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/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
  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   return true;
  32 #elif defined(OS_LINUX)
  33   *out_sec = st.st_mtim.tv_sec;
  34   *out_nsec = st.st_mtim.tv_nsec;
  35   return true;
  36 #elif defined(OS_MACOSX) || defined(OS_IOS) || defined(OS_BSD)
  37   *out_sec = st.st_mtimespec.tv_sec;
  38   *out_nsec = st.st_mtimespec.tv_nsec;
  39   return true;
  40 #else
  41   return false;
  42 #endif
  43 }
  44
  45 }  // namespace
  46
  47 namespace disk_cache {
  48
  49 namespace simple_util {
  50
  51 std::string ConvertEntryHashKeyToHexString(uint64 hash_key) {
  52   const std::string hash_key_str = base::StringPrintf("%016" PRIx64, hash_key);
  53   DCHECK_EQ(kEntryHashKeyAsHexStringSize, hash_key_str.size());
  54   return hash_key_str;
  55 }
  56
  57 std::string GetEntryHashKeyAsHexString(const std::string& key) {
  58   std::string hash_key_str =
  59       ConvertEntryHashKeyToHexString(GetEntryHashKey(key));
  60   DCHECK_EQ(kEntryHashKeyAsHexStringSize, hash_key_str.size());
  61   return hash_key_str;
  62 }
  63
  64 bool GetEntryHashKeyFromHexString(const base::StringPiece& hash_key,
  65                                   uint64* hash_key_out) {
  66   if (hash_key.size() != kEntryHashKeyAsHexStringSize) {
  67     return false;
  68   }
  69   return base::HexStringToUInt64(hash_key, hash_key_out);
  70 }
  71
  72 uint64 GetEntryHashKey(const std::string& key) {
  73   union {
  74     unsigned char sha_hash[base::kSHA1Length];
  75     uint64 key_hash;
  76   } u;
  77   base::SHA1HashBytes(reinterpret_cast<const unsigned char*>(key.data()),
  78                       key.size(), u.sha_hash);
  79   return u.key_hash;
  80 }
  81
  82 std::string GetFilenameFromEntryHashAndFileIndex(uint64 entry_hash,
  83                                                  int file_index) {
  84   return base::StringPrintf("%016" PRIx64 "_%1d", entry_hash, file_index);
  85 }
  86
  87 std::string GetSparseFilenameFromEntryHash(uint64 entry_hash) {
  88   return base::StringPrintf("%016" PRIx64 "_s", entry_hash);
  89 }
  90
  91 std::string GetFilenameFromKeyAndFileIndex(const std::string& key,
  92                                            int file_index) {
  93   return GetEntryHashKeyAsHexString(key) +
  94          base::StringPrintf("_%1d", file_index);
  95 }
  96
  97 int32 GetDataSizeFromKeyAndFileSize(const std::string& key, int64 file_size) {
  98   int64 data_size = file_size - key.size() - sizeof(SimpleFileHeader) -
  99                     sizeof(SimpleFileEOF);
 100   DCHECK_GE(implicit_cast<int64>(std::numeric_limits<int32>::max()), data_size);
 101   return 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