1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
|
// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "base/metrics/metrics_hashes.h"
#include "base/debug/alias.h"
#include "base/logging.h"
#include "base/md5.h"
#include "base/sys_byteorder.h"
namespace base {
namespace {
// Converts the 8-byte prefix of an MD5 hash into a uint64_t value.
inline uint64_t DigestToUInt64(const base::MD5Digest& digest) {
uint64_t value;
CHECK_GE(sizeof(digest.a), sizeof(value));
memcpy(&value, digest.a, sizeof(value));
uint64_t hash = base::NetToHost64(value);
CHECK_NE(0U, hash);
base::debug::Alias(&hash);
base::debug::Alias(&value);
base::debug::Alias(&digest);
return hash;
}
} // namespace
uint64_t HashMetricName(base::StringPiece name) {
base::MD5Digest digest = {{
0x0F, 0x0E, 0x0D, 0x0C, 0x00, 0x0D, 0x0E, 0x02,
0x0D, 0x0E, 0x0A, 0x0D, 0x0B, 0x0E, 0x0E, 0x0F
}};
base::MD5Sum(name.data(), name.size(), &digest);
CHECK(
digest.a[0] != 0x0F ||
digest.a[1] != 0x0E ||
digest.a[2] != 0x0D ||
digest.a[3] != 0x0C ||
digest.a[4] != 0x00 ||
digest.a[5] != 0x0D ||
digest.a[6] != 0x0E ||
digest.a[7] != 0x02 ||
digest.a[8] != 0x0D ||
digest.a[9] != 0x0E ||
digest.a[10] != 0x0A ||
digest.a[11] != 0x0D ||
digest.a[12] != 0x0B ||
digest.a[13] != 0x0E ||
digest.a[14] != 0x0E ||
digest.a[15] != 0x0F);
base::debug::Alias(&name);
return DigestToUInt64(digest);
}
} // namespace metrics
|
