gr_block.h

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/* -*- c++ -*- */
/*
 * Copyright 2004 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 2, 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., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#ifndef INCLUDED_GR_BLOCK_H
#define INCLUDED_GR_BLOCK_H

#include <gr_runtime.h>
#include <string>

class gr_block {

 public:
  
  virtual ~gr_block ();
  
  std::string name () const { return d_name; }
  gr_io_signature_sptr input_signature () const  { return d_input_signature; }
  gr_io_signature_sptr output_signature () const { return d_output_signature; }
  long unique_id () const { return d_unique_id; }

  unsigned history () const { return d_history; }
  void  set_history (unsigned history) { d_history = history; }
  
  bool fixed_rate() const { return d_fixed_rate; }

  // ----------------------------------------------------------------
  //            override these to define your behavior
  // ----------------------------------------------------------------

  virtual void forecast (int noutput_items,
                         gr_vector_int &ninput_items_required);

  virtual int general_work (int noutput_items,
                            gr_vector_int &ninput_items,
                            gr_vector_const_void_star &input_items,
                            gr_vector_void_star &output_items) = 0;

  virtual bool check_topology (int ninputs, int noutputs);

  virtual bool start();

  virtual bool stop();

  // ----------------------------------------------------------------

  void set_output_multiple (int multiple);
  int  output_multiple () const { return d_output_multiple; }

  void consume (int which_input, int how_many_items);

  void consume_each (int how_many_items);

  void  set_relative_rate (double relative_rate);

  double relative_rate () const { return d_relative_rate; }

  /*
   * The following two methods provide special case info to the
   * scheduler in the event that a block has a fixed input to output
   * ratio.  gr_sync_block, gr_sync_decimator and gr_sync_interpolator
   * override these.  If you're fixed rate, subclass one of those.
   */
  virtual int fixed_rate_ninput_to_noutput(int ninput);

  virtual int fixed_rate_noutput_to_ninput(int noutput);

  // ----------------------------------------------------------------------------

 private:

  std::string           d_name;
  gr_io_signature_sptr  d_input_signature;
  gr_io_signature_sptr  d_output_signature;
  int                   d_output_multiple;
  double                d_relative_rate;        // approx output_rate / input_rate
  gr_block_detail_sptr  d_detail;               // implementation details
  long                  d_unique_id;            // convenient for debugging
  unsigned              d_history;
  bool                  d_fixed_rate;

  
 protected:

  gr_block (const std::string &name,
            gr_io_signature_sptr input_signature,
            gr_io_signature_sptr output_signature);

  void set_input_signature (gr_io_signature_sptr iosig){
    d_input_signature = iosig;
  }

  void set_output_signature (gr_io_signature_sptr iosig){
    d_output_signature = iosig;
  }

  void set_fixed_rate(bool fixed_rate){ d_fixed_rate = fixed_rate; }

  // These are really only for internal use, but leaving them public avoids
  // having to work up an ever-varying list of friends

 public:
  gr_block_detail_sptr detail () const { return d_detail; }
  void set_detail (gr_block_detail_sptr detail) { d_detail = detail; }
};

long gr_block_ncurrently_allocated ();

#endif /* INCLUDED_GR_BLOCK_H */

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