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Python

"""Hybrid search engine orchestrating parallel exact/fuzzy/vector searches with RRF fusion.
Coordinates multiple search backends in parallel using ThreadPoolExecutor and combines
results via Reciprocal Rank Fusion (RRF) algorithm.
"""
from __future__ import annotations
import logging
import time
from concurrent.futures import ThreadPoolExecutor, TimeoutError as FuturesTimeoutError, as_completed
from contextlib import contextmanager
from pathlib import Path
from typing import Any, Dict, List, Optional
@contextmanager
def timer(name: str, logger: logging.Logger, level: int = logging.DEBUG):
"""Context manager for timing code blocks.
Args:
name: Name of the operation being timed
logger: Logger instance to use
level: Logging level (default DEBUG)
"""
start = time.perf_counter()
try:
yield
finally:
elapsed_ms = (time.perf_counter() - start) * 1000
logger.log(level, "[TIMING] %s: %.2fms", name, elapsed_ms)
from codexlens.config import Config
from codexlens.config import VECTORS_HNSW_NAME
from codexlens.entities import SearchResult
from codexlens.search.ranking import (
DEFAULT_WEIGHTS,
FTS_FALLBACK_WEIGHTS,
QueryIntent,
apply_symbol_boost,
cross_encoder_rerank,
detect_query_intent,
filter_results_by_category,
get_rrf_weights,
reciprocal_rank_fusion,
rerank_results,
simple_weighted_fusion,
tag_search_source,
)
from codexlens.storage.dir_index import DirIndexStore
# Optional LSP imports (for real-time graph expansion)
try:
from codexlens.lsp import LspBridge, LspGraphBuilder
HAS_LSP = True
except ImportError:
HAS_LSP = False
# Three-way fusion weights (FTS + Vector + SPLADE)
THREE_WAY_WEIGHTS = {
"exact": 0.2,
"splade": 0.3,
"vector": 0.5,
}
class HybridSearchEngine:
"""Hybrid search engine with parallel execution and RRF fusion.
Orchestrates searches across exact FTS, fuzzy FTS, and optional vector backends,
executing them in parallel and fusing results via Reciprocal Rank Fusion.
Attributes:
logger: Python logger instance
default_weights: Default RRF weights for each source
"""
# NOTE: DEFAULT_WEIGHTS imported from ranking.py - single source of truth
# Default RRF weights: SPLADE-based hybrid (splade: 0.4, vector: 0.6)
# FTS fallback mode uses FTS_FALLBACK_WEIGHTS (exact: 0.3, fuzzy: 0.1, vector: 0.6)
def __init__(
self,
weights: Optional[Dict[str, float]] = None,
config: Optional[Config] = None,
embedder: Any = None,
):
"""Initialize hybrid search engine.
Args:
weights: Optional custom RRF weights (default: DEFAULT_WEIGHTS)
config: Optional runtime config (enables optional reranking features)
embedder: Optional embedder instance for embedding-based reranking
Raises:
TypeError: If weights is not a dict (e.g., if a Path is passed)
"""
self.logger = logging.getLogger(__name__)
# Validate weights type to catch common usage errors
if weights is not None and not isinstance(weights, dict):
raise TypeError(
f"weights must be a dict, got {type(weights).__name__}. "
f"Did you mean to pass index_path to search() instead of __init__()?"
)
self.weights = weights or DEFAULT_WEIGHTS.copy()
self._config = config
self.embedder = embedder
self.reranker: Any = None
self._use_gpu = config.embedding_use_gpu if config else True
def search(
self,
index_path: Path,
query: str,
limit: int = 20,
enable_fuzzy: bool = True,
enable_vector: bool = False,
pure_vector: bool = False,
enable_splade: bool = False,
enable_lsp_graph: bool = False,
lsp_max_depth: int = 1,
lsp_max_nodes: int = 20,
) -> List[SearchResult]:
"""Execute hybrid search with parallel retrieval and RRF fusion.
Args:
index_path: Path to _index.db file
query: FTS5 query string (for FTS) or natural language query (for vector)
limit: Maximum results to return after fusion
enable_fuzzy: Enable fuzzy FTS search (default True)
enable_vector: Enable vector search (default False)
pure_vector: If True, only use vector search without FTS fallback (default False)
enable_splade: If True, force SPLADE sparse neural search (default False)
enable_lsp_graph: If True, enable real-time LSP graph expansion (default False)
lsp_max_depth: Maximum depth for LSP graph BFS expansion (default 1)
lsp_max_nodes: Maximum nodes to collect in LSP graph (default 20)
Returns:
List of SearchResult objects sorted by fusion score
Examples:
>>> engine = HybridSearchEngine()
>>> # Hybrid search (exact + fuzzy + vector)
>>> results = engine.search(Path("project/_index.db"), "authentication",
... enable_vector=True)
>>> # Pure vector search (semantic only)
>>> results = engine.search(Path("project/_index.db"),
... "how to authenticate users",
... enable_vector=True, pure_vector=True)
>>> # SPLADE sparse neural search
>>> results = engine.search(Path("project/_index.db"), "auth flow",
... enable_splade=True, enable_vector=True)
>>> # With LSP graph expansion (real-time)
>>> results = engine.search(Path("project/_index.db"), "auth flow",
... enable_vector=True, enable_lsp_graph=True)
>>> for r in results[:5]:
... print(f"{r.path}: {r.score:.3f}")
"""
