f6f1a7d889
* fix: zeroentropy rerank URL missing /v1 prefix and MCP routing tests - Fix ZeroEntropy reranker URL: /models/rerank -> /v1/models/rerank (#453) - Fix test_mcp_routing tests: update assertions to use submit_async_retain instead of the non-existent async_processing=False/retain_batch_async pattern * fix(openclaw): pass retainEveryNTurns through getPluginConfig and set it to 1 in tests getPluginConfig was not forwarding retainEveryNTurns from the raw config, so pluginConfig.retainEveryNTurns was always undefined (defaulting to 10). The integration tests use retainEveryNTurns: 1 so retain fires every turn.
1128 lines
41 KiB
Python
1128 lines
41 KiB
Python
"""
|
|
Cross-encoder abstraction for reranking.
|
|
|
|
Provides an interface for reranking with different backends.
|
|
|
|
Configuration via environment variables - see hindsight_api.config for all env var names.
|
|
"""
|
|
|
|
import asyncio
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|
import logging
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|
import os
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|
import warnings
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|
from abc import ABC, abstractmethod
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from concurrent.futures import ThreadPoolExecutor
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|
|
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import httpx
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|
|
|
from ..config import (
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DEFAULT_LITELLM_API_BASE,
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DEFAULT_RERANKER_COHERE_MODEL,
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|
DEFAULT_RERANKER_FLASHRANK_CACHE_DIR,
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|
DEFAULT_RERANKER_FLASHRANK_MODEL,
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|
DEFAULT_RERANKER_LITELLM_MODEL,
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|
DEFAULT_RERANKER_LITELLM_SDK_MODEL,
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|
DEFAULT_RERANKER_LOCAL_FORCE_CPU,
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|
DEFAULT_RERANKER_LOCAL_MAX_CONCURRENT,
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|
DEFAULT_RERANKER_LOCAL_MODEL,
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DEFAULT_RERANKER_LOCAL_TRUST_REMOTE_CODE,
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|
DEFAULT_RERANKER_PROVIDER,
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DEFAULT_RERANKER_TEI_BATCH_SIZE,
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|
DEFAULT_RERANKER_TEI_MAX_CONCURRENT,
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|
DEFAULT_RERANKER_ZEROENTROPY_MODEL,
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|
ENV_RERANKER_COHERE_API_KEY,
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|
ENV_RERANKER_COHERE_MODEL,
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|
ENV_RERANKER_FLASHRANK_CACHE_DIR,
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|
ENV_RERANKER_FLASHRANK_MODEL,
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|
ENV_RERANKER_LITELLM_SDK_API_KEY,
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|
ENV_RERANKER_LOCAL_FORCE_CPU,
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|
ENV_RERANKER_LOCAL_MAX_CONCURRENT,
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|
ENV_RERANKER_LOCAL_MODEL,
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|
ENV_RERANKER_LOCAL_TRUST_REMOTE_CODE,
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|
ENV_RERANKER_PROVIDER,
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|
ENV_RERANKER_TEI_BATCH_SIZE,
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|
ENV_RERANKER_TEI_MAX_CONCURRENT,
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|
ENV_RERANKER_TEI_URL,
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|
ENV_RERANKER_ZEROENTROPY_API_KEY,
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|
)
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|
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logger = logging.getLogger(__name__)
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|
|
|
|
|
class CrossEncoderModel(ABC):
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"""
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Abstract base class for cross-encoder reranking.
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|
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Cross-encoders take query-document pairs and return relevance scores.
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"""
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|
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|
@property
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@abstractmethod
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def provider_name(self) -> str:
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|
"""Return a human-readable name for this provider (e.g., 'local', 'tei')."""
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pass
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|
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|
@abstractmethod
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|
async def initialize(self) -> None:
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|
"""
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|
Initialize the cross-encoder model asynchronously.
|
|
|
|
This should be called during startup to load/connect to the model
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|
and avoid cold start latency on first predict() call.
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|
"""
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pass
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|
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@abstractmethod
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async def predict(self, pairs: list[tuple[str, str]]) -> list[float]:
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|
"""
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Score query-document pairs for relevance.
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|
|
|
Args:
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|
pairs: List of (query, document) tuples to score
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|
|
|
Returns:
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List of relevance scores (higher = more relevant)
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"""
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pass
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|
|
|
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|
class LocalSTCrossEncoder(CrossEncoderModel):
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|
"""
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|
Local cross-encoder implementation using SentenceTransformers.
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|
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|
Call initialize() during startup to load the model and avoid cold starts.
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|
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|
Default model is cross-encoder/ms-marco-MiniLM-L-6-v2:
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- Fast inference (~80ms for 100 pairs on CPU)
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- Small model (80MB)
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- Trained for passage re-ranking
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|
|
|
Uses a dedicated thread pool to limit concurrent CPU-bound work.
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|
"""
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|
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# Shared executor across all instances (one model loaded anyway)
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_executor: ThreadPoolExecutor | None = None
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_max_concurrent: int = 4 # Limit concurrent CPU-bound reranking calls
|
|
|
|
def __init__(
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|
self,
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|
model_name: str | None = None,
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|
max_concurrent: int = 4,
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|
force_cpu: bool = False,
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|
trust_remote_code: bool = False,
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|
):
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|
"""
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|
Initialize local SentenceTransformers cross-encoder.
|
|
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|
Args:
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|
model_name: Name of the CrossEncoder model to use.
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|
Default: cross-encoder/ms-marco-MiniLM-L-6-v2
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max_concurrent: Maximum concurrent reranking calls (default: 2).
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Higher values may cause CPU thrashing under load.
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|
force_cpu: Force CPU mode (avoids MPS/XPC issues on macOS in daemon mode).
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|
Default: False
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|
trust_remote_code: Allow loading models with custom code (security risk).
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|
Required for some models like jina-reranker-v2-base-multilingual.
