Mirror/zeek
1
0
Fork 0
mirror of https://github.com/zeek/zeek.git synced 2025-10-14 04:28:20 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 2

Merge remote-tracking branch 'origin/topic/matthias/bloom-filter'

Browse source 
* origin/topic/matthias/bloom-filter:
  Add new BiF for low-level Bloom filter initialization.
  Introduce global_hash_seed script variable.
This commit is contained in:
Robin Sommer 2013-07-31 11:41:08 -07:00
commit 6c197fbebf
8 changed files with 157 additions and 79 deletions
Download patch file Download diff file Expand all files Collapse all files

83
src/probabilistic/Hasher.cc
View file

@ -3,11 +3,34 @@
#include <typeinfo>
#include "Hasher.h"
#include "NetVar.h"
#include "digest.h"
#include "Serializer.h"
using namespace probabilistic;
size_t Hasher::MakeSeed(const void* data, size_t size)
{
u_char buf[SHA256_DIGEST_LENGTH];
SHA256_CTX ctx;
sha256_init(&ctx);
if ( data )
sha256_update(&ctx, data, size);
else if ( global_hash_seed && global_hash_seed->Len() > 0 )
sha256_update(&ctx, global_hash_seed->Bytes(), global_hash_seed->Len());
else
{
unsigned int first_seed = initial_seed();
sha256_update(&ctx, &first_seed, sizeof(first_seed));
}
sha256_final(&ctx, buf);
return *reinterpret_cast<size_t*>(buf); // Use the first bytes as seed.
}
bool Hasher::Serialize(SerialInfo* info) const
{
return SerialObj::Serialize(info);
@ -25,7 +48,7 @@ bool Hasher::DoSerialize(SerialInfo* info) const
if ( ! SERIALIZE(static_cast<uint16>(k)) )
return false;
return SERIALIZE_STR(name.c_str(), name.size());
return SERIALIZE(static_cast<uint64>(seed));
}
bool Hasher::DoUnserialize(UnserialInfo* info)
@ -39,26 +62,24 @@ bool Hasher::DoUnserialize(UnserialInfo* info)
k = serial_k;
assert(k > 0);
const char* serial_name;
if ( ! UNSERIALIZE_STR(&serial_name, 0) )
uint64 serial_seed;
if ( ! UNSERIALIZE(&serial_seed) )
return false;
name = serial_name;
delete [] serial_name;
seed = serial_seed;
return true;
}
Hasher::Hasher(size_t k, const std::string& arg_name)
: k(k)
Hasher::Hasher(size_t arg_k, size_t arg_seed)
{
k = k;
name = arg_name;
k = arg_k;
seed = arg_seed;
}
UHF::UHF(size_t seed, const std::string& extra)
: h(compute_seed(seed, extra))
UHF::UHF(size_t seed)
: h(seed)
{
}
@ -68,33 +89,11 @@ Hasher::digest UHF::hash(const void* x, size_t n) const
return n == 0 ? 0 : h(x, n);
}
size_t UHF::compute_seed(size_t seed, const std::string& extra)
DefaultHasher::DefaultHasher(size_t k, size_t seed)
: Hasher(k, seed)
{
u_char buf[SHA256_DIGEST_LENGTH];
SHA256_CTX ctx;
sha256_init(&ctx);
if ( extra.empty() )
{
unsigned int first_seed = initial_seed();
sha256_update(&ctx, &first_seed, sizeof(first_seed));
}
else
sha256_update(&ctx, extra.c_str(), extra.size());
sha256_update(&ctx, &seed, sizeof(seed));
sha256_final(&ctx, buf);
// Take the first sizeof(size_t) bytes as seed.
return *reinterpret_cast<size_t*>(buf);
}
DefaultHasher::DefaultHasher(size_t k, const std::string& name)
: Hasher(k, name)
{
for ( size_t i = 0; i < k; ++i )
hash_functions.push_back(UHF(i, name));
for ( size_t i = 1; i <= k; ++i )
hash_functions.push_back(UHF(Seed() + bro_prng(i)));
}
Hasher::digest_vector DefaultHasher::Hash(const void* x, size_t n) const
@ -137,13 +136,13 @@ bool DefaultHasher::DoUnserialize(UnserialInfo* info)
hash_functions.clear();
for ( size_t i = 0; i < K(); ++i )
hash_functions.push_back(UHF(i, Name()));
hash_functions.push_back(UHF(Seed() + bro_prng(i)));
return true;
}
DoubleHasher::DoubleHasher(size_t k, const std::string& name)
: Hasher(k, name), h1(1, name), h2(2, name)
DoubleHasher::DoubleHasher(size_t k, size_t seed)
: Hasher(k, seed), h1(seed + bro_prng(1)), h2(seed + bro_prng(2))
{
}
@ -187,8 +186,8 @@ bool DoubleHasher::DoUnserialize(UnserialInfo* info)
{
DO_UNSERIALIZE(Hasher);
h1 = UHF(1, Name());
h2 = UHF(2, Name());
h1 = UHF(Seed() + bro_prng(1));
h2 = UHF(Seed() + bro_prng(2));
return true;
}