# Defensive: avoid creating/locking an index database when callers pass
# an empty placeholder file (common in tests and misconfigured callers).
try:
if index_path.exists() and index_path.stat().st_size == 0:
return []
except OSError:
return []
# Detect query intent early for category filtering at index level
query_intent = detect_query_intent(query)
# Map intent to category for vector search:
# - KEYWORD (code intent) -> filter to 'code' only
# - SEMANTIC (doc intent) -> no filter (allow docs to surface)
# - MIXED -> no filter (allow all)
vector_category: Optional[str] = None
if query_intent == QueryIntent.KEYWORD:
vector_category = "code"
# Determine which backends to use
backends = {}
# Check if SPLADE is available
splade_available = False
# Respect config.enable_splade flag and use_fts_fallback flag
if self._config and getattr(self._config, 'use_fts_fallback', False):
# Config explicitly requests FTS fallback - disable SPLADE
splade_available = False
elif self._config and not getattr(self._config, 'enable_splade', True):
# Config explicitly disabled SPLADE
splade_available = False
else:
# Check if SPLADE dependencies are available
try:
from codexlens.semantic.splade_encoder import check_splade_available
ok, _ = check_splade_available()
if ok:
# SPLADE tables are in main index database, will check table existence in _search_splade
splade_available = True
except Exception:
pass
if pure_vector:
# Pure vector mode: only use vector search, no FTS fallback
if enable_vector:
backends["vector"] = True
else:
# Invalid configuration: pure_vector=True but enable_vector=False
self.logger.warning(
"pure_vector=True requires enable_vector=True. "
"Falling back to exact search. "
"To use pure vector search, enable vector search mode."
)
backends["exact"] = True
elif enable_splade:
# Explicit SPLADE mode requested via CLI --method splade
if splade_available:
backends["splade"] = True
if enable_vector:
backends["vector"] = True
else:
# SPLADE requested but not available - warn and fallback
self.logger.warning(
"SPLADE search requested but not available. "
"Falling back to FTS. Run 'codexlens index splade' to enable."
)
backends["exact"] = True
if enable_fuzzy:
backends["fuzzy"] = True
if enable_vector:
backends["vector"] = True
else:
# Hybrid mode: default to SPLADE if available, otherwise use FTS
if splade_available:
# Default: enable SPLADE, disable exact and fuzzy
backends["splade"] = True
if enable_vector:
backends["vector"] = True
else:
# Fallback mode: enable exact+fuzzy when SPLADE unavailable
backends["exact"] = True
if enable_fuzzy:
backends["fuzzy"] = True
if enable_vector:
backends["vector"] = True
# Add LSP graph expansion if requested and available
if enable_lsp_graph and HAS_LSP:
backends["lsp_graph"] = True
elif enable_lsp_graph and not HAS_LSP:
self.logger.warning(
"LSP graph search requested but dependencies not available. "
"Install: pip install aiohttp"
)
# Execute parallel searches
with timer("parallel_search_total", self.logger):
results_map = self._search_parallel(
index_path, query, backends, limit, vector_category,
lsp_max_depth, lsp_max_nodes
)
# Provide helpful message if pure-vector mode returns no results
if pure_vector and enable_vector and len(results_map.get("vector", [])) == 0:
self.logger.warning(
"Pure vector search returned no results. "
"This usually means embeddings haven't been generated. "
"Run: codexlens embeddings-generate %s",
index_path.parent if index_path.name == "_index.db" else index_path
)
# Apply RRF fusion
# Filter weights to only active backends
active_weights = {
source: weight
for source, weight in self.weights.items()
if source in results_map
}
# Determine fusion method from config (default: rrf)
fusion_method = "rrf"
rrf_k = 60
if self._config is not None:
fusion_method = getattr(self._config, "fusion_method", "rrf") or "rrf"
rrf_k = getattr(self._config, "rrf_k", 60) or 60
with timer("fusion", self.logger):
adaptive_weights = get_rrf_weights(query, active_weights)
if fusion_method == "simple":
fused_results = simple_weighted_fusion(results_map, adaptive_weights)
else:
# Default to RRF
fused_results = reciprocal_rank_fusion(
results_map, adaptive_weights, k=rrf_k
)
# Optional: boost results that include explicit symbol matches
boost_factor = (
self._config.symbol_boost_factor
if self._config is not None
else 1.5
)
with timer("symbol_boost", self.logger):
fused_results = apply_symbol_boost(
fused_results, boost_factor=boost_factor
)
# Optional: embedding-based reranking on top results
if self._config is not None and self._config.enable_reranking:
with timer("reranking", self.logger):
if self.embedder is None:
self.embedder = self._get_reranking_embedder()
fused_results = rerank_results(
query,
fused_results[:100],
self.embedder,
top_k=(
100
if self._config.enable_cross_encoder_rerank
else self._config.reranking_top_k
),
)
# Optional: cross-encoder reranking as a second stage
if (
self._config is not None
and self._config.enable_reranking
and self._config.enable_cross_encoder_rerank
):
with timer("cross_encoder_rerank", self.logger):
if self.reranker is None:
self.reranker = self._get_cross_encoder_reranker()
if self.reranker is not None:
fused_results = cross_encoder_rerank(
query,
fused_results,
self.reranker,
top_k=self._config.reranker_top_k,
)
# Apply category filtering to avoid code/doc pollution
# This ensures KEYWORD queries return code files, SEMANTIC queries prefer docs
enable_category_filter = (
self._config is None
or getattr(self._config, 'enable_category_filter', True)
)
if enable_category_filter and not pure_vector:
with timer("category_filter", self.logger):
query_intent = detect_query_intent(query)
fused_results = filter_results_by_category(
fused_results, query_intent, allow_mixed=True
)
# Apply final limit
return fused_results[:limit]
def _get_reranking_embedder(self) -> Any:
"""Create an embedder for reranking based on Config embedding settings."""