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|
Default: False (disabled for security)
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"""
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self.model_name = model_name or DEFAULT_RERANKER_LOCAL_MODEL
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self.force_cpu = force_cpu
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self.trust_remote_code = trust_remote_code
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self._model = None
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LocalSTCrossEncoder._max_concurrent = max_concurrent
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|
|
|
@property
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|
def provider_name(self) -> str:
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|
return "local"
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|
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|
async def initialize(self) -> None:
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|
"""Load the cross-encoder model and initialize the executor."""
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if self._model is not None:
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|
return
|
|
|
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try:
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from sentence_transformers import CrossEncoder
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|
except ImportError:
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|
raise ImportError(
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|
"sentence-transformers is required for LocalSTCrossEncoder. "
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|
"Install it with: pip install sentence-transformers"
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)
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|
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|
logger.info(f"Reranker: initializing local provider with model {self.model_name}")
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|
|
|
# Determine device based on hardware availability.
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|
# We always set low_cpu_mem_usage=False to prevent lazy loading (meta tensors)
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|
# which can cause issues when accelerate is installed but no GPU is available.
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|
# Note: We do NOT use device_map because CrossEncoder internally calls .to(device)
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|
# after loading, which conflicts with accelerate's device_map handling.
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|
import torch
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|
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|
# Force CPU mode if configured (used in daemon mode to avoid MPS/XPC issues on macOS)
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|
if self.force_cpu:
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device = "cpu"
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logger.info("Reranker: forcing CPU mode (HINDSIGHT_API_RERANKER_LOCAL_FORCE_CPU=1)")
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else:
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# Check for GPU (CUDA) or Apple Silicon (MPS)
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|
# Wrap in try-except to gracefully handle any device detection issues
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|
# (e.g., in CI environments or when PyTorch is built without GPU support)
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|
device = "cpu" # Default to CPU
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try:
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|
has_gpu = torch.cuda.is_available() or (
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|
hasattr(torch.backends, "mps") and torch.backends.mps.is_available()
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|
)
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|
if has_gpu:
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|
device = None # Let sentence-transformers auto-detect GPU/MPS
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|
except Exception as e:
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|
logger.warning(f"Failed to detect GPU/MPS, falling back to CPU: {e}")
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|
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|
# Suppress verbose transformers warnings during model loading
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|
# This suppresses the "UNEXPECTED" warnings from CrossEncoder which are harmless
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|
# but look alarming to users (e.g., "embeddings.position_ids | UNEXPECTED")
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with warnings.catch_warnings():
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warnings.filterwarnings("ignore", category=UserWarning)
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warnings.filterwarnings("ignore", message=".*was not found in model state dict.*")
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warnings.filterwarnings("ignore", message=".*UNEXPECTED.*")
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|
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# Also suppress transformers library logging temporarily
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transformers_logger = logging.getLogger("transformers")
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original_level = transformers_logger.level
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transformers_logger.setLevel(logging.ERROR)
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|
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try:
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self._model = CrossEncoder(
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self.model_name,
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device=device,
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model_kwargs={"low_cpu_mem_usage": False},
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trust_remote_code=self.trust_remote_code,
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)
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finally:
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|
# Restore original logging level
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transformers_logger.setLevel(original_level)
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|
|
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# Initialize shared executor (limited workers naturally limits concurrency)
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|
if LocalSTCrossEncoder._executor is None:
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LocalSTCrossEncoder._executor = ThreadPoolExecutor(
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max_workers=LocalSTCrossEncoder._max_concurrent,
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thread_name_prefix="reranker",
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)
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logger.info(f"Reranker: local provider initialized (max_concurrent={LocalSTCrossEncoder._max_concurrent})")
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else:
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logger.info("Reranker: local provider initialized (using existing executor)")
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|
|
|
def _predict_sync(self, pairs: list[tuple[str, str]]) -> list[float]:
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|
"""Synchronous prediction wrapper for thread pool execution."""
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|
scores = self._model.predict(pairs, show_progress_bar=False)
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|
return scores.tolist() if hasattr(scores, "tolist") else list(scores)
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|
|
|
async def predict(self, pairs: list[tuple[str, str]]) -> list[float]:
|
|
"""
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|
Score query-document pairs for relevance.
|
|
|
|
Uses a dedicated thread pool with limited workers to prevent CPU thrashing.
|
|
|
|
Args:
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|
pairs: List of (query, document) tuples to score
|
|
|
|
Returns:
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List of relevance scores (raw logits from the model)
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"""
|
|
if self._model is None:
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raise RuntimeError("Reranker not initialized. Call initialize() first.")
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|
|
|
# Use dedicated executor - limited workers naturally limits concurrency
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|
loop = asyncio.get_event_loop()
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|
return await loop.run_in_executor(
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|
LocalSTCrossEncoder._executor,
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self._predict_sync,
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|
pairs,
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|
)
|
|
|
|
|
|
class RemoteTEICrossEncoder(CrossEncoderModel):
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|
"""
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|
Remote cross-encoder implementation using HuggingFace Text Embeddings Inference (TEI) HTTP API.
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|
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|
TEI supports reranking via the /rerank endpoint.
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|
See: https://github.com/huggingface/text-embeddings-inference
|
|
|
|
Note: The TEI server must be running a cross-encoder/reranker model.
|
|
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|
Requests are made in parallel with configurable batch size and max concurrency (backpressure).
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|
Uses a GLOBAL semaphore to limit concurrent requests across ALL recall operations.
