simple_util.cc revision 58537e28ecd584eab876aee8be7156509866d23a 
1// Copyright (c) 2013 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#include "net/disk_cache/simple/simple_util.h"
6
7#include <limits>
8
9#include "base/file_util.h"
10#include "base/format_macros.h"
11#include "base/logging.h"
12#include "base/sha1.h"
13#include "base/strings/string_number_conversions.h"
14#include "base/strings/stringprintf.h"
15#include "base/threading/thread_restrictions.h"
16#include "base/time/time.h"
17#include "net/disk_cache/simple/simple_entry_format.h"
18
19namespace {
20
21// Size of the uint64 hash_key number in Hex format in a string.
22const size_t kEntryHashKeyAsHexStringSize = 2 * sizeof(uint64);
23
24// TODO(clamy, gavinp): this should go in base
25bool GetNanoSecsFromStat(const struct stat& st,
26                         time_t* out_sec,
27                         long* out_nsec) {
28#if defined(OS_ANDROID)
29  *out_sec = st.st_mtime;
30  *out_nsec = st.st_mtime_nsec;
31#elif defined(OS_LINUX)
32  *out_sec = st.st_mtim.tv_sec;
33  *out_nsec = st.st_mtim.tv_nsec;
34#elif defined(OS_MACOSX) || defined(OS_IOS) || defined(OS_BSD)
35  *out_sec = st.st_mtimespec.tv_sec;
36  *out_nsec = st.st_mtimespec.tv_nsec;
37#else
38  return false;
39#endif
40  return true;
41}
42
43}  // namespace
44
45namespace disk_cache {
46
47namespace simple_util {
48
49std::string ConvertEntryHashKeyToHexString(uint64 hash_key) {
50  const std::string hash_key_str = base::StringPrintf("%016" PRIx64, hash_key);
51  DCHECK_EQ(kEntryHashKeyAsHexStringSize, hash_key_str.size());
52  return hash_key_str;
53}
54
55std::string GetEntryHashKeyAsHexString(const std::string& key) {
56  std::string hash_key_str =
57      ConvertEntryHashKeyToHexString(GetEntryHashKey(key));
58  DCHECK_EQ(kEntryHashKeyAsHexStringSize, hash_key_str.size());
59  return hash_key_str;
60}
61
62bool GetEntryHashKeyFromHexString(const base::StringPiece& hash_key,
63                                  uint64* hash_key_out) {
64  if (hash_key.size() != kEntryHashKeyAsHexStringSize) {
65    return false;
66  }
67  return base::HexStringToUInt64(hash_key, hash_key_out);
68}
69
70uint64 GetEntryHashKey(const std::string& key) {
71  union {
72    unsigned char sha_hash[base::kSHA1Length];
73    uint64 key_hash;
74  } u;
75  base::SHA1HashBytes(reinterpret_cast<const unsigned char*>(key.data()),
76                      key.size(), u.sha_hash);
77  return u.key_hash;
78}
79
80std::string GetFilenameFromEntryHashAndIndex(uint64 entry_hash,
81                                             int index) {
82  return base::StringPrintf("%016" PRIx64 "_%1d", entry_hash, index);
83}
84
85std::string GetFilenameFromKeyAndIndex(const std::string& key, int index) {
86  return GetEntryHashKeyAsHexString(key) + base::StringPrintf("_%1d", index);
87}
88
89int32 GetDataSizeFromKeyAndFileSize(const std::string& key, int64 file_size) {
90  int64 data_size = file_size - key.size() - sizeof(SimpleFileHeader) -
91                    sizeof(SimpleFileEOF);
92  DCHECK_GE(implicit_cast<int64>(std::numeric_limits<int32>::max()), data_size);
93  return data_size;
94}
95
96int64 GetFileSizeFromKeyAndDataSize(const std::string& key, int32 data_size) {
97  return data_size + key.size() + sizeof(SimpleFileHeader) +
98      sizeof(SimpleFileEOF);
99}
100
101int64 GetFileOffsetFromKeyAndDataOffset(const std::string& key,
102                                        int data_offset) {
103  const int64 headers_size = sizeof(disk_cache::SimpleFileHeader) + key.size();
104  return headers_size + data_offset;
105}
106
107// TODO(clamy, gavinp): this should go in base
108bool GetMTime(const base::FilePath& path, base::Time* out_mtime) {
109  DCHECK(out_mtime);
110#if defined(OS_POSIX)
111  base::ThreadRestrictions::AssertIOAllowed();
112  struct stat file_stat;
113  if (stat(path.value().c_str(), &file_stat) != 0)
114    return false;
115  time_t sec;
116  long nsec;
117  if (GetNanoSecsFromStat(file_stat, &sec, &nsec)) {
118    int64 usec = (nsec / base::Time::kNanosecondsPerMicrosecond);
119    *out_mtime = base::Time::FromTimeT(sec)
120        + base::TimeDelta::FromMicroseconds(usec);
121    return true;
122  }
123#endif
124  base::PlatformFileInfo file_info;
125  if (!file_util::GetFileInfo(path, &file_info))
126    return false;
127  *out_mtime = file_info.last_modified;
128  return true;
129}
130
131}  // namespace simple_backend
132
133}  // namespace disk_cache
134