c api - faiss_index_cpu_to_gpu_multiple_with_options not available from c api

[AviadHAv]

Summary

Platform

OS: linux ubuntu 18.04

Faiss version: c08cbff v1.7.2

Installed from: compiled from source

Faiss compilation options: -DBUILD_TESTING=OFF -DFAISS_ENABLE_GPU=ON -DCMAKE_CXX_COMPILER=g++-6 -DFAISS_ENABLE_C_API=ON -DBUILD_SHARED_LIBS=ON -DFAISS_ENABLE_PYTHON=OFF -DFAISS_OPT_LEVEL=avx2

Running on:

• CPU
• GPU

Interface:

• C
• C++
• Python

Reproduction instructions

compiling faiss from source version 1.7.2

cd /faiss && git checkout v1.7.2 && cmake -B build . -DBUILD_TESTING=OFF -DFAISS_ENABLE_GPU=ON -DCMAKE_CXX_COMPILER=g++-6 -DFAISS_ENABLE_C_API=ON -DBUILD_SHARED_LIBS=ON -DFAISS_ENABLE_PYTHON=OFF -DFAISS_OPT_LEVEL=avx2\
    && make -C build -j4 faiss \
    && make -C build -j4 install \
    && cp ./build/c_api/libfaiss_c.so /usr/lib/

Problem

while compiling faiss to consume from c app the function faiss_index_cpu_to_gpu_multiple_with_options is supported only in cpp and not from c

root@2d434f518b21:/build/reid-service# readelf --symbols --wide /usr/lib/libfaiss_c.so | grep faiss_index_cpu_to_gpu_multiple_with_options
   272: 0000000000030475  1170 FUNC    GLOBAL DEFAULT   12 _Z44faiss_index_cpu_to_gpu_multiple_with_optionsPP27FaissGpuResourcesProvider_HmPimPK12FaissIndex_HPK23FaissGpuClonerOptions_HPPS3_
   491: 0000000000030475  1170 FUNC    GLOBAL DEFAULT   12 _Z44faiss_index_cpu_to_gpu_multiple_with_optionsPP27FaissGpuResourcesProvider_HmPimPK12FaissIndex_HPK23FaissGpuClonerOptions_HPPS3_

i wanted to get this from readelf faiss_index_cpu_to_gpu_multiple_with_options but got this_Z44faiss_index_cpu_to_gpu_multiple_with_optionsPP27FaissGpuResourcesProvider_HmPimPK12FaissIndex_HPK23FaissGpuClonerOptions_HPPS3_

while other functions are aviable for c api

566: 000000000002fff7  1150 FUNC    GLOBAL DEFAULT   12 faiss_index_cpu_to_gpu_multiple
   308: 000000000002fff7  1150 FUNC    GLOBAL DEFAULT   12 faiss_index_cpu_to_gpu_multiple

[AviadHAv]

int faiss_nothing(
        FaissGpuResourcesProvider* const* providers_vec,
        size_t providers_vec_size,
        const int* devices,
        size_t devices_size,
        const FaissIndex* index,
        void* x,
        FaissGpuIndex** p_out) {
    FaissGpuMultipleClonerOptions* options = reinterpret_cast<FaissGpuMultipleClonerOptions*>(x);
    try {
        std::vector<GpuResourcesProvider*> res(providers_vec_size);
        for (auto i = 0u; i < providers_vec_size; ++i) {
            res[i] = reinterpret_cast<GpuResourcesProvider*>(providers_vec[i]);
        }

        std::vector<int> dev(devices, devices + devices_size);

        auto gpu_index = faiss::gpu::index_cpu_to_gpu_multiple(
                res,
                dev,
                reinterpret_cast<const Index*>(index),
                reinterpret_cast<const GpuMultipleClonerOptions*>(options));
        *p_out = reinterpret_cast<FaissGpuIndex*>(gpu_index);
    }
    CATCH_AND_HANDLE
}

seems when replacing FaissGpuMultipleClonerOptions with void pointer and do casting solve the problem