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paperless-ngx/src/paperless_ai/vector_store.py
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stumpylogandClaude Sonnet 5 15938945d7 Simplify: dedupe file-swap rebuild, migration-check locking, and test mocks
Prompted by an automated simplification review of the branch. Applies the
highest-value findings, all behavior-preserving (full suite still green):

- vector_store.py: extract _rebuild_file() (temp-file lifecycle: open,
  populate, swap-in-or-discard-on-failure) and _rebuild_into() (create
  table, copy meta, stream rows) out of compact() and the v1->v2
  migration, which had duplicated both almost verbatim. The migration
  module shrinks to a single _rebuild_into() call instead of reaching
  into four PaperlessSqliteVecVectorStore privates.
- vector_store.py: extract _stored_schema_version() out of
  has_pending_migration() and check_and_run_migrations(), which
  duplicated the same schema_version read and its "missing key means
  current" default.
- indexing.py: extract _with_exclusive_access(), collapsing three
  identical _exclude_readers()/Timeout/log-and-skip blocks (compaction
  in update_llm_index() and llm_index_compact(), the migration check in
  _check_and_run_migrations()) to one line each. Also trims
  _check_and_run_migrations()'s docstring, which had grown to restate
  content already documented on has_pending_migration() and
  check_and_run_migrations(), including a claim that was now stale
  (llm_index_migrate() is a second consumer of the re-embed signal).
- test_ai_indexing.py: add a mock_store fixture for the
  write_store()-yields-a-MagicMock pattern that 8 tests were hand-rolling
  identically.
- migrations/__init__.py: consolidate the "how to add a migration"
  instructions to one place instead of three.
- docs/administration.md: fix two now-inaccurate claims -- the bare-metal
  migrate step doesn't run "automatically" (it's the manual step being
  documented), and the self-contradictory "if enabled... no-op if
  disabled" phrasing on the same step.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
2026-07-28 12:32:59 -07:00

712 lines
29 KiB
Python

import json
import logging
import sqlite3
import struct
from collections.abc import Iterator
from collections.abc import Sequence
from contextlib import contextmanager
from pathlib import Path
from types import TracebackType
from typing import Any
import sqlite_vec
from llama_index.core.bridge.pydantic import PrivateAttr
from llama_index.core.schema import BaseNode
from llama_index.core.vector_stores.types import BasePydanticVectorStore
from llama_index.core.vector_stores.types import FilterCondition
from llama_index.core.vector_stores.types import FilterOperator
from llama_index.core.vector_stores.types import MetadataFilter
from llama_index.core.vector_stores.types import MetadataFilters
from llama_index.core.vector_stores.types import VectorStoreQuery
from llama_index.core.vector_stores.types import VectorStoreQueryResult
from llama_index.core.vector_stores.utils import metadata_dict_to_node
from llama_index.core.vector_stores.utils import node_to_metadata_dict
from paperless_ai.migrations import MIGRATIONS
from paperless_ai.migrations import Migration
logger = logging.getLogger("paperless_ai.vector_store")
DB_FILENAME = "llmindex.db"
DEFAULT_TABLE_NAME = "documents"
_INSERT = (
"INSERT INTO "
+ DEFAULT_TABLE_NAME
+ " (id, document_id, modified, node_content, embedding) VALUES (?, ?, ?, ?, ?)"
)
_INSERT_CHUNK_INDEX = (
"INSERT INTO document_chunks (chunk_id, document_id) VALUES (?, ?)"
