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 }  // namespace
  25
  26 namespace disk_cache {
  27
  28 namespace simple_util {
  29
  30 std::string ConvertEntryHashKeyToHexString(uint64 hash_key) {
  31   const std::string hash_key_str = base::StringPrintf("%016" PRIx64, hash_key);
  32   DCHECK_EQ(kEntryHashKeyAsHexStringSize, hash_key_str.size());
  33   return hash_key_str;
  34 }
  35
  36 std::string GetEntryHashKeyAsHexString(const std::string& key) {
  37   std::string hash_key_str =
  38       ConvertEntryHashKeyToHexString(GetEntryHashKey(key));
  39   DCHECK_EQ(kEntryHashKeyAsHexStringSize, hash_key_str.size());
  40   return hash_key_str;
  41 }
  42
  43 bool GetEntryHashKeyFromHexString(const base::StringPiece& hash_key,
  44                                   uint64* hash_key_out) {
  45   if (hash_key.size() != kEntryHashKeyAsHexStringSize) {
  46     return false;
  47   }
  48   return base::HexStringToUInt64(hash_key, hash_key_out);
  49 }
  50
  51 uint64 GetEntryHashKey(const std::string& key) {
  52   union {
  53     unsigned char sha_hash[base::kSHA1Length];
  54     uint64 key_hash;
  55   } u;
  56   base::SHA1HashBytes(reinterpret_cast<const unsigned char*>(key.data()),
  57                       key.size(), u.sha_hash);
  58   return u.key_hash;
  59 }
  60
  61 std::string GetFilenameFromEntryHashAndIndex(uint64 entry_hash,
  62                                              int index) {
  63   return base::StringPrintf("%016" PRIx64 "_%1d", entry_hash, index);
  64 }
  65
  66 std::string GetFilenameFromKeyAndIndex(const std::string& key, int index) {
  67   return GetEntryHashKeyAsHexString(key) + base::StringPrintf("_%1d", index);
  68 }
  69
  70 int32 GetDataSizeFromKeyAndFileSize(const std::string& key, int64 file_size) {
  71   int64 data_size = file_size - key.size() - sizeof(SimpleFileHeader) -
  72                     sizeof(SimpleFileEOF);
  73   DCHECK_GE(implicit_cast<int64>(std::numeric_limits<int32>::max()), data_size);
  74   return data_size;
  75 }
  76
  77 int64 GetFileSizeFromKeyAndDataSize(const std::string& key, int32 data_size) {
  78   return data_size + key.size() + sizeof(SimpleFileHeader) +
  79       sizeof(SimpleFileEOF);
  80 }
  81
  82 int64 GetFileOffsetFromKeyAndDataOffset(const std::string& key,
  83                                         int data_offset) {
  84   const int64 headers_size = sizeof(disk_cache::SimpleFileHeader) + key.size();
  85   return headers_size + data_offset;
  86 }
  87
  88 // TODO(clamy, gavinp): this should go in base
  89 bool GetMTime(const base::FilePath& path, base::Time* out_mtime) {
  90   DCHECK(out_mtime);
  91   base::PlatformFileInfo file_info;
  92   if (!file_util::GetFileInfo(path, &file_info))
  93     return false;
  94   *out_mtime = file_info.last_modified;
  95   return true;
  96 }
  97
  98 }  // namespace simple_backend
  99
 100 }  // namespace disk_cache