int* SHPSearchDiskTreeEx( SHPTreeDiskHandle hDiskTree,
double *padfBoundsMin, double *padfBoundsMax,
int *pnShapeCount )
{
int i, bNeedSwap, nBufferMax = 0;
unsigned char abyBuf[16];
int *panResultBuffer = NULL;
*pnShapeCount = 0;
/* -------------------------------------------------------------------- */
/* Establish the byte order on this machine. */
/* -------------------------------------------------------------------- */
i = 1;
if( *((unsigned char *) &i) == 1 )
bBigEndian = FALSE;
else
bBigEndian = TRUE;
/* -------------------------------------------------------------------- */
/* Read the header. */
/* -------------------------------------------------------------------- */
hDiskTree->sHooks.FSeek( hDiskTree->fpQIX, 0, SEEK_SET );
hDiskTree->sHooks.FRead( abyBuf, 16, 1, hDiskTree->fpQIX );
if( memcmp( abyBuf, "SQT", 3 ) != 0 )
return NULL;
if( (abyBuf[3] == 2 && bBigEndian)
|| (abyBuf[3] == 1 && !bBigEndian) )
bNeedSwap = FALSE;
else
bNeedSwap = TRUE;
/* -------------------------------------------------------------------- */
/* Search through root node and it's descendants. */
/* -------------------------------------------------------------------- */
if( !SHPSearchDiskTreeNode( hDiskTree, padfBoundsMin, padfBoundsMax,
&panResultBuffer, &nBufferMax,
pnShapeCount, bNeedSwap, 0 ) )
{
if( panResultBuffer != NULL )
free( panResultBuffer );
*pnShapeCount = 0;
return NULL;
}
/* -------------------------------------------------------------------- */
/* Sort the id array */
/* -------------------------------------------------------------------- */
/* To distinguish between empty intersection from error case */
if( panResultBuffer == NULL )
panResultBuffer = (int*) calloc(1, sizeof(int));
else
qsort(panResultBuffer, *pnShapeCount, sizeof(int), compare_ints);
return panResultBuffer;
}
SHPSearchDiskTree( FILE *fp,
double *padfBoundsMin, double *padfBoundsMax,
int *pnShapeCount )
{
int i, bNeedSwap, nBufferMax = 0;
unsigned char abyBuf[16];
int *panResultBuffer = NULL;
*pnShapeCount = 0;
/* -------------------------------------------------------------------- */
/* Establish the byte order on this machine. */
/* -------------------------------------------------------------------- */
i = 1;
if( *((unsigned char *) &i) == 1 )
bBigEndian = FALSE;
else
bBigEndian = TRUE;
/* -------------------------------------------------------------------- */
/* Read the header. */
/* -------------------------------------------------------------------- */
fseek( fp, 0, SEEK_SET );
fread( abyBuf, 16, 1, fp );
if( memcmp( abyBuf, "SQT", 3 ) != 0 )
return NULL;
if( (abyBuf[3] == 2 && bBigEndian)
|| (abyBuf[3] == 1 && !bBigEndian) )
bNeedSwap = FALSE;
else
bNeedSwap = TRUE;
/* -------------------------------------------------------------------- */
/* Search through root node and it's decendents. */
/* -------------------------------------------------------------------- */
if( !SHPSearchDiskTreeNode( fp, padfBoundsMin, padfBoundsMax,
&panResultBuffer, &nBufferMax,
pnShapeCount, bNeedSwap ) )
{
if( panResultBuffer != NULL )
free( panResultBuffer );
*pnShapeCount = 0;
return NULL;
}
/* -------------------------------------------------------------------- */
/* Sort the id array */
/* -------------------------------------------------------------------- */
qsort(panResultBuffer, *pnShapeCount, sizeof(int), compare_ints);
return panResultBuffer;
}
static int
SHPSearchDiskTreeNode( FILE *fp, double *padfBoundsMin, double *padfBoundsMax,
int **ppanResultBuffer, int *pnBufferMax,
int *pnResultCount, int bNeedSwap )
{
int i;
int offset;
int numshapes, numsubnodes;
double adfNodeBoundsMin[2], adfNodeBoundsMax[2];
/* -------------------------------------------------------------------- */
/* Read and unswap first part of node info. */
/* -------------------------------------------------------------------- */
fread( &offset, 4, 1, fp );
if ( bNeedSwap ) SwapWord ( 4, &offset );
fread( adfNodeBoundsMin, sizeof(double), 2, fp );
fread( adfNodeBoundsMax, sizeof(double), 2, fp );
if ( bNeedSwap )
{
SwapWord( 8, adfNodeBoundsMin + 0 );
SwapWord( 8, adfNodeBoundsMin + 1 );
SwapWord( 8, adfNodeBoundsMax + 0 );
SwapWord( 8, adfNodeBoundsMax + 1 );
}
fread( &numshapes, 4, 1, fp );
if ( bNeedSwap ) SwapWord ( 4, &numshapes );
/* -------------------------------------------------------------------- */
/* If we don't overlap this node at all, we can just fseek() */
/* pass this node info and all subnodes. */
/* -------------------------------------------------------------------- */
if( !SHPCheckBoundsOverlap( adfNodeBoundsMin, adfNodeBoundsMax,
padfBoundsMin, padfBoundsMax, 2 ) )
{
offset += numshapes*sizeof(int) + sizeof(int);
fseek(fp, offset, SEEK_CUR);
return TRUE;
}
/* -