)
# Current schema version. Bump when adding a migration -- see
# paperless_ai/migrations/__init__.py for the full procedure.
SCHEMA_VERSION = 2
# compact(): rebuild when the cumulative rowid count exceeds this multiple of
# the live row count. DELETEs on vec0 tables never reclaim space (upstream
# asg017/sqlite-vec#54), so per-document re-index churn grows the file until
# a rebuild copies the live rows into a fresh table.
COMPACT_BLOAT_RATIO = 2.0
# compact(): number of rows copied per executemany() when rebuilding the file.
# Rows are streamed from the source cursor in batches of this size rather than
# materialized all at once, keeping memory bounded regardless of index size.
COMPACT_BATCH_SIZE = 500
# Filterable vec0 metadata columns. _build_where() only ever receives filter
# keys we construct ourselves, but allowlisting keeps SQL identifiers safe by
# construction.
_FILTER_COLUMNS = frozenset({"document_id", "modified"})
def _pack(embedding: Sequence[float]) -> bytes:
return struct.pack(f"{len(embedding)}f", *embedding)
def _unpack(blob: bytes) -> list[float]:
return list(struct.unpack(f"{len(blob) // 4}f", blob))
def _copy_rows(src_conn: sqlite3.Connection, dst_conn: sqlite3.Connection) -> int:
"""Copy every live vec0 row from ``src_conn`` into ``dst_conn``, recording
each one in ``dst_conn``'s document_chunks side table. Returns the number
of rows copied. The caller owns ``dst_conn``'s transaction.
Rows are streamed from the source cursor in batches instead of being
materialized all at once, so a large index does not cause an OOM during a
routine compaction or migration.
"""
src_cursor = src_conn.execute(
"SELECT id, document_id, modified, node_content, embedding FROM "
+ DEFAULT_TABLE_NAME,
)
copied = 0
while batch := src_cursor.fetchmany(COMPACT_BATCH_SIZE):
dst_conn.executemany(
_INSERT,
[
(
r["id"],
r["document_id"],
r["modified"],
r["node_content"],
bytes(r["embedding"]),
)
for r in batch
],
)
dst_conn.executemany(
_INSERT_CHUNK_INDEX,
[(r["id"], r["document_id"]) for r in batch],
)
copied += len(batch)
return copied
def _build_where(filters: MetadataFilters | None) -> tuple[str, list[str]]:
"""Translate the EQ / IN / NE filters we use into a parameterized SQL clause
on vec0 metadata columns. Returns ("", []) when there is nothing to filter.
"""
if filters is None or not filters.filters:
return "", []
clauses: list[str] = []
params: list[str] = []
for f in filters.filters:
# filters.filters is Union[MetadataFilter, ExactMatchFilter, MetadataFilters];
# we only build MetadataFilter entries, so skip anything else at runtime.
if not isinstance(f, MetadataFilter):
continue
if f.key not in _FILTER_COLUMNS: # pragma: no cover - we build the keys
raise NotImplementedError(f"Unsupported filter column: {f.key}")
if f.operator == FilterOperator.IN:
values = [str(v) for v in f.value] # type: ignore[union-attr] # value is list when operator is IN
if not values: # pragma: no cover
clauses.append("1 = 0")
continue
placeholders = ",".join("?" for _ in values)
clauses.append(f"{f.key} IN ({placeholders})")
params.extend(values)
elif f.operator == FilterOperator.EQ:
clauses.append(f"{f.key} = ?")
params.append(str(f.value))
elif f.operator == FilterOperator.NE:
clauses.append(f"{f.key} != ?")
params.append(str(f.value))
else: # pragma: no cover - we only ever build EQ/IN/NE filters
raise NotImplementedError(f"Unsupported filter operator: {f.operator}")
if not clauses:
# Filters were requested but none could be translated. Fail closed
# rather than emit "()" (invalid SQL): filters scope document access,
# so an empty translation must match no rows, never widen the scope.
return "1 = 0", []
joiner = " OR " if filters.condition == FilterCondition.OR else " AND "
return "(" + joiner.join(clauses) + ")", params
class PaperlessSqliteVecVectorStore(BasePydanticVectorStore):
"""A llama-index vector store backed by a sqlite-vec vec0 table.
Stores one row per node: the node id (TEXT primary key), its document id
(metadata column, used for EQ/IN filtering and per-document delete), the
document's modified timestamp, the embedding (float32, cosine metric), and
the serialized node (text + metadata) as JSON in an auxiliary column.
``stores_text`` lets llama-index run off this store alone, with no
separate docstore or index store.
