File size: 4,694 Bytes
3b2f6c9
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
from argparse import ArgumentParser
import json
import numpy as np 
import os
import faiss
import time
from multiprocessing.pool import  Pool
import cohere 
import zstandard

cohere_key = os.environ["COHERE_API_KEY"]
co = cohere.Client(cohere_key)

faiss.omp_set_num_threads(4)

def get_bin_embedding(query, model):
    query_emb = np.asarray(co.embed(texts=[query], model=model, input_type="search_query").embeddings)
    query_emb_bin = np.zeros_like(query_emb, dtype=np.int8)
    query_emb_bin[query_emb > 0] = 1
    query_emb_bin = np.packbits(query_emb_bin, axis=-1)
    return query_emb, query_emb_bin



def search_cluster(args):
    #1) Open Centroid
    with open(os.path.join(args['input_path'], f"emb/{args['cid_folder']}/{args['cid']}.npy"), "rb") as fIn:
        cluster_emb = np.load(fIn)
        cluster_index = faiss.IndexBinaryFlat(cluster_emb.shape[1]*8)
        cluster_index.add(cluster_emb)

    #2) Search
    cluster_scores, cluster_doc_ids = cluster_index.search(args['query_emb_bin'], args['topk'])
    
    return [{'cid': args['cid'], 'doc_idx': doc_idx, 'doc_score': doc_score, 'doc_emb': cluster_emb[doc_idx]} for doc_score, doc_idx in zip(cluster_scores[0], cluster_doc_ids[0])]

def search(args, centroids, query):
    num_rescore = args.topk*5 

    #Query encoding
    start_time = time.time()
    query_emb, query_emb_bin = get_bin_embedding(query, args.model)
    print(f"Query encoding took {(time.time()-start_time)*1000:.2f}ms")

    start_time = time.time()
    #Search nprobe closest centroids
    centroid_scores, centroid_ids = centroids.search(query_emb_bin, args.nprobe)
    centroid_ids = centroid_ids[0]
    print(f"Centroid search took {(time.time()-start_time)*1000:.2f}ms")

    start_time = time.time()
    all_hits = []

    #for cid in centroid_ids:
    #    global_scores.extend(search_cluster(cid, query_emb_bin))

    pool_args = []
    for cid in centroid_ids:
        cid_str = str(cid.item()).zfill(args.ivf['zfill'])
        cid_folder = cid_str[-args.ivf['folder']:]
        pool_args.append({'cid': cid_str, 'cid_folder': cid_folder, 'input_path': args.input, 'topk': args.topk, 'query_emb_bin': query_emb_bin})

    for result in pool.imap_unordered(search_cluster, pool_args, chunksize=10):
        all_hits.extend(result)
 
    #Sort global scores
    all_hits.sort(key=lambda x: x['doc_score'])
    all_hits = all_hits[0:num_rescore]

    print(f"Searching in clusters took {(time.time()-start_time)*1000:.2f}ms"); start_time = time.time()

    #Dense - Binary Rescoring
    for hit in all_hits:
        doc_emb = hit['doc_emb']
        doc_emb_bin_unpacked = np.unpackbits(doc_emb, axis=-1).astype("int")
        doc_emb_bin_unpacked = 2*doc_emb_bin_unpacked-1
        hit['cont_score'] = (query_emb @ doc_emb_bin_unpacked.T).item()

    all_hits.sort(key=lambda x: x['cont_score'], reverse=True)
    all_hits = all_hits[0:args.topk]
    print(f"Dense-Binary rescoring took {(time.time()-start_time)*1000:.2f}ms"); start_time = time.time()
    

    #Fetch documents
    results = []

    for hit in all_hits:
        with zstandard.open(os.path.join(args.input, f"text/{hit['cid'][-args.ivf['folder']:]}/{hit['cid']}.jsonl.zst"), "rt") as fIn:
            for line_idx, line in enumerate(fIn):
                if line_idx == hit['doc_idx']:
                    data = json.loads(line)
                    data['_score'] = hit['cont_score']
                    results.append(data)
                    break

    print(f"Fetch docs took {(time.time()-start_time)*1000:.2f}ms")

    for hit in results[0:3]:
        print(hit)
        print("-------------")


def main():
    parser = ArgumentParser()
    parser.add_argument("--model", default="embed-english-v3.0")
    parser.add_argument("--input", required=True, help="IVF Folder")
    parser.add_argument("--nprobe", type=int, default=100)
    parser.add_argument("--topk", type=int, default=10)
    args = parser.parse_args()

    #Load config
    with open(f"{args.input}/config.json") as fIn:
        args.ivf = json.load(fIn)
    
    
    #Restore centroid index
    with open(os.path.join(args.input, "centroid_vecs.npy"), "rb") as fIn:
        centroid_vec = np.load(fIn)
        print("Centroids shape:", centroid_vec.shape)
        centroids = faiss.IndexBinaryFlat(centroid_vec.shape[1]*8)
        centroids.add(centroid_vec)


    while True:
        query = input("Query: ")
        search(args, centroids, query)
        print("\n===========================\n")


if __name__ == "__main__":
    pool = Pool(processes=8)
    main()