src/net/disk_cache/cache_creator.cc

   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 #include "base/files/file_path.h"
   6 #include "base/metrics/field_trial.h"
   7 #include "base/profiler/scoped_tracker.h"
   8 #include "base/single_thread_task_runner.h"
   9 #include "base/strings/stringprintf.h"
  10 #include "net/base/cache_type.h"
  11 #include "net/base/net_errors.h"
  12 #include "net/disk_cache/blockfile/backend_impl.h"
  13 #include "net/disk_cache/cache_util.h"
  14 #include "net/disk_cache/disk_cache.h"
  15 #include "net/disk_cache/memory/mem_backend_impl.h"
  16 #include "net/disk_cache/simple/simple_backend_impl.h"
  17
  18 namespace {
  19
  20 // Builds an instance of the backend depending on platform, type, experiments
  21 // etc. Takes care of the retry state. This object will self-destroy when
  22 // finished.
  23 class CacheCreator {
  24  public:
  25   CacheCreator(const base::FilePath& path,
  26                bool force,
  27                int max_bytes,
  28                net::CacheType type,
  29                net::BackendType backend_type,
  30                uint32 flags,
  31                const scoped_refptr<base::SingleThreadTaskRunner>& thread,
  32                net::NetLog* net_log,
  33                scoped_ptr<disk_cache::Backend>* backend,
  34                const net::CompletionCallback& callback);
  35
  36   // Creates the backend.
  37   int Run();
  38
  39  private:
  40   ~CacheCreator();
  41
  42   void DoCallback(int result);
  43
  44   void OnIOComplete(int result);
  45
  46   const base::FilePath path_;
  47   bool force_;
  48   bool retry_;
  49   int max_bytes_;
  50   net::CacheType type_;
  51   net::BackendType backend_type_;
  52   uint32 flags_;
  53   scoped_refptr<base::SingleThreadTaskRunner> thread_;
  54   scoped_ptr<disk_cache::Backend>* backend_;
  55   net::CompletionCallback callback_;
  56   scoped_ptr<disk_cache::Backend> created_cache_;
  57   net::NetLog* net_log_;
  58
  59   DISALLOW_COPY_AND_ASSIGN(CacheCreator);
  60 };
  61
  62 CacheCreator::CacheCreator(
  63     const base::FilePath& path,
  64     bool force,
  65     int max_bytes,
  66     net::CacheType type,
  67     net::BackendType backend_type,
  68     uint32 flags,
  69     const scoped_refptr<base::SingleThreadTaskRunner>& thread,
  70     net::NetLog* net_log,
  71     scoped_ptr<disk_cache::Backend>* backend,
  72     const net::CompletionCallback& callback)
  73     : path_(path),
  74       force_(force),
  75       retry_(false),
  76       max_bytes_(max_bytes),
  77       type_(type),
  78       backend_type_(backend_type),
  79       flags_(flags),
  80       thread_(thread),
  81       backend_(backend),
  82       callback_(callback),
  83       net_log_(net_log) {
  84 }
  85
  86 CacheCreator::~CacheCreator() {
  87 }
  88
  89 int CacheCreator::Run() {
  90 #if defined(OS_ANDROID)
  91   static const bool kSimpleBackendIsDefault = true;
  92 #else
  93   static const bool kSimpleBackendIsDefault = false;
  94 #endif
  95   if (backend_type_ == net::CACHE_BACKEND_SIMPLE ||
  96       (backend_type_ == net::CACHE_BACKEND_DEFAULT &&
  97        kSimpleBackendIsDefault)) {
  98     disk_cache::SimpleBackendImpl* simple_cache =
  99         new disk_cache::SimpleBackendImpl(
 100             path_, max_bytes_, type_, thread_, net_log_);
 101     created_cache_.reset(simple_cache);
 102     return simple_cache->Init(
 103         base::Bind(&CacheCreator::OnIOComplete, base::Unretained(this)));
 104   }
 105
 106   // Avoid references to blockfile functions on Android to reduce binary size.
 107 #if defined(OS_ANDROID)
 108   return net::ERR_FAILED;
 109 #else
 110   disk_cache::BackendImpl* new_cache =
 111       new disk_cache::BackendImpl(path_, thread_, net_log_);
 112   created_cache_.reset(new_cache);
 113   new_cache->SetMaxSize(max_bytes_);
 114   new_cache->SetType(type_);
 115   new_cache->SetFlags(flags_);
 116   int rv = new_cache->Init(
 117       base::Bind(&CacheCreator::OnIOComplete, base::Unretained(this)));
 118   DCHECK_EQ(net::ERR_IO_PENDING, rv);
 119   return rv;
 120 #endif
 121 }
 122
 123 void CacheCreator::DoCallback(int result) {
 124   DCHECK_NE(net::ERR_IO_PENDING, result);
 125   if (result == net::OK) {
 126 #ifndef USE_TRACING_CACHE_BACKEND
 127     *backend_ = created_cache_.Pass();
 128 #else
 129     *backend_.reset(
 130         new disk_cache::TracingCacheBackend(created_cache_.Pass()));
 131 #endif
 132   } else {
 133     LOG(ERROR) << "Unable to create cache";
 134     created_cache_.reset();
 135   }
 136   callback_.Run(result);
 137   delete this;
 138 }
 139
 140 // If the initialization of the cache fails, and |force| is true, we will
 141 // discard the whole cache and create a new one.
 142 void CacheCreator::OnIOComplete(int result) {
 143   // TODO(vadimt): Remove ScopedTracker below once crbug.com/422516 is fixed.
 144   tracked_objects::ScopedTracker tracking_profile(
 145       FROM_HERE_WITH_EXPLICIT_FUNCTION("422516 CacheCreator::OnIOComplete"));
 146
 147   if (result == net::OK || !force_ || retry_)
 148     return DoCallback(result);
 149
 150   // This is a failure and we are supposed to try again, so delete the object,
 151   // delete all the files, and try again.
 152   retry_ = true;
 153   created_cache_.reset();
 154   if (!disk_cache::DelayedCacheCleanup(path_))
 155     return DoCallback(result);
 156
 157   // The worker thread will start deleting files soon, but the original folder
 158   // is not there anymore... let's create a new set of files.
 159   int rv = Run();
 160   DCHECK_EQ(net::ERR_IO_PENDING, rv);
 161 }
 162
 163 }  // namespace
 164
 165 namespace disk_cache {
 166
 167 int CreateCacheBackend(
 168     net::CacheType type,
 169     net::BackendType backend_type,
 170     const base::FilePath& path,
 171     int max_bytes,
 172     bool force,
 173     const scoped_refptr<base::SingleThreadTaskRunner>& thread,
 174     net::NetLog* net_log,
 175     scoped_ptr<Backend>* backend,
 176     const net::CompletionCallback& callback) {
 177   DCHECK(!callback.is_null());
 178   if (type == net::MEMORY_CACHE) {
 179     *backend = disk_cache::MemBackendImpl::CreateBackend(max_bytes, net_log);
 180     return *backend ? net::OK : net::ERR_FAILED;
 181   }
 182   DCHECK(thread.get());
 183   CacheCreator* creator = new CacheCreator(path,
 184                                            force,
 185                                            max_bytes,
 186                                            type,
 187                                            backend_type,
 188                                            kNone,
 189                                            thread,
 190                                            net_log,
 191                                            backend,
 192                                            callback);
 193   return creator->Run();
 194 }
 195
 196 }  // namespace disk_cache