Everything lives in one SQLite database file (``DB_FILENAME``) inside the
directory given as ``uri`` (kept as a directory for compatibility with the
previous LanceDB layout). WAL mode allows readers in other processes to
proceed while the (FileLock-serialized) writer holds a transaction.
Implemented surface of ``BasePydanticVectorStore``
---------------------------------------------------
Only the methods actively used by this codebase are implemented.
``delete_nodes`` and the ``node_ids`` lookup path of ``get_nodes`` are
part of the llama-index interface contract and may be needed if a future
retriever or extension invokes them — add them then, with tests.
"""
stores_text: bool = True
flat_metadata: bool = False
_uri: str = PrivateAttr()
_embed_model_name: str | None = PrivateAttr()
_conn: Any = PrivateAttr()
def __init__(
self,
uri: str,
embed_model_name: str | None = None,
) -> None:
super().__init__(stores_text=True, flat_metadata=False)
self._uri = uri
self._embed_model_name = embed_model_name
self._conn = self._open_connection(str(Path(uri) / DB_FILENAME))
@staticmethod
def _open_connection(db_path: str) -> sqlite3.Connection:
conn = sqlite3.connect(
db_path,
timeout=30,
isolation_level=None, # autocommit; explicit transactions below
)
conn.row_factory = sqlite3.Row
conn.enable_load_extension(True) # noqa: FBT003
sqlite_vec.load(conn)
conn.enable_load_extension(False) # noqa: FBT003
conn.execute("PRAGMA journal_mode=WAL")
conn.execute("PRAGMA synchronous=NORMAL")
conn.execute(
"CREATE TABLE IF NOT EXISTS index_meta (key TEXT PRIMARY KEY, value TEXT)",
)
# vec0 metadata columns only get an efficient lookup path inside a KNN
# (MATCH) query; a plain `WHERE document_id = ?` is a full table scan
# regardless of index size. This plain, indexed table is how delete()/
# upsert_document() find a document's chunk ids without that scan.
# document_id is INTEGER here (unlike vec0's own TEXT metadata
# column): this is a normal SQLite table, so standard type affinity
# correctly coerces the TEXT document ids written/looked-up
# elsewhere in this module -- it does not share vec0's own
# metadata-column comparison code, which silently mismatches
# non-TEXT bound values instead of coercing them.
conn.execute(
"CREATE TABLE IF NOT EXISTS document_chunks "
"(chunk_id TEXT PRIMARY KEY, document_id INTEGER NOT NULL)",
)
conn.execute(
"CREATE INDEX IF NOT EXISTS idx_document_chunks_document_id "
"ON document_chunks (document_id)",
)
return conn
@property
def client(self) -> Any:
return self._conn
def close(self) -> None:
"""Close the underlying SQLite connection (idempotent)."""
self._conn.close()
def __enter__(self) -> "PaperlessSqliteVecVectorStore":
return self
def __exit__(
self,
exc_type: type[BaseException] | None,
exc_val: BaseException | None,
exc_tb: TracebackType | None,
) -> None:
# Deterministically release the connection (and its WAL/SHM handles) so
# it is never left open across a compaction/migration file swap.
self.close()
@contextmanager
def _transaction(self) -> Iterator[None]:
self._conn.execute("BEGIN IMMEDIATE")
try:
yield
except BaseException: # pragma: no cover
self._conn.execute("ROLLBACK")
raise
else:
self._conn.execute("COMMIT")
@staticmethod
def _meta_get_on(conn: sqlite3.Connection, key: str) -> str | None:
row = conn.execute(
"SELECT value FROM index_meta WHERE key = ?",
(key,),
).fetchone()
return row["value"] if row else None
def _meta_get(self, key: str) -> str | None:
return self._meta_get_on(self._conn, key)
@staticmethod
def _meta_set_on(conn: sqlite3.Connection, key: str, value: str) -> None:
conn.execute(
"INSERT INTO index_meta (key, value) VALUES (?, ?) "
"ON CONFLICT(key) DO UPDATE SET value = excluded.value",
(key, value),
)
def _meta_set(self, key: str, value: str) -> None:
self._meta_set_on(self._conn, key, value)
def table_exists(self) -> bool:
return (
self._conn.execute(
"SELECT 1 FROM sqlite_master WHERE type = 'table' AND name = ?",
(DEFAULT_TABLE_NAME,),
).fetchone()
is not None
)
def vector_dim(self) -> int | None:
if not self.table_exists():
return None
value = self._meta_get("dim")
return int(value) if value else None
def drop_table(self) -> None:
self._conn.execute("DROP TABLE IF EXISTS " + DEFAULT_TABLE_NAME)
self._conn.execute("DELETE FROM index_meta")
self._conn.execute("DELETE FROM document_chunks")
def stored_model_name(self) -> str | None:
"""Return the embedding model name recorded at table creation, or None."""
