Add new simple disk cache backend.

net/disk_cache/backend_impl.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/disk_cache/backend_impl.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/file_path.h"
 #include "base/file_util.h"
@@ skipping 10 matching lines @@
 #include "base/threading/thread_restrictions.h"
 #include "base/time.h"
 #include "base/timer.h"
 #include "net/base/net_errors.h"
 #include "net/disk_cache/cache_util.h"
 #include "net/disk_cache/entry_impl.h"
 #include "net/disk_cache/errors.h"
 #include "net/disk_cache/experiments.h"
 #include "net/disk_cache/file.h"
 #include "net/disk_cache/mem_backend_impl.h"
+#include "net/disk_cache/simple/simple_backend_impl.h"
 
 // This has to be defined before including histogram_macros.h from this file.
 #define NET_DISK_CACHE_BACKEND_IMPL_CC_
 #include "net/disk_cache/histogram_macros.h"
 
 using base::Time;
 using base::TimeDelta;
 using base::TimeTicks;
 
 namespace {
@@ skipping 214 matching lines @@
 
 // ------------------------------------------------------------------------
 
 namespace disk_cache {
 
 int CreateCacheBackend(net::CacheType type, const base::FilePath& path,
                        int max_bytes,
                        bool force, base::MessageLoopProxy* thread,
                        net::NetLog* net_log, Backend** backend,
                        const net::CompletionCallback& callback) {
+  // TODO(pasko): Separate out cache creation when landing cache tracer.
   DCHECK(!callback.is_null());
   if (type == net::MEMORY_CACHE) {
     *backend = MemBackendImpl::CreateBackend(max_bytes, net_log);
     return *backend ? net::OK : net::ERR_FAILED;
   }
   DCHECK(thread);
 
+#if defined(USE_SIMPLE_BACKEND)

[felipeg, 2013/02/12 13:25:20]

SIMPLE_BACKEND is too generic when defining in the GYP files or in the build
command line.
Maybe USE_SIMPLE_CACHE_BACKEND
or just USE_SIMPLE_CACHE ?

Not a big deal though. You can keep it if you want.

[gavinp, 2013/02/12 15:45:57]

Done.

+  return SimpleBackendImpl::CreateBackend(path, force, max_bytes, type, kNone,
+                                          thread, net_log, backend, callback);
+#else
   return BackendImpl::CreateBackend(path, force, max_bytes, type, kNone, thread,
                                     net_log, backend, callback);
+#endif
 }
 
 // Returns the preferred maximum number of bytes for the cache given the
 // number of available bytes.
 int PreferedCacheSize(int64 available) {
   // Return 80% of the available space if there is not enough space to use
   // kDefaultCacheSize.
   if (available < kDefaultCacheSize * 10 / 8)
     return static_cast<int32>(available * 8 / 10);
 
@@ skipping 1955 matching lines @@
     if (total_memory > kMaxBuffersSize || total_memory <= 0)
       total_memory = kMaxBuffersSize;
 
     done = true;
   }
 
   return static_cast<int>(total_memory);
 }
 
 }  // namespace disk_cache