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import numpy as np | |
import pandas as pd | |
import faiss | |
from pathlib import Path | |
from sentence_transformers import SentenceTransformer, util | |
import streamlit as st | |
class SemanticSearch: | |
def __init__(self, shard_dir="compressed_shards"): | |
self.shard_dir = Path(shard_dir) | |
self.shard_dir.mkdir(exist_ok=True, parents=True) | |
self.model = None | |
self.index_shards = [] | |
def load_model(_self): | |
return SentenceTransformer('all-MiniLM-L6-v2') | |
def initialize_system(self): | |
self.model = self.load_model() | |
self._load_index_shards() | |
def _load_index_shards(self): | |
"""Load FAISS shards directly from local directory""" | |
for shard_path in sorted(self.shard_dir.glob("*.index")): | |
self.index_shards.append(faiss.read_index(str(shard_path))) | |
def search(self, query, top_k=5): | |
"""Search across all shards""" | |
query_embedding = self.model.encode([query], convert_to_numpy=True) | |
all_scores = [] | |
all_indices = [] | |
for shard_idx, index in enumerate(self.index_shards): | |
distances, indices = index.search(query_embedding, top_k) | |
# Convert local indices to global shard offsets | |
global_indices = [ | |
self._calculate_global_index(shard_idx, idx) | |
for idx in indices[0] | |
] | |
all_scores.extend(distances[0]) | |
all_indices.extend(global_indices) | |
return self._process_results(np.array(all_scores), np.array(all_indices), top_k) | |
def _calculate_global_index(self, shard_idx, local_idx): | |
"""Convert shard-local index to global index""" | |
# Implement your specific shard indexing logic here | |
# Example: return f"{shard_idx}-{local_idx}" | |
return local_idx # Simple version if using unique IDs | |
def _process_results(self, distances, indices, top_k): | |
"""Format search results""" | |
results = pd.DataFrame({ | |
'global_index': indices, | |
'similarity': 1 - (distances / 2) # L2 to cosine approximation | |
}) | |
return results.sort_values('similarity', ascending=False).head(top_k) | |
def search_with_threshold(self, query, top_k=5, similarity_threshold=0.6): | |
"""Threshold-filtered search""" | |
results = self.search(query, top_k*2) | |
filtered = results[results['similarity'] > similarity_threshold].head(top_k) | |
return filtered.reset_index(drop=True) |