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 #if defined(OS_POSIX)
  26 // TODO(clamy, gavinp): this should go in base
  27 bool GetNanoSecsFromStat(const struct stat& st,
  28                          time_t* out_sec,
  29                          long* out_nsec) {
  30 #if defined(OS_ANDROID)
  31   *out_sec = st.st_mtime;
  32   *out_nsec = st.st_mtime_nsec;
  33   return true;
  34 #elif defined(OS_LINUX)
  35   *out_sec = st.st_mtim.tv_sec;
  36   *out_nsec = st.st_mtim.tv_nsec;
  37   return true;
  38 #elif defined(OS_MACOSX) || defined(OS_IOS) || defined(OS_BSD)
  39   *out_sec = st.st_mtimespec.tv_sec;
  40   *out_nsec = st.st_mtimespec.tv_nsec;
  41   return true;
  42 #else
  43   return false;
  44 #endif
  45 }
  46 #endif  // defined(OS_POSIX)
  47
  48 }  // namespace
  49
  50 namespace disk_cache {
  51
  52 namespace simple_util {
  53
  54 std::string ConvertEntryHashKeyToHexString(uint64 hash_key) {
  55   const std::string hash_key_str = base::StringPrintf("%016" PRIx64, hash_key);
  56   DCHECK_EQ(kEntryHashKeyAsHexStringSize, hash_key_str.size());
  57   return hash_key_str;
  58 }
  59
  60 std::string GetEntryHashKeyAsHexString(const std::string& key) {
  61   std::string hash_key_str =
  62       ConvertEntryHashKeyToHexString(GetEntryHashKey(key));
  63   DCHECK_EQ(kEntryHashKeyAsHexStringSize, hash_key_str.size());
  64   return hash_key_str;
  65 }
  66
  67 bool GetEntryHashKeyFromHexString(const base::StringPiece& hash_key,
  68                                   uint64* hash_key_out) {
  69   if (hash_key.size() != kEntryHashKeyAsHexStringSize) {
  70     return false;
  71   }
  72   return base::HexStringToUInt64(hash_key, hash_key_out);
  73 }
  74
  75 uint64 GetEntryHashKey(const std::string& key) {
  76   union {
  77     unsigned char sha_hash[base::kSHA1Length];
  78     uint64 key_hash;
  79   } u;
  80   base::SHA1HashBytes(reinterpret_cast<const unsigned char*>(key.data()),
  81                       key.size(), u.sha_hash);
  82   return u.key_hash;
  83 }
  84
  85 std::string GetFilenameFromEntryHashAndFileIndex(uint64 entry_hash,
  86                                                  int file_index) {
  87   return base::StringPrintf("%016" PRIx64 "_%1d", entry_hash, file_index);
  88 }
  89
  90 std::string GetSparseFilenameFromEntryHash(uint64 entry_hash) {
  91   return base::StringPrintf("%016" PRIx64 "_s", entry_hash);
  92 }
  93
  94 std::string GetFilenameFromKeyAndFileIndex(const std::string& key,
  95                                            int file_index) {
  96   return GetEntryHashKeyAsHexString(key) +
  97          base::StringPrintf("_%1d", file_index);
  98 }
  99
 100 int32 GetDataSizeFromKeyAndFileSize(const std::string& key, int64 file_size) {
 101   int64 data_size = file_size - key.size() - sizeof(SimpleFileHeader) -
 102                     sizeof(SimpleFileEOF);
 103   return base::checked_cast<int32>(data_size);
 104 }
 105
 106 int64 GetFileSizeFromKeyAndDataSize(const std::string& key, int32 data_size) {
 107   return data_size + key.size() + sizeof(SimpleFileHeader) +
 108       sizeof(SimpleFileEOF);
 109 }
 110
 111 int GetFileIndexFromStreamIndex(int stream_index) {
 112   return (stream_index == 2) ? 1 : 0;
 113 }
 114
 115 // TODO(clamy, gavinp): this should go in base
 116 bool GetMTime(const base::FilePath& path, base::Time* out_mtime) {
 117   DCHECK(out_mtime);
 118 #if defined(OS_POSIX)
 119   base::ThreadRestrictions::AssertIOAllowed();
 120   struct stat file_stat;
 121   if (stat(path.value().c_str(), &file_stat) != 0)
 122     return false;
 123   time_t sec;
 124   long nsec;
 125   if (GetNanoSecsFromStat(file_stat, &sec, &nsec)) {
 126     int64 usec = (nsec / base::Time::kNanosecondsPerMicrosecond);
 127     *out_mtime = base::Time::FromTimeT(sec)
 128         + base::TimeDelta::FromMicroseconds(usec);
 129     return true;
 130   }
 131 #endif
 132   base::File::Info file_info;
 133   if (!base::GetFileInfo(path, &file_info))
 134     return false;
 135   *out_mtime = file_info.last_modified;
 136   return true;
 137 }
 138
 139 }  // namespace simple_backend
 140
 141 }  // namespace disk_cache