/****************************************************************************** * $Id: rawblockedimage.cpp 10646 2007-01-18 02:38:10Z warmerdam $ * * Project:  GeoTIFF Overview Builder * Purpose:  Implement the RawBlockedImage class, for holding ``under *           construction'' overviews in a temporary file.  * Author:   Frank Warmerdam, warmerda@home.com * ****************************************************************************** * Copyright (c) 1999, Frank Warmerdam * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included * in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER * DEALINGS IN THE SOFTWARE. ****************************************************************************/#include <assert.h>#include <string.h>#include <stdlib.h>#ifndef _WIN32#  include <unistd.h>#endif#include "rawblockedimage.h"#ifndef FALSE#  define FALSE 0#  define TRUE 1#endif#ifndef MAX#  define MIN(a,b)      ((a<b) ? a : b)#  define MAX(a,b)      ((a>b) ? a : b)#endif/************************************************************************//*                          RawBlockedImage()                           *//************************************************************************/RawBlockedImage::RawBlockedImage( int nXSizeIn, int nYSizeIn,                                  int nBlockXSizeIn, int nBlockYSizeIn,                                  int nBitsPerPixelIn ){    static int		nTempCounter = 0;    char		szFilename[128];    /* -------------------------------------------------------------------- *//*      Initialize stuff.                                               *//* -------------------------------------------------------------------- */    nXSize = nXSizeIn;    nYSize = nYSizeIn;    nBlockXSize = nBlockXSizeIn;    nBlockYSize = nBlockYSizeIn;    nBitsPerPixel = nBitsPerPixelIn;/* -------------------------------------------------------------------- *//*      Create the raw temporary file, trying to verify first that      *//*      it doesn't already exist.                                       *//* -------------------------------------------------------------------- */    fp = NULL;    while( fp == NULL )    {        sprintf( szFilename, "temp_%d.rbi", nTempCounter++ );        fp = fopen( szFilename, "r" );        if( fp != NULL )            fclose( fp );        else            fp = fopen( szFilename, "w+b" );    }    pszFilename = strdup( szFilename );    nCurFileSize = 0;/* -------------------------------------------------------------------- *//*      Initialize other stuff.                                         *//* -------------------------------------------------------------------- */    nBlocksPerRow = (nXSize + nBlockXSize - 1) / nBlockXSize;    nBlocksPerColumn = (nYSize + nBlockYSize - 1) / nBlockYSize;    nBytesPerBlock = (nBlockXSize*nBlockYSize*nBitsPerPixel + 7) / 8;    nBlocks = nBlocksPerRow * nBlocksPerColumn;    nBlocksInCache = 0;    nMaxBlocksInCache = MIN(nBlocks, 2*nBlocksPerRow);    papoBlocks = (RawBlock **) calloc(sizeof(RawBlock*),nBlocks);    poLRUHead = NULL;    poLRUTail = NULL;}/************************************************************************//*                          ~RawBlockedImage()                          *//************************************************************************/RawBlockedImage::~RawBlockedImage(){    int		i;    for( i = 0; i < nBlocks; i++ )    {        if( papoBlocks[i] != NULL )        {            if( papoBlocks[i]->pabyData != NULL )                free( papoBlocks[i]->pabyData );            delete papoBlocks[i];        }    }    if( papoBlocks != NULL)        free( papoBlocks );    fclose( fp );    unlink( pszFilename );	/* wrap this? */    free( pszFilename );}/************************************************************************//*                          InsertInLRUList()                           *//*                                                                      *//*      Insert this link at the beginning of the LRU list.  First       *//*      removed from it's current position if it is in the list.        *//************************************************************************/void RawBlockedImage::InsertInLRUList( RawBlock * poBlock ){/* -------------------------------------------------------------------- *//*      Remove from list, if it is currently in it.                     *//* -------------------------------------------------------------------- */    if( poBlock->poPrevLRU != NULL || poLRUHead == poBlock )        RemoveFromLRUList( poBlock );/* -------------------------------------------------------------------- *//*      Add at the head.                                                *//* -------------------------------------------------------------------- */    if( poLRUHead != NULL )    {        poLRUHead->poPrevLRU = poBlock;    }    poBlock->poNextLRU = poLRUHead;    poLRUHead = poBlock;    if( poLRUTail == NULL )        poLRUTail = poBlock;}/************************************************************************//*                         RemoveFromLRUList()                          *//*                                                                      *//*      Remove this block from the LRU list, if present.                *//************************************************************************/void RawBlockedImage::RemoveFromLRUList( RawBlock * poBlock ){/* -------------------------------------------------------------------- *//*      Is it even in the list?                                         *//* -------------------------------------------------------------------- */    if( poBlock->poPrevLRU == NULL && poLRUHead != poBlock )        return;/* -------------------------------------------------------------------- *//*      Fix the link before this in the list (or head pointer).         *//* -------------------------------------------------------------------- */    if( poBlock->poPrevLRU == NULL )    {        poLRUHead = poBlock->poNextLRU;    }    else    {        poBlock->poPrevLRU->poNextLRU = poBlock->poNextLRU;    }    /* -------------------------------------------------------------------- *//*      Fix the link after this one, or the tail pointer.               *//* -------------------------------------------------------------------- */    if( poBlock->poNextLRU == NULL )    {        poLRUTail = poBlock->poPrevLRU;    }    else    {        poBlock->poNextLRU->poPrevLRU = poBlock->poPrevLRU;    }/* -------------------------------------------------------------------- *//*      Update this link to indicate it isn't in the list now.          *//* -------------------------------------------------------------------- */    poBlock->poPrevLRU = poBlock->poNextLRU = NULL;}/************************************************************************//*                             FlushBlock()                             *//************************************************************************/void RawBlockedImage::FlushBlock( RawBlock * poBlock ){/* -------------------------------------------------------------------- *//*      If we aren't given a particular block to flush, then select     *//*      the lest recently used one from the LRU list.                   *//* -------------------------------------------------------------------- */    if( poBlock == NULL )    {        if( poLRUTail == NULL )            return;                poBlock = poLRUTail;    }/* -------------------------------------------------------------------- *//*      Remove from the LRU list.                                       *//* -------------------------------------------------------------------- */    RemoveFromLRUList( poBlock );/* -------------------------------------------------------------------- *//*      If the block has no data, then it doesn't really need to be     *//*      flushed.                                                        *//* -------------------------------------------------------------------- */    if( poBlock->pabyData == NULL )        return;/* -------------------------------------------------------------------- *//*      Is this block dirty?  If so we will have to try and save it.    *//* -------------------------------------------------------------------- */    if( poBlock->nDirty )    {        if( poBlock->nPositionInFile == -1 )            poBlock->nPositionInFile = nCurFileSize;        nCurFileSize += nBytesPerBlock;        if( fseek( fp, poBlock->nPositionInFile, SEEK_SET ) != 0 )        {            fprintf( stderr,                     "Seek to %d in overview spill file %s failed.\n",                     poBlock->nPositionInFile, pszFilename );            exit( 1 );        }        if( fwrite( poBlock->pabyData, 1, nBytesPerBlock, fp )            != (size_t) nBytesPerBlock )        {            fprintf( stderr,                      "Write of %d bytes at %d in overview spill file %s.\n"                     "Is the disk full?\n",                     nBytesPerBlock, poBlock->nPositionInFile, pszFilename );            exit( 1 );        }                poBlock->nDirty = FALSE;    }/* -------------------------------------------------------------------- *//*      Free the data block, and decrement used count.                  *//* -------------------------------------------------------------------- */    nBlocksInCache--;    if( poBlock->pabyData != NULL )        free( poBlock->pabyData );    poBlock->pabyData = NULL;}/************************************************************************//*                            GetRawBlock()                             *//************************************************************************/RawBlock *RawBlockedImage::GetRawBlock( int nXOff, int nYOff ){    int		nBlock = nXOff + nYOff * nBlocksPerRow;    RawBlock	*poBlock;    assert( nBlock >= 0 && nBlock < nBlocks );/* -------------------------------------------------------------------- *//*      Is this the first request?  If so, create the block object,     *//*      initialize the data memory, and return it.                      *//* -------------------------------------------------------------------- */    poBlock = papoBlocks[nBlock];    if( poBlock == NULL )    {        poBlock = papoBlocks[nBlock] = new RawBlock;        poBlock->nDirty = FALSE;        poBlock->poPrevLRU = poBlock->poNextLRU = NULL;        poBlock->nPositionInFile = -1;        poBlock->pabyData = (unsigned char *) calloc(1,nBytesPerBlock);        nBlocksInCache++;        if( poBlock->pabyData == NULL )        {            fprintf( stderr,                     "RawBlockedImage::GetRawBlock() - out of memory\n" );            exit( 1 );        }    }/* -------------------------------------------------------------------- *//*      Does this block need to be read off disk?                       *//* -------------------------------------------------------------------- */    else if( poBlock->nPositionInFile >= 0 && poBlock->pabyData == NULL )    {        nBlocksInCache++;        poBlock->pabyData = (unsigned char *) calloc(1,nBytesPerBlock);        fseek( fp, poBlock->nPositionInFile, SEEK_SET );        fread( poBlock->pabyData, nBytesPerBlock, 1, fp );    }/* -------------------------------------------------------------------- *//*      Does the data need to be allocated?                             *//* -------------------------------------------------------------------- */    else if( poBlock->pabyData == NULL )    {        poBlock->pabyData = (unsigned char *) calloc(1,nBytesPerBlock);        if( poBlock->pabyData == NULL )        {            fprintf( stderr,                     "RawBlockedImage::GetRawBlock() - out of memory\n" );            exit( 1 );        }    }/* -------------------------------------------------------------------- *//*      Push on the LRU stack, or pop it back to the top.               *//* -------------------------------------------------------------------- */    InsertInLRUList( poBlock );/* -------------------------------------------------------------------- *//*      If we have exceeded our self imposed caching limit, flush       *//*      one block.                                                      *//* -------------------------------------------------------------------- */    if( nBlocksInCache > nMaxBlocksInCache )        FlushBlock( NULL );    return( poBlock );}/************************************************************************//*                              GetTile()                               *//************************************************************************/unsigned char *RawBlockedImage::GetTile( int nXOff, int nYOff ){    RawBlock	*poBlock;    poBlock = GetRawBlock(nXOff,nYOff);    if( poBlock != NULL )        return poBlock->pabyData;    else        return NULL;}/************************************************************************//*                          GetTileForUpdate()                          *//************************************************************************/unsigned char *RawBlockedImage::GetTileForUpdate( int nXOff, int nYOff ){    RawBlock	*poBlock;    poBlock = GetRawBlock(nXOff,nYOff);    if( poBlock != NULL )    {        poBlock->nDirty = TRUE;                return poBlock->pabyData;    }    else        return NULL;}