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Also switch BloomFilters from H3 to siphash.

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This removes all dependencies on H3 in our source tree.
This commit is contained in:
Johanna Amann 2016-07-13 09:04:10 -07:00
parent e1218cc7fa
commit f1bae871e9
8 changed files with 78 additions and 178 deletions
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52
src/probabilistic/Hasher.cc
View file

@ -8,15 +8,21 @@
#include "digest.h"
#include "Serializer.h"
extern "C" {
extern int siphash( uint8_t *out, const uint8_t *in, uint64_t inlen, const uint8_t *k );
}
using namespace probabilistic;
uint64 Hasher::MakeSeed(const void* data, size_t size)
Hasher::seed_t Hasher::MakeSeed(const void* data, size_t size)
{
u_char buf[SHA256_DIGEST_LENGTH];
uint64 tmpseed;
seed_t tmpseed;
SHA256_CTX ctx;
sha256_init(&ctx);
assert(sizeof(tmpseed) == 16);
if ( data )
sha256_update(&ctx, data, size);
@ -56,7 +62,8 @@ bool Hasher::DoSerialize(SerialInfo* info) const
if ( ! SERIALIZE(static_cast<uint16>(k)) )
return false;
return SERIALIZE(static_cast<uint64>(seed));
return SERIALIZE(static_cast<uint64>(seed.h1));
return SERIALIZE(static_cast<uint64>(seed.h2));
}
bool Hasher::DoUnserialize(UnserialInfo* info)
@ -70,8 +77,10 @@ bool Hasher::DoUnserialize(UnserialInfo* info)
k = serial_k;
assert(k > 0);
uint64 serial_seed;
if ( ! UNSERIALIZE(&serial_seed) )
seed_t serial_seed;
if ( ! UNSERIALIZE(&serial_seed.h1) )
return false;
if ( ! UNSERIALIZE(&serial_seed.h2) )
return false;
seed = serial_seed;
@ -79,14 +88,18 @@ bool Hasher::DoUnserialize(UnserialInfo* info)
return true;
}
Hasher::Hasher(size_t arg_k, size_t arg_seed)
Hasher::Hasher(size_t arg_k, seed_t arg_seed)
{
k = arg_k;
seed = arg_seed;
}
UHF::UHF(size_t arg_seed)
: h(arg_seed)
UHF::UHF()
{
memset(&seed, 0, sizeof(seed));
}
UHF::UHF(Hasher::seed_t arg_seed)
{
seed = arg_seed;
}
@ -96,8 +109,13 @@ UHF::UHF(size_t arg_seed)
// times.
Hasher::digest UHF::hash(const void* x, size_t n) const
{
assert(sizeof(Hasher::seed_t) == 16);
hash_t outdigest;
if ( n <= UHASH_KEY_SIZE )
return n == 0 ? 0 : h(x, n);
{
siphash(reinterpret_cast<uint8_t*>(&outdigest), reinterpret_cast<const uint8_t*>(x), n, reinterpret_cast<const uint8_t*>(&seed));
return outdigest;
}
unsigned char d[16];
MD5(reinterpret_cast<const unsigned char*>(x), n, d);
@ -111,11 +129,15 @@ Hasher::digest UHF::hash(const void* x, size_t n) const
return *reinterpret_cast<const Hasher::digest*>(d);
}
DefaultHasher::DefaultHasher(size_t k, size_t seed)
DefaultHasher::DefaultHasher(size_t k, Hasher::seed_t seed)
: Hasher(k, seed)
{
for ( size_t i = 1; i <= k; ++i )
hash_functions.push_back(UHF(Seed() + bro_prng(i)));
{
seed_t s = Seed();
s.h1 += bro_prng(i);
hash_functions.push_back(UHF(s));
}
}
Hasher::digest_vector DefaultHasher::Hash(const void* x, size_t n) const
@ -158,12 +180,16 @@ bool DefaultHasher::DoUnserialize(UnserialInfo* info)
hash_functions.clear();
for ( size_t i = 0; i < K(); ++i )
hash_functions.push_back(UHF(Seed() + bro_prng(i)));
{
Hasher::seed_t s = Seed();
s.h1 += bro_prng(i);
hash_functions.push_back(UHF(s));
}
return true;
}
DoubleHasher::DoubleHasher(size_t k, size_t seed)
DoubleHasher::DoubleHasher(size_t k, seed_t seed)
: Hasher(k, seed), h1(seed + bro_prng(1)), h2(seed + bro_prng(2))
{
}