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|
"""
|
|
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|
# Global semaphore shared across all instances and calls to prevent thundering herd
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|
_global_semaphore: asyncio.Semaphore | None = None
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|
_global_max_concurrent: int = DEFAULT_RERANKER_TEI_MAX_CONCURRENT
|
|
|
|
def __init__(
|
|
self,
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|
base_url: str,
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|
timeout: float = 30.0,
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|
batch_size: int = DEFAULT_RERANKER_TEI_BATCH_SIZE,
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|
max_concurrent: int = DEFAULT_RERANKER_TEI_MAX_CONCURRENT,
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|
max_retries: int = 3,
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|
retry_delay: float = 0.5,
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|
):
|
|
"""
|
|
Initialize remote TEI cross-encoder client.
|
|
|
|
Args:
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|
base_url: Base URL of the TEI server (e.g., "http://localhost:8080")
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|
timeout: Request timeout in seconds (default: 30.0)
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|
batch_size: Maximum batch size for rerank requests (default: 128)
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|
max_concurrent: Maximum concurrent requests for backpressure (default: 8).
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|
This is a GLOBAL limit across all parallel recall operations.
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|
max_retries: Maximum number of retries for failed requests (default: 3)
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|
retry_delay: Initial delay between retries in seconds, doubles each retry (default: 0.5)
|
|
"""
|
|
self.base_url = base_url.rstrip("/")
|
|
self.timeout = timeout
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|
self.batch_size = batch_size
|
|
self.max_concurrent = max_concurrent
|
|
self.max_retries = max_retries
|
|
self.retry_delay = retry_delay
|
|
self._async_client: httpx.AsyncClient | None = None
|
|
self._model_id: str | None = None
|
|
|
|
# Update global semaphore if max_concurrent changed
|
|
if (
|
|
RemoteTEICrossEncoder._global_semaphore is None
|
|
or RemoteTEICrossEncoder._global_max_concurrent != max_concurrent
|
|
):
|
|
RemoteTEICrossEncoder._global_max_concurrent = max_concurrent
|
|
RemoteTEICrossEncoder._global_semaphore = asyncio.Semaphore(max_concurrent)
|
|
|
|
@property
|
|
def provider_name(self) -> str:
|
|
return "tei"
|
|
|
|
async def _async_request_with_retry(
|
|
self,
|
|
client: httpx.AsyncClient,
|
|
semaphore: asyncio.Semaphore,
|
|
method: str,
|
|
url: str,
|
|
**kwargs,
|
|
) -> httpx.Response:
|
|
"""Make an async HTTP request with automatic retries on transient errors and semaphore for backpressure."""
|
|
last_error = None
|
|
delay = self.retry_delay
|
|
|
|
async with semaphore:
|
|
for attempt in range(self.max_retries + 1):
|
|
try:
|
|
if method == "GET":
|
|
response = await client.get(url, **kwargs)
|
|
else:
|
|
response = await client.post(url, **kwargs)
|
|
response.raise_for_status()
|
|
return response
|
|
except (httpx.ConnectError, httpx.ReadTimeout, httpx.WriteTimeout) as e:
|
|
last_error = e
|
|
if attempt < self.max_retries:
|
|
logger.warning(
|
|
f"TEI request failed (attempt {attempt + 1}/{self.max_retries + 1}): {e}. "
|
|
f"Retrying in {delay}s..."
|
|
)
|
|
await asyncio.sleep(delay)
|
|
delay *= 2 # Exponential backoff
|
|
except httpx.HTTPStatusError as e:
|
|
# Retry on 5xx server errors
|
|
if e.response.status_code >= 500 and attempt < self.max_retries:
|
|
last_error = e
|
|
logger.warning(
|
|
f"TEI server error (attempt {attempt + 1}/{self.max_retries + 1}): {e}. "
|
|
f"Retrying in {delay}s..."
|
|
)
|
|
await asyncio.sleep(delay)
|
|
delay *= 2
|
|
else:
|
|
raise
|
|
|
|
raise last_error
|
|
|
|
async def initialize(self) -> None:
|
|
"""Initialize the HTTP client and verify server connectivity."""
|
|
if self._async_client is not None:
|
|
return
|
|
|
|
logger.info(
|
|
f"Reranker: initializing TEI provider at {self.base_url} "
|
|
f"(batch_size={self.batch_size}, max_concurrent={self.max_concurrent})"
|
|
)
|
|
self._async_client = httpx.AsyncClient(timeout=self.timeout)
|
|
|
|
# Verify server is reachable and get model info
|
|
# Use a temporary semaphore for initialization
|
|
init_semaphore = asyncio.Semaphore(1)
|
|
try:
|
|
response = await self._async_request_with_retry(
|
|
self._async_client, init_semaphore, "GET", f"{self.base_url}/info"
|
|
)
|
|
info = response.json()
|
|
self._model_id = info.get("model_id", "unknown")
|
|
logger.info(f"Reranker: TEI provider initialized (model: {self._model_id})")
|
|
except httpx.HTTPError as e:
|
|
self._async_client = None
|
|
raise RuntimeError(f"Failed to connect to TEI server at {self.base_url}: {e}")
|
|
|
|
async def _rerank_query_group(
|
|
self,
|
|
client: httpx.AsyncClient,
|
|
semaphore: asyncio.Semaphore,
|
|
query: str,
|
|
texts: list[str],
|
|
) -> list[tuple[int, float]]:
|
|
"""Rerank a single query group and return list of (original_index, score) tuples."""
|
|
try:
|
|
response = await self._async_request_with_retry(
|
|
client,
|
|
semaphore,
|
|
"POST",
|
|
f"{self.base_url}/rerank",
|
|
json={
|
|
"query": query,
|
|
"texts": texts,
|
|
"return_text": False,
|
|
},
|
|
)
|
|
results = response.json()
|
|
# TEI returns results sorted by score descending, with original index
|
|
return [(result["index"], result["score"]) for result in results]
|
|
except httpx.HTTPError as e:
|
|
raise RuntimeError(f"TEI rerank request failed: {e}")
|
|
|
|
async def _predict_async(self, pairs: list[tuple[str, str]]) -> list[float]:
|
|
"""Async implementation of predict that runs requests in parallel with backpressure."""
