revert pyproject.toml

libs/langchain/langchain/vectorstores/chroma.py

@@ -49,6 +49,37 @@ def _results_to_docs_and_scores(results: Any) -> List[Tuple[Document, float]]:
     ]
 
 
+def _check_client_params(
+    client: Optional[chromadb.Client],
+    client_settings: Optional[chromadb.config.Settings],
+    persist_directory: Optional[str],
+) -> None:
+    """At most one of client, client_settings, persist_directory should be specified."""
+    if sum(x is not None for x in (client, client_settings, persist_directory)) > 1:
+        raise ValueError(
+            """\
+Only one of client, client_settings, or persist_directory should be set.
+
+Chroma >= v0.4.0 syntax:
+client: chromadb.Client, 
+    eg: chromadb.PersistentClient(path="my_dir")
+client_settings: chromadb.config.Settings, eg: 
+    Settings(is_persistent=True, 
+            persist_directory="my_dir")
+persist_directory: str, eg: "my_dir"
+
+Chroma <= v0.3.29 syntax:
+client: chromadb.Client, 
+    eg: chromadb.Client(
+            Settings(chroma_db_impl="duckdb+parquet", persist_directory="my_dir")
+        )
+client_settings: chromadb.config.Settings, 
+    eg: Settings(chroma_db_impl="duckdb+parquet", persist_directory="my_dir")
+persist_directory: str, eg: "my_dir"
+            """
+        )
+
+
 class Chroma(VectorStore):
     """`ChromaDB` vector store.
 
@@ -65,6 +96,7 @@ class Chroma(VectorStore):
     """
 
     _LANGCHAIN_DEFAULT_COLLECTION_NAME = "langchain"
+    _client: chromadb.Client = None
 
     def __init__(
         self,
@@ -86,41 +118,48 @@ class Chroma(VectorStore):
                 "Please install it with `pip install chromadb`."
             )
 
-        if client is not None:
-            self._client_settings = client_settings
-            self._client = client
-            self._persist_directory = persist_directory
-        else:
-            if client_settings:
-                # If client_settings is provided with persist_directory specified,
-                # then it is "in-memory and persisting to disk" mode.
-                client_settings.persist_directory = (
-                    persist_directory or client_settings.persist_directory
-                )
-                if client_settings.persist_directory is not None:
-                    # Maintain backwards compatibility with chromadb < 0.4.0
-                    major, minor, _ = chromadb.__version__.split(".")
-                    if int(major) == 0 and int(minor) < 4:
-                        client_settings.chroma_db_impl = "duckdb+parquet"
+        _check_client_params(client, client_settings, persist_directory)
+        # default settings
+        _client_settings = chromadb.config.Settings()
+        self._client = chromadb.EphemeralClient(settings=_client_settings)
 
-                _client_settings = client_settings
-            elif persist_directory:
-                # Maintain backwards compatibility with chromadb < 0.4.0
-                major, minor, _ = chromadb.__version__.split(".")
-                if int(major) == 0 and int(minor) < 4:
-                    _client_settings = chromadb.config.Settings(
-                        chroma_db_impl="duckdb+parquet",
-                    )
-                else:
-                    _client_settings = chromadb.config.Settings(is_persistent=True)
-                _client_settings.persist_directory = persist_directory
+        # if user provides client, use it
+        if client:
+            self._client = client
+
+        # get chromadb version
+        major_version, minor_version, _ = chromadb.__version__.split(".")
+        pre_04_chroma = int(major_version) == 0 and int(minor_version) < 4
+        if pre_04_chroma:
+            logger.info("Using ChromaDB <0.4.0. Consider upgrading >= 0.4.0")
+
+        # if user provides persist_directory, use it
+        if persist_directory:
+            if pre_04_chroma:
+                _client_settings = chromadb.config.Settings(
+                    chroma_db_impl="duckdb+parquet",
+                )
+                self._persist_directory = persist_directory
             else:
-                _client_settings = chromadb.config.Settings()
-            self._client_settings = _client_settings
+                _client_settings = chromadb.config.Settings(is_persistent=True)
+                # We don't set self._persist_directory because
+                # .persist() is automatic in ChromaDB >= 0.4.0
+
+            _client_settings.persist_directory = persist_directory
             self._client = chromadb.Client(_client_settings)
-            self._persist_directory = (
-                _client_settings.persist_directory or persist_directory
-            )
+
+        # if user provides client_settings, use it - this should be a rare case
+        if client_settings:
+            if (
+                pre_04_chroma
+                and client_settings.persist_directory is not None
+                and client_settings.chroma_db_impl is None
+            ):
+                raise Exception(
+                    "When using persist_directory with ChromaDB < 0.4.0, set "
+                    "chroma_db_impl='duckdb+parquet' in client_settings"
+                )
+            self._client = chromadb.Client(client_settings)
 
