net/disk_cache/storage_block-inl.h

   1 // Copyright (c) 2012 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 #ifndef NET_DISK_CACHE_STORAGE_BLOCK_INL_H_
   6 #define NET_DISK_CACHE_STORAGE_BLOCK_INL_H_
   7
   8 #include "net/disk_cache/storage_block.h"
   9
  10 #include "base/hash.h"
  11 #include "base/logging.h"
  12 #include "net/disk_cache/trace.h"
  13
  14 namespace disk_cache {
  15
  16 template<typename T> StorageBlock<T>::StorageBlock(MappedFile* file,
  17                                                    Addr address)
  18     : data_(NULL), file_(file), address_(address), modified_(false),
  19       own_data_(false), extended_(false) {
  20   if (address.num_blocks() > 1)
  21     extended_ = true;
  22   DCHECK(!address.is_initialized() || sizeof(*data_) == address.BlockSize());
  23 }
  24
  25 template<typename T> StorageBlock<T>::~StorageBlock() {
  26   if (modified_)
  27     Store();
  28   DeleteData();
  29 }
  30
  31 template<typename T> void* StorageBlock<T>::buffer() const {
  32   return data_;
  33 }
  34
  35 template<typename T> size_t StorageBlock<T>::size() const {
  36   if (!extended_)
  37     return sizeof(*data_);
  38   return address_.num_blocks() * sizeof(*data_);
  39 }
  40
  41 template<typename T> int StorageBlock<T>::offset() const {
  42   return address_.start_block() * address_.BlockSize();
  43 }
  44
  45 template<typename T> bool StorageBlock<T>::LazyInit(MappedFile* file,
  46                                                     Addr address) {
  47   if (file_ || address_.is_initialized()) {
  48     NOTREACHED();
  49     return false;
  50   }
  51   file_ = file;
  52   address_.set_value(address.value());
  53   if (address.num_blocks() > 1)
  54     extended_ = true;
  55
  56   DCHECK(sizeof(*data_) == address.BlockSize());
  57   return true;
  58 }
  59
  60 template<typename T> void StorageBlock<T>::SetData(T* other) {
  61   DCHECK(!modified_);
  62   DeleteData();
  63   data_ = other;
  64 }
  65
  66 template<typename T> void  StorageBlock<T>::Discard() {
  67   if (!data_)
  68     return;
  69   if (!own_data_) {
  70     NOTREACHED();
  71     return;
  72   }
  73   DeleteData();
  74   data_ = NULL;
  75   modified_ = false;
  76   extended_ = false;
  77 }
  78
  79 template<typename T> void  StorageBlock<T>::StopSharingData() {
  80   if (!data_ || own_data_)
  81     return;
  82   DCHECK(!modified_);
  83   data_ = NULL;
  84 }
  85
  86 template<typename T> void StorageBlock<T>::set_modified() {
  87   DCHECK(data_);
  88   modified_ = true;
  89 }
  90
  91 template<typename T> void StorageBlock<T>::clear_modified() {
  92   modified_ = false;
  93 }
  94
  95 template<typename T> T* StorageBlock<T>::Data() {
  96   if (!data_)
  97     AllocateData();
  98   return data_;
  99 }
 100
 101 template<typename T> bool StorageBlock<T>::HasData() const {
 102   return (NULL != data_);
 103 }
 104
 105 template<typename T> bool StorageBlock<T>::VerifyHash() const {
 106   uint32 hash = CalculateHash();
 107   return (!data_->self_hash || data_->self_hash == hash);
 108 }
 109
 110 template<typename T> bool StorageBlock<T>::own_data() const {
 111   return own_data_;
 112 }
 113
 114 template<typename T> const Addr StorageBlock<T>::address() const {
 115   return address_;
 116 }
 117
 118 template<typename T> bool StorageBlock<T>::Load() {
 119   if (file_) {
 120     if (!data_)
 121       AllocateData();
 122
 123     if (file_->Load(this)) {
 124       modified_ = false;
 125       return true;
 126     }
 127   }
 128   LOG(WARNING) << "Failed data load.";
 129   Trace("Failed data load.");
 130   return false;
 131 }
 132
 133 template<typename T> bool StorageBlock<T>::Store() {
 134   if (file_ && data_) {
 135     data_->self_hash = CalculateHash();
 136     if (file_->Store(this)) {
 137       modified_ = false;
 138       return true;
 139     }
 140   }
 141   LOG(ERROR) << "Failed data store.";
 142   Trace("Failed data store.");
 143   return false;
 144 }
 145
 146 template<typename T> bool StorageBlock<T>::Load(FileIOCallback* callback,
 147                                                 bool* completed) {
 148   if (file_) {
 149     if (!data_)
 150       AllocateData();
 151
 152     if (file_->Load(this, callback, completed)) {
 153       modified_ = false;
 154       return true;
 155     }
 156   }
 157   LOG(WARNING) << "Failed data load.";
 158   Trace("Failed data load.");
 159   return false;
 160 }
 161
 162 template<typename T> bool StorageBlock<T>::Store(FileIOCallback* callback,
 163                                                  bool* completed) {
 164   if (file_ && data_) {
 165     data_->self_hash = CalculateHash();
 166     if (file_->Store(this, callback, completed)) {
 167       modified_ = false;
 168       return true;
 169     }
 170   }
 171   LOG(ERROR) << "Failed data store.";
 172   Trace("Failed data store.");
 173   return false;
 174 }
 175
 176 template<typename T> void StorageBlock<T>::AllocateData() {
 177   DCHECK(!data_);
 178   if (!extended_) {
 179     data_ = new T;
 180   } else {
 181     void* buffer = new char[address_.num_blocks() * sizeof(*data_)];
 182     data_ = new(buffer) T;
 183   }
 184   own_data_ = true;
 185 }
 186
 187 template<typename T> void StorageBlock<T>::DeleteData() {
 188   if (own_data_) {
 189     if (!extended_) {
 190       delete data_;
 191     } else {
 192       data_->~T();
 193       delete[] reinterpret_cast<char*>(data_);
 194     }
 195     own_data_ = false;
 196   }
 197 }
 198
 199 template<typename T> uint32 StorageBlock<T>::CalculateHash() const {
 200   return base::Hash(reinterpret_cast<char*>(data_), offsetof(T, self_hash));
 201 }
 202
 203 }  // namespace disk_cache
 204
 205 #endif  // NET_DISK_CACHE_STORAGE_BLOCK_INL_H_