Verified Commit 330eb623 authored by Marc Vef's avatar Marc Vef
Browse files

Remove double hash from random slicing

parent 52a03054

src/common/rpc/distributor.cpp

+0 −2
Original line number Diff line number Diff line
@@ -322,8 +322,6 @@ host_t 
RandomSlicingDistributor::locate_file_metadata(const std::string& path,

                                               const int num_copy) const {

    auto myhash = str_hash(path);

    // TODO placeExtent hashes the hash with it's own hash, is this a problem?

    // (migh be unavoidable if multiple copies should be stored sometime)

    return dist_impl_->placeExtent(myhash);

}

src/common/rpc/random_slicing/dist_rand_slice.cpp

+11 −3
Original line number Diff line number Diff line
@@ -262,6 +262,7 @@ DistRandSlice::partition_capacity(Disk* disk, uint64_t new_total_capacity) { 
/**

 * 64 bit Integer Hash Function

 * found at http://www.concentric.net/~Ttwang/tech/inthash.htm by Thomas Wang

 * currently unused

 */

static inline uint64_t

my_hash(int64_t i) {
@@ -287,11 +288,18 @@ my_hash(int64_t i) { 


uint64_t

DistRandSlice::placeExtent(int64_t position) {

    // function heavily modified for GekkoFS

    assert(m_copies == 1);

    uint64_t key = my_hash(position);

    // original uses my_hash function.

    //    uint64_t key = my_hash(position);

    // For debugging with smaller VSPACE_MAX.

    if(DistRandSlice::VSPACE_MAX != UINT64_MAX) {

#ifndef DEBUG

        assert(!"Running with VSPACE_MAX != UINT64_MAX but no DEBUG");

#endif

        position = position % DistRandSlice::VSPACE_MAX;

    }

    uint64_t partition_id = 0;

    m_interval_tree->search_tree(key, partition_id);

    m_interval_tree->search_tree(position, partition_id);

    return partition_id;

}