llama-stack/llama_stack/providers/inline/meta_reference/memory/faiss.py
2024-11-06 14:54:05 -08:00

141 lines
4.3 KiB
Python

# Copyright (c) Meta Platforms, Inc. and affiliates.
# All rights reserved.
#
# This source code is licensed under the terms described in the LICENSE file in
# the root directory of this source tree.
import logging
from typing import Any, Dict, List, Optional
import faiss
import numpy as np
from numpy.typing import NDArray
from llama_models.llama3.api.datatypes import * # noqa: F403
from llama_stack.apis.memory import * # noqa: F403
from llama_stack.providers.datatypes import MemoryBanksProtocolPrivate
from llama_stack.providers.utils.kvstore import kvstore_impl
from llama_stack.providers.utils.memory.vector_store import (
ALL_MINILM_L6_V2_DIMENSION,
BankWithIndex,
EmbeddingIndex,
)
from llama_stack.providers.utils.telemetry import tracing
from .config import FaissImplConfig
logger = logging.getLogger(__name__)
MEMORY_BANKS_PREFIX = "memory_banks:"
class FaissIndex(EmbeddingIndex):
id_by_index: Dict[int, str]
chunk_by_index: Dict[int, str]
def __init__(self, dimension: int):
self.index = faiss.IndexFlatL2(dimension)
self.id_by_index = {}
self.chunk_by_index = {}
@tracing.span(name="add_chunks")
async def add_chunks(self, chunks: List[Chunk], embeddings: NDArray):
indexlen = len(self.id_by_index)
for i, chunk in enumerate(chunks):
self.chunk_by_index[indexlen + i] = chunk
self.id_by_index[indexlen + i] = chunk.document_id
self.index.add(np.array(embeddings).astype(np.float32))
async def query(
self, embedding: NDArray, k: int, score_threshold: float
) -> QueryDocumentsResponse:
distances, indices = self.index.search(
embedding.reshape(1, -1).astype(np.float32), k
)
chunks = []
scores = []
for d, i in zip(distances[0], indices[0]):
if i < 0:
continue
chunks.append(self.chunk_by_index[int(i)])
scores.append(1.0 / float(d))
return QueryDocumentsResponse(chunks=chunks, scores=scores)
class FaissMemoryImpl(Memory, MemoryBanksProtocolPrivate):
def __init__(self, config: FaissImplConfig) -> None:
self.config = config
self.cache = {}
self.kvstore = None
async def initialize(self) -> None:
self.kvstore = await kvstore_impl(self.config.kvstore)
# Load existing banks from kvstore
start_key = MEMORY_BANKS_PREFIX
end_key = f"{MEMORY_BANKS_PREFIX}\xff"
stored_banks = await self.kvstore.range(start_key, end_key)
for bank_data in stored_banks:
bank = VectorMemoryBankDef.model_validate_json(bank_data)
index = BankWithIndex(
bank=bank, index=FaissIndex(ALL_MINILM_L6_V2_DIMENSION)
)
self.cache[bank.identifier] = index
async def shutdown(self) -> None:
# Cleanup if needed
pass
async def register_memory_bank(
self,
memory_bank: MemoryBankDef,
) -> None:
assert (
memory_bank.type == MemoryBankType.vector.value
), f"Only vector banks are supported {memory_bank.type}"
# Store in kvstore
key = f"{MEMORY_BANKS_PREFIX}{memory_bank.identifier}"
await self.kvstore.set(
key=key,
value=memory_bank.json(),
)
# Store in cache
index = BankWithIndex(
bank=memory_bank, index=FaissIndex(ALL_MINILM_L6_V2_DIMENSION)
)
self.cache[memory_bank.identifier] = index
async def list_memory_banks(self) -> List[MemoryBankDef]:
return [i.bank for i in self.cache.values()]
async def insert_documents(
self,
bank_id: str,
documents: List[MemoryBankDocument],
ttl_seconds: Optional[int] = None,
) -> None:
index = self.cache.get(bank_id)
if index is None:
raise ValueError(f"Bank {bank_id} not found")
await index.insert_documents(documents)
async def query_documents(
self,
bank_id: str,
query: InterleavedTextMedia,
params: Optional[Dict[str, Any]] = None,
) -> QueryDocumentsResponse:
index = self.cache.get(bank_id)
if index is None:
raise ValueError(f"Bank {bank_id} not found")
return await index.query_documents(query, params)