.add_edge("put_stuff", "search_stuff")
# Compile
with PostgresStore.from_conn_string(
    "postgres://postgres:postgres@localhost:5441",
    embedding=emb_config,
) as store:
    chain = builder.compile(store=store)

    result = chain.invoke({"query": "sour apple"})

# Print results
for doc in result["results"]:
    print(doc.key)
    print(doc.value)
    print(doc.response_metadata)

```
2024-11-28 04:40:12 +00:00

508 lines
17 KiB
Python

# type: ignore
import itertools
import sys
import uuid
from collections.abc import AsyncIterator
from contextlib import asynccontextmanager
from typing import Any, Optional
import pytest
from langchain_core.embeddings import Embeddings
from psycopg import AsyncConnection
from langgraph.store.base import GetOp, Item, ListNamespacesOp, PutOp, SearchOp
from langgraph.store.postgres import AsyncPostgresStore
from tests.conftest import (
DEFAULT_URI,
VECTOR_TYPES,
CharacterEmbeddings,
)
@pytest.fixture(scope="function", params=["default", "pipe", "pool"])
async def store(request) -> AsyncIterator[AsyncPostgresStore]:
if sys.version_info < (3, 10):
pytest.skip("Async Postgres tests require Python 3.10+")
database = f"test_{uuid.uuid4().hex[:16]}"
uri_parts = DEFAULT_URI.split("/")
uri_base = "/".join(uri_parts[:-1])
query_params = ""
if "?" in uri_parts[-1]:
db_name, query_params = uri_parts[-1].split("?", 1)
query_params = "?" + query_params
conn_string = f"{uri_base}/{database}{query_params}"
admin_conn_string = DEFAULT_URI
async with await AsyncConnection.connect(
admin_conn_string, autocommit=True
) as conn:
await conn.execute(f"CREATE DATABASE {database}")
try:
async with AsyncPostgresStore.from_conn_string(conn_string) as store:
await store.setup()
if request.param == "pipe":
async with AsyncPostgresStore.from_conn_string(
conn_string, pipeline=True
) as store:
yield store
elif request.param == "pool":
async with AsyncPostgresStore.from_conn_string(
conn_string, pool_config={"min_size": 1, "max_size": 10}
) as store:
yield store
else: # default
async with AsyncPostgresStore.from_conn_string(conn_string) as store:
yield store
finally:
async with await AsyncConnection.connect(
admin_conn_string, autocommit=True
) as conn:
await conn.execute(f"DROP DATABASE {database}")
async def test_abatch_order(store: AsyncPostgresStore) -> None:
# Setup test data
await store.aput(("test", "foo"), "key1", {"data": "value1"})
await store.aput(("test", "bar"), "key2", {"data": "value2"})
ops = [
GetOp(namespace=("test", "foo"), key="key1"),
PutOp(namespace=("test", "bar"), key="key2", value={"data": "value2"}),
SearchOp(
namespace_prefix=("test",), filter={"data": "value1"}, limit=10, offset=0
),
ListNamespacesOp(match_conditions=None, max_depth=None, limit=10, offset=0),
GetOp(namespace=("test",), key="key3"),
]
results = await store.abatch(ops)
assert len(results) == 5
assert isinstance(results[0], Item)
assert isinstance(results[0].value, dict)
assert results[0].value == {"data": "value1"}
assert results[0].key == "key1"
assert results[1] is None
assert isinstance(results[2], list)
assert len(results[2]) == 1
assert isinstance(results[3], list)
assert ("test", "foo") in results[3] and ("test", "bar") in results[3]
assert results[4] is None
ops_reordered = [
SearchOp(namespace_prefix=("test",), filter=None, limit=5, offset=0),
GetOp(namespace=("test", "bar"), key="key2"),
ListNamespacesOp(match_conditions=None, max_depth=None, limit=5, offset=0),
PutOp(namespace=("test",), key="key3", value={"data": "value3"}),
GetOp(namespace=("test", "foo"), key="key1"),
]
results_reordered = await store.abatch(ops_reordered)
assert len(results_reordered) == 5
assert isinstance(results_reordered[0], list)
assert len(results_reordered[0]) == 2
assert isinstance(results_reordered[1], Item)
assert results_reordered[1].value == {"data": "value2"}
assert results_reordered[1].key == "key2"
assert isinstance(results_reordered[2], list)
assert ("test", "foo") in results_reordered[2] and (