if not self.table_exists():
return None
return self._meta_get("embed_model")
def config_mismatch(self, model_name: str) -> bool:
"""True when the stored model name differs from ``model_name``.
Returns False when no table exists or when the table predates
model-name tracking — conservative default avoids spurious rebuilds.
"""
stored = self.stored_model_name()
if stored is None:
return False
return stored != model_name
@staticmethod
def _create_vec_table(conn: sqlite3.Connection, dim: int) -> None:
# document_id is deliberately a metadata column, NOT a partition key:
# partition keys change KNN `k` to per-partition semantics under IN
# filters (asg017/sqlite-vec#142); metadata columns give a correct
# global top-k.
conn.execute( # nosemgrep: python.sqlalchemy.security.sqlalchemy-execute-raw-query.sqlalchemy-execute-raw-query
"CREATE VIRTUAL TABLE "
+ DEFAULT_TABLE_NAME
+ " USING vec0("
+ "id TEXT PRIMARY KEY,"
+ " document_id TEXT,"
+ " modified TEXT,"
+ " +node_content TEXT,"
+ " embedding float["
+ str(int(dim))
+ "] distance_metric=cosine"
+ ")",
)
def _create_table(self, dim: int) -> None:
self._create_vec_table(self._conn, dim)
self._meta_set("dim", str(dim))
self._meta_set("schema_version", str(SCHEMA_VERSION))
if self._embed_model_name:
self._meta_set("embed_model", self._embed_model_name)
def _ensure_table(self, dim: int) -> None:
if not self.table_exists():
self._create_table(dim)
def _row(self, node: BaseNode) -> tuple[str, str, str, str, bytes]:
meta = node_to_metadata_dict(
node,
remove_text=False,
flat_metadata=self.flat_metadata,
)
# vec0 metadata columns reject NULL (asg017/sqlite-vec#141): coerce
# every value to a string, with "" as the absent sentinel.
document_id = node.ref_doc_id or node.metadata.get("document_id")
return (
node.node_id,
str(document_id or ""),
str(node.metadata.get("modified") or ""),
json.dumps(meta),
_pack(node.get_embedding()),
)
def _index_chunks(self, rows: list[tuple[str, str, str, str, bytes]]) -> None:
"""Record each row's (chunk_id, document_id) in the document_chunks
side table, kept in lockstep with every insert into the vec0 table."""
self._conn.executemany(
_INSERT_CHUNK_INDEX,
[(chunk_id, document_id) for chunk_id, document_id, *_ in rows],
)
def _delete_chunks_by_document_id(self, document_id: str) -> None:
"""Delete all of a document's chunks via point-deletes on `id`.
vec0 has no efficient lookup on the document_id metadata column
outside a KNN query (see _open_connection), so a plain
`DELETE ... WHERE document_id = ?` is a full table scan regardless of
index size. Looking the chunk ids up in document_chunks first (a real
indexed lookup) and deleting each by its `id` primary key instead
turns that scan into a handful of O(1) point deletes.
