multipart_response_delegate.h

// Copyright (c) 2011 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.
//
// A delegate class of WebURLLoaderImpl that handles multipart/x-mixed-replace
// data.  We special case multipart/x-mixed-replace because WebCore expects a
// separate didReceiveResponse for each new message part.
//
// Most of the logic and edge case handling are based on the Mozilla's
// implementation in netwerk/streamconv/converters/nsMultiMixedConv.cpp.
// This seems like a derivative work, so here's the original license:

/* ***** BEGIN LICENSE BLOCK *****
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 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is mozilla.org code.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1998
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
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 * either the GNU General Public License Version 2 or later (the "GPL"), or
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#ifndef WEBKIT_CHILD_MULTIPART_RESPONSE_DELEGATE_H_
#define WEBKIT_CHILD_MULTIPART_RESPONSE_DELEGATE_H_

#include <string>

#include "base/basictypes.h"
#include "third_party/WebKit/public/platform/WebURLResponse.h"
#include "webkit/child/webkit_child_export.h"

namespace WebKit {
class WebURLLoader;
class WebURLLoaderClient;
}

namespace webkit_glue {

// Used by unit tests to access private members.
class MultipartResponseDelegateTester;

class WEBKIT_CHILD_EXPORT MultipartResponseDelegate {
 public:
  MultipartResponseDelegate(WebKit::WebURLLoaderClient* client,
                            WebKit::WebURLLoader* loader,
                            const WebKit::WebURLResponse& response,
                            const std::string& boundary);

  // Passed through from ResourceHandleInternal
  void OnReceivedData(const char* data, int data_len, int encoded_data_length);
  void OnCompletedRequest();

  // The request has been canceled, so stop making calls to the client.
  void Cancel() {
    client_ = NULL;
    loader_ = NULL;
  }

  // Returns the multi part boundary string from the Content-type header
  // in the response.
  // Returns true on success.
  static bool ReadMultipartBoundary(const WebKit::WebURLResponse& response,
                                    std::string* multipart_boundary);

  // Returns the lower and higher content ranges from an individual multipart
  // in a multipart response.
  // Returns true on success.
  static bool ReadContentRanges(
      const WebKit::WebURLResponse& response,
      int64* content_range_lower_bound,
      int64* content_range_upper_bound,
      int64* content_range_instance_size);

 private:
  friend class MultipartResponseDelegateTester;  // For unittests.

  // Pointers to the client and associated loader so we can make callbacks as
  // we parse pieces of data.
  WebKit::WebURLLoaderClient* client_;
  WebKit::WebURLLoader* loader_;

  // The original resource response for this request.  We use this as a
  // starting point for each parts response.
  WebKit::WebURLResponse original_response_;

  // Checks to see if data[pos] character is a line break; handles crlf, lflf,
  // lf, or cr. Returns the number of characters to skip over (0, 1 or 2).
  int PushOverLine(const std::string& data, size_t pos);

  // Tries to parse http headers from the start of data_.  Returns true if it
  // succeeds and sends a didReceiveResponse to m_client.  Returns false if
  // the header is incomplete (in which case we just wait for more data).
  bool ParseHeaders();

  // Find the next boundary in data_.  Returns std::string::npos if there's no
  // full token.
  size_t FindBoundary();

  // Transferred data size accumulated between client callbacks.
  int encoded_data_length_;

  // A temporary buffer to hold data between reads for multipart data that
  // gets split in the middle of a header.
  std::string data_;

  // Multipart boundary token
  std::string boundary_;

  // true until we get our first on received data call
  bool first_received_data_;

  // true if we're truncated in the middle of a header
  bool processing_headers_;

  // true when we're done sending information.  At that point, we stop
  // processing AddData requests.
  bool stop_sending_;

  // true after we've sent our first response to the WebURLLoaderClient.
  bool has_sent_first_response_;

  DISALLOW_COPY_AND_ASSIGN(MultipartResponseDelegate);
};

}  // namespace webkit_glue

#endif  // WEBKIT_CHILD_MULTIPART_RESPONSE_DELEGATE_H_