if self._config is None:
return None
try:
from codexlens.semantic.factory import get_embedder
except Exception as exc:
self.logger.debug("Reranking embedder unavailable: %s", exc)
return None
try:
if self._config.embedding_backend == "fastembed":
return get_embedder(
backend="fastembed",
profile=self._config.embedding_model,
use_gpu=self._config.embedding_use_gpu,
)
if self._config.embedding_backend == "litellm":
return get_embedder(
backend="litellm",
model=self._config.embedding_model,
endpoints=self._config.embedding_endpoints,
strategy=self._config.embedding_strategy,
cooldown=self._config.embedding_cooldown,
)
except Exception as exc:
self.logger.debug("Failed to initialize reranking embedder: %s", exc)
return None
self.logger.debug(
"Unknown embedding backend for reranking: %s",
self._config.embedding_backend,
)
return None
def _get_cross_encoder_reranker(self) -> Any:
if self._config is None:
return None
try:
from codexlens.semantic.reranker import (
check_reranker_available,
get_reranker,
)
except Exception as exc:
self.logger.debug("Reranker factory unavailable: %s", exc)
return None
backend = (getattr(self._config, "reranker_backend", "") or "").strip().lower() or "onnx"
ok, err = check_reranker_available(backend)
if not ok:
self.logger.debug(
"Reranker backend unavailable (backend=%s): %s",
backend,
err,
)
return None
try:
model_name = (getattr(self._config, "reranker_model", "") or "").strip() or None
if backend != "legacy" and model_name == "cross-encoder/ms-marco-MiniLM-L-6-v2":
model_name = None
device: str | None = None
kwargs: dict[str, Any] = {}
if backend == "onnx":
kwargs["use_gpu"] = bool(getattr(self._config, "embedding_use_gpu", True))
elif backend == "legacy":
if not bool(getattr(self._config, "embedding_use_gpu", True)):
device = "cpu"
elif backend == "api":
# Pass max_input_tokens for adaptive batching
max_tokens = getattr(self._config, "reranker_max_input_tokens", None)
if max_tokens:
kwargs["max_input_tokens"] = max_tokens
return get_reranker(
backend=backend,
model_name=model_name,
device=device,
**kwargs,
)
except Exception as exc:
self.logger.debug(
"Failed to initialize reranker (backend=%s): %s",
backend,
exc,
)
return None
def _search_parallel(
self,
index_path: Path,
query: str,
backends: Dict[str, bool],
limit: int,
category: Optional[str] = None,
lsp_max_depth: int = 1,
lsp_max_nodes: int = 20,
) -> Dict[str, List[SearchResult]]:
"""Execute parallel searches across enabled backends.