|
|
if not pairs:
|
|
return []
|
|
|
|
# Group all pairs by query
|
|
query_groups: dict[str, list[tuple[int, str]]] = {}
|
|
for idx, (query, text) in enumerate(pairs):
|
|
if query not in query_groups:
|
|
query_groups[query] = []
|
|
query_groups[query].append((idx, text))
|
|
|
|
# Split each query group into batches
|
|
tasks_info: list[tuple[str, list[int], list[str]]] = [] # (query, indices, texts)
|
|
for query, indexed_texts in query_groups.items():
|
|
indices = [idx for idx, _ in indexed_texts]
|
|
texts = [text for _, text in indexed_texts]
|
|
|
|
# Split into batches
|
|
for i in range(0, len(texts), self.batch_size):
|
|
batch_indices = indices[i : i + self.batch_size]
|
|
batch_texts = texts[i : i + self.batch_size]
|
|
tasks_info.append((query, batch_indices, batch_texts))
|
|
|
|
# Run all requests in parallel with GLOBAL semaphore for backpressure
|
|
# This ensures max_concurrent is respected across ALL parallel recall operations
|
|
all_scores = [0.0] * len(pairs)
|
|
semaphore = RemoteTEICrossEncoder._global_semaphore
|
|
|
|
tasks = [
|
|
self._rerank_query_group(self._async_client, semaphore, query, texts) for query, _, texts in tasks_info
|
|
]
|
|
results = await asyncio.gather(*tasks)
|
|
|
|
# Map scores back to original positions
|
|
for (_, indices, _), result_scores in zip(tasks_info, results):
|
|
for original_idx_in_batch, score in result_scores:
|
|
global_idx = indices[original_idx_in_batch]
|
|
all_scores[global_idx] = score
|
|
|
|
return all_scores
|
|
|
|
async def predict(self, pairs: list[tuple[str, str]]) -> list[float]:
|
|
"""
|
|
Score query-document pairs using the remote TEI reranker.
|
|
|
|
Requests are made in parallel with configurable backpressure.
|
|
|
|
Args:
|
|
pairs: List of (query, document) tuples to score
|
|
|
|
Returns:
|
|
List of relevance scores
|
|
"""
|
|
if self._async_client is None:
|
|
raise RuntimeError("Reranker not initialized. Call initialize() first.")
|
|
|
|
return await self._predict_async(pairs)
|
|
|
|
|
|
class CohereCrossEncoder(CrossEncoderModel):
|
|
"""
|
|
Cohere cross-encoder implementation using the Cohere Rerank API.
|
|
|
|
Supports rerank-english-v3.0 and rerank-multilingual-v3.0 models.
|
|
"""
|
|
|
|
def __init__(
|
|
self,
|
|
api_key: str,
|
|
model: str = DEFAULT_RERANKER_COHERE_MODEL,
|
|
base_url: str | None = None,
|
|
timeout: float = 60.0,
|
|
):
|
|
"""
|
|
Initialize Cohere cross-encoder client.
|
|
|
|
Args:
|
|
api_key: Cohere API key
|
|
model: Cohere rerank model name (default: rerank-english-v3.0)
|
|
base_url: Custom base URL for Cohere-compatible API (e.g., Azure-hosted endpoint)
|
|
timeout: Request timeout in seconds (default: 60.0)
|
|
"""
|
|
self.api_key = api_key
|
|
self.model = model
|
|
self.base_url = base_url
|
|
self.timeout = timeout
|
|
self._client = None
|
|
|
|
@property
|
|
def provider_name(self) -> str:
|
|
return "cohere"
|
|
|
|
async def initialize(self) -> None:
|
|
"""Initialize the Cohere client."""
|
|
if self._client is not None:
|
|
return
|
|
|
|
try:
|
|
import cohere
|
|
except ImportError:
|
|
raise ImportError("cohere is required for CohereCrossEncoder. Install it with: pip install cohere")
|
|
|
|
base_url_msg = f" at {self.base_url}" if self.base_url else ""
|
|
logger.info(f"Reranker: initializing Cohere provider with model {self.model}{base_url_msg}")
|
|
|
|
# Build client kwargs, only including base_url if set (for Azure or custom endpoints)
|
|
client_kwargs = {"api_key": self.api_key, "timeout": self.timeout}
|
|
if self.base_url:
|
|
client_kwargs["base_url"] = self.base_url
|
|
self._client = cohere.Client(**client_kwargs)
|
|
logger.info("Reranker: Cohere provider initialized")
|
|
|
|
async def predict(self, pairs: list[tuple[str, str]]) -> list[float]:
|
|
"""
|
|
Score query-document pairs using the Cohere Rerank API.
|
|
|
|
Args:
|
|
pairs: List of (query, document) tuples to score
|
|
|
|
Returns:
|
|
List of relevance scores
|
|
"""
|
|
if self._client is None:
|
|
raise RuntimeError("Reranker not initialized. Call initialize() first.")
|
|
|
|
if not pairs:
|
|
return []
|
|
|
|
# Run sync Cohere API calls in thread pool
|
|
loop = asyncio.get_event_loop()
|
|
return await loop.run_in_executor(None, self._predict_sync, pairs)
|
|
|
|
def _predict_sync(self, pairs: list[tuple[str, str]]) -> list[float]:
|
|
"""Synchronous predict implementation for Cohere API."""
|
|
# Group pairs by query for efficient batching
|
|
# Cohere rerank expects one query with multiple documents
|
|
query_groups: dict[str, list[tuple[int, str]]] = {}
|
|
for idx, (query, text) in enumerate(pairs):
|
|
if query not in query_groups:
|
|
query_groups[query] = []
|
|
query_groups[query].append((idx, text))
|
|
|
|
all_scores = [0.0] * len(pairs)
|
|
|
|
for query, indexed_texts in query_groups.items():
|
|
texts = [text for _, text in indexed_texts]
|
|
indices = [idx for idx, _ in indexed_texts]
|
|
|
|
response = self._client.rerank(
|
|
query=query,
|
|
documents=texts,
|
|
model=self.model,
|
|
return_documents=False,
|
|
)
|
|
|
|
# Map scores back to original positions
|
|
for result in response.results:
|
|
original_idx = result.index
|
|
score = result.relevance_score
|
|
all_scores[indices[original_idx]] = score
|
|
|
|
return all_scores
|
|
|
|
|
|
class ZeroEntropyCrossEncoder(CrossEncoderModel):
|
|
"""
|
|
ZeroEntropy cross-encoder implementation using the ZeroEntropy Rerank API.
