[ServiceWorkerCache] Make the cache operations run serially.

content/browser/service_worker/service_worker_cache.h

 // Copyright 2014 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.
 
 #ifndef CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_CACHE_H_
 #define CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_CACHE_H_
 
+#include <list>
+
 #include "base/callback.h"
 #include "base/files/file_path.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "content/common/service_worker/service_worker_types.h"
 #include "net/base/completion_callback.h"
 #include "net/disk_cache/disk_cache.h"
 
 namespace net {
 class URLRequestContext;
 class IOBufferWithSize;
 }
 
 namespace storage {
 class BlobData;
 class BlobDataHandle;
 class BlobStorageContext;
 class QuotaManagerProxy;
 }
 
 namespace content {
 class ChromeBlobStorageContext;
 class ServiceWorkerCacheMetadata;
 class TestServiceWorkerCache;
 
 // Represents a ServiceWorker Cache as seen in
 // https://slightlyoff.github.io/ServiceWorker/spec/service_worker/index.html.
-// Callbacks to the public functions will be called so long as the cache object
-// lives.
+// The asynchronous methods are executed serially. Callbacks to the
+// public functions will be called so long as the cache object lives.
 class CONTENT_EXPORT ServiceWorkerCache
     : public base::RefCounted<ServiceWorkerCache> {
  public:
   enum ErrorType {
     ErrorTypeOK = 0,
     ErrorTypeExists,
     ErrorTypeStorage,
     ErrorTypeNotFound
   };
 
@@ skipping 73 matching lines @@
       const GURL& origin,
       const base::FilePath& path,
       net::URLRequestContext* request_context,
       const scoped_refptr<storage::QuotaManagerProxy>& quota_manager_proxy,
       base::WeakPtr<storage::BlobStorageContext> blob_context);
 
   // Async operations in progress will cancel and not run their callbacks.
   virtual ~ServiceWorkerCache();
 
   // Match callbacks
+  void MatchImpl(scoped_ptr<ServiceWorkerFetchRequest> request,
+                 const ResponseCallback& callback);
   void MatchDidOpenEntry(scoped_ptr<MatchContext> match_context, int rv);
   void MatchDidReadMetadata(scoped_ptr<MatchContext> match_context,
                             scoped_ptr<ServiceWorkerCacheMetadata> headers);
   void MatchDidReadResponseBodyData(scoped_ptr<MatchContext> match_context,
                                     int rv);
   void MatchDoneWithBody(scoped_ptr<MatchContext> match_context);
 
   // Put callbacks.
   void PutImpl(scoped_ptr<PutContext> put_context);
   void PutDidDelete(scoped_ptr<PutContext> put_context, ErrorType delete_error);
   void PutDidCreateEntry(scoped_ptr<PutContext> put_context, int rv);
   void PutDidWriteHeaders(scoped_ptr<PutContext> put_context,
                           int expected_bytes,
                           int rv);
   void PutDidWriteBlobToCache(scoped_ptr<PutContext> put_context,
                               scoped_ptr<BlobReader> blob_reader,
                               disk_cache::ScopedEntryPtr entry,
                               bool success);
 
   // Delete callbacks
+  void DeleteImpl(scoped_ptr<ServiceWorkerFetchRequest> request,
+                  const ErrorCallback& callback);
   void DeleteDidOpenEntry(
       const GURL& origin,
       scoped_ptr<ServiceWorkerFetchRequest> request,
       const ServiceWorkerCache::ErrorCallback& callback,
       scoped_ptr<disk_cache::Entry*> entryptr,
       const scoped_refptr<storage::QuotaManagerProxy>& quota_manager_proxy,
       int rv);
 
   // Keys callbacks.
+  void KeysImpl(const RequestsCallback& callback);
   void KeysDidOpenNextEntry(scoped_ptr<KeysContext> keys_context, int rv);
   void KeysProcessNextEntry(scoped_ptr<KeysContext> keys_context,
                             const Entries::iterator& iter);
   void KeysDidReadMetadata(scoped_ptr<KeysContext> keys_context,
                            const Entries::iterator& iter,
                            scoped_ptr<ServiceWorkerCacheMetadata> metadata);
 
   void CloseImpl(const base::Closure& callback);
 
   // Loads the backend and calls the callback with the result (true for
   // success). The callback will always be called. Virtual for tests.
   virtual void CreateBackend(const ErrorCallback& callback);
   void CreateBackendDidCreate(const ServiceWorkerCache::ErrorCallback& callback,
                               scoped_ptr<ScopedBackendPtr> backend_ptr,
                               int rv);
 
   void InitBackend(const base::Closure& callback);
-  void InitDone(ErrorType error);
+  void InitDone(const base::Closure& callback, ErrorType error);
 
-  void IncPendingOps() { pending_ops_++; }
-  void DecPendingOps();
+  void CompleteOperationAndRunNext();
+  void RunOperationIfIdle();
+  void PendingClosure(const base::Closure& callback);
   void PendingErrorCallback(const ErrorCallback& callback, ErrorType error);
   void PendingResponseCallback(
       const ResponseCallback& callback,
       ErrorType error,
       scoped_ptr<ServiceWorkerResponse> response,
       scoped_ptr<storage::BlobDataHandle> blob_data_handle);
   void PendingRequestsCallback(const RequestsCallback& callback,
                                ErrorType error,
                                scoped_ptr<Requests> requests);
 
   // The backend can be deleted via the Close function at any time so always
   // check for its existence before use.
   scoped_ptr<disk_cache::Backend> backend_;
   GURL origin_;
   base::FilePath path_;
   net::URLRequestContext* request_context_;
   scoped_refptr<storage::QuotaManagerProxy> quota_manager_proxy_;
   base::WeakPtr<storage::BlobStorageContext> blob_storage_context_;
   BackendState backend_state_;
-  std::vector<base::Closure> init_callbacks_;
+  std::list<base::Closure> pending_operations_;
+  bool initializing_;
 
   // Whether or not to store data in disk or memory.
   bool memory_only_;
 
-  // The number of started operations that have yet to complete.
-  // TODO(jkarlin): pending_ops_ gets double counted on lazy initialization (say
-  // in ::Put). The counting still works but pending_ops_ doesn't accurately
-  // represent the number of operations in flight. Fix this by having the lazy
-  // init callback call a different function than the original caller (::Put).
-  size_t pending_ops_;
-  base::Closure ops_complete_callback_;
-
   base::WeakPtrFactory<ServiceWorkerCache> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ServiceWorkerCache);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_CACHE_H_