/* | |
Copyright (C) 2005 Apple Inc. All rights reserved. | |
This library is free software; you can redistribute it and/or | |
modify it under the terms of the GNU Library General Public | |
License as published by the Free Software Foundation; either | |
version 2 of the License, or (at your option) any later version. | |
This library is distributed in the hope that it will be useful, | |
but WITHOUT ANY WARRANTY; without even the implied warranty of | |
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
Library General Public License for more details. | |
You should have received a copy of the GNU Library General Public License | |
along with this library; see the file COPYING.LIB. If not, write to | |
the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, | |
Boston, MA 02110-1301, USA. | |
*/ | |
#include "config.h" | |
#include "HashTable.h" | |
namespace WTF { | |
#if DUMP_HASHTABLE_STATS | |
int HashTableStats::numAccesses; | |
int HashTableStats::numCollisions; | |
int HashTableStats::collisionGraph[4096]; | |
int HashTableStats::maxCollisions; | |
int HashTableStats::numRehashes; | |
int HashTableStats::numRemoves; | |
int HashTableStats::numReinserts; | |
static HashTableStats logger; | |
static Mutex& hashTableStatsMutex() | |
{ | |
AtomicallyInitializedStatic(Mutex&, mutex = *new Mutex); | |
return mutex; | |
} | |
HashTableStats::~HashTableStats() | |
{ | |
// Don't lock hashTableStatsMutex here because it can cause deadlocks at shutdown | |
// if any thread was killed while holding the mutex. | |
printf("\nWTF::HashTable statistics\n\n"); | |
printf("%d accesses\n", numAccesses); | |
printf("%d total collisions, average %.2f probes per access\n", numCollisions, 1.0 * (numAccesses + numCollisions) / numAccesses); | |
printf("longest collision chain: %d\n", maxCollisions); | |
for (int i = 1; i <= maxCollisions; i++) { | |
printf(" %d lookups with exactly %d collisions (%.2f%% , %.2f%% with this many or more)\n", collisionGraph[i], i, 100.0 * (collisionGraph[i] - collisionGraph[i+1]) / numAccesses, 100.0 * collisionGraph[i] / numAccesses); | |
} | |
printf("%d rehashes\n", numRehashes); | |
printf("%d reinserts\n", numReinserts); | |
} | |
void HashTableStats::recordCollisionAtCount(int count) | |
{ | |
MutexLocker lock(hashTableStatsMutex()); | |
if (count > maxCollisions) | |
maxCollisions = count; | |
numCollisions++; | |
collisionGraph[count]++; | |
} | |
#endif | |
} // namespace WTF |