void
CountMinSketchAdd(CountMinSketch *cms, void *key, Size size, uint32_t count)
{
/*
* Since we only have positive increments, we're using the conservative update
* variant which apparently has better accuracy--albeit moderately slower.
*
* http://dimacs.rutgers.edu/~graham/pubs/papers/cmencyc.pdf
*/
uint32_t min = UINT_MAX;
uint32_t i;
uint64_t hash[2];
MurmurHash3_128(key, size, MURMUR_SEED, &hash);
for (i = 0; i < cms->d; i++)
{
uint32_t start = i * cms->w;
uint32_t j = (hash[0] + (i * hash[1])) % cms->w;
min = Min(min, cms->table[start + j]);
}
for (i = 0; i < cms->d; i++)
{
uint32_t start = i * cms->w;
uint32_t j = (hash[0] + (i * hash[1])) % cms->w;
cms->table[start + j] = Max(cms->table[start + j], min + count);
}
cms->count += count;
}
//-----------------------------------------------------------------------------
String ProgramManager::generateHash(const String& programString)
{
//Different programs must have unique hash values.
uint32_t hash[4];
MurmurHash3_128(programString.c_str(), programString.size(), 0, hash);
//Generate the string
char str[33];
sprintf(str, "%08x%08x%08x%08x", hash[0], hash[1], hash[2], hash[3]);
return String(str);
}
Bool CheckKmerInBloomFilter(BloomFilter* const bf, const Kmer word) {
uint128_t last_hash = bf->seed;
uint idx;
uint128_t hash;
for (idx = 0; idx < bf->num_hash_functions; idx++) {
if (MurmurHash3_128((char*)&word,
sizeof(Kmer),
last_hash,
&hash) == FALSE) {
PrintThenDie("could not ascertain hash for kmer");
}
if (CheckBit(bf->bs, hash % bf->num_bits) == 0) {
return FALSE;
}
last_hash = hash;
}
return TRUE;
}
uint32_t
CountMinSketchEstimateCount(CountMinSketch *cms, void *key, Size size)
{
uint32_t count = UINT_MAX;
uint32_t i;
uint64_t hash[2];
MurmurHash3_128(key, size, MURMUR_SEED, &hash);
for (i = 0; i < cms->d; i++)
{
uint32_t start = i * cms->w;
uint32_t j = (hash[0] + (i * hash[1])) % cms->w;
count = Min(count, cms->table[start + j]);
}
return count;
}
void AddKmerToBloomFilter(BloomFilter* const bf, const Kmer word) {
uint128_t last_hash = bf->seed;
uint idx;
uint128_t hash;
Bool is_added = FALSE;
for (idx = 0; idx < bf->num_hash_functions; idx++){
if (MurmurHash3_128((char*)&word,
sizeof(Kmer),
last_hash,
&hash) == FALSE) {
PrintThenDie("could not ascertain hash for kmer");
}
if(SetBit(bf->bs, hash % bf->num_bits) == FALSE){
assert(CheckBit(bf->bs, hash % bf->num_bits) > 0);
bf->num_set_bits += 1;
is_added = TRUE;
}
last_hash = hash;
}
if (is_added == TRUE) {
bf->num_entries_added += 1;
}
}
