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VrSink.h

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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 _VRSINK_H_
00038 #define _VRSINK_H_
00039 
00040 #include <VrSigProc.h>
00041 
00042 template<class iType> 
00043 class VrSink : public VrSigProc {
00044 private:
00045   unsigned int optimalSize;
00046 
00047 public: 
00048   virtual const char *name() { return "VrSink"; }
00049 
00050   //set this if you want the sink to use smaller chunks
00051   //  than the maxLatency would dictate
00052   void setOptimalSize(unsigned int s) { optimalSize = s;} 
00053 
00054   virtual void setup();
00055   void setup_upstream(); 
00056 
00057   virtual int work(VrSampleRange output, void *o[],
00058                    VrSampleRange inputs[], void *i[]) {
00059     return work3 (output, inputs, i);
00060   };
00061 
00062   virtual int work3(VrSampleRange output, 
00063                     VrSampleRange inputs[], void *i[]) = 0; 
00064 
00065   VrSink() : VrSigProc(0, sizeof(iType), 0),
00066              optimalSize(0x70000000){ }
00067 };
00068 
00069 template <class iType> void
00070 VrSink<iType>::setup()
00071 {
00072   VrSink<iType>::setup_upstream();
00073 }
00074 
00075 template <class iType> void
00076 VrSink<iType>::setup_upstream()
00077 {
00078   float m = memoryTouched(); //returns memory accesses / second of chain
00079 
00080   //Compute a globally optimal size to run on for the whole chain
00081   //(every input and output stays in cache for entire length of chain)
00082   unsigned int cachedSize = (int) (cacheSize * (getSamplingFrequency() / m));
00083 
00084   fprintf(stderr,"%s cachedSize = %d\n",name(),cachedSize);
00085   if(cachedSize/getSamplingFrequency() > maxLatency) {
00086     fprintf(stderr,"   reducing latency from %f",cachedSize/getSamplingFrequency());
00087     cachedSize = (unsigned int) (getSamplingFrequency() * maxLatency);
00088     fprintf(stderr," to %f seconds\n",cachedSize/getSamplingFrequency());
00089   }
00090   if(optimalSize < cachedSize) {
00091     fprintf(stderr,"   manually specified optimalSize of %d (%f sec)\n",optimalSize,optimalSize/getSamplingFrequency());
00092     cachedSize=optimalSize;
00093   }
00094   //round down
00095   if((cachedSize % getOutputSize()) != 0) {
00096     cachedSize = (cachedSize/getOutputSize()) * getOutputSize();
00097   }
00098   if(cachedSize==0) cachedSize=getOutputSize(); 
00099   maxDSReadSize=optimalSize=cachedSize;
00100 
00101   VrSigProc::setup_upstream(); 
00102 }
00103 
00104 #endif
00105 

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