Args:
index_path: Path to _index.db file
query: FTS5 query string
backends: Dictionary of backend name to enabled flag
limit: Results limit per backend
category: Optional category filter for vector search ('code' or 'doc')
lsp_max_depth: Maximum depth for LSP graph BFS expansion (default 1)
lsp_max_nodes: Maximum nodes to collect in LSP graph (default 20)
Returns:
Dictionary mapping source name to results list
"""
results_map: Dict[str, List[SearchResult]] = {}
timing_data: Dict[str, float] = {}
# Use ThreadPoolExecutor for parallel I/O-bound searches
with ThreadPoolExecutor(max_workers=len(backends)) as executor:
# Submit search tasks with timing
future_to_source = {}
submit_times = {}
if backends.get("exact"):
submit_times["exact"] = time.perf_counter()
future = executor.submit(
self._search_exact, index_path, query, limit
)
future_to_source[future] = "exact"
if backends.get("fuzzy"):
submit_times["fuzzy"] = time.perf_counter()
future = executor.submit(
self._search_fuzzy, index_path, query, limit
)
future_to_source[future] = "fuzzy"
if backends.get("vector"):
submit_times["vector"] = time.perf_counter()
future = executor.submit(
self._search_vector, index_path, query, limit, category
)
future_to_source[future] = "vector"
if backends.get("splade"):
submit_times["splade"] = time.perf_counter()
future = executor.submit(
self._search_splade, index_path, query, limit
)
future_to_source[future] = "splade"
if backends.get("lsp_graph"):
submit_times["lsp_graph"] = time.perf_counter()
future = executor.submit(
self._search_lsp_graph, index_path, query, limit,
lsp_max_depth, lsp_max_nodes
)
future_to_source[future] = "lsp_graph"
# Collect results as they complete with timeout protection
try:
for future in as_completed(future_to_source, timeout=30.0):
source = future_to_source[future]
elapsed_ms = (time.perf_counter() - submit_times[source]) * 1000
timing_data[source] = elapsed_ms
try:
results = future.result(timeout=10.0)
# Tag results with source for debugging
tagged_results = tag_search_source(results, source)
results_map[source] = tagged_results
self.logger.debug(
"[TIMING] %s_search: %.2fms (%d results)",
source, elapsed_ms, len(results)
)
except (Exception, FuturesTimeoutError) as exc:
self.logger.error("Search failed for %s: %s", source, exc)
results_map[source] = []
except FuturesTimeoutError:
self.logger.warning("Search timeout: some backends did not respond in time")
# Cancel remaining futures
for future in future_to_source:
future.cancel()
# Set empty results for sources that didn't complete
for source in backends:
if source not in results_map:
results_map[source] = []
# Log timing summary
if timing_data:
timing_str = ", ".join(f"{k}={v:.1f}ms" for k, v in timing_data.items())
self.logger.debug("[TIMING] search_backends: {%s}", timing_str)
return results_map
def _search_exact(
self, index_path: Path, query: str, limit: int
) -> List[SearchResult]:
"""Execute exact FTS search using unicode61 tokenizer.
Args:
index_path: Path to _index.db file
query: FTS5 query string
limit: Maximum results
Returns:
List of SearchResult objects
"""
try:
with DirIndexStore(index_path) as store:
return store.search_fts_exact(
query, limit=limit, return_full_content=True
)
except Exception as exc:
self.logger.debug("Exact search error: %s", exc)
return []
def _search_fuzzy(
self, index_path: Path, query: str, limit: int
) -> List[SearchResult]:
"""Execute fuzzy FTS search using trigram/extended unicode61 tokenizer.
Args:
index_path: Path to _index.db file
query: FTS5 query string
limit: Maximum results
Returns:
List of SearchResult objects
"""
try:
with DirIndexStore(index_path) as store:
return store.search_fts_fuzzy(
query, limit=limit, return_full_content=True
)
except Exception as exc:
self.logger.debug("Fuzzy search error: %s", exc)
return []
def _find_vectors_hnsw(self, index_path: Path) -> Optional[Path]:
"""Find the centralized _vectors.hnsw file by traversing up from index_path.
Similar to _search_splade's approach, this method searches for the
centralized dense vector index file in parent directories.
Args:
index_path: Path to the current _index.db file
Returns:
Path to _vectors.hnsw if found, None otherwise
"""
current_dir = index_path.parent
for _ in range(10): # Limit search depth
candidate = current_dir / VECTORS_HNSW_NAME
if candidate.exists():
return candidate
parent = current_dir.parent
if parent == current_dir: # Reached root
break
current_dir = parent
return None
def _search_vector_centralized(
self,
index_path: Path,
hnsw_path: Path,
query: str,
limit: int,
category: Optional[str] = None,
) -> List[SearchResult]:
"""Search using centralized vector index.
Args:
index_path: Path to _index.db file (for metadata lookup)
hnsw_path: Path to centralized _vectors.hnsw file
query: Natural language query string
limit: Maximum results
category: Optional category filter ('code' or 'doc')
Returns:
List of SearchResult objects ordered by semantic similarity
"""
try:
import sqlite3
import json
from codexlens.semantic.factory import get_embedder
from codexlens.semantic.ann_index import ANNIndex
# Get model config from the first index database we can find
# (all indexes should use the same embedding model)
index_root = hnsw_path.parent
model_config = None
# Try to get model config from the centralized index root first
# (not the sub-directory index_path, which may have outdated config)
try:
from codexlens.semantic.vector_store import VectorStore
central_index_path = index_root / "_index.db"
if central_index_path.exists():
with VectorStore(central_index_path) as vs:
model_config = vs.get_model_config()
self.logger.debug(
"Loaded model config from centralized index: %s",
model_config
)
except Exception as e:
self.logger.debug("Failed to load model config from centralized index: %s", e)
# Detect dimension from HNSW file if model config not found
if model_config is None:
self.logger.debug("Model config not found, will detect from HNSW index")
# Create a temporary ANNIndex to load and detect dimension
# We need to know the dimension to properly load the index
# Get embedder based on model config or default
if model_config:
backend = model_config.get("backend", "fastembed")
model_name = model_config["model_name"]
model_profile = model_config["model_profile"]
embedding_dim = model_config["embedding_dim"]
if backend == "litellm":
embedder = get_embedder(backend="litellm", model=model_name)
else:
embedder = get_embedder(backend="fastembed", profile=model_profile)
else:
# Default to code profile
embedder = get_embedder(backend="fastembed", profile="code")
embedding_dim = embedder.embedding_dim
# Load centralized ANN index
start_load = time.perf_counter()
ann_index = ANNIndex.create_central(
index_root=index_root,
dim=embedding_dim,
)
if not ann_index.load():
self.logger.warning("Failed to load centralized vector index from %s", hnsw_path)
return []
self.logger.debug(
"[TIMING] central_ann_load: %.2fms (%d vectors)",
(time.perf_counter() - start_load) * 1000,
ann_index.count()
)
# Generate query embedding
start_embed = time.perf_counter()
query_embedding = embedder.embed_single(query)
self.logger.debug(
"[TIMING] query_embedding: %.2fms",
(time.perf_counter() - start_embed) * 1000
)
# Search ANN index
start_search = time.perf_counter()
import numpy as np
query_vec = np.array(query_embedding, dtype=np.float32)
ids, distances = ann_index.search(query_vec, top_k=limit * 2) # Fetch extra for filtering
self.logger.debug(
"[TIMING] central_ann_search: %.2fms (%d results)",
(time.perf_counter() - start_search) * 1000,
len(ids) if ids else 0
)
if not ids:
return []
# Convert distances to similarity scores (for cosine: score = 1 - distance)
scores = [1.0 - d for d in distances]
# Fetch chunk metadata from semantic_chunks tables
# We need to search across all _index.db files in the project
results = self._fetch_chunks_by_ids_centralized(
index_root, ids, scores, category
)
return results[:limit]
except ImportError as exc:
self.logger.debug("Semantic dependencies not available: %s", exc)
return []
except Exception as exc:
self.logger.error("Centralized vector search error: %s", exc)
return []
def _fetch_chunks_by_ids_centralized(
self,
index_root: Path,
chunk_ids: List[int],
scores: List[float],
category: Optional[str] = None,
) -> List[SearchResult]:
"""Fetch chunk metadata from centralized _vectors_meta.db for fast lookup.
This method uses the centralized VectorMetadataStore for O(1) lookup
instead of traversing all _index.db files (O(n) where n = number of indexes).
Falls back to the legacy per-index lookup if centralized metadata is unavailable.
Args:
index_root: Root directory containing _vectors_meta.db
chunk_ids: List of chunk IDs from ANN search
scores: Corresponding similarity scores
category: Optional category filter
Returns:
List of SearchResult objects
"""
from codexlens.config import VECTORS_META_DB_NAME
# Build score map
score_map = {cid: score for cid, score in zip(chunk_ids, scores)}
# Try centralized metadata store first (fast path)
vectors_meta_path = index_root / VECTORS_META_DB_NAME
if vectors_meta_path.exists():
try:
return self._fetch_from_vector_meta_store(
vectors_meta_path, chunk_ids, score_map, category
)
except Exception as e:
self.logger.warning(
"Centralized metadata lookup failed, falling back to legacy traversal: %s. "
"Consider regenerating embeddings with: codexlens embeddings-generate --centralized",
e
)
# Fallback: traverse _index.db files (legacy path)
return self._fetch_chunks_by_ids_legacy(
index_root, chunk_ids, score_map, category
)
def _fetch_from_vector_meta_store(
self,
meta_db_path: Path,
chunk_ids: List[int],
score_map: Dict[int, float],
category: Optional[str] = None,
) -> List[SearchResult]:
"""Fetch chunks from centralized VectorMetadataStore.
Args:
meta_db_path: Path to _vectors_meta.db
chunk_ids: List of chunk IDs to fetch
score_map: Mapping of chunk_id to score
category: Optional category filter
Returns:
List of SearchResult objects
"""
from codexlens.storage.vector_meta_store import VectorMetadataStore
results = []
with VectorMetadataStore(meta_db_path) as meta_store:
rows = meta_store.get_chunks_by_ids(chunk_ids, category=category)
for row in rows:
chunk_id = row["chunk_id"]
file_path = row["file_path"]
content = row["content"] or ""
metadata = row.get("metadata") or {}
start_line = row.get("start_line")
end_line = row.get("end_line")
score = score_map.get(chunk_id, 0.0)
# Build excerpt
excerpt = content[:200] + "..." if len(content) > 200 else content
# Extract symbol information
symbol_name = metadata.get("symbol_name")
symbol_kind = metadata.get("symbol_kind")
# Build Symbol object if available
symbol = None
if symbol_name and symbol_kind and start_line and end_line:
try:
from codexlens.entities import Symbol
symbol = Symbol(
name=symbol_name,
kind=symbol_kind,
range=(start_line, end_line)
)
except Exception:
pass
results.append(SearchResult(
path=file_path,
score=score,
excerpt=excerpt,
content=content,
symbol=symbol,
metadata=metadata,
start_line=start_line,
end_line=end_line,
symbol_name=symbol_name,
symbol_kind=symbol_kind,
))
# Sort by score descending
results.sort(key=lambda r: r.score, reverse=True)
return results
def _fetch_chunks_by_ids_legacy(
self,
index_root: Path,
chunk_ids: List[int],
score_map: Dict[int, float],
category: Optional[str] = None,
) -> List[SearchResult]:
"""Legacy fallback: fetch chunk metadata by traversing all _index.db files.