|
|
|
|
Supports zerank-2 (flagship) and zerank-2-small models.
|
|
See: https://docs.zeroentropy.dev/models
|
|
"""
|
|
|
|
RERANK_URL = "https://api.zeroentropy.dev/v1/models/rerank"
|
|
|
|
def __init__(
|
|
self,
|
|
api_key: str,
|
|
model: str = DEFAULT_RERANKER_ZEROENTROPY_MODEL,
|
|
timeout: float = 60.0,
|
|
):
|
|
"""
|
|
Initialize ZeroEntropy cross-encoder client.
|
|
|
|
Args:
|
|
api_key: ZeroEntropy API key
|
|
model: ZeroEntropy rerank model name (default: zerank-2)
|
|
timeout: Request timeout in seconds (default: 60.0)
|
|
"""
|
|
self.api_key = api_key
|
|
self.model = model
|
|
self.timeout = timeout
|
|
self._async_client: httpx.AsyncClient | None = None
|
|
|
|
@property
|
|
def provider_name(self) -> str:
|
|
return "zeroentropy"
|
|
|
|
async def initialize(self) -> None:
|
|
"""Initialize the async HTTP client."""
|
|
if self._async_client is not None:
|
|
return
|
|
|
|
logger.info(f"Reranker: initializing ZeroEntropy provider with model {self.model}")
|
|
self._async_client = httpx.AsyncClient(
|
|
timeout=self.timeout,
|
|
headers={
|
|
"Authorization": f"Bearer {self.api_key}",
|
|
"Content-Type": "application/json",
|
|
},
|
|
)
|
|
logger.info("Reranker: ZeroEntropy provider initialized")
|
|
|
|
async def predict(self, pairs: list[tuple[str, str]]) -> list[float]:
|
|
"""
|
|
Score query-document pairs using the ZeroEntropy Rerank API.
|
|
|
|
Args:
|
|
pairs: List of (query, document) tuples to score
|
|
|
|
Returns:
|
|
List of relevance scores
|
|
"""
|
|
if self._async_client is None:
|
|
raise RuntimeError("Reranker not initialized. Call initialize() first.")
|
|
|
|
if not pairs:
|
|
return []
|
|
|
|
# Group pairs by query for efficient batching
|
|
query_groups: dict[str, list[tuple[int, str]]] = {}
|
|
for idx, (query, text) in enumerate(pairs):
|
|
if query not in query_groups:
|
|
query_groups[query] = []
|
|
query_groups[query].append((idx, text))
|
|
|
|
all_scores = [0.0] * len(pairs)
|
|
|
|
for query, indexed_texts in query_groups.items():
|
|
texts = [text for _, text in indexed_texts]
|
|
indices = [idx for idx, _ in indexed_texts]
|
|
|
|
response = await self._async_client.post(
|
|
self.RERANK_URL,
|
|
json={
|
|
"model": self.model,
|
|
"query": query,
|
|
"documents": texts,
|
|
"top_n": len(texts),
|
|
},
|
|
)
|
|
response.raise_for_status()
|
|
result = response.json()
|
|
|
|
# Map scores back to original positions
|
|
for item in result.get("results", []):
|
|
original_idx = item["index"]
|
|
score = item["relevance_score"]
|
|
all_scores[indices[original_idx]] = score
|
|
|
|
return all_scores
|
|
|
|
|
|
class RRFPassthroughCrossEncoder(CrossEncoderModel):
|
|
"""
|
|
Passthrough cross-encoder that preserves RRF scores without neural reranking.
|
|
|
|
This is useful for:
|
|
- Testing retrieval quality without reranking overhead
|
|
- Deployments where reranking latency is unacceptable
|
|
- Debugging to isolate retrieval vs reranking issues
|
|
"""
|
|
|
|
def __init__(self):
|
|
"""Initialize RRF passthrough cross-encoder."""
|
|
pass
|
|
|
|
@property
|
|
def provider_name(self) -> str:
|
|
return "rrf"
|
|
|
|
async def initialize(self) -> None:
|
|
"""No initialization needed."""
|
|
logger.info("Reranker: RRF passthrough provider initialized (neural reranking disabled)")
|
|
|
|
async def predict(self, pairs: list[tuple[str, str]]) -> list[float]:
|
|
"""
|
|
Return neutral scores - actual ranking uses RRF scores from retrieval.
|
|
|
|
Args:
|
|
pairs: List of (query, document) tuples (ignored)
|
|
|
|
Returns:
|
|
List of 0.5 scores (neutral, lets RRF scores dominate)
|
|
"""
|
|
# Return neutral scores so RRF ranking is preserved
|
|
return [0.5] * len(pairs)
|
|
|
|
|
|
class FlashRankCrossEncoder(CrossEncoderModel):
|
|
"""
|
|
FlashRank cross-encoder implementation.
|
|
|
|
FlashRank is an ultra-lite reranking library that runs on CPU without
|
|
requiring PyTorch or Transformers. It's ideal for serverless deployments
|
|
with minimal cold-start overhead.
|
|
|
|
Available models:
|
|
- ms-marco-TinyBERT-L-2-v2: Fastest, ~4MB
|
|
- ms-marco-MiniLM-L-12-v2: Best quality, ~34MB (default)
|
|
- rank-T5-flan: Best zero-shot, ~110MB
|
|
- ms-marco-MultiBERT-L-12: Multi-lingual, ~150MB
|
|
"""
|
|
|
|
# Shared executor for CPU-bound reranking
|
|
_executor: ThreadPoolExecutor | None = None
|
|
_max_concurrent: int = 4
|
|
|
|
def __init__(
|
|
self,
|
|
model_name: str | None = None,
|
|
cache_dir: str | None = None,
|
|
max_length: int = 512,
|
|
max_concurrent: int = 4,
|
|
):
|
|
"""
|
|
Initialize FlashRank cross-encoder.