"""
doc_id = str(document_id)
chunk_rows = self._conn.execute(
"SELECT chunk_id FROM document_chunks WHERE document_id = ?",
(doc_id,),
).fetchall()
self._conn.executemany(
"DELETE FROM " + DEFAULT_TABLE_NAME + " WHERE id = ?",
[(row["chunk_id"],) for row in chunk_rows],
)
self._conn.execute(
"DELETE FROM document_chunks WHERE document_id = ?",
(doc_id,),
)
def _increment_total_inserts(self, count: int) -> None:
"""Increment the cumulative insert counter stored in index_meta.
This counter never decreases (DELETEs do not decrement it) and is
used by compact() to estimate the bloat ratio: when total_inserts /
live_rows exceeds COMPACT_BLOAT_RATIO the table has accumulated
enough deleted-but-not-freed rows to warrant a rebuild.
"""
current = int(self._meta_get("total_inserts") or "0")
self._meta_set("total_inserts", str(current + count))
def add(self, nodes: Sequence[BaseNode], **add_kwargs: Any) -> list[str]:
if not nodes:
return []
rows = [self._row(node) for node in nodes]
with self._transaction():
self._ensure_table(len(nodes[0].get_embedding()))
self._conn.executemany(_INSERT, rows)
self._index_chunks(rows)
self._increment_total_inserts(len(rows))
return [node.node_id for node in nodes]
def upsert_document(self, document_id: str, nodes: list[BaseNode]) -> list[str]:
"""Atomically replace all stored chunks of ``document_id`` with ``nodes``.
One transaction deletes the document's existing rows and inserts the
new set (vec0's INSERT OR REPLACE is broken upstream, #259, so
delete+insert it is). WAL readers in other processes see either the
old or the new chunk set, never a partial state.
"""
rows = [self._row(node) for node in nodes]
with self._transaction():
if nodes:
self._ensure_table(len(nodes[0].get_embedding()))
if self.table_exists():
self._delete_chunks_by_document_id(document_id)
if rows:
self._conn.executemany(_INSERT, rows)
self._index_chunks(rows)
self._increment_total_inserts(len(rows))
return [node.node_id for node in nodes]
def delete(self, ref_doc_id: str, **delete_kwargs: Any) -> None:
if self.table_exists():
with self._transaction():
self._delete_chunks_by_document_id(ref_doc_id)
def _rows_to_nodes(self, rows: list[sqlite3.Row]) -> list[BaseNode]:
nodes: list[BaseNode] = []
for row in rows:
node = metadata_dict_to_node(json.loads(row["node_content"]))
node.embedding = _unpack(row["embedding"])
nodes.append(node)
return nodes
def get_nodes(
self,
node_ids: list[str] | None = None,
filters: MetadataFilters | None = None,
**kwargs: Any,
) -> list[BaseNode]:
if node_ids is not None: # pragma: no cover
# node_ids lookup is not implemented; see class docstring.
raise NotImplementedError(
"PaperlessSqliteVecVectorStore does not support node_ids lookup",
)
if not self.table_exists():
return []
where, params = _build_where(filters)
sql = "SELECT node_content, embedding FROM " + DEFAULT_TABLE_NAME
if where:
sql += " WHERE " + where
return self._rows_to_nodes(self._conn.execute(sql, params).fetchall())
def query(
self,
query: VectorStoreQuery,
**kwargs: Any,
) -> VectorStoreQueryResult:
if not self.table_exists():
return VectorStoreQueryResult(nodes=[], similarities=[], ids=[])
if query.query_embedding is None: # pragma: no cover
return VectorStoreQueryResult(nodes=[], similarities=[], ids=[])
top_k = query.similarity_top_k if query.similarity_top_k is not None else 10
where, params = _build_where(query.filters)
sql = (
"SELECT id, node_content, embedding, distance FROM "
+ DEFAULT_TABLE_NAME
+ " WHERE embedding MATCH ? AND k = ?"
