LEANN/examples/document_search.py

#!/usr/bin/env python3
"""
Document search demo with recompute mode
"""

import shutil
import time
from pathlib import Path

# Import backend packages to trigger plugin registration
try:
    import leann_backend_diskann  # noqa: F401
    import leann_backend_hnsw  # noqa: F401

    print("INFO: Backend packages imported successfully.")
except ImportError as e:
    print(f"WARNING: Could not import backend packages. Error: {e}")

# Import upper-level API from leann-core
from leann.api import LeannBuilder, LeannChat, LeannSearcher


def load_sample_documents():
    """Create sample documents for demonstration"""
    docs = [
        {
            "title": "Intro to Python",
            "content": "Python is a high-level, interpreted language known for simplicity.",
        },
        {
            "title": "ML Basics",
            "content": "Machine learning builds systems that learn from data.",
        },
        {
            "title": "Data Structures",
            "content": "Data structures like arrays, lists, and graphs organize data.",
        },
    ]
    return docs


def main():
    print("==========================================================")
    print("=== Leann Document Search Demo (DiskANN + Recompute) ===")
    print("==========================================================")

    INDEX_DIR = Path("./test_indices")
    INDEX_PATH = str(INDEX_DIR / "documents.diskann")
    BACKEND_TO_TEST = "diskann"

    if INDEX_DIR.exists():
        print(f"--- Cleaning up old index directory: {INDEX_DIR} ---")
        shutil.rmtree(INDEX_DIR)

    # --- 1. Build index ---
    print(f"\n[PHASE 1] Building index using '{BACKEND_TO_TEST}' backend...")

    builder = LeannBuilder(backend_name=BACKEND_TO_TEST, graph_degree=32, complexity=64)

    documents = load_sample_documents()
    print(f"Loaded {len(documents)} sample documents.")
    for doc in documents:
        builder.add_text(doc["content"], metadata={"title": doc["title"]})

    builder.build_index(INDEX_PATH)
    print("\nIndex built!")

    # --- 2. Basic search demo ---
    print(f"\n[PHASE 2] Basic search using '{BACKEND_TO_TEST}' backend...")
    searcher = LeannSearcher(index_path=INDEX_PATH)

    query = "What is machine learning?"
    print(f"\nQuery: '{query}'")

    print("\n--- Basic search mode (PQ computation) ---")
    start_time = time.time()
    results = searcher.search(query, top_k=2)
    basic_time = time.time() - start_time

    print(f"⏱️  Basic search time: {basic_time:.3f} seconds")
    print(">>> Basic search results <<<")
    for i, res in enumerate(results, 1):
        print(
            f"  {i}. ID: {res.id}, Score: {res.score:.4f}, Text: '{res.text}', Metadata: {res.metadata}"
        )

    # --- 3. Recompute search demo ---
    print("\n[PHASE 3] Recompute search using embedding server...")

    print("\n--- Recompute search mode (get real embeddings via network) ---")

    # Configure recompute parameters
    recompute_params = {
        "recompute_beighbor_embeddings": True,  # Enable network recomputation
        "USE_DEFERRED_FETCH": False,  # Don't use deferred fetch
        "skip_search_reorder": True,  # Skip search reordering
        "dedup_node_dis": True,  # Enable node distance deduplication
        "prune_ratio": 0.1,  # Pruning ratio 10%
        "batch_recompute": False,  # Don't use batch recomputation
        "global_pruning": False,  # Don't use global pruning
        "zmq_port": 5555,  # ZMQ port
        "embedding_model": "sentence-transformers/all-mpnet-base-v2",
    }

    print("Recompute parameter configuration:")
    for key, value in recompute_params.items():
        print(f"  {key}: {value}")

    print("\n🔄 Executing Recompute search...")
    try:
        start_time = time.time()
        recompute_results = searcher.search(query, top_k=2, **recompute_params)
        recompute_time = time.time() - start_time

        print(f"⏱️  Recompute search time: {recompute_time:.3f} seconds")
        print(">>> Recompute search results <<<")
        for i, res in enumerate(recompute_results, 1):
            print(
                f"  {i}. ID: {res.id}, Score: {res.score:.4f}, Text: '{res.text}', Metadata: {res.metadata}"
            )

        # Compare results
        print("\n--- Result comparison ---")
        print(f"Basic search time: {basic_time:.3f} seconds")
        print(f"Recompute time: {recompute_time:.3f} seconds")

        print("\nBasic search vs Recompute results:")
        for i in range(min(len(results), len(recompute_results))):
            basic_score = results[i].score
            recompute_score = recompute_results[i].score
            score_diff = abs(basic_score - recompute_score)
            print(
                f"  Position {i + 1}: PQ={basic_score:.4f}, Recompute={recompute_score:.4f}, Difference={score_diff:.4f}"
            )

        if recompute_time > basic_time:
            print("✅ Recompute mode working correctly (more accurate but slower)")
        else:
            print("i️  Recompute time is unusually fast, network recomputation may not be enabled")

    except Exception as e:
        print(f"❌ Recompute search failed: {e}")
        print("This usually indicates an embedding server connection issue")

    # --- 4. Chat demo ---
    print("\n[PHASE 4] Starting chat session...")
    chat = LeannChat(index_path=INDEX_PATH)
    chat_response = chat.ask(query)
    print(f"You: {query}")
    print(f"Leann: {chat_response}")

    print("\n==========================================================")
    print("✅ Demo finished successfully!")
    print("==========================================================")


if __name__ == "__main__":
    main()