/ray/src/lib/sourcepos/spcache.cc

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/*
 * lib/sourcepos/spcache.cc
 * 
 * Classes for sophisticated source position (file/line/lpos, 
 * include hierarchy) handling. 
 * 
 * Copyright (c) 2003--2004 by Wolfgang Wieser ] wwieser (a) gmx <*> de [ 
 * 
 * This file may be distributed and/or modified under the terms of the 
 * GNU General Public License version 2 as published by the Free Software 
 * Foundation. (See COPYING.GPL for details.)
 * 
 * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
 * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 * 
 */

#include "spcache.h"

#include <stdio.h>


SourcePosition SourcePositionCache::find(int line,int lpos)
{
    SourcePosition sp;
    
    // [Need not check for top<0 here, the for() loop is safe.] 
    // Do a linear lookup. A binary search or something like that 
    // would just be overkill at the applied cache size of 4..8. 
    for(int i=cache_size; i>0; i--)  // <-- CORRECT!!
    {
        const SourcePosition &spi=(cache[(top+i)%cache_size]);
        if(!spi)  break;
        if(spi->line()==line && spi->lpos()==lpos)
        {  sp=spi;  ++hits;  return(sp);  }
    }
    
    ++misses;
    return(sp); 
}


SourcePositionCache::SourcePositionCache()
{
    top=-1;  // correct
    
    hits=0;
    misses=0;
}

SourcePositionCache::~SourcePositionCache()
{
    // This is debug; should be commented out. 
    fprintf(stderr,"SourcePositionCache: hits=%d, misses=%d\n",
        hits,misses);
}

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