)
if where:
sql += " AND " + where
rows = self._conn.execute(
sql,
[_pack(query.query_embedding), top_k, *params],
).fetchall()
# vec0 returns rows distance-sorted ascending; slice defensively in
# case future schema changes alter k semantics (e.g. partition keys
# return k rows per partition).
rows = rows[:top_k]
nodes = self._rows_to_nodes(rows)
# Cosine distance in [0, 2]; map to a descending similarity.
# vec0 returns None distance when the query embedding is the zero vector
# (no meaningful cosine angle); treat that as maximum distance (1.0) so
# the row is included but ranked last.
sims = [
1.0 - float(row["distance"] if row["distance"] is not None else 1.0)
for row in rows
]
ids = [row["id"] for row in rows]
return VectorStoreQueryResult(nodes=nodes, similarities=sims, ids=ids)
def get_modified_times(self) -> dict[str, str]:
"""Return {document_id: stored_modified_isoformat} for all indexed documents.
All chunks of a document share the same ``modified`` value, so the
first row seen per document is sufficient.
"""
if not self.table_exists():
return {}
result: dict[str, str] = {}
for row in self._conn.execute(
"SELECT document_id, modified FROM " + DEFAULT_TABLE_NAME,
):
doc_id = str(row["document_id"])
if doc_id not in result:
result[doc_id] = str(row["modified"] or "")
return result
@property
def _db_path(self) -> str:
return str(Path(self._uri) / DB_FILENAME)
@contextmanager
def _rebuild_file(self) -> Iterator[sqlite3.Connection]:
"""Open a fresh temp database file for a file-swap rebuild (compact
or structural migration), yielding its connection for the caller to
populate.
On success, swaps the temp file in as the live database (closing
this store's current connection first -- see _swap_in_compact()).
On any exception, discards the temp file, including its -wal/-shm,
instead, and this store's own connection is left untouched.
"""
compact_path = self._db_path + ".compact"
new_conn = self._open_connection(compact_path)
try:
yield new_conn
except BaseException:
new_conn.close()
for suffix in ["", "-wal", "-shm"]:
Path(compact_path + suffix).unlink(missing_ok=True)
raise
else:
new_conn.close()
self._swap_in_compact(compact_path, self._db_path)
@staticmethod
def _rebuild_into(
src_conn: sqlite3.Connection,
dst_conn: sqlite3.Connection,
dim: int,
meta_keys: tuple[str, ...] = ("dim", "embed_model", "schema_version"),
) -> int:
"""Create the vec0 table in ``dst_conn``, copy ``meta_keys`` from
``src_conn``'s index_meta, and stream every live row across
(populating document_chunks as it goes -- see _copy_rows()).
Returns the number of rows copied.
Used by both compact() (default meta_keys: the schema is unchanged)
and structural migrations (meta_keys minus "schema_version", which
the migration sets to its own target version instead of preserving
the source's).
"""
PaperlessSqliteVecVectorStore._create_vec_table(dst_conn, dim)
for key in meta_keys:
value = PaperlessSqliteVecVectorStore._meta_get_on(src_conn, key)
if value is not None:
PaperlessSqliteVecVectorStore._meta_set_on(dst_conn, key, value)
dst_conn.execute("BEGIN IMMEDIATE")
copied = _copy_rows(src_conn, dst_conn)
# Reset the cumulative counter: after a rebuild, total_inserts == live.
PaperlessSqliteVecVectorStore._meta_set_on(
dst_conn,
"total_inserts",
str(copied),
)
dst_conn.execute("COMMIT")
return copied
def compact(self, *, force: bool = False) -> None:
"""Rebuild the database file to reclaim space left behind by DELETEs.
vec0 DELETE only invalidates rows; the vector data stays in the file
forever (asg017/sqlite-vec#54), and per-document re-indexing is a
delete+insert. The cumulative insert counter in ``index_meta`` tracks
total rows ever written; when that exceeds ``COMPACT_BLOAT_RATIO`` x
the live row count (or when forced), live rows are copied into a fresh
database file and swapped in via ``os.replace``.
Note: ``ALTER TABLE ... RENAME TO`` on vec0 virtual tables does NOT
rename the shadow tables (sqlite-vec upstream limitation), so
an in-place rename-based rebuild is not safe. The file-swap approach
is the maintainer-endorsed workaround (asg017/sqlite-vec#205).
