faiss/tests/test_pq_encoding.cpp

99 lines
2.3 KiB
C++

/**
* Copyright (c) Facebook, Inc. and its affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*/
#include <iostream>
#include <vector>
#include <memory>
#include <gtest/gtest.h>
#include <faiss/impl/ProductQuantizer.h>
namespace {
const std::vector<uint64_t> random_vector(size_t s) {
std::vector<uint64_t> v(s, 0);
for (size_t i = 0; i < s; ++i) {
v[i] = rand();
}
return v;
}
} // namespace
TEST(PQEncoderGeneric, encode) {
const int nsubcodes = 97;
const int minbits = 1;
const int maxbits = 24;
const std::vector<uint64_t> values = random_vector(nsubcodes);
for(int nbits = minbits; nbits <= maxbits; ++nbits) {
std::cerr << "nbits = " << nbits << std::endl;
const uint64_t mask = (1ull << nbits) - 1;
std::unique_ptr<uint8_t[]> codes(
new uint8_t[(nsubcodes * maxbits + 7) / 8]
);
// NOTE(hoss): Necessary scope to ensure trailing bits are flushed to mem.
{
faiss::PQEncoderGeneric encoder(codes.get(), nbits);
for (const auto& v : values) {
encoder.encode(v & mask);
}
}
faiss::PQDecoderGeneric decoder(codes.get(), nbits);
for (int i = 0; i < nsubcodes; ++i) {
uint64_t v = decoder.decode();
EXPECT_EQ(values[i] & mask, v);
}
}
}
TEST(PQEncoder8, encode) {
const int nsubcodes = 100;
const std::vector<uint64_t> values = random_vector(nsubcodes);
const uint64_t mask = 0xFF;
std::unique_ptr<uint8_t[]> codes(new uint8_t[nsubcodes]);
faiss::PQEncoder8 encoder(codes.get(), 8);
for (const auto& v : values) {
encoder.encode(v & mask);
}
faiss::PQDecoder8 decoder(codes.get(), 8);
for (int i = 0; i < nsubcodes; ++i) {
uint64_t v = decoder.decode();
EXPECT_EQ(values[i] & mask, v);
}
}
TEST(PQEncoder16, encode) {
const int nsubcodes = 100;
const std::vector<uint64_t> values = random_vector(nsubcodes);
const uint64_t mask = 0xFFFF;
std::unique_ptr<uint8_t[]> codes(new uint8_t[2 * nsubcodes]);
faiss::PQEncoder16 encoder(codes.get(), 16);
for (const auto& v : values) {
encoder.encode(v & mask);
}
faiss::PQDecoder16 decoder(codes.get(), 16);
for (int i = 0; i < nsubcodes; ++i) {
uint64_t v = decoder.decode();
EXPECT_EQ(values[i] & mask, v);
}
}