net: Make UploadDataStream::Init() asynchronous.

net/base/upload_data_stream.h

 // 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.
 
 #ifndef NET_BASE_UPLOAD_DATA_STREAM_H_
 #define NET_BASE_UPLOAD_DATA_STREAM_H_
 
 #include "base/memory/ref_counted.h"
+#include "net/base/completion_callback.h"
 #include "net/base/net_export.h"
 #include "net/base/upload_data.h"
 
 namespace net {
 
 class FileStream;
 class IOBuffer;
 
 class NET_EXPORT UploadDataStream {
  public:
   explicit UploadDataStream(UploadData* upload_data);
   ~UploadDataStream();
 
-  // Initializes the stream. This function must be called exactly once,
-  // before calling any other method. It is not valid to call any method
-  // (other than the destructor) if Init() returns a failure.
+  // Initializes the stream synchronously or asynchronously depending on
+  // whether the upload data is in memory or not. This function must be called
+  // exactly once, before calling any other method. It is not valid to call any
+  // method (other than the destructor) if the initialization failed.
   //
-  // Returns OK on success. Returns ERR_UPLOAD_FILE_CHANGED if the expected
-  // file modification time is set (usually not set, but set for sliced
-  // files) and the target file is changed.
-  int Init();
+  // If the upload data is in memory, the initialization is done synchronously.
+  // Returns OK or some other error code.
+  //
+  // If initialization requires file IO, returns ERR_IO_PENDING, and runs
+  // |callback| with a result code on the original thread once the
+  // initialization is done.
+  //
+  // ERR_UPLOAD_FILE_CHANGED is passed to |callback| if the expected file
+  // modification time is set (usually not set, but set for sliced files) and
+  // the target file is changed.
+  int Init(const CompletionCallback& callback);
+
+  // Similar to Init() but performs the operation always synchronously. This
+  // version may perform file IO on the current thread. Usually used for
+  // testing, but Chrome Frame also uses this version.
+  int InitSync();
 
   // Reads up to |buf_len| bytes from the upload data stream to |buf|. The
   // number of bytes read is returned. Partial reads are allowed.  Zero is
   // returned on a call to Read when there are no remaining bytes in the
   // stream, and IsEof() will return true hereafter.
   //
   // If there's less data to read than we initially observed (i.e. the actual
   // upload data is smaller than size()), zeros are padded to ensure that
   // size() bytes can be read, which can happen for TYPE_FILE payloads.
   //
@@ skipping 27 matching lines @@
  private:
   friend class SpdyHttpStreamSpdy2Test;
   friend class SpdyHttpStreamSpdy3Test;
   friend class SpdyNetworkTransactionSpdy2Test;
   friend class SpdyNetworkTransactionSpdy3Test;
 
   // These methods are provided only to be used by unit tests.
   static void ResetMergeChunks();
   static void set_merge_chunks(bool merge) { merge_chunks_ = merge; }
 
+  // Called when InitInternal() is completed. Used to implement Init().
+  void OnInitComplete(const CompletionCallback& callback,
+                      uint64* content_length,
+                      int* result);
+
   scoped_refptr<UploadData> upload_data_;
 
   // Index of the current upload element (i.e. the element currently being
   // read). The index is used as a cursor to iterate over elements in
   // |upload_data_|.
   size_t element_index_;
 
   // Size and current read position within the upload data stream.
   uint64 total_size_;
   uint64 current_position_;
 
   // True if the initialization was successful.
   bool initialized_successfully_;
 
   // TODO(satish): Remove this once we have a better way to unit test POST
   // requests with chunked uploads.
   static bool merge_chunks_;
 
+  base::WeakPtrFactory<UploadDataStream> weak_ptr_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(UploadDataStream);
 };
 
 }  // namespace net
 
 #endif  // NET_BASE_UPLOAD_DATA_STREAM_H_