"""
if not self.table_exists():
return
live = self._conn.execute(
"SELECT count(*) FROM " + DEFAULT_TABLE_NAME,
).fetchone()[0]
total = int(self._meta_get("total_inserts") or str(live))
if not force and total <= max(live, 1) * COMPACT_BLOAT_RATIO:
return
dim = self.vector_dim()
if dim is None: # pragma: no cover - dim is written at creation
logger.warning("Skipping compact: no stored vector dimension")
return
logger.info(
"Compacting LLM index (%d live rows, %d cumulative inserts)",
live,
total,
)
with self._rebuild_file() as new_conn:
self._rebuild_into(self._conn, new_conn, dim)
def _swap_in_compact(self, compact_path: str, db_path: str) -> None:
"""Atomically replace the live database with the compacted copy."""
self._conn.close()
for suffix in ["-wal", "-shm"]:
stale = Path(compact_path + suffix)
if stale.exists(): # pragma: no cover
stale.unlink()
Path(compact_path).replace(db_path)
self._conn = self._open_connection(db_path)
def _stored_schema_version(self) -> int | None:
"""The schema_version recorded in index_meta, or None if no table
exists. A missing key (a store predating version tracking) is
treated as SCHEMA_VERSION -- i.e. already current -- since no
migration in MIGRATIONS targets a version before tracking began.
"""
if not self.table_exists():
return None
raw = self._meta_get("schema_version")
return int(raw) if raw is not None else SCHEMA_VERSION
def has_pending_migration(self) -> bool:
"""Cheaply check whether a migration is pending, with no exclusive
access needed -- just a metadata read under the connection callers
already hold via the write FileLock.
Callers should only pay for check_and_run_migrations()'s exclusive
access (a structural migration's file swap must not run while
readers are active) when this returns True, so that the common
case -- already at SCHEMA_VERSION -- never contends with readers
or a concurrent compaction.
"""
current = self._stored_schema_version()
return current is not None and current < SCHEMA_VERSION
def check_and_run_migrations(self) -> bool:
"""Apply any pending schema migrations to the store.
Structural migrations copy live rows into a new-schema file with no
re-embedding. Re-embed migrations cannot be applied automatically;
this method returns True when one is encountered so the caller can
force a full rebuild (which recreates the table at SCHEMA_VERSION).
Must be called under the write FileLock, with readers excluded (see
has_pending_migration() for a cheap pre-check that avoids paying for
that exclusion in the common case). No-op when the table does not
exist or is already at SCHEMA_VERSION.
"""
current = self._stored_schema_version()
if current is None or current >= SCHEMA_VERSION:
return False
pending = sorted(
[m for m in MIGRATIONS if current <= m.from_version < SCHEMA_VERSION],
key=lambda m: m.from_version,
)
for migration in pending:
if migration.kind == "re-embed":
logger.warning(
"LLM index schema v%d -> v%d requires re-embedding (%s); "
"the caller must force a rebuild.",
migration.from_version,
migration.to_version,
migration.description,
)
return True
logger.info(
"Running structural LLM index migration v%d -> v%d: %s",
migration.from_version,
migration.to_version,
migration.description,
)
self._run_structural_migration(migration)
return False
def _run_structural_migration(self, migration: Migration) -> None:
"""Execute a structural migration using the same file-swap as compact()."""
assert migration.apply is not None, "structural migration must have apply()"
dim = self.vector_dim()
if dim is None: # pragma: no cover
raise RuntimeError("Cannot migrate: no stored vector dimension")
with self._rebuild_file() as new_conn:
migration.apply(self._conn, new_conn, dim)
self._meta_set_on(new_conn, "schema_version", str(migration.to_version))
# Registers m0001 into MIGRATIONS; must be at the bottom (needs
# PaperlessSqliteVecVectorStore fully defined) -- see
# paperless_ai/migrations/__init__.py for the full procedure.
from paperless_ai.migrations import m0001_add_document_chunks # noqa: E402, F401