Files
LEANN/packages/leann-backend-diskann/leann_backend_diskann/diskann_backend.py
Andy Lee fecee94af1 Experiments (#68)
* feat: finance bench

* docs: results

* chore: ignroe data README

* feat: fix financebench

* feat: laion, also required idmaps support

* style: format

* style: format

* fix: resolve ruff linting errors

- Remove unused variables in benchmark scripts
- Rename unused loop variables to follow convention

* feat: enron email bench

* experiments for running DiskANN & BM25 on Arch 4090

* style: format

* chore(ci): remove paru-bin submodule and config to fix checkout --recurse-submodules

* docs: data

* docs: data updated

* fix: as package

* fix(ci): only run pre-commit

* chore: use http url of astchunk; use group for some dev deps

* fix(ci): should checkout modules as well since `uv sync` checks

* fix(ci): run with lint only

* fix: find links to install wheels available

* CI: force local wheels in uv install step

* CI: install local wheels via file paths

* CI: pick wheels matching current Python tag

* CI: handle python tag mismatches for local wheels

* CI: use matrix python venv and set macOS deployment target

* CI: revert install step to match main

* CI: use uv group install with local wheel selection

* CI: rely on setup-uv for Python and tighten group install

* CI: install build deps with uv python interpreter

* CI: use temporary uv venv for build deps

* CI: add build venv scripts path for wheel repair
2025-09-24 11:19:04 -07:00

473 lines
19 KiB
Python

import contextlib
import logging
import os
import struct
import sys
from pathlib import Path
from typing import Any, Literal, Optional
import numpy as np
import psutil
from leann.interface import (
LeannBackendBuilderInterface,
LeannBackendFactoryInterface,
LeannBackendSearcherInterface,
)
from leann.registry import register_backend
from leann.searcher_base import BaseSearcher
logger = logging.getLogger(__name__)
@contextlib.contextmanager
def suppress_cpp_output_if_needed():
"""Suppress C++ stdout/stderr based on LEANN_LOG_LEVEL"""
# In CI we avoid fiddling with low-level file descriptors to prevent aborts
if os.getenv("CI") == "true":
yield
return
log_level = os.getenv("LEANN_LOG_LEVEL", "WARNING").upper()
# Only suppress if log level is WARNING or higher (ERROR, CRITICAL)
should_suppress = log_level in ["WARNING", "ERROR", "CRITICAL"]
if not should_suppress:
# Don't suppress, just yield
yield
return
# Save original file descriptors
stdout_fd = sys.stdout.fileno()
stderr_fd = sys.stderr.fileno()
# Save original stdout/stderr
stdout_dup = os.dup(stdout_fd)
stderr_dup = os.dup(stderr_fd)
try:
# Redirect to /dev/null
devnull = os.open(os.devnull, os.O_WRONLY)
os.dup2(devnull, stdout_fd)
os.dup2(devnull, stderr_fd)
os.close(devnull)
yield
finally:
# Restore original file descriptors
os.dup2(stdout_dup, stdout_fd)
os.dup2(stderr_dup, stderr_fd)
os.close(stdout_dup)
os.close(stderr_dup)
def _get_diskann_metrics():
from . import _diskannpy as diskannpy # type: ignore
return {
"mips": diskannpy.Metric.INNER_PRODUCT,
"l2": diskannpy.Metric.L2,
"cosine": diskannpy.Metric.COSINE,
}
@contextlib.contextmanager
def chdir(path):
original_dir = os.getcwd()
os.chdir(path)
try:
yield
finally:
os.chdir(original_dir)
def _write_vectors_to_bin(data: np.ndarray, file_path: Path):
num_vectors, dim = data.shape
with open(file_path, "wb") as f:
f.write(struct.pack("I", num_vectors))
f.write(struct.pack("I", dim))
f.write(data.tobytes())
def _calculate_smart_memory_config(data: np.ndarray) -> tuple[float, float]:
"""
Calculate smart memory configuration for DiskANN based on data size and system specs.
Args:
data: The embedding data array
Returns:
tuple: (search_memory_maximum, build_memory_maximum) in GB
"""
num_vectors, dim = data.shape
# Calculate embedding storage size
embedding_size_bytes = num_vectors * dim * 4 # float32 = 4 bytes
embedding_size_gb = embedding_size_bytes / (1024**3)
# search_memory_maximum: 1/10 of embedding size for optimal PQ compression
# This controls Product Quantization size - smaller means more compression
search_memory_gb = max(0.1, embedding_size_gb / 10) # At least 100MB
