[CacheStorage] Temporarily preserve recently opened caches from CacheStorageDispatcherHost

content/browser/cache_storage/cache_storage_dispatcher_host.cc

 // Copyright 2015 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 "content/browser/cache_storage/cache_storage_dispatcher_host.h"
 
 #include <stddef.h>
 #include <utility>
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/strings/string16.h"
 #include "base/strings/utf_string_conversions.h"
+#include "base/threading/thread_task_runner_handle.h"
+#include "base/time/time.h"
 #include "base/trace_event/trace_event.h"
 #include "content/browser/bad_message.h"
 #include "content/browser/cache_storage/cache_storage_cache.h"
 #include "content/browser/cache_storage/cache_storage_cache_handle.h"
 #include "content/browser/cache_storage/cache_storage_context_impl.h"
 #include "content/browser/cache_storage/cache_storage_manager.h"
 #include "content/common/cache_storage/cache_storage_messages.h"
 #include "content/public/browser/content_browser_client.h"
 #include "content/public/common/origin_util.h"
 #include "storage/browser/blob/blob_data_handle.h"
 #include "third_party/WebKit/public/platform/modules/serviceworker/WebServiceWorkerCacheError.h"
 #include "url/gurl.h"
 #include "url/origin.h"
 
 namespace content {
 
 namespace {
 
 const uint32_t kFilteredMessageClasses[] = {CacheStorageMsgStart};
+const int32_t kCachePreservationSeconds = 5;
 
 blink::WebServiceWorkerCacheError ToWebServiceWorkerCacheError(
     CacheStorageError err) {
   switch (err) {
     case CACHE_STORAGE_OK:
       NOTREACHED();
       return blink::WebServiceWorkerCacheErrorNotImplemented;
     case CACHE_STORAGE_ERROR_EXISTS:
       return blink::WebServiceWorkerCacheErrorExists;
     case CACHE_STORAGE_ERROR_STORAGE:
       // TODO(nhiroki): Add WebServiceWorkerCacheError equivalent to
       // CACHE_STORAGE_ERROR_STORAGE.
       return blink::WebServiceWorkerCacheErrorNotFound;
     case CACHE_STORAGE_ERROR_NOT_FOUND:
       return blink::WebServiceWorkerCacheErrorNotFound;
     case CACHE_STORAGE_ERROR_QUOTA_EXCEEDED:
       return blink::WebServiceWorkerCacheErrorQuotaExceeded;
     case CACHE_STORAGE_ERROR_CACHE_NAME_NOT_FOUND:
       return blink::WebServiceWorkerCacheErrorCacheNameNotFound;
   }
   NOTREACHED();
   return blink::WebServiceWorkerCacheErrorNotImplemented;
 }
 
 bool OriginCanAccessCacheStorage(const url::Origin& origin) {
   return !origin.unique() && IsOriginSecure(GURL(origin.Serialize()));
 }
 
+void StopPreservingCache(
+    std::unique_ptr<CacheStorageCacheHandle> cache_handle) {}
+
 }  // namespace
 
 CacheStorageDispatcherHost::CacheStorageDispatcherHost()
     : BrowserMessageFilter(kFilteredMessageClasses,
-                           arraysize(kFilteredMessageClasses)) {
-}
+                           arraysize(kFilteredMessageClasses)) {}
 
 CacheStorageDispatcherHost::~CacheStorageDispatcherHost() {
 }
 
 void CacheStorageDispatcherHost::Init(CacheStorageContextImpl* context) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   BrowserThread::PostTask(
       BrowserThread::IO, FROM_HERE,
       base::Bind(&CacheStorageDispatcherHost::CreateCacheListener, this,
                  base::RetainedRef(context)));
@@ skipping 269 matching lines @@
 void CacheStorageDispatcherHost::OnCacheStorageOpenCallback(
     int thread_id,
     int request_id,
     std::unique_ptr<CacheStorageCacheHandle> cache_handle,
     CacheStorageError error) {
   if (error != CACHE_STORAGE_OK) {
     Send(new CacheStorageMsg_CacheStorageOpenError(
         thread_id, request_id, ToWebServiceWorkerCacheError(error)));
     return;
   }
+
+  // Hang on to the cache for a few seconds. This way if the user quickly closes
+  // and reopens it the cache backend won't have to be reinitialized.
+  base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
+      FROM_HERE,
+      base::Bind(&StopPreservingCache, base::Passed(cache_handle->Clone())),
+      base::TimeDelta::FromSeconds(kCachePreservationSeconds));
+
   CacheID cache_id = StoreCacheReference(std::move(cache_handle));
   Send(new CacheStorageMsg_CacheStorageOpenSuccess(thread_id, request_id,
                                                    cache_id));
 }
 
 void CacheStorageDispatcherHost::OnCacheStorageDeleteCallback(
     int thread_id,
     int request_id,
     bool deleted,
     CacheStorageError error) {
@@ skipping 165 matching lines @@
   UUIDToBlobDataHandleList::iterator it = blob_handle_store_.find(uuid);
   if (it == blob_handle_store_.end())
     return;
   DCHECK(!it->second.empty());
   it->second.pop_front();
   if (it->second.empty())
     blob_handle_store_.erase(it);
 }
 
 }  // namespace content