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
19 namespace {
20
21 // Size of the uint64 hash_key number in Hex format in a string.
22 const size_t kEntryHashKeyAsHexStringSize = 2 * sizeof(uint64);
23
24 // TODO(clamy, gavinp): this should go in base
GetNanoSecsFromStat(const struct stat & st,time_t * out_sec,long * out_nsec)25 bool 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
45 namespace disk_cache {
46
47 namespace simple_util {
48
ConvertEntryHashKeyToHexString(uint64 hash_key)49 std::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
GetEntryHashKeyAsHexString(const std::string & key)55 std::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
GetEntryHashKeyFromHexString(const base::StringPiece & hash_key,uint64 * hash_key_out)62 bool 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
GetEntryHashKey(const std::string & key)70 uint64 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
GetFilenameFromEntryHashAndFileIndex(uint64 entry_hash,int file_index)80 std::string GetFilenameFromEntryHashAndFileIndex(uint64 entry_hash,
81 int file_index) {
82 return base::StringPrintf("%016" PRIx64 "_%1d", entry_hash, file_index);
83 }
84
GetSparseFilenameFromEntryHash(uint64 entry_hash)85 std::string GetSparseFilenameFromEntryHash(uint64 entry_hash) {
86 return base::StringPrintf("%016" PRIx64 "_s", entry_hash);
87 }
88
GetFilenameFromKeyAndFileIndex(const std::string & key,int file_index)89 std::string GetFilenameFromKeyAndFileIndex(const std::string& key,
90 int file_index) {
91 return GetEntryHashKeyAsHexString(key) +
92 base::StringPrintf("_%1d", file_index);
93 }
94
GetDataSizeFromKeyAndFileSize(const std::string & key,int64 file_size)95 int32 GetDataSizeFromKeyAndFileSize(const std::string& key, int64 file_size) {
96 int64 data_size = file_size - key.size() - sizeof(SimpleFileHeader) -
97 sizeof(SimpleFileEOF);
98 DCHECK_GE(implicit_cast<int64>(std::numeric_limits<int32>::max()), data_size);
99 return data_size;
100 }
101
GetFileSizeFromKeyAndDataSize(const std::string & key,int32 data_size)102 int64 GetFileSizeFromKeyAndDataSize(const std::string& key, int32 data_size) {
103 return data_size + key.size() + sizeof(SimpleFileHeader) +
104 sizeof(SimpleFileEOF);
105 }
106
GetFileIndexFromStreamIndex(int stream_index)107 int GetFileIndexFromStreamIndex(int stream_index) {
108 return (stream_index == 2) ? 1 : 0;
109 }
110
111 // TODO(clamy, gavinp): this should go in base
GetMTime(const base::FilePath & path,base::Time * out_mtime)112 bool GetMTime(const base::FilePath& path, base::Time* out_mtime) {
113 DCHECK(out_mtime);
114 #if defined(OS_POSIX)
115 base::ThreadRestrictions::AssertIOAllowed();
116 struct stat file_stat;
117 if (stat(path.value().c_str(), &file_stat) != 0)
118 return false;
119 time_t sec;
120 long nsec;
121 if (GetNanoSecsFromStat(file_stat, &sec, &nsec)) {
122 int64 usec = (nsec / base::Time::kNanosecondsPerMicrosecond);
123 *out_mtime = base::Time::FromTimeT(sec)
124 + base::TimeDelta::FromMicroseconds(usec);
125 return true;
126 }
127 #endif
128 base::PlatformFileInfo file_info;
129 if (!base::GetFileInfo(path, &file_info))
130 return false;
131 *out_mtime = file_info.last_modified;
132 return true;
133 }
134
135 } // namespace simple_backend
136
137 } // namespace disk_cache
138