This is the O(n) fallback path used when centralized metadata is unavailable.
Args:
index_root: Root directory containing _index.db files
chunk_ids: List of chunk IDs from ANN search
score_map: Mapping of chunk_id to score
category: Optional category filter
Returns:
List of SearchResult objects
"""
import sqlite3
import json
# Find all _index.db files
index_files = list(index_root.rglob("_index.db"))
results = []
found_ids = set()
for index_path in index_files:
try:
with sqlite3.connect(index_path) as conn:
conn.row_factory = sqlite3.Row
# Check if semantic_chunks table exists
cursor = conn.execute(
"SELECT name FROM sqlite_master WHERE type='table' AND name='semantic_chunks'"
)
if cursor.fetchone() is None:
continue
# Build query for chunk IDs we haven't found yet
remaining_ids = [cid for cid in chunk_ids if cid not in found_ids]
if not remaining_ids:
break
placeholders = ",".join("?" * len(remaining_ids))
if category:
query = f"""
SELECT id, file_path, content, metadata
FROM semantic_chunks
WHERE id IN ({placeholders}) AND category = ?
"""
params = remaining_ids + [category]
else:
query = f"""
SELECT id, file_path, content, metadata
FROM semantic_chunks
WHERE id IN ({placeholders})
"""
params = remaining_ids
rows = conn.execute(query, params).fetchall()
for row in rows:
chunk_id = row["id"]
if chunk_id in found_ids:
continue
found_ids.add(chunk_id)
file_path = row["file_path"]
content = row["content"]
metadata_json = row["metadata"]
metadata = json.loads(metadata_json) if metadata_json else {}
score = score_map.get(chunk_id, 0.0)
# Build excerpt
excerpt = content[:200] + "..." if len(content) > 200 else content
# Extract symbol information
symbol_name = metadata.get("symbol_name")
symbol_kind = metadata.get("symbol_kind")
start_line = metadata.get("start_line")
end_line = metadata.get("end_line")
# Build Symbol object if available
symbol = None
if symbol_name and symbol_kind and start_line and end_line:
try:
from codexlens.entities import Symbol
symbol = Symbol(
name=symbol_name,
kind=symbol_kind,
range=(start_line, end_line)
)
except Exception:
pass
results.append(SearchResult(
path=file_path,
score=score,
excerpt=excerpt,
content=content,
symbol=symbol,
metadata=metadata,
start_line=start_line,
end_line=end_line,
symbol_name=symbol_name,
symbol_kind=symbol_kind,
))
except Exception as e:
self.logger.debug("Failed to fetch chunks from %s: %s", index_path, e)
continue
# Sort by score descending
results.sort(key=lambda r: r.score, reverse=True)
return results
def _search_vector(
self, index_path: Path, query: str, limit: int, category: Optional[str] = None
) -> List[SearchResult]:
"""Execute vector similarity search using semantic embeddings.
Supports both centralized vector storage (single _vectors.hnsw at project root)
and distributed storage (per-directory .hnsw files).
Args:
index_path: Path to _index.db file
query: Natural language query string
limit: Maximum results
category: Optional category filter ('code' or 'doc')
Returns:
List of SearchResult objects ordered by semantic similarity
"""
try:
# First, check for centralized vector index
central_hnsw_path = self._find_vectors_hnsw(index_path)
if central_hnsw_path is not None:
self.logger.debug("Found centralized vector index at %s", central_hnsw_path)
return self._search_vector_centralized(
index_path, central_hnsw_path, query, limit, category
)
# Fallback to distributed (per-index) vector storage
# Check if semantic chunks table exists
import sqlite3
start_check = time.perf_counter()
try:
with sqlite3.connect(index_path) as conn:
cursor = conn.execute(
"SELECT name FROM sqlite_master WHERE type='table' AND name='semantic_chunks'"
)
has_semantic_table = cursor.fetchone() is not None
except sqlite3.Error as e:
self.logger.error("Database check failed in vector search: %s", e)
return []
self.logger.debug(
"[TIMING] vector_table_check: %.2fms",
(time.perf_counter() - start_check) * 1000
)
if not has_semantic_table:
self.logger.info(
"No embeddings found in index. "
"Generate embeddings with: codexlens embeddings-generate %s",
index_path.parent if index_path.name == "_index.db" else index_path
)
return []
# Initialize embedder and vector store
from codexlens.semantic.factory import get_embedder
from codexlens.semantic.vector_store import VectorStore
start_init = time.perf_counter()
vector_store = VectorStore(index_path)
self.logger.debug(
"[TIMING] vector_store_init: %.2fms",
(time.perf_counter() - start_init) * 1000
)
# Check if vector store has data
if vector_store.count_chunks() == 0:
self.logger.info(
"Vector store is empty (0 chunks). "
"Generate embeddings with: codexlens embeddings-generate %s",
index_path.parent if index_path.name == "_index.db" else index_path
)
return []
# Get stored model configuration (preferred) or auto-detect from dimension
start_embedder = time.perf_counter()
model_config = vector_store.get_model_config()
if model_config:
backend = model_config.get("backend", "fastembed")
model_name = model_config["model_name"]
model_profile = model_config["model_profile"]
self.logger.debug(
"Using stored model config: %s backend, %s (%s, %dd)",
backend, model_profile, model_name, model_config["embedding_dim"]
)
# Get embedder based on backend
if backend == "litellm":
embedder = get_embedder(backend="litellm", model=model_name)
else:
embedder = get_embedder(backend="fastembed", profile=model_profile)