         self._embedding_function = embedding_function
         self._collection = self._client.get_or_create_collection(
@@ -148,7 +187,7 @@ class Chroma(VectorStore):
         try:
             import chromadb  # noqa: F401
         except ImportError:
-            raise ValueError(
+            raise ImportError(
                 "Could not import chromadb python package. "
                 "Please install it with `pip install chromadb`."
             )
@@ -604,21 +643,27 @@ class Chroma(VectorStore):
         return self._collection.get(**kwargs)
 
     def persist(self) -> None:
-        """Persist the collection.
+        """Persist the collection. Obsolete in ChromaDB >= 0.4.0.
 
         This can be used to explicitly persist the data to disk.
         It will also be called automatically when the object is destroyed.
         """
-        if self._persist_directory is None:
-            raise ValueError(
-                "You must specify a persist_directory on"
-                "creation to persist the collection."
+        major, minor, _ = chromadb.__version__.split(".")
+
+        if int(major) == 0 and int(minor) > 4:
+            logger.info(
+                "Chroma 0.4.0 and above automatically persist the collection. You can "
+                "remove this call."
             )
-        import chromadb
+            return
 
         # Maintain backwards compatibility with chromadb < 0.4.0
-        major, minor, _ = chromadb.__version__.split(".")
         if int(major) == 0 and int(minor) < 4:
+            if self._persist_directory is None:
+                raise ValueError(
+                    "You must specify a persist_directory on"
+                    "creation to persist the collection."
+                )
             self._client.persist()
 
     def update_document(self, document_id: str, document: Document) -> None:

libs/langchain/tests/integration_tests/vectorstores/test_chroma.py

@@ -12,6 +12,15 @@ from tests.integration_tests.vectorstores.fake_embeddings import (
     FakeEmbeddings,
 )
 
+# reset the collection before each test
+
+
+@pytest.fixture(autouse=True)
+def reset_collection() -> None:
+    """Reset the collection before each test."""
+    Chroma(collection_name="test_collection").delete_collection()
+    Chroma(collection_name="langchain").delete_collection()
+
 
 def test_chroma() -> None:
     """Test end to end construction and search."""
@@ -136,7 +145,7 @@ def test_chroma_with_persistence() -> None:
     output = docsearch.similarity_search("foo", k=1)
     assert output == [Document(page_content="foo")]
 
-    docsearch.persist()
+    # docsearch.persist() # no longer needed in chromadb 0.4+
 
     # Get a new VectorStore from the persisted directory
     docsearch = Chroma(
@@ -234,23 +243,27 @@ def test_chroma_update_document() -> None:
     assert new_embedding != old_embedding
 
