小组成员:谢瑞阳、徐翔宇
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// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file. See the AUTHORS file for names of contributors.
#include "util/crc32c.h"
#include "util/testharness.h"
namespace leveldb {
namespace crc32c {
class CRC { };
TEST(CRC, StandardResults) {
// From rfc3720 section B.4.
char buf[32];
memset(buf, 0, sizeof(buf));
ASSERT_EQ(0x8a9136aa, Value(buf, sizeof(buf)));
memset(buf, 0xff, sizeof(buf));
ASSERT_EQ(0x62a8ab43, Value(buf, sizeof(buf)));
for (int i = 0; i < 32; i++) {
buf[i] = i;
}
ASSERT_EQ(0x46dd794e, Value(buf, sizeof(buf)));
for (int i = 0; i < 32; i++) {
buf[i] = 31 - i;
}
ASSERT_EQ(0x113fdb5c, Value(buf, sizeof(buf)));
unsigned char data[48] = {
0x01, 0xc0, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x14, 0x00, 0x00, 0x00,
0x00, 0x00, 0x04, 0x00,
0x00, 0x00, 0x00, 0x14,
0x00, 0x00, 0x00, 0x18,
0x28, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x02, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
};
ASSERT_EQ(0xd9963a56, Value(reinterpret_cast<char*>(data), sizeof(data)));
}
TEST(CRC, Values) {
ASSERT_NE(Value("a", 1), Value("foo", 3));
}
TEST(CRC, Extend) {
ASSERT_EQ(Value("hello world", 11),
Extend(Value("hello ", 6), "world", 5));
}
TEST(CRC, Mask) {
uint32_t crc = Value("foo", 3);
ASSERT_NE(crc, Mask(crc));
ASSERT_NE(crc, Mask(Mask(crc)));
ASSERT_EQ(crc, Unmask(Mask(crc)));
ASSERT_EQ(crc, Unmask(Unmask(Mask(Mask(crc)))));
}
TEST(CRC, Benchmark) {
std::string data(1048576 * 100, 'x');
double start = Env::Default()->NowMicros() * 1e-6;
static const int kIters = 10;
uint32_t crc = 0;
for (int i = 0; i < kIters; i++) {
crc |= Value(data.data(), data.size());
}
double finish = Env::Default()->NowMicros() * 1e-6;
double mb = (static_cast<long long int>(data.size()) * kIters) / 1048576.0;
fprintf(stderr, "CRC %0.0f MB: %.3f secs; %.1f MB/s, crc=0x%08x\n",
mb, (finish - start), mb / (finish - start), crc);
}
}
}
int main(int argc, char** argv) {
return leveldb::test::RunAllTests();
}