Main Page | Namespace List | Class Hierarchy | Class List | Directories | File List | Namespace Members | Class Members | File Members | Related Pages

VrBuffer.h

Go to the documentation of this file.
00001 /* -*- Mode: c++ -*- */
00002 /*
00003  * Copyright 2001 Free Software Foundation, Inc.
00004  * 
00005  * This file is part of GNU Radio
00006  * 
00007  * GNU Radio is free software; you can redistribute it and/or modify
00008  * it under the terms of the GNU General Public License as published by
00009  * the Free Software Foundation; either version 2, or (at your option)
00010  * any later version.
00011  * 
00012  * GNU Radio is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00015  * GNU General Public License for more details.
00016  * 
00017  * You should have received a copy of the GNU General Public License
00018  * along with GNU Radio; see the file COPYING.  If not, write to
00019  * the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
00020  * Boston, MA 02111-1307, USA.
00021  */
00022 /*
00023  *  Copyright 1997 Massachusetts Institute of Technology
00024  * 
00025  *  Permission to use, copy, modify, distribute, and sell this software and its
00026  *  documentation for any purpose is hereby granted without fee, provided that
00027  *  the above copyright notice appear in all copies and that both that
00028  *  copyright notice and this permission notice appear in supporting
00029  *  documentation, and that the name of M.I.T. not be used in advertising or
00030  *  publicity pertaining to distribution of the software without specific,
00031  *  written prior permission.  M.I.T. makes no representations about the
00032  *  suitability of this software for any purpose.  It is provided "as is"
00033  *  without express or implied warranty.
00034  * 
00035  */
00036 
00037 #ifndef _VRBUFFER_H_
00038 #define _VRBUFFER_H_
00039 #include "VrTypes.h"
00040 
00041 extern int BufferSizeMultiplier;
00042 class VrConnect;
00043 class VrSigProc;
00044 
00045 class VrBuffer {
00046 protected:
00047   //duplicate start = end of unique + 1 = start + bufferSize
00048   char* bufferDupStart; 
00049   unsigned int bufferSize;       // size in items.  = bufferDupStart - buffer start
00050   unsigned int type_size;        // size of 1 unit of data 
00051   VrSampleIndex WPdupstart;      // VrSampleIndex at bufferDupStart
00052   MUTEX_DECLARE(dupstartlock);
00053   VrSampleIndex minRP;           // hint; <= min_i(connectors[i]->minRP) -- updated rarely
00054   VrSigProc* upstream;           // who writes to this buffer 
00055   VrConnect ** connectors;       // who reads from this buffer
00056   unsigned int numberConnectors; // how many of above
00057   unsigned int setupCalled;      // count of how many setup requests we've received 
00058   virtual void allocateBuffer(unsigned int arg_type_size); 
00059 
00060 public: 
00061   unsigned int buffersize() { return bufferSize; };
00062   unsigned int getNumberConnectors() { return numberConnectors; }
00063   // Add c as a reader of this buffer
00064   void connect_buffer(VrConnect *c);
00065   double buffer_getSamplingFrequency();
00066   VrSigProc* getUpstreamModule() {return upstream;} 
00067   //Called once from upstream module
00068   void setup(unsigned int arg_type_size);
00069   //recompute the hint minRP
00070   VrSampleIndex updateMinRP();
00071 
00072   //returns how much space will be left if the write pointer is updated to WP
00073   //  if >0, write can proceed
00074   int writespace(VrSampleIndex WP) {
00075     int s = bufferSize - (WP - minRP);
00076     if(s <= 0)
00077       updateMinRP();
00078     s = bufferSize - (WP - minRP);
00079     return s;
00080   }
00081 
00082   //called from the upstream VrSigProc (in prepareRead)
00083   char *getWritePointer(VrSampleRange r);
00084   //called from a downstream VrSigProc, via VrConnect
00085   virtual char *getReadPointer(VrSampleRange r);
00086   VrBuffer(VrSigProc *m); 
00087   virtual ~VrBuffer() { };
00088 };
00089 #define PAGE_SIZE getpagesize()
00090 #endif

Generated on Tue Mar 15 23:48:04 2005 for GNU Radio by  doxygen 1.4.0