/*
 * 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 NGX_MESSAGE_HANDLER_H_
#define NGX_MESSAGE_HANDLER_H_

extern "C" {
  #include <ngx_auto_config.h>
#if (NGX_THREADS)
  #include <ngx_thread.h>
#endif
  #include <ngx_core.h>
  #include <ngx_log.h>
}

#include <cstdarg>

#include "pagespeed/kernel/base/basictypes.h"
#include "pagespeed/kernel/base/message_handler.h"
#include "pagespeed/kernel/base/string.h"
#include "pagespeed/kernel/base/string_util.h"
#include "pagespeed/system/system_message_handler.h"

namespace net_instaweb {

class AbstractMutex;
class Timer;

// Implementation of a message handler that uses ngx_log_error()
// logging to emit messages, with a fallback to GoogleMessageHandler
class NgxMessageHandler : public SystemMessageHandler {
 public:
  explicit NgxMessageHandler(Timer* timer, AbstractMutex* mutex);

  // Installs a signal handler for common crash signals that tries to print
  // out a backtrace.
  static void InstallCrashHandler(ngx_log_t* log);

  void set_log(ngx_log_t* log) { log_ = log; }
  ngx_log_t* log() { return log_; }

 protected:
  virtual void MessageSImpl(MessageType type, const GoogleString& message);

  virtual void FileMessageSImpl(MessageType type, const char* file,
                                int line, const GoogleString& message);

 private:
  ngx_uint_t GetNgxLogLevel(MessageType type);
  ngx_log_t* log_;

  DISALLOW_COPY_AND_ASSIGN(NgxMessageHandler);
};

}  // namespace net_instaweb

#endif  // NGX_MESSAGE_HANDLER_H_