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 #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
  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
  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
  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
  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
  80 std::string GetFilenameFromEntryHashAndIndex(uint64 entry_hash,
  81                                              int index) {
  82   return base::StringPrintf("%016" PRIx64 "_%1d", entry_hash, index);
  83 }
  84
  85 std::string GetFilenameFromKeyAndIndex(const std::string& key, int index) {
  86   return GetEntryHashKeyAsHexString(key) + base::StringPrintf("_%1d", index);
  87 }
  88
  89 int32 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
  96 int64 GetFileSizeFromKeyAndDataSize(const std::string& key, int32 data_size) {
  97   return data_size + key.size() + sizeof(SimpleFileHeader) +
  98       sizeof(SimpleFileEOF);
  99 }
 100
 101 int64 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
 108 bool 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