gr_message.h

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/* -*- c++ -*- */
/*
 * Copyright 2005 Free Software Foundation, Inc.
 * 
 * This file is part of GNU Radio
 * 
 * GNU Radio is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3, or (at your option)
 * any later version.
 * 
 * GNU Radio is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with GNU Radio; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street,
 * Boston, MA 02110-1301, USA.
 */
#ifndef INCLUDED_GR_MESSAGE_H
#define INCLUDED_GR_MESSAGE_H

#include <gr_core_api.h>
#include <gr_types.h>
#include <string>

class gr_message;
typedef boost::shared_ptr<gr_message> gr_message_sptr;

/*!
 * \brief public constructor for gr_message
 */
GR_CORE_API gr_message_sptr 
gr_make_message(long type = 0, double arg1 = 0, double arg2 = 0, size_t length = 0);

GR_CORE_API gr_message_sptr
gr_make_message_from_string(const std::string s, long type = 0, double arg1 = 0, double arg2 = 0);

/*!
 * \brief Message class.
 *
 * \ingroup misc
 * The ideas and method names for adjustable message length were
 * lifted from the click modular router "Packet" class.
 */
class GR_CORE_API gr_message {
  gr_message_sptr d_next;       // link field for msg queue
  long            d_type;       // type of the message
  double          d_arg1;       // optional arg1
  double          d_arg2;       // optional arg2

  unsigned char  *d_buf_start;  // start of allocated buffer
  unsigned char  *d_msg_start;  // where the msg starts
  unsigned char  *d_msg_end;    // one beyond end of msg
  unsigned char  *d_buf_end;    // one beyond end of allocated buffer
  
  gr_message (long type, double arg1, double arg2, size_t length);

  friend GR_CORE_API gr_message_sptr
    gr_make_message (long type, double arg1, double arg2, size_t length);

  friend GR_CORE_API gr_message_sptr
    gr_make_message_from_string (const std::string s, long type, double arg1, double arg2);

  friend class gr_msg_queue;

  unsigned char *buf_data() const  { return d_buf_start; }
  size_t buf_len() const           { return d_buf_end - d_buf_start; }

public:
  ~gr_message ();

  long type() const   { return d_type; }
  double arg1() const { return d_arg1; }
  double arg2() const { return d_arg2; }

  void set_type(long type)   { d_type = type; }
  void set_arg1(double arg1) { d_arg1 = arg1; }
  void set_arg2(double arg2) { d_arg2 = arg2; }

  unsigned char *msg() const { return d_msg_start; }
  size_t length() const      { return d_msg_end - d_msg_start; }
  std::string to_string() const;

};

GR_CORE_API long gr_message_ncurrently_allocated ();

#endif /* INCLUDED_GR_MESSAGE_H */