"test",
"bar",
) in results_reordered[2]
assert results_reordered[3] is None
assert isinstance(results_reordered[4], Item)
assert results_reordered[4].value == {"data": "value1"}
assert results_reordered[4].key == "key1"
async def test_batch_get_ops(store: AsyncPostgresStore) -> None:
# Setup test data
await store.aput(("test",), "key1", {"data": "value1"})
await store.aput(("test",), "key2", {"data": "value2"})
ops = [
GetOp(namespace=("test",), key="key1"),
GetOp(namespace=("test",), key="key2"),
GetOp(namespace=("test",), key="key3"),
]
results = await store.abatch(ops)
assert len(results) == 3
assert results[0] is not None
assert results[1] is not None
assert results[2] is None
assert results[0].key == "key1"
assert results[1].key == "key2"
async def test_batch_put_ops(store: AsyncPostgresStore) -> None:
ops = [
PutOp(namespace=("test",), key="key1", value={"data": "value1"}),
PutOp(namespace=("test",), key="key2", value={"data": "value2"}),
PutOp(namespace=("test",), key="key3", value=None),
]
results = await store.abatch(ops)
assert len(results) == 3
assert all(result is None for result in results)
# Verify the puts worked
items = await store.asearch(["test"], limit=10)
assert len(items) == 2 # key3 had None value so wasn't stored
async def test_batch_search_ops(store: AsyncPostgresStore) -> None:
# Setup test data
await store.aput(("test", "foo"), "key1", {"data": "value1"})
await store.aput(("test", "bar"), "key2", {"data": "value2"})
ops = [
SearchOp(
namespace_prefix=("test",), filter={"data": "value1"}, limit=10, offset=0
),
SearchOp(namespace_prefix=("test",), filter=None, limit=5, offset=0),
]
results = await store.abatch(ops)
assert len(results) == 2
assert len(results[0]) == 1 # Filtered results
assert len(results[1]) == 2 # All results
async def test_batch_list_namespaces_ops(store: AsyncPostgresStore) -> None:
# Setup test data
await store.aput(("test", "namespace1"), "key1", {"data": "value1"})
await store.aput(("test", "namespace2"), "key2", {"data": "value2"})
ops = [ListNamespacesOp(match_conditions=None, max_depth=None, limit=10, offset=0)]
results = await store.abatch(ops)
assert len(results) == 1
assert len(results[0]) == 2
assert ("test", "namespace1") in results[0]
assert ("test", "namespace2") in results[0]
@asynccontextmanager
async def _create_vector_store(
vector_type: str,
distance_type: str,
fake_embeddings: CharacterEmbeddings,
text_fields: Optional[list[str]] = None,
) -> AsyncIterator[AsyncPostgresStore]:
"""Create a store with vector search enabled."""
if sys.version_info < (3, 10):
pytest.skip("Async Postgres tests require Python 3.10+")
database = f"test_{uuid.uuid4().hex[:16]}"
uri_parts = DEFAULT_URI.split("/")
uri_base = "/".join(uri_parts[:-1])
query_params = ""
if "?" in uri_parts[-1]:
db_name, query_params = uri_parts[-1].split("?", 1)
query_params = "?" + query_params
conn_string = f"{uri_base}/{database}{query_params}"
admin_conn_string = DEFAULT_URI
index_config = {
"dims": fake_embeddings.dims,
"embed": fake_embeddings,
"ann_index_config": {
"vector_type": vector_type,
},
"distance_type": distance_type,
"text_fields": text_fields,
}
async with await AsyncConnection.connect(
admin_conn_string, autocommit=True
) as conn:
await conn.execute(f"CREATE DATABASE {database}")
try:
async with AsyncPostgresStore.from_conn_string(
conn_string,
index=index_config,
) as store:
await store.setup()
yield store
finally:
async with await AsyncConnection.connect(
admin_conn_string, autocommit=True
) as conn:
await conn.execute(f"DROP DATABASE {database}")
@pytest.fixture(
scope="function",
params=[
(vector_type, distance_type)
for vector_type in VECTOR_TYPES
for distance_type in (
["hamming"] if vector_type == "bit" else ["l2", "inner_product", "cosine"]
)
],
ids=lambda p: f"{p[0]}_{p[1]}",
)
async def vector_store(
request,
fake_embeddings: CharacterEmbeddings,
) -> AsyncIterator[AsyncPostgresStore]:
"""Create a store with vector search enabled."""