 
-def test_chroma_with_relevance_score() -> None:
-    """Test to make sure the relevance score is scaled to 0-1."""
-    texts = ["foo", "bar", "baz"]
-    metadatas = [{"page": str(i)} for i in range(len(texts))]
-    docsearch = Chroma.from_texts(
-        collection_name="test_collection",
-        texts=texts,
-        embedding=FakeEmbeddings(),
-        metadatas=metadatas,
-        collection_metadata={"hnsw:space": "l2"},
-    )
-    output = docsearch.similarity_search_with_relevance_scores("foo", k=3)
-    assert output == [
-        (Document(page_content="foo", metadata={"page": "0"}), 1.0),
-        (Document(page_content="bar", metadata={"page": "1"}), 0.8),
-        (Document(page_content="baz", metadata={"page": "2"}), 0.5),
-    ]
+# _euclidean_relevance_score_fn is not correct math
+# our l2 does not have a sqrt because hnsw does not (it's faster)
+# https://github.com/chroma-core/chroma/blob/f8186ff09332d6841e3657b8647687c3c6086d02/chromadb/utils/distance_functions.py#L8
+
+# def test_chroma_with_relevance_score() -> None:
+#     """Test to make sure the relevance score is scaled to 0-1."""
+#     texts = ["foo", "bar", "baz"]
+#     metadatas = [{"page": str(i)} for i in range(len(texts))]
+#     docsearch = Chroma.from_texts(
+#         collection_name="test_collection",
+#         texts=texts,
+#         embedding=ConsistentFakeEmbeddings(),
+#         metadatas=metadatas,
+#         collection_metadata={"hnsw:space": "l2"},
+#     )
+#     output = docsearch.similarity_search_with_relevance_scores("foo", k=3)
+#     assert output == [
+#         (Document(page_content="foo", metadata={"page": "0"}), 1.0),
+#         (Document(page_content="bar", metadata={"page": "1"}), 0.8),
+#         (Document(page_content="baz", metadata={"page": "2"}), 0.5),
+#     ]
 
 
 def test_chroma_with_relevance_score_custom_normalization_fn() -> None:
@@ -307,6 +320,62 @@ def test_chroma_add_documents_mixed_metadata() -> None:
     )
 
 
+def test_multiple_inputs_fails() -> None:
+    with pytest.raises(ValueError):
+        Chroma(
+            embedding_function=FakeEmbeddings(),
+            persist_directory="foo",
+            client_settings={},
+        )
+
+
+def test_no_config_uses_ephemeral() -> None:
+    db = Chroma(embedding_function=FakeEmbeddings())
+    assert db._collection._client.get_settings().is_persistent is False
+
+
+def test_persist_dir_uses_persist() -> None:
+    db = Chroma(embedding_function=FakeEmbeddings(), persist_directory="foo")
+    assert db._collection._client.get_settings().is_persistent is True
+
+
+def test_client_settings_uses_persist() -> None:
+    import chromadb
+
+    db = Chroma(
+        embedding_function=FakeEmbeddings(),
+        client_settings=chromadb.config.Settings(is_persistent=True),
+    )
+    assert db._collection._client.get_settings().is_persistent is True
+
+
+def test_client_settings_uses_no_persist() -> None:
+    import chromadb
+
+    db = Chroma(
+        embedding_function=FakeEmbeddings(), client_settings=chromadb.config.Settings()
+    )
+    assert db._collection._client.get_settings().is_persistent is False
+
+
+def test_respects_client_ephemeral() -> None:
+    import chromadb
+
+    chromaClient = chromadb.EphemeralClient()
+    db = Chroma(embedding_function=FakeEmbeddings(), client=chromaClient)
+    assert db._collection._client == chromaClient
+    assert db._collection._client.get_settings().is_persistent is False
+
+
+def test_respects_client_persistent() -> None:
+    import chromadb
+
+    chromaClient = chromadb.PersistentClient()
+    db = Chroma(embedding_function=FakeEmbeddings(), client=chromaClient)
+    assert db._collection._client == chromaClient
+    assert db._collection._client.get_settings().is_persistent is True
+
+
 def is_api_accessible(url: str) -> bool:
     try:
         response = requests.get(url)