100 lines
2.4 KiB
C++
100 lines
2.4 KiB
C++
/**
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* Copyright (c) Facebook, Inc. and its affiliates.
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*
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* This source code is licensed under the MIT license found in the
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* LICENSE file in the root directory of this source tree.
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*/
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#include <cstdio>
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#include <cstdlib>
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#include <random>
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#include <faiss/IndexFlat.h>
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#include <faiss/gpu/GpuAutoTune.h>
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#include <faiss/gpu/GpuCloner.h>
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#include <faiss/gpu/GpuIndexFlat.h>
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#include <faiss/gpu/StandardGpuResources.h>
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#include <faiss/gpu/utils/DeviceUtils.h>
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int main() {
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int d = 64; // dimension
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int nb = 100000; // database size
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int nq = 10000; // nb of queries
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std::mt19937 rng;
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std::uniform_real_distribution<> distrib;
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float* xb = new float[d * nb];
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float* xq = new float[d * nq];
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for (int i = 0; i < nb; i++) {
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for (int j = 0; j < d; j++)
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xb[d * i + j] = distrib(rng);
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xb[d * i] += i / 1000.;
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}
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for (int i = 0; i < nq; i++) {
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for (int j = 0; j < d; j++)
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xq[d * i + j] = distrib(rng);
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xq[d * i] += i / 1000.;
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}
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int ngpus = faiss::gpu::getNumDevices();
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printf("Number of GPUs: %d\n", ngpus);
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std::vector<faiss::gpu::GpuResourcesProvider*> res;
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std::vector<int> devs;
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for (int i = 0; i < ngpus; i++) {
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res.push_back(new faiss::gpu::StandardGpuResources);
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devs.push_back(i);
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}
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faiss::IndexFlatL2 cpu_index(d);
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faiss::Index* gpu_index =
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faiss::gpu::index_cpu_to_gpu_multiple(res, devs, &cpu_index);
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printf("is_trained = %s\n", gpu_index->is_trained ? "true" : "false");
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gpu_index->add(nb, xb); // add vectors to the index
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printf("ntotal = %ld\n", gpu_index->ntotal);
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int k = 4;
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{ // search xq
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long* I = new long[k * nq];
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float* D = new float[k * nq];
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gpu_index->search(nq, xq, k, D, I);
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// print results
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printf("I (5 first results)=\n");
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for (int i = 0; i < 5; i++) {
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for (int j = 0; j < k; j++)
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printf("%5ld ", I[i * k + j]);
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printf("\n");
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}
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printf("I (5 last results)=\n");
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for (int i = nq - 5; i < nq; i++) {
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for (int j = 0; j < k; j++)
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printf("%5ld ", I[i * k + j]);
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printf("\n");
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}
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delete[] I;
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delete[] D;
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}
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delete gpu_index;
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for (int i = 0; i < ngpus; i++) {
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delete res[i];
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}
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delete[] xb;
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delete[] xq;
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return 0;
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}
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