vector_type, distance_type = request.param
async with _create_vector_store(
vector_type, distance_type, fake_embeddings
) as store:
yield store
async def test_vector_store_initialization(
vector_store: AsyncPostgresStore, fake_embeddings: CharacterEmbeddings
) -> None:
"""Test store initialization with embedding config."""
assert vector_store.index_config is not None
assert vector_store.index_config["dims"] == fake_embeddings.dims
if isinstance(vector_store.index_config["embed"], Embeddings):
assert vector_store.index_config["embed"] == fake_embeddings
async def test_vector_insert_with_auto_embedding(
vector_store: AsyncPostgresStore,
) -> None:
"""Test inserting items that get auto-embedded."""
docs = [
("doc1", {"text": "short text"}),
("doc2", {"text": "longer text document"}),
("doc3", {"text": "longest text document here"}),
("doc4", {"description": "text in description field"}),
("doc5", {"content": "text in content field"}),
("doc6", {"body": "text in body field"}),
]
for key, value in docs:
await vector_store.aput(("test",), key, value)
results = await vector_store.asearch(("test",), query="long text")
assert len(results) > 0
doc_order = [r.key for r in results]
assert "doc2" in doc_order
assert "doc3" in doc_order
async def test_vector_update_with_embedding(vector_store: AsyncPostgresStore) -> None:
"""Test that updating items properly updates their embeddings."""
await vector_store.aput(("test",), "doc1", {"text": "zany zebra Xerxes"})
await vector_store.aput(("test",), "doc2", {"text": "something about dogs"})
await vector_store.aput(("test",), "doc3", {"text": "text about birds"})
results_initial = await vector_store.asearch(("test",), query="Zany Xerxes")
assert len(results_initial) > 0
assert results_initial[0].key == "doc1"
initial_score = results_initial[0].score
await vector_store.aput(("test",), "doc1", {"text": "new text about dogs"})
results_after = await vector_store.asearch(("test",), query="Zany Xerxes")
after_score = next((r.score for r in results_after if r.key == "doc1"), 0.0)
assert after_score < initial_score
results_new = await vector_store.asearch(("test",), query="new text about dogs")
for r in results_new:
if r.key == "doc1":
assert r.score > after_score
# Don't index this one
await vector_store.aput(
("test",), "doc4", {"text": "new text about dogs"}, index=False
)
results_new = await vector_store.asearch(
("test",), query="new text about dogs", limit=3
)
assert not any(r.key == "doc4" for r in results_new)
async def test_vector_search_with_filters(vector_store: AsyncPostgresStore) -> None:
"""Test combining vector search with filters."""
docs = [
("doc1", {"text": "red apple", "color": "red", "score": 4.5}),
("doc2", {"text": "red car", "color": "red", "score": 3.0}),
("doc3", {"text": "green apple", "color": "green", "score": 4.0}),
("doc4", {"text": "blue car", "color": "blue", "score": 3.5}),
]
for key, value in docs:
await vector_store.aput(("test",), key, value)
results = await vector_store.asearch(
("test",), query="apple", filter={"color": "red"}
)
assert len(results) == 2
assert results[0].key == "doc1"
results = await vector_store.asearch(
("test",), query="car", filter={"color": "red"}
)
assert len(results) == 2
assert results[0].key == "doc2"
results = await vector_store.asearch(
("test",), query="bbbbluuu", filter={"score": {"$gt": 3.2}}
)
assert len(results) == 3
assert results[0].key == "doc4"
results = await vector_store.asearch(
("test",), query="apple", filter={"score": {"$gte": 4.0}, "color": "green"}
)
assert len(results) == 1
assert results[0].key == "doc3"
async def test_vector_search_pagination(vector_store: AsyncPostgresStore) -> None:
"""Test pagination with vector search."""
