[BlobAsync] Asynchronous Blob Construction Final Patch

content/child/blob_storage/blob_transport_controller.h

 // 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.
 
 #ifndef CONTENT_CHILD_BLOB_STORAGE_BLOB_TRANSPORT_CONTROLLER_H_
 #define CONTENT_CHILD_BLOB_STORAGE_BLOB_TRANSPORT_CONTROLLER_H_
 
 #include <stddef.h>
 
 #include <map>
 #include <string>
 #include <vector>
 
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/shared_memory_handle.h"
 #include "content/common/content_export.h"
 #include "ipc/ipc_platform_file.h"
 #include "storage/common/blob_storage/blob_storage_constants.h"
 
 namespace base {
 template <typename T>
 struct DefaultLazyInstanceTraits;
+class SingleThreadTaskRunner;
 }
 
 namespace storage {
 class DataElement;
 struct BlobItemBytesRequest;
 struct BlobItemBytesResponse;
 }
 
 namespace IPC {
 class Sender;
@@ skipping 12 matching lines @@
 // * include shortcut data in the descriptions,
 // * generate responses to blob memory requests, and
 // * send IPC responses.
 // Must be used on the IO thread.
 class CONTENT_EXPORT BlobTransportController {
  public:
   static BlobTransportController* GetInstance();
 
   // This kicks off a blob transfer to the browser thread, which involves
   // sending an IPC message and storing the blob consolidation object.
-  void InitiateBlobTransfer(const std::string& uuid,
-                            const std::string& type,
-                            scoped_ptr<BlobConsolidation> consolidation,
-                            IPC::Sender* sender);
+  // If we have no pending blobs, we also call ChildProcess::AddRefProcess to
+  // keep our process around while we transfer. This will be decremented when
+  // we finish our last pending transfer (when our map is empty).
+  void InitiateBlobTransfer(
+      const std::string& uuid,
+      scoped_ptr<BlobConsolidation> consolidation,
+      IPC::Sender* sender,
+      scoped_refptr<base::SingleThreadTaskRunner> main_runner);
 
   // This responds to the request using the sender.
   void OnMemoryRequest(
       const std::string& uuid,
       const std::vector<storage::BlobItemBytesRequest>& requests,
       std::vector<base::SharedMemoryHandle>* memory_handles,
       const std::vector<IPC::PlatformFileForTransit>& file_handles,
       IPC::Sender* sender);
 
   void OnCancel(const std::string& uuid,
                 storage::IPCBlobCreationCancelCode code);
 
   void OnDone(const std::string& uuid);
 
-  // Clears all internal state for testing and such.
-  void Clear();
 
   bool IsTransporting(const std::string& uuid) {
     return blob_storage_.find(uuid) != blob_storage_.end();
   }
 
   ~BlobTransportController();
 
  private:
+  friend class BlobTransportControllerTest;
   FRIEND_TEST_ALL_PREFIXES(BlobTransportControllerTest, Descriptions);
   FRIEND_TEST_ALL_PREFIXES(BlobTransportControllerTest, Responses);
   FRIEND_TEST_ALL_PREFIXES(BlobTransportControllerTest, SharedMemory);
   FRIEND_TEST_ALL_PREFIXES(BlobTransportControllerTest, ResponsesErrors);
 
+  // Clears all internal state. If our map wasn't previously empty, then we call
+  // ChildProcess::ReleaseProcess to release our previous reference.
+  void ClearForTesting();
+
   enum class ResponsesStatus {
     BLOB_NOT_FOUND,
     SHARED_MEMORY_MAP_FAILED,
     SUCCESS
   };
   friend struct base::DefaultLazyInstanceTraits<BlobTransportController>;
 
   BlobTransportController();
 
-  // Sends the IPC to cancel the blob transfer, and releases the blob from
-  // internal storage.
-  void CancelBlobTransfer(const std::string& uuid,
-                          storage::IPCBlobCreationCancelCode code,
-                          IPC::Sender* sender);
-
   void GetDescriptions(BlobConsolidation* consolidation,
                        size_t max_data_population,
                        std::vector<storage::DataElement>* out);
 
   ResponsesStatus GetResponses(
       const std::string& uuid,
       const std::vector<storage::BlobItemBytesRequest>& requests,
       std::vector<base::SharedMemoryHandle>* memory_handles,
       const std::vector<IPC::PlatformFileForTransit>& file_handles,
       std::vector<storage::BlobItemBytesResponse>* output);
 
+  // Deletes the consolidation, and if we removed the last consolidation from
+  // our map, we call ChildProcess::ReleaseProcess to release our previous
+  // reference.
   void ReleaseBlobConsolidation(const std::string& uuid);
 
+  scoped_refptr<base::SingleThreadTaskRunner> main_thread_runner_;
   std::map<std::string, scoped_ptr<BlobConsolidation>> blob_storage_;
 
   DISALLOW_COPY_AND_ASSIGN(BlobTransportController);
 };
 
 }  // namespace content
 #endif  // CONTENT_CHILD_BLOB_STORAGE_BLOB_TRANSPORT_CONTROLLER_H_