[BlobAsync] Renderer support for blob file writing.

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 <memory>
 #include <string>
+#include <utility>
 #include <vector>
 
+#include "base/callback_forward.h"
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/shared_memory_handle.h"
+#include "base/memory/weak_ptr.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;
+class TaskRunner;
 }
 
 namespace storage {
 class DataElement;
 struct BlobItemBytesRequest;
 struct BlobItemBytesResponse;
 }
 
 namespace IPC {
+class Message;
 class Sender;
 }
 
 namespace content {
 
 class BlobConsolidation;
 class ThreadSafeSender;
 
 // This class is used to manage all the asynchronous transporation of blobs from
 // the Renderer to the Browser process, where it's handling the Renderer side.
@@ skipping 10 matching lines @@
   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. Designed
   // to be called by the main thread or a worker thread.
   // This also calls ChildProcess::AddRefProcess to keep our process around
   // while we transfer.
   static void InitiateBlobTransfer(
       const std::string& uuid,
       const std::string& content_type,
-      std::unique_ptr<BlobConsolidation> consolidation,
+      scoped_refptr<BlobConsolidation> consolidation,
       scoped_refptr<ThreadSafeSender> sender,
       base::SingleThreadTaskRunner* io_runner,
       scoped_refptr<base::SingleThreadTaskRunner> main_runner);
 
-  // This responds to the request using the sender.
+  // This responds to the request using the |sender|. If we need to save files
+  // then we we hold onto the sender to send the (possibly multiple) reponses
+  // asynchronously. Use CancelAllBlobTransfers to stop usage of 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,
+      base::TaskRunner* file_runner,
       IPC::Sender* sender);
 
   void OnCancel(const std::string& uuid,
                 storage::IPCBlobCreationCancelCode code);
 
   void OnDone(const std::string& uuid);
 
   bool IsTransporting(const std::string& uuid) {
     return blob_storage_.find(uuid) != blob_storage_.end();
   }
 
+  // Invalidates all asynchronously running memory request handlers and clears
+  // the internal state. If our map wasn't previously empty, then we call
+  // ChildProcess::ReleaseProcess to release our previous reference.
+  void CancelAllBlobTransfers();
+
  private:
+  friend struct base::DefaultLazyInstanceTraits<BlobTransportController>;
   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, Disk);
   FRIEND_TEST_ALL_PREFIXES(BlobTransportControllerTest, ResponsesErrors);
 
+  enum class ResponsesStatus {
+    BLOB_NOT_FOUND,
+    SHARED_MEMORY_MAP_FAILED,
+    PENDING_IO,
+    SUCCESS
+  };
+
   static void GetDescriptions(BlobConsolidation* consolidation,
                               size_t max_data_population,
                               std::vector<storage::DataElement>* out);
 
   BlobTransportController();
   ~BlobTransportController();
 
-  // 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>;
+  void OnFileWriteComplete(
+      IPC::Sender* sender,
+      const std::string& uuid,
+      const std::pair<std::vector<storage::BlobItemBytesResponse>,
+                      storage::IPCBlobCreationCancelCode>& result);
 
   void StoreBlobDataForRequests(
       const std::string& uuid,
-      std::unique_ptr<BlobConsolidation> consolidation,
+      scoped_refptr<BlobConsolidation> consolidation,
       scoped_refptr<base::SingleThreadTaskRunner> main_runner);
 
-  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

[michaeln, 2016/04/28 00:16:57]

comments describing aggregated process refcounting are stale

the fact that the class fiddles with the childprocess refcount when in the act
of transporting a blob could be a class level comment instead of a comment on
each method that may affect it

[dmurph, 2016/05/09 19:55:47]

Done.

   // reference.
   void ReleaseBlobConsolidation(const std::string& uuid);
 
   scoped_refptr<base::SingleThreadTaskRunner> main_thread_runner_;
-  std::map<std::string, std::unique_ptr<BlobConsolidation>> blob_storage_;
+  std::map<std::string, scoped_refptr<BlobConsolidation>> blob_storage_;
+  base::WeakPtrFactory<BlobTransportController> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(BlobTransportController);
 };
 
 }  // namespace content
 #endif  // CONTENT_CHILD_BLOB_STORAGE_BLOB_TRANSPORT_CONTROLLER_H_