text: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
   * 
   * Unless required by applicable law or agreed to in writing,
   * software distributed under the License is distributed on an
   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   * KIND, either express or implied.  See the License for the
   * specific language governing permissions and limitations
   * under the License.
   */
  
  #ifndef PAGESPEED_KERNEL_BASE_JSON_WRITER_H_
  #define PAGESPEED_KERNEL_BASE_JSON_WRITER_H_
  
  #include <utility>
  #include <vector>
  
  #include "pagespeed/kernel/base/basictypes.h"
  #include "pagespeed/kernel/base/string.h"
  #include "pagespeed/kernel/base/string_util.h"
  #include "pagespeed/kernel/base/writer.h"
  
  namespace Json {
  class Value;
  }  // namespace Json
  
  namespace net_instaweb {
  
  static const char kInstanceHtml[] = "instance_html";
  
  class HtmlElement;
  class MessageHandler;
  
  // Pair of panel json and start Element corresponding to the panel.
  typedef std::pair<HtmlElement*, Json::Value*> ElementJsonPair;
  
  // Writes bytes to top json of the stack.
  class JsonWriter : public Writer {
   public:
    // It is assumed that the element_json_stack is available till the destruction
    // of the writer
    JsonWriter(Writer* writer,
               const std::vector<ElementJsonPair>* element_json_stack);
    ~JsonWriter() override;
  
    bool Write(const StringPiece& str, MessageHandler* message_handler) override;
    bool Flush(MessageHandler* message_handler) override;
    // Updates the json dictionary with the buffer content so far.
    void UpdateDictionary();
  
   private:
    Writer* writer_;
    GoogleString buffer_;
    const std::vector<ElementJsonPair>* element_json_stack_;
  
    DISALLOW_COPY_AND_ASSIGN(JsonWriter);
  };
  
  }  // namespace net_instaweb
  
  #endif  // PAGESPEED_KERNEL_BASE_JSON_WRITER_H_
  