# build_memory_maximum: Based on available system RAM for sharding control
# This controls how much memory DiskANN uses during index construction
available_memory_gb = psutil.virtual_memory().available / (1024**3)
total_memory_gb = psutil.virtual_memory().total / (1024**3)
# Use 50% of available memory, but at least 2GB and at most 75% of total
build_memory_gb = max(2.0, min(available_memory_gb * 0.5, total_memory_gb * 0.75))
logger.info(
f"Smart memory config - Data: {embedding_size_gb:.2f}GB, "
f"Search mem: {search_memory_gb:.2f}GB (PQ control), "
f"Build mem: {build_memory_gb:.2f}GB (sharding control)"
)
return search_memory_gb, build_memory_gb
@register_backend("diskann")
class DiskannBackend(LeannBackendFactoryInterface):
@staticmethod
def builder(**kwargs) -> LeannBackendBuilderInterface:
return DiskannBuilder(**kwargs)
@staticmethod
def searcher(index_path: str, **kwargs) -> LeannBackendSearcherInterface:
return DiskannSearcher(index_path, **kwargs)
class DiskannBuilder(LeannBackendBuilderInterface):
def __init__(self, **kwargs):
self.build_params = kwargs
def _safe_cleanup_after_partition(self, index_dir: Path, index_prefix: str):
"""
Safely cleanup files after partition.
In partition mode, C++ doesn't read _disk.index content,
so we can delete it if all derived files exist.
"""
disk_index_file = index_dir / f"{index_prefix}_disk.index"
beam_search_file = index_dir / f"{index_prefix}_disk_beam_search.index"
# Required files that C++ partition mode needs
# Note: C++ generates these with _disk.index suffix
disk_suffix = "_disk.index"
required_files = [
f"{index_prefix}{disk_suffix}_medoids.bin", # Critical: assert fails if missing
# Note: _centroids.bin is not created in single-shot build - C++ handles this automatically
f"{index_prefix}_pq_pivots.bin", # PQ table
f"{index_prefix}_pq_compressed.bin", # PQ compressed vectors
]
# Check if all required files exist
missing_files = []
for filename in required_files:
file_path = index_dir / filename
if not file_path.exists():
missing_files.append(filename)
if missing_files:
logger.warning(
f"Cannot safely delete _disk.index - missing required files: {missing_files}"
)
logger.info("Keeping all original files for safety")
return
# Calculate space savings
space_saved = 0
files_to_delete = []
if disk_index_file.exists():
space_saved += disk_index_file.stat().st_size
files_to_delete.append(disk_index_file)
if beam_search_file.exists():
space_saved += beam_search_file.stat().st_size
files_to_delete.append(beam_search_file)
# Safe to delete!
for file_to_delete in files_to_delete:
try:
os.remove(file_to_delete)
logger.info(f"✅ Safely deleted: {file_to_delete.name}")
except Exception as e:
logger.warning(f"Failed to delete {file_to_delete.name}: {e}")
if space_saved > 0:
space_saved_mb = space_saved / (1024 * 1024)
logger.info(f"💾 Space saved: {space_saved_mb:.1f} MB")
# Show what files are kept
logger.info("📁 Kept essential files for partition mode:")
for filename in required_files:
file_path = index_dir / filename
if file_path.exists():
size_mb = file_path.stat().st_size / (1024 * 1024)
logger.info(f" - {filename} ({size_mb:.1f} MB)")
def build(self, data: np.ndarray, ids: list[str], index_path: str, **kwargs):
path = Path(index_path)
index_dir = path.parent
index_prefix = path.stem
index_dir.mkdir(parents=True, exist_ok=True)
if data.dtype != np.float32:
logger.warning(f"Converting data to float32, shape: {data.shape}")
data = data.astype(np.float32)
data_filename = f"{index_prefix}_data.bin"
_write_vectors_to_bin(data, index_dir / data_filename)
build_kwargs = {**self.build_params, **kwargs}
# Extract is_recompute from nested backend_kwargs if needed
is_recompute = build_kwargs.get("is_recompute", False)
if not is_recompute and "backend_kwargs" in build_kwargs:
is_recompute = build_kwargs["backend_kwargs"].get("is_recompute", False)
# Flatten all backend_kwargs parameters to top level for compatibility
if "backend_kwargs" in build_kwargs:
nested_params = build_kwargs.pop("backend_kwargs")
build_kwargs.update(nested_params)
metric_enum = _get_diskann_metrics().get(
build_kwargs.get("distance_metric", "mips").lower()
)
if metric_enum is None:
raise ValueError(
f"Unsupported distance_metric '{build_kwargs.get('distance_metric', 'unknown')}'."
)
# Calculate smart memory configuration if not explicitly provided
if (
"search_memory_maximum" not in build_kwargs
or "build_memory_maximum" not in build_kwargs
):
smart_search_mem, smart_build_mem = _calculate_smart_memory_config(data)
else:
smart_search_mem = build_kwargs.get("search_memory_maximum", 4.0)
smart_build_mem = build_kwargs.get("build_memory_maximum", 8.0)
try:
from . import _diskannpy as diskannpy # type: ignore
with chdir(index_dir):
diskannpy.build_disk_float_index(
metric_enum,
data_filename,
index_prefix,
build_kwargs.get("complexity", 64),
build_kwargs.get("graph_degree", 32),
build_kwargs.get("search_memory_maximum", smart_search_mem),
build_kwargs.get("build_memory_maximum", smart_build_mem),
build_kwargs.get("num_threads", 8),
build_kwargs.get("pq_disk_bytes", 0),
"",
)
# Auto-partition if is_recompute is enabled
if build_kwargs.get("is_recompute", False):
logger.info("is_recompute=True, starting automatic graph partitioning...")
from .graph_partition import partition_graph
# Partition the index using absolute paths
# Convert to absolute paths to avoid issues with working directory changes
absolute_index_dir = Path(index_dir).resolve()
absolute_index_prefix_path = str(absolute_index_dir / index_prefix)
disk_graph_path, partition_bin_path = partition_graph(
index_prefix_path=absolute_index_prefix_path,
output_dir=str(absolute_index_dir),
partition_prefix=index_prefix,
)
# Safe cleanup: In partition mode, C++ doesn't read _disk.index content
# but still needs the derived files (_medoids.bin, _centroids.bin, etc.)
self._safe_cleanup_after_partition(index_dir, index_prefix)
logger.info("✅ Graph partitioning completed successfully!")
logger.info(f" - Disk graph: {disk_graph_path}")
logger.info(f" - Partition file: {partition_bin_path}")
finally:
temp_data_file = index_dir / data_filename
if temp_data_file.exists():
os.remove(temp_data_file)
logger.debug(f"Cleaned up temporary data file: {temp_data_file}")
class DiskannSearcher(BaseSearcher):
def __init__(self, index_path: str, **kwargs):
super().__init__(
index_path,
backend_module_name="leann_backend_diskann.diskann_embedding_server",
**kwargs,
)
# Initialize DiskANN index with suppressed C++ output based on log level
with suppress_cpp_output_if_needed():
from . import _diskannpy as diskannpy # type: ignore
distance_metric = kwargs.get("distance_metric", "mips").lower()
metric_enum = _get_diskann_metrics().get(distance_metric)
if metric_enum is None:
raise ValueError(f"Unsupported distance_metric '{distance_metric}'.")
self.num_threads = kwargs.get("num_threads", 8)
# For DiskANN, we need to reinitialize the index when zmq_port changes
# Store the initialization parameters for later use
# Note: C++ load method expects the BASE path (without _disk.index suffix)
# C++ internally constructs: index_prefix + "_disk.index"
index_name = self.index_path.stem # "simple_test.leann" -> "simple_test"
diskann_index_prefix = str(self.index_dir / index_name) # /path/to/simple_test
full_index_prefix = diskann_index_prefix # /path/to/simple_test (base path)
# Auto-detect partition files and set partition_prefix
partition_graph_file = self.index_dir / f"{index_name}_disk_graph.index"
partition_bin_file = self.index_dir / f"{index_name}_partition.bin"
partition_prefix = ""
if partition_graph_file.exists() and partition_bin_file.exists():
# C++ expects full path prefix, not just filename
partition_prefix = str(self.index_dir / index_name) # /path/to/simple_test
logger.info(
f"✅ Detected partition files, using partition_prefix='{partition_prefix}'"
)
else:
logger.debug("No partition files detected, using standard index files")
self._init_params = {
"metric_enum": metric_enum,
"full_index_prefix": full_index_prefix,
"num_threads": self.num_threads,
"num_nodes_to_cache": kwargs.get("num_nodes_to_cache", 0),
# 1 -> initialize cache using sample_data; 2 -> ready cache without init; others disable cache
"cache_mechanism": kwargs.get("cache_mechanism", 1),
"pq_prefix": "",
"partition_prefix": partition_prefix,
}
# Log partition configuration for debugging
if partition_prefix:
logger.info(
f"✅ Detected partition files, using partition_prefix='{partition_prefix}'"
)
self._diskannpy = diskannpy
self._current_zmq_port = None
self._index = None
logger.debug("DiskANN searcher initialized (index will be loaded on first search)")
def _ensure_index_loaded(self, zmq_port: int):
"""Ensure the index is loaded with the correct zmq_port."""
if self._index is None or self._current_zmq_port != zmq_port:
# Need to (re)load the index with the correct zmq_port
with suppress_cpp_output_if_needed():
if self._index is not None:
logger.debug(f"Reloading DiskANN index with new zmq_port: {zmq_port}")
else:
logger.debug(f"Loading DiskANN index with zmq_port: {zmq_port}")
self._index = self._diskannpy.StaticDiskFloatIndex(
self._init_params["metric_enum"],
self._init_params["full_index_prefix"],
self._init_params["num_threads"],
self._init_params["num_nodes_to_cache"],
self._init_params["cache_mechanism"],
zmq_port,
self._init_params["pq_prefix"],
self._init_params["partition_prefix"],
)
self._current_zmq_port = zmq_port
def search(
self,
query: np.ndarray,
top_k: int,
complexity: int = 64,
beam_width: int = 1,
prune_ratio: float = 0.0,
recompute_embeddings: bool = False,
pruning_strategy: Literal["global", "local", "proportional"] = "global",
zmq_port: Optional[int] = None,
batch_recompute: bool = False,
dedup_node_dis: bool = False,
**kwargs,
) -> dict[str, Any]:
"""
Search for nearest neighbors using DiskANN index.
Args:
query: Query vectors (B, D) where B is batch size, D is dimension
top_k: Number of nearest neighbors to return
complexity: Search complexity/candidate list size, higher = more accurate but slower
beam_width: Number of parallel IO requests per iteration
prune_ratio: Ratio of neighbors to prune via approximate distance (0.0-1.0)
recompute_embeddings: Whether to fetch fresh embeddings from server
pruning_strategy: PQ candidate selection strategy:
- "global": Use global pruning strategy (default)
- "local": Use local pruning strategy
- "proportional": Not supported in DiskANN, falls back to global
zmq_port: ZMQ port for embedding server communication. Must be provided if recompute_embeddings is True.
batch_recompute: Whether to batch neighbor recomputation (DiskANN-specific)
dedup_node_dis: Whether to cache and reuse distance computations (DiskANN-specific)
**kwargs: Additional DiskANN-specific parameters (for legacy compatibility)
Returns:
Dict with 'labels' (list of lists) and 'distances' (ndarray)
"""
# Handle zmq_port compatibility: Ensure index is loaded with correct port
if recompute_embeddings:
if zmq_port is None:
raise ValueError("zmq_port must be provided if recompute_embeddings is True")
self._ensure_index_loaded(zmq_port)
else:
# If not recomputing, we still need an index, use a default port
if self._index is None:
self._ensure_index_loaded(6666) # Default port when not recomputing
# DiskANN doesn't support "proportional" strategy
if pruning_strategy == "proportional":
raise NotImplementedError(
"DiskANN backend does not support 'proportional' pruning strategy. Use 'global' or 'local' instead."
)
if query.dtype != np.float32:
query = query.astype(np.float32)
# Map pruning_strategy to DiskANN's global_pruning parameter
if pruning_strategy == "local":
use_global_pruning = False
else: # "global"
use_global_pruning = True
# Strategy:
# - Traversal always uses PQ distances
# - If recompute_embeddings=True, do a single final rerank via deferred fetch
# (fetch embeddings for the final candidate set only)
# - Do not recompute neighbor distances along the path
use_deferred_fetch = True if recompute_embeddings else False
recompute_neighors = False # Expected typo. For backward compatibility.
with suppress_cpp_output_if_needed():
labels, distances = self._index.batch_search(
query,
query.shape[0],
top_k,
complexity,
beam_width,
self.num_threads,
use_deferred_fetch,
kwargs.get("skip_search_reorder", False),
recompute_neighors,
dedup_node_dis,
prune_ratio,
batch_recompute,
use_global_pruning,
)
string_labels = [[str(int_label) for int_label in batch_labels] for batch_labels in labels]
return {"labels": string_labels, "distances": distances}