else:
# Fallback: auto-detect from embedding dimension
detected_dim = vector_store.dimension
if detected_dim is None:
self.logger.info("Vector store dimension unknown, using default profile")
embedder = get_embedder(backend="fastembed", profile="code")
elif detected_dim == 384:
embedder = get_embedder(backend="fastembed", profile="fast")
elif detected_dim == 768:
embedder = get_embedder(backend="fastembed", profile="code")
elif detected_dim == 1024:
embedder = get_embedder(backend="fastembed", profile="multilingual")
elif detected_dim == 1536:
# Likely OpenAI text-embedding-3-small or ada-002
self.logger.info(
"Detected 1536-dim embeddings (likely OpenAI), using litellm backend with text-embedding-3-small"
)
embedder = get_embedder(backend="litellm", model="text-embedding-3-small")
elif detected_dim == 3072:
# Likely OpenAI text-embedding-3-large
self.logger.info(
"Detected 3072-dim embeddings (likely OpenAI), using litellm backend with text-embedding-3-large"
)
embedder = get_embedder(backend="litellm", model="text-embedding-3-large")
else:
self.logger.debug(
"Unknown dimension %s, using default fastembed profile 'code'",
detected_dim
)
embedder = get_embedder(backend="fastembed", profile="code")
self.logger.debug(
"[TIMING] embedder_init: %.2fms",
(time.perf_counter() - start_embedder) * 1000
)
# Generate query embedding
start_embed = time.perf_counter()
query_embedding = embedder.embed_single(query)
self.logger.debug(
"[TIMING] query_embedding: %.2fms",
(time.perf_counter() - start_embed) * 1000
)
# Search for similar chunks
start_search = time.perf_counter()
results = vector_store.search_similar(
query_embedding=query_embedding,
top_k=limit,
min_score=0.0, # Return all results, let RRF handle filtering
return_full_content=True,
category=category,
)
self.logger.debug(
"[TIMING] vector_similarity_search: %.2fms (%d results)",
(time.perf_counter() - start_search) * 1000, len(results)
)
return results
except ImportError as exc:
self.logger.debug("Semantic dependencies not available: %s", exc)
return []
except Exception as exc:
self.logger.error("Vector search error: %s", exc)
return []
def _search_splade(
self, index_path: Path, query: str, limit: int
) -> List[SearchResult]:
"""SPLADE sparse retrieval via inverted index.
Args:
index_path: Path to _index.db file
query: Natural language query string
limit: Maximum results
Returns:
List of SearchResult ordered by SPLADE score
"""
try:
from codexlens.semantic.splade_encoder import get_splade_encoder, check_splade_available
from codexlens.storage.splade_index import SpladeIndex
from codexlens.config import SPLADE_DB_NAME
import sqlite3
import json
# Check dependencies
ok, err = check_splade_available()
if not ok:
self.logger.debug("SPLADE not available: %s", err)
return []
# SPLADE index is stored in _splade.db at the project index root
# Traverse up from the current index to find the root _splade.db
current_dir = index_path.parent
splade_db_path = None
for _ in range(10): # Limit search depth
candidate = current_dir / SPLADE_DB_NAME
if candidate.exists():
splade_db_path = candidate
break
parent = current_dir.parent
if parent == current_dir: # Reached root
break
current_dir = parent
if not splade_db_path:
self.logger.debug("SPLADE index not found in ancestor directories of %s", index_path)
return []
splade_index = SpladeIndex(splade_db_path)
if not splade_index.has_index():
self.logger.debug("SPLADE index not initialized")
return []
# Encode query to sparse vector
encoder = get_splade_encoder(use_gpu=self._use_gpu)
query_sparse = encoder.encode_text(query)
# Search inverted index for top matches
raw_results = splade_index.search(query_sparse, limit=limit, min_score=0.0)
if not raw_results:
return []
# Fetch chunk details from splade_chunks table (self-contained)
chunk_ids = [chunk_id for chunk_id, _ in raw_results]
score_map = {chunk_id: score for chunk_id, score in raw_results}
# Get chunk metadata from SPLADE database
rows = splade_index.get_chunks_by_ids(chunk_ids)
# Build SearchResult objects
results = []
for row in rows:
chunk_id = row["id"]
file_path = row["file_path"]
content = row["content"]
metadata_json = row["metadata"]
metadata = json.loads(metadata_json) if metadata_json else {}
score = score_map.get(chunk_id, 0.0)
# Build excerpt (short preview)
excerpt = content[:200] + "..." if len(content) > 200 else content
# Extract symbol information from metadata
symbol_name = metadata.get("symbol_name")
symbol_kind = metadata.get("symbol_kind")
start_line = metadata.get("start_line")
end_line = metadata.get("end_line")
# Build Symbol object if we have symbol info
symbol = None
if symbol_name and symbol_kind and start_line and end_line:
try:
from codexlens.entities import Symbol
symbol = Symbol(
name=symbol_name,
kind=symbol_kind,
range=(start_line, end_line)
)
except Exception:
pass
results.append(SearchResult(
path=file_path,
score=score,
excerpt=excerpt,
content=content,
symbol=symbol,
metadata=metadata,
start_line=start_line,
end_line=end_line,
symbol_name=symbol_name,
symbol_kind=symbol_kind,
))
return results
except Exception as exc:
self.logger.debug("SPLADE search error: %s", exc)
return []
def _search_lsp_graph(
self,
index_path: Path,
query: str,
limit: int,
max_depth: int = 1,
max_nodes: int = 20,
) -> List[SearchResult]:
"""Execute LSP-based graph expansion search.
