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1 /* | |
2 Copyright (C) 2005 Apple Inc. All rights reserved. | |
3 | |
4 This library is free software; you can redistribute it and/or | |
5 modify it under the terms of the GNU Library General Public | |
6 License as published by the Free Software Foundation; either | |
7 version 2 of the License, or (at your option) any later version. | |
8 | |
9 This library is distributed in the hope that it will be useful, | |
10 but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
12 Library General Public License for more details. | |
13 | |
14 You should have received a copy of the GNU Library General Public License | |
15 along with this library; see the file COPYING.LIB. If not, write to | |
16 the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, | |
17 Boston, MA 02110-1301, USA. | |
18 */ | |
19 | |
20 #include "config.h" | |
21 #include "HashTable.h" | |
22 #include "DataLog.h" | |
23 | |
24 namespace WTF { | |
25 | |
26 #if DUMP_HASHTABLE_STATS | |
27 | |
28 int HashTableStats::numAccesses; | |
29 int HashTableStats::numCollisions; | |
30 int HashTableStats::collisionGraph[4096]; | |
31 int HashTableStats::maxCollisions; | |
32 int HashTableStats::numRehashes; | |
33 int HashTableStats::numRemoves; | |
34 int HashTableStats::numReinserts; | |
35 | |
36 static Mutex& hashTableStatsMutex() | |
37 { | |
38 AtomicallyInitializedStatic(Mutex&, mutex = *new Mutex); | |
39 return mutex; | |
40 } | |
41 | |
42 void HashTableStats::recordCollisionAtCount(int count) | |
43 { | |
44 MutexLocker lock(hashTableStatsMutex()); | |
45 if (count > maxCollisions) | |
46 maxCollisions = count; | |
47 numCollisions++; | |
48 collisionGraph[count]++; | |
49 } | |
50 | |
51 void HashTableStats::dumpStats() | |
52 { | |
53 MutexLocker lock(hashTableStatsMutex()); | |
54 | |
55 dataLogF("\nWTF::HashTable statistics\n\n"); | |
56 dataLogF("%d accesses\n", numAccesses); | |
57 dataLogF("%d total collisions, average %.2f probes per access\n", numCollisi
ons, 1.0 * (numAccesses + numCollisions) / numAccesses); | |
58 dataLogF("longest collision chain: %d\n", maxCollisions); | |
59 for (int i = 1; i <= maxCollisions; i++) { | |
60 dataLogF(" %d lookups with exactly %d collisions (%.2f%% , %.2f%% with
this many or more)\n", collisionGraph[i], i, 100.0 * (collisionGraph[i] - collis
ionGraph[i+1]) / numAccesses, 100.0 * collisionGraph[i] / numAccesses); | |
61 } | |
62 dataLogF("%d rehashes\n", numRehashes); | |
63 dataLogF("%d reinserts\n", numReinserts); | |
64 } | |
65 | |
66 #endif | |
67 | |
68 } // namespace WTF | |
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