|
|
|
|
Args:
|
|
model_name: FlashRank model name. Default: ms-marco-MiniLM-L-12-v2
|
|
cache_dir: Directory to cache downloaded models. Default: system cache
|
|
max_length: Maximum sequence length for reranking. Default: 512
|
|
max_concurrent: Maximum concurrent reranking calls. Default: 4
|
|
"""
|
|
self.model_name = model_name or DEFAULT_RERANKER_FLASHRANK_MODEL
|
|
self.cache_dir = cache_dir or DEFAULT_RERANKER_FLASHRANK_CACHE_DIR
|
|
self.max_length = max_length
|
|
self._ranker = None
|
|
FlashRankCrossEncoder._max_concurrent = max_concurrent
|
|
|
|
@property
|
|
def provider_name(self) -> str:
|
|
return "flashrank"
|
|
|
|
async def initialize(self) -> None:
|
|
"""Load the FlashRank model."""
|
|
if self._ranker is not None:
|
|
return
|
|
|
|
try:
|
|
from flashrank import Ranker
|
|
except ImportError:
|
|
raise ImportError("flashrank is required for FlashRankCrossEncoder. Install it with: pip install flashrank")
|
|
|
|
logger.info(f"Reranker: initializing FlashRank provider with model {self.model_name}")
|
|
|
|
# Initialize ranker with optional cache directory
|
|
ranker_kwargs = {"model_name": self.model_name, "max_length": self.max_length}
|
|
if self.cache_dir:
|
|
ranker_kwargs["cache_dir"] = self.cache_dir
|
|
|
|
self._ranker = Ranker(**ranker_kwargs)
|
|
|
|
# Initialize shared executor
|
|
if FlashRankCrossEncoder._executor is None:
|
|
FlashRankCrossEncoder._executor = ThreadPoolExecutor(
|
|
max_workers=FlashRankCrossEncoder._max_concurrent,
|
|
thread_name_prefix="flashrank",
|
|
)
|
|
logger.info(
|
|
f"Reranker: FlashRank provider initialized (max_concurrent={FlashRankCrossEncoder._max_concurrent})"
|
|
)
|
|
else:
|
|
logger.info("Reranker: FlashRank provider initialized (using existing executor)")
|
|
|
|
def _predict_sync(self, pairs: list[tuple[str, str]]) -> list[float]:
|
|
"""Synchronous predict - processes each query group."""
|
|
from flashrank import RerankRequest
|
|
|
|
if not pairs:
|
|
return []
|
|
|
|
# Group pairs by query
|
|
query_groups: dict[str, list[tuple[int, str]]] = {}
|
|
for idx, (query, text) in enumerate(pairs):
|
|
if query not in query_groups:
|
|
query_groups[query] = []
|
|
query_groups[query].append((idx, text))
|
|
|
|
all_scores = [0.0] * len(pairs)
|
|
|
|
for query, indexed_texts in query_groups.items():
|
|
# Build passages list for FlashRank
|
|
passages = [{"id": i, "text": text} for i, (_, text) in enumerate(indexed_texts)]
|
|
global_indices = [idx for idx, _ in indexed_texts]
|
|
|
|
# Create rerank request
|
|
request = RerankRequest(query=query, passages=passages)
|
|
results = self._ranker.rerank(request)
|
|
|
|
# Map scores back to original positions
|
|
for result in results:
|
|
local_idx = result["id"]
|
|
score = result["score"]
|
|
global_idx = global_indices[local_idx]
|
|
all_scores[global_idx] = score
|
|
|
|
return all_scores
|
|
|
|
async def predict(self, pairs: list[tuple[str, str]]) -> list[float]:
|
|
"""
|
|
Score query-document pairs using FlashRank.
|
|
|
|
Args:
|
|
pairs: List of (query, document) tuples to score
|
|
|
|
Returns:
|
|
List of relevance scores (higher = more relevant)
|
|
"""
|
|
if self._ranker is None:
|
|
raise RuntimeError("Reranker not initialized. Call initialize() first.")
|
|
|
|
# Run in thread pool to avoid blocking event loop
|
|
loop = asyncio.get_event_loop()
|
|
return await loop.run_in_executor(FlashRankCrossEncoder._executor, self._predict_sync, pairs)
|
|
|
|
|
|
class LiteLLMCrossEncoder(CrossEncoderModel):
|
|
"""
|
|
LiteLLM cross-encoder implementation using LiteLLM proxy's /rerank endpoint.
|
|
|
|
LiteLLM provides a unified interface for multiple reranking providers via
|
|
the Cohere-compatible /rerank endpoint.
|
|
See: https://docs.litellm.ai/docs/rerank
|
|
|
|
Supported providers via LiteLLM:
|
|
- Cohere (rerank-english-v3.0, etc.) - prefix with cohere/
|
|
- Together AI - prefix with together_ai/
|
|
- Azure AI - prefix with azure_ai/
|
|
- Jina AI - prefix with jina_ai/
|
|
- AWS Bedrock - prefix with bedrock/
|
|
- Voyage AI - prefix with voyage/
|
|
"""
|
|
|
|
def __init__(
|
|
self,
|
|
api_base: str = DEFAULT_LITELLM_API_BASE,
|
|
api_key: str | None = None,
|
|
model: str = DEFAULT_RERANKER_LITELLM_MODEL,
|
|
timeout: float = 60.0,
|
|
):
|
|
"""
|
|
Initialize LiteLLM cross-encoder client.