Uses real-time LSP to expand from seed results and find related code.
This provides accurate, up-to-date code relationships.
Args:
index_path: Path to _index.db file
query: Natural language query string
limit: Maximum results
max_depth: Maximum depth for LSP graph BFS expansion (default 1)
max_nodes: Maximum nodes to collect in LSP graph (default 20)
Returns:
List of SearchResult from graph expansion
"""
import asyncio
if not HAS_LSP:
self.logger.debug("LSP dependencies not available")
return []
try:
# Try multiple seed sources in priority order
seeds = []
seed_source = "none"
# 1. Try vector search first (best semantic match)
seeds = self._search_vector(index_path, query, limit=3, category="code")
if seeds:
seed_source = "vector"
# 2. Fallback to SPLADE if vector returns nothing
if not seeds:
self.logger.debug("Vector search returned no seeds, trying SPLADE")
seeds = self._search_splade(index_path, query, limit=3)
if seeds:
seed_source = "splade"
# 3. Fallback to exact FTS if SPLADE also fails
if not seeds:
self.logger.debug("SPLADE returned no seeds, trying exact FTS")
seeds = self._search_exact(index_path, query, limit=3)
if seeds:
seed_source = "exact_fts"
# 4. No seeds available from any source
if not seeds:
self.logger.debug("No seed results available for LSP graph expansion")
return []
self.logger.debug(
"LSP graph expansion using %d seeds from %s",
len(seeds),
seed_source,
)
# Convert SearchResult to CodeSymbolNode for LSP processing
from codexlens.hybrid_search.data_structures import CodeSymbolNode, Range
seed_nodes = []
for seed in seeds:
try:
node = CodeSymbolNode(
id=f"{seed.path}:{seed.symbol_name or 'unknown'}:{seed.start_line or 0}",
name=seed.symbol_name or "unknown",
kind=seed.symbol_kind or "unknown",
file_path=seed.path,
range=Range(
start_line=seed.start_line or 1,
start_character=0,
end_line=seed.end_line or seed.start_line or 1,
end_character=0,
),
raw_code=seed.content or "",
docstring=seed.excerpt or "",
)
seed_nodes.append(node)
except Exception as e:
self.logger.debug("Failed to create seed node: %s", e)
continue
if not seed_nodes:
return []
# Run async LSP expansion in sync context
async def expand_graph():
async with LspBridge() as bridge:
builder = LspGraphBuilder(max_depth=max_depth, max_nodes=max_nodes)
graph = await builder.build_from_seeds(seed_nodes, bridge)
return graph
# Run the async code
try:
loop = asyncio.get_event_loop()
if loop.is_running():
# Already in async context - use run_coroutine_threadsafe
import concurrent.futures
future = asyncio.run_coroutine_threadsafe(expand_graph(), loop)
graph = future.result(timeout=5.0)
else:
graph = loop.run_until_complete(expand_graph())
except RuntimeError:
# No event loop - create new one
graph = asyncio.run(expand_graph())
# Convert graph nodes to SearchResult
# Create set of seed identifiers for fast lookup
seed_ids = set()
for seed in seeds:
seed_id = f"{seed.path}:{seed.symbol_name or 'unknown'}:{seed.start_line or 0}"
seed_ids.add(seed_id)
results = []
for node_id, node in graph.nodes.items():
# Skip seed nodes using ID comparison (already in other results)
if node_id in seed_ids or node.id in seed_ids:
continue
# Calculate score based on graph position
# Nodes closer to seeds get higher scores
depth = 1 # Simple heuristic, could be improved
score = 0.8 / (1 + depth) # Score decreases with depth
results.append(SearchResult(
path=node.file_path,
score=score,
excerpt=node.docstring[:200] if node.docstring else node.raw_code[:200] if node.raw_code else "",
content=node.raw_code,
symbol=None,
metadata={"lsp_node_id": node_id, "lsp_kind": node.kind},
start_line=node.range.start_line,
end_line=node.range.end_line,
symbol_name=node.name,
symbol_kind=node.kind,
))
# Sort by score
results.sort(key=lambda r: r.score, reverse=True)
return results[:limit]
except Exception as exc:
self.logger.debug("LSP graph search error: %s", exc)
return []