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      1 // Copyright (c) 2006-2008 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 #pragma once
      8 
      9 #include "net/disk_cache/storage_block.h"
     10 
     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> T* StorageBlock<T>::Data() {
     92   if (!data_)
     93     AllocateData();
     94   return data_;
     95 }
     96 
     97 template<typename T> bool StorageBlock<T>::HasData() const {
     98   return (NULL != data_);
     99 }
    100 
    101 template<typename T> bool StorageBlock<T>::own_data() const {
    102   return own_data_;
    103 }
    104 
    105 template<typename T> const Addr StorageBlock<T>::address() const {
    106   return address_;
    107 }
    108 
    109 template<typename T> bool StorageBlock<T>::Load() {
    110   if (file_) {
    111     if (!data_)
    112       AllocateData();
    113 
    114     if (file_->Load(this)) {
    115       modified_ = false;
    116       return true;
    117     }
    118   }
    119   LOG(WARNING) << "Failed data load.";
    120   Trace("Failed data load.");
    121   return false;
    122 }
    123 
    124 template<typename T> bool StorageBlock<T>::Store() {
    125   if (file_ && data_) {
    126     if (file_->Store(this)) {
    127       modified_ = false;
    128       return true;
    129     }
    130   }
    131   LOG(ERROR) << "Failed data store.";
    132   Trace("Failed data store.");
    133   return false;
    134 }
    135 
    136 template<typename T> void StorageBlock<T>::AllocateData() {
    137   DCHECK(!data_);
    138   if (!extended_) {
    139     data_ = new T;
    140   } else {
    141     void* buffer = new char[address_.num_blocks() * sizeof(*data_)];
    142     data_ = new(buffer) T;
    143   }
    144   own_data_ = true;
    145 }
    146 
    147 template<typename T> void StorageBlock<T>::DeleteData() {
    148   if (own_data_) {
    149     if (!extended_) {
    150       delete data_;
    151     } else {
    152       data_->~T();
    153       delete[] reinterpret_cast<char*>(data_);
    154     }
    155     own_data_ = false;
    156   }
    157 }
    158 
    159 }  // namespace disk_cache
    160 
    161 #endif  // NET_DISK_CACHE_STORAGE_BLOCK_INL_H_
    162