for i in range(5):
await vector_store.aput(
("test",), f"doc{i}", {"text": f"test document number {i}"}
)
results_page1 = await vector_store.asearch(("test",), query="test", limit=2)
results_page2 = await vector_store.asearch(
("test",), query="test", limit=2, offset=2
)
assert len(results_page1) == 2
assert len(results_page2) == 2
assert results_page1[0].key != results_page2[0].key
all_results = await vector_store.asearch(("test",), query="test", limit=10)
assert len(all_results) == 5
async def test_vector_search_edge_cases(vector_store: AsyncPostgresStore) -> None:
"""Test edge cases in vector search."""
await vector_store.aput(("test",), "doc1", {"text": "test document"})
perfect_match = await vector_store.asearch(("test",), query="text test document")
perfect_score = perfect_match[0].score
results = await vector_store.asearch(("test",), query="")
assert len(results) == 1
assert results[0].score is None
results = await vector_store.asearch(("test",), query=None)
assert len(results) == 1
assert results[0].score is None
long_query = "foo " * 100
results = await vector_store.asearch(("test",), query=long_query)
assert len(results) == 1
assert results[0].score < perfect_score
special_query = "test!@#$%^&*()"
results = await vector_store.asearch(("test",), query=special_query)
assert len(results) == 1
assert results[0].score < perfect_score
@pytest.mark.parametrize(
"vector_type,distance_type",
[
*itertools.product(["vector", "halfvec"], ["cosine", "inner_product", "l2"]),
],
)
async def test_embed_with_path(
request: Any,
fake_embeddings: CharacterEmbeddings,
vector_type: str,
distance_type: str,
) -> None:
"""Test vector search with specific text fields in Postgres store."""
async with _create_vector_store(
vector_type,
distance_type,
fake_embeddings,
text_fields=["key0", "key1", "key3"],
) as store:
# This will have 2 vectors representing it
doc1 = {
# Omit key0 - check it doesn't raise an error
"key1": "xxx",
"key2": "yyy",
"key3": "zzz",
}
# This will have 3 vectors representing it
doc2 = {
"key0": "uuu",
"key1": "vvv",
"key2": "www",
"key3": "xxx",
}
await store.aput(("test",), "doc1", doc1)
await store.aput(("test",), "doc2", doc2)
# doc2.key3 and doc1.key1 both would have the highest score
results = await store.asearch(("test",), query="xxx")
assert len(results) == 2
assert results[0].key != results[1].key
ascore = results[0].score
bscore = results[1].score
assert ascore == pytest.approx(bscore, abs=1e-3)
results = await store.asearch(("test",), query="uuu")
assert len(results) == 2
assert results[0].key != results[1].key
assert results[0].key == "doc2"
assert results[0].score > results[1].score
assert ascore == pytest.approx(results[0].score, abs=1e-3)
# Un-indexed - will have low results for both. Not zero (because we're projecting)
# but less than the above.
results = await store.asearch(("test",), query="www")
assert len(results) == 2
assert results[0].score < ascore
assert results[1].score < ascore
@pytest.mark.parametrize(
"vector_type,distance_type",
[
*itertools.product(["vector", "halfvec"], ["cosine", "inner_product", "l2"]),
],
)
async def test_search_sorting(
request: Any,
fake_embeddings: CharacterEmbeddings,
vector_type: str,
distance_type: str,
) -> None:
"""Test operation-level field configuration for vector search."""
async with _create_vector_store(
vector_type,
distance_type,
fake_embeddings,
text_fields=["key1"], # Default fields that won't match our test data
) as store:
amatch = {
"key1": "mmm",
}
await store.aput(("test", "M"), "M", amatch)
N = 100
for i in range(N):
await store.aput(("test", "A"), f"A{i}", {"key1": "no"})
for i in range(N):
await store.aput(("test", "Z"), f"Z{i}", {"key1": "no"})
results = await store.asearch(("test",), query="mmm", limit=10)
assert len(results) == 10
assert len(set(r.key for r in results)) == 10
assert results[0].key == "M"
assert results[0].score > results[1].score