blob: cf9d65c59edbb6f344c0f7b945443d7b21fbdf3c [file] [log] [blame]
epoger@google.com4adfab82012-11-02 18:35:04 +00001/*
2 * Copyright 2012 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
epoger@google.com31114c62012-12-12 17:22:23 +00007
epoger@google.com4adfab82012-11-02 18:35:04 +00008#include "SkChecksum.h"
commit-bot@chromium.org2b0f7c32014-01-09 17:48:48 +00009#include "SkRandom.h"
10#include "Test.h"
epoger@google.com0bba6bd2012-12-07 15:12:01 +000011
epoger@google.com4adfab82012-11-02 18:35:04 +000012
commit-bot@chromium.org2b0f7c32014-01-09 17:48:48 +000013// Murmur3 has an optional third seed argument, so we wrap it to fit a uniform type.
reedbbf9f6d2014-07-10 14:29:43 -070014static uint32_t murmur_noseed(const uint32_t* d, size_t l) { return SkChecksum::Murmur3(d, l); }
commit-bot@chromium.org2b0f7c32014-01-09 17:48:48 +000015
16#define ASSERT(x) REPORTER_ASSERT(r, x)
17
18DEF_TEST(Checksum, r) {
19 // Algorithms to test. They're currently all uint32_t(const uint32_t*, size_t).
reedbbf9f6d2014-07-10 14:29:43 -070020 typedef uint32_t(*algorithmProc)(const uint32_t*, size_t);
mtklein56da0252015-11-16 11:16:23 -080021 const algorithmProc kAlgorithms[] = { &murmur_noseed };
commit-bot@chromium.org2b0f7c32014-01-09 17:48:48 +000022
23 // Put 128 random bytes into two identical buffers. Any multiple of 4 will do.
24 const size_t kBytes = SkAlign4(128);
25 SkRandom rand;
26 uint32_t data[kBytes/4], tweaked[kBytes/4];
27 for (size_t i = 0; i < SK_ARRAY_COUNT(tweaked); ++i) {
28 data[i] = tweaked[i] = rand.nextU();
29 }
30
31 // Test each algorithm.
32 for (size_t i = 0; i < SK_ARRAY_COUNT(kAlgorithms); ++i) {
33 const algorithmProc algorithm = kAlgorithms[i];
34
halcanary96fcdcc2015-08-27 07:41:13 -070035 // Hash of nullptr is always 0.
36 ASSERT(algorithm(nullptr, 0) == 0);
commit-bot@chromium.org2b0f7c32014-01-09 17:48:48 +000037
38 const uint32_t hash = algorithm(data, kBytes);
39 // Should be deterministic.
40 ASSERT(hash == algorithm(data, kBytes));
41
42 // Changing any single element should change the hash.
43 for (size_t j = 0; j < SK_ARRAY_COUNT(tweaked); ++j) {
44 const uint32_t saved = tweaked[j];
45 tweaked[j] = rand.nextU();
46 const uint32_t tweakedHash = algorithm(tweaked, kBytes);
47 ASSERT(tweakedHash != hash);
48 ASSERT(tweakedHash == algorithm(tweaked, kBytes));
49 tweaked[j] = saved;
epoger@google.com4adfab82012-11-02 18:35:04 +000050 }
commit-bot@chromium.org2b0f7c32014-01-09 17:48:48 +000051 }
epoger@google.com4adfab82012-11-02 18:35:04 +000052}
mtklein02f46cf2015-03-20 13:48:42 -070053
54DEF_TEST(GoodHash, r) {
mtkleinc8d1dd42015-10-15 12:23:01 -070055 ASSERT(SkGoodHash()(( int32_t)4) == 614249093); // 4 bytes. Hits SkChecksum::Mix fast path.
56 ASSERT(SkGoodHash()((uint32_t)4) == 614249093); // (Ditto)
mtklein02f46cf2015-03-20 13:48:42 -070057
58 // None of these are 4 byte sized, so they use SkChecksum::Murmur3, not SkChecksum::Mix.
mtkleinc8d1dd42015-10-15 12:23:01 -070059 ASSERT(SkGoodHash()((uint64_t)4) == 3491892518);
60 ASSERT(SkGoodHash()((uint16_t)4) == 899251846);
61 ASSERT(SkGoodHash()( (uint8_t)4) == 962700458);
mtklein02f46cf2015-03-20 13:48:42 -070062
63 // Tests SkString is correctly specialized.
mtkleinc8d1dd42015-10-15 12:23:01 -070064 ASSERT(SkGoodHash()(SkString("Hi")) == 55667557);
mtklein02f46cf2015-03-20 13:48:42 -070065}