net/disk_cache/simple/simple_util.cc

   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/files/file_util.h"
  10 #include "base/format_macros.h"
  11 #include "base/logging.h"
  12 #include "base/numerics/safe_conversions.h"
  13 #include "base/sha1.h"
  14 #include "base/strings/string_number_conversions.h"
  15 #include "base/strings/stringprintf.h"
  16 #include "base/threading/thread_restrictions.h"
  17 #include "base/time/time.h"
  18 #include "net/disk_cache/simple/simple_entry_format.h"
  19
  20 namespace {
  21
  22 // Size of the uint64 hash_key number in Hex format in a string.
  23 const size_t kEntryHashKeyAsHexStringSize = 2 * sizeof(uint64);
  24
  25 // TODO(clamy, gavinp): this should go in base
  26 bool GetNanoSecsFromStat(const struct stat& st,
  27                          time_t* out_sec,
  28                          long* out_nsec) {
  29 #if defined(OS_ANDROID)
  30   *out_sec = st.st_mtime;
  31   *out_nsec = st.st_mtime_nsec;
  32   return true;
  33 #elif defined(OS_LINUX)
  34   *out_sec = st.st_mtim.tv_sec;
  35   *out_nsec = st.st_mtim.tv_nsec;
  36   return true;
  37 #elif defined(OS_MACOSX) || defined(OS_IOS) || defined(OS_BSD)
  38   *out_sec = st.st_mtimespec.tv_sec;
  39   *out_nsec = st.st_mtimespec.tv_nsec;
  40   return true;
  41 #else
  42   return false;
  43 #endif
  44 }
  45
  46 }  // namespace
  47
  48 namespace disk_cache {
  49
  50 namespace simple_util {
  51
  52 std::string ConvertEntryHashKeyToHexString(uint64 hash_key) {
  53   const std::string hash_key_str = base::StringPrintf("%016" PRIx64, hash_key);
  54   DCHECK_EQ(kEntryHashKeyAsHexStringSize, hash_key_str.size());
  55   return hash_key_str;
  56 }
  57
  58 std::string GetEntryHashKeyAsHexString(const std::string& key) {
  59   std::string hash_key_str =
  60       ConvertEntryHashKeyToHexString(GetEntryHashKey(key));
  61   DCHECK_EQ(kEntryHashKeyAsHexStringSize, hash_key_str.size());
  62   return hash_key_str;
  63 }
  64
  65 bool GetEntryHashKeyFromHexString(const base::StringPiece& hash_key,
  66                                   uint64* hash_key_out) {
  67   if (hash_key.size() != kEntryHashKeyAsHexStringSize) {
  68     return false;
  69   }
  70   return base::HexStringToUInt64(hash_key, hash_key_out);
  71 }
  72
  73 uint64 GetEntryHashKey(const std::string& key) {
  74   union {
  75     unsigned char sha_hash[base::kSHA1Length];
  76     uint64 key_hash;
  77   } u;
  78   base::SHA1HashBytes(reinterpret_cast<const unsigned char*>(key.data()),
  79                       key.size(), u.sha_hash);
  80   return u.key_hash;
  81 }
  82
  83 std::string GetFilenameFromEntryHashAndFileIndex(uint64 entry_hash,
  84                                                  int file_index) {
  85   return base::StringPrintf("%016" PRIx64 "_%1d", entry_hash, file_index);
  86 }
  87
  88 std::string GetSparseFilenameFromEntryHash(uint64 entry_hash) {
  89   return base::StringPrintf("%016" PRIx64 "_s", entry_hash);
  90 }
  91
  92 std::string GetFilenameFromKeyAndFileIndex(const std::string& key,
  93                                            int file_index) {
  94   return GetEntryHashKeyAsHexString(key) +
  95          base::StringPrintf("_%1d", file_index);
  96 }
  97
  98 int32 GetDataSizeFromKeyAndFileSize(const std::string& key, int64 file_size) {
  99   int64 data_size = file_size - key.size() - sizeof(SimpleFileHeader) -
 100                     sizeof(SimpleFileEOF);
 101   return base::checked_cast<int32>(data_size);
 102 }
 103
 104 int64 GetFileSizeFromKeyAndDataSize(const std::string& key, int32 data_size) {
 105   return data_size + key.size() + sizeof(SimpleFileHeader) +
 106       sizeof(SimpleFileEOF);
 107 }
 108
 109 int GetFileIndexFromStreamIndex(int stream_index) {
 110   return (stream_index == 2) ? 1 : 0;
 111 }
 112
 113 // TODO(clamy, gavinp): this should go in base
 114 bool GetMTime(const base::FilePath& path, base::Time* out_mtime) {
 115   DCHECK(out_mtime);
 116 #if defined(OS_POSIX)
 117   base::ThreadRestrictions::AssertIOAllowed();
 118   struct stat file_stat;
 119   if (stat(path.value().c_str(), &file_stat) != 0)
 120     return false;
 121   time_t sec;
 122   long nsec;
 123   if (GetNanoSecsFromStat(file_stat, &sec, &nsec)) {
 124     int64 usec = (nsec / base::Time::kNanosecondsPerMicrosecond);
 125     *out_mtime = base::Time::FromTimeT(sec)
 126         + base::TimeDelta::FromMicroseconds(usec);
 127     return true;
 128   }
 129 #endif
 130   base::File::Info file_info;
 131   if (!base::GetFileInfo(path, &file_info))
 132     return false;
 133   *out_mtime = file_info.last_modified;
 134   return true;
 135 }
 136
 137 }  // namespace simple_backend
 138
 139 }  // namespace disk_cache