|
|
|
|
Args:
|
|
api_base: Base URL of the LiteLLM proxy (default: http://localhost:4000)
|
|
api_key: API key for the LiteLLM proxy (optional, depends on proxy config)
|
|
model: Reranking model name (default: cohere/rerank-english-v3.0)
|
|
Use provider prefix (e.g., cohere/, together_ai/, voyage/)
|
|
timeout: Request timeout in seconds (default: 60.0)
|
|
"""
|
|
self.api_base = api_base.rstrip("/")
|
|
self.api_key = api_key
|
|
self.model = model
|
|
self.timeout = timeout
|
|
self._async_client: httpx.AsyncClient | None = None
|
|
|
|
@property
|
|
def provider_name(self) -> str:
|
|
return "litellm"
|
|
|
|
async def initialize(self) -> None:
|
|
"""Initialize the async HTTP client."""
|
|
if self._async_client is not None:
|
|
return
|
|
|
|
logger.info(f"Reranker: initializing LiteLLM provider at {self.api_base} with model {self.model}")
|
|
|
|
headers = {"Content-Type": "application/json"}
|
|
if self.api_key:
|
|
headers["Authorization"] = f"Bearer {self.api_key}"
|
|
|
|
self._async_client = httpx.AsyncClient(timeout=self.timeout, headers=headers)
|
|
logger.info("Reranker: LiteLLM provider initialized")
|
|
|
|
async def predict(self, pairs: list[tuple[str, str]]) -> list[float]:
|
|
"""
|
|
Score query-document pairs using the LiteLLM proxy's /rerank endpoint.
|
|
|
|
Args:
|
|
pairs: List of (query, document) tuples to score
|
|
|
|
Returns:
|
|
List of relevance scores
|
|
"""
|
|
if self._async_client is None:
|
|
raise RuntimeError("Reranker not initialized. Call initialize() first.")
|
|
|
|
if not pairs:
|
|
return []
|
|
|
|
# Group pairs by query (LiteLLM rerank expects one query with multiple documents)
|
|
query_groups: dict[str, list[tuple[int, str]]] = {}
|
|
for idx, (query, text) in enumerate(pairs):
|
|
if query not in query_groups:
|
|
query_groups[query] = []
|
|
query_groups[query].append((idx, text))
|
|
|
|
all_scores = [0.0] * len(pairs)
|
|
|
|
for query, indexed_texts in query_groups.items():
|
|
texts = [text for _, text in indexed_texts]
|
|
indices = [idx for idx, _ in indexed_texts]
|
|
|
|
# LiteLLM /rerank follows Cohere API format
|
|
response = await self._async_client.post(
|
|
f"{self.api_base}/rerank",
|
|
json={
|
|
"model": self.model,
|
|
"query": query,
|
|
"documents": texts,
|
|
"top_n": len(texts), # Return all scores
|
|
},
|
|
)
|
|
response.raise_for_status()
|
|
result = response.json()
|
|
|
|
# Map scores back to original positions
|
|
# Response format: {"results": [{"index": 0, "relevance_score": 0.9}, ...]}
|
|
for item in result.get("results", []):
|
|
original_idx = item["index"]
|
|
score = item.get("relevance_score", item.get("score", 0.0))
|
|
all_scores[indices[original_idx]] = score
|
|
|
|
return all_scores
|
|
|
|
|
|
class LiteLLMSDKCrossEncoder(CrossEncoderModel):
|
|
"""
|
|
LiteLLM SDK cross-encoder for direct API integration.
|
|
|
|
Supports reranking via LiteLLM SDK without requiring a proxy server.
|
|
Supported providers: Cohere, DeepInfra, Together AI, HuggingFace, Jina AI, Voyage AI, AWS Bedrock.
|
|
|
|
Example model names:
|
|
- cohere/rerank-english-v3.0
|
|
- deepinfra/Qwen3-reranker-8B
|
|
- together_ai/Salesforce/Llama-Rank-V1
|
|
- huggingface/BAAI/bge-reranker-v2-m3
|
|
"""
|
|
|
|
def __init__(
|
|
self,
|
|
api_key: str,
|
|
model: str = DEFAULT_RERANKER_LITELLM_SDK_MODEL,
|
|
api_base: str | None = None,
|
|
timeout: float = 60.0,
|
|
):
|
|
"""
|
|
Initialize LiteLLM SDK cross-encoder client.
|
|
|
|
Args:
|
|
api_key: API key for the reranking provider
|
|
model: Model name with provider prefix (e.g., "deepinfra/Qwen3-reranker-8B")
|
|
api_base: Custom base URL for API (optional)
|
|
timeout: Request timeout in seconds (default: 60.0)
|
|
"""
|
|
self.api_key = api_key
|
|
self.model = model
|
|
self.api_base = api_base
|
|
self.timeout = timeout
|
|
self._initialized = False
|
|
self._litellm = None # Will be set during initialization
|
|
|
|
@property
|
|
def provider_name(self) -> str:
|
|
return "litellm-sdk"
|
|
|
|
async def initialize(self) -> None:
|
|
"""Initialize the LiteLLM SDK client."""
|
|
if self._initialized:
|
|
return
|
|
|
|
try:
|
|
import litellm
|
|
|
|
self._litellm = litellm # Store reference
|
|
except ImportError:
|
|
raise ImportError("litellm is required for LiteLLMSDKCrossEncoder. Install it with: pip install litellm")
|
|
|
|
api_base_msg = f" at {self.api_base}" if self.api_base else ""
|
|
logger.info(f"Reranker: initializing LiteLLM SDK provider with model {self.model}{api_base_msg}")
|
|
|
|
self._initialized = True
|
|
logger.info("Reranker: LiteLLM SDK provider initialized")
|
|
|
|
async def predict(self, pairs: list[tuple[str, str]]) -> list[float]:
|
|
"""
|
|
Score query-document pairs using the LiteLLM SDK.
|
|
|
|
Args:
|
|
pairs: List of (query, document) tuples to score
|
|
|
|
Returns:
|
|
List of relevance scores
|
|
"""
|
|
if not self._initialized:
|
|
raise RuntimeError("Reranker not initialized. Call initialize() first.")
|
|
|
|
if not pairs:
|
|
return []
|
|
|
|
# Group pairs by query for efficient batching
|
|
# LiteLLM rerank expects one query with multiple documents
|
|
query_groups: dict[str, list[tuple[int, str]]] = {}
|
|
for idx, (query, text) in enumerate(pairs):
|
|
if query not in query_groups:
|
|
query_groups[query] = []
|
|
query_groups[query].append((idx, text))
|
|
|
|
all_scores = [0.0] * len(pairs)
|
|
|
|
for query, indexed_texts in query_groups.items():
|
|
texts = [text for _, text in indexed_texts]
|
|
indices = [idx for idx, _ in indexed_texts]
|
|
|
|
# Build kwargs for rerank call
|
|
rerank_kwargs = {
|
|
"model": self.model,
|
|
"query": query,
|
|
"documents": texts,
|
|
"api_key": self.api_key,
|
|
}
|
|
if self.api_base:
|
|
rerank_kwargs["api_base"] = self.api_base
|
|
|
|
response = await self._litellm.arerank(**rerank_kwargs)
|
|
|
|
# Map scores back to original positions
|
|
# Response format: RerankResponse with results list
|
|
# Each result is a TypedDict with "index" and "relevance_score"
|
|
if hasattr(response, "results") and response.results:
|
|
for result in response.results:
|
|
# Results are TypedDicts, use dict-style access
|
|
original_idx = result["index"]
|
|
score = result.get("relevance_score", result.get("score", 0.0))
|
|
all_scores[indices[original_idx]] = score
|
|
elif isinstance(response, list):
|
|
# Direct list of scores (unlikely but defensive)
|
|
for i, score in enumerate(response):
|
|
all_scores[indices[i]] = score
|
|
else:
|
|
logger.warning(f"Unexpected response format from LiteLLM rerank: {type(response)}")
|
|
|
|
return all_scores
|
|
|
|
|
|
def create_cross_encoder_from_env() -> CrossEncoderModel:
|
|
"""
|
|
Create a CrossEncoderModel instance based on configuration.
|
|
|
|
Reads configuration via get_config() to ensure consistency across the codebase.
|
|
|
|
Returns:
|
|
Configured CrossEncoderModel instance
|
|
"""
|
|
from ..config import get_config
|
|
|
|
config = get_config()
|
|
provider = config.reranker_provider.lower()
|
|
|
|
if provider == "tei":
|
|
url = config.reranker_tei_url
|
|
if not url:
|
|
raise ValueError(f"{ENV_RERANKER_TEI_URL} is required when {ENV_RERANKER_PROVIDER} is 'tei'")
|
|
return RemoteTEICrossEncoder(
|
|
base_url=url,
|
|
batch_size=config.reranker_tei_batch_size,
|
|
max_concurrent=config.reranker_tei_max_concurrent,
|
|
)
|
|
elif provider == "local":
|
|
return LocalSTCrossEncoder(
|
|
model_name=config.reranker_local_model,
|
|
max_concurrent=config.reranker_local_max_concurrent,
|
|
force_cpu=config.reranker_local_force_cpu,
|
|
trust_remote_code=config.reranker_local_trust_remote_code,
|
|
)
|
|
elif provider == "cohere":
|
|
api_key = config.reranker_cohere_api_key
|
|
if not api_key:
|
|
raise ValueError(f"{ENV_RERANKER_COHERE_API_KEY} is required when {ENV_RERANKER_PROVIDER} is 'cohere'")
|
|
return CohereCrossEncoder(
|
|
api_key=api_key,
|
|
model=config.reranker_cohere_model,
|
|
base_url=config.reranker_cohere_base_url,
|
|
)
|
|
elif provider == "flashrank":
|
|
model = os.environ.get(ENV_RERANKER_FLASHRANK_MODEL, DEFAULT_RERANKER_FLASHRANK_MODEL)
|
|
cache_dir = os.environ.get(ENV_RERANKER_FLASHRANK_CACHE_DIR, DEFAULT_RERANKER_FLASHRANK_CACHE_DIR)
|
|
return FlashRankCrossEncoder(model_name=model, cache_dir=cache_dir)
|
|
elif provider == "litellm":
|
|
return LiteLLMCrossEncoder(
|
|
api_base=config.reranker_litellm_api_base,
|
|
api_key=config.reranker_litellm_api_key,
|
|
model=config.reranker_litellm_model,
|
|
)
|
|
elif provider == "litellm-sdk":
|
|
api_key = config.reranker_litellm_sdk_api_key
|
|
if not api_key:
|
|
raise ValueError(
|
|
f"{ENV_RERANKER_LITELLM_SDK_API_KEY} is required when {ENV_RERANKER_PROVIDER} is 'litellm-sdk'"
|
|
)
|
|
return LiteLLMSDKCrossEncoder(
|
|
api_key=api_key,
|
|
model=config.reranker_litellm_sdk_model,
|
|
api_base=config.reranker_litellm_sdk_api_base,
|
|
)
|
|
elif provider == "zeroentropy":
|
|
api_key = config.reranker_zeroentropy_api_key
|
|
if not api_key:
|
|
raise ValueError(
|
|
f"{ENV_RERANKER_ZEROENTROPY_API_KEY} is required when {ENV_RERANKER_PROVIDER} is 'zeroentropy'"
|
|
)
|
|
return ZeroEntropyCrossEncoder(
|
|
api_key=api_key,
|
|
model=config.reranker_zeroentropy_model,
|
|
)
|
|
elif provider == "rrf":
|
|
return RRFPassthroughCrossEncoder()
|
|
else:
|
|
raise ValueError(
|
|
f"Unknown reranker provider: {provider}. Supported: 'local', 'tei', 'cohere', 'zeroentropy', 'flashrank', 'litellm', 'litellm-sdk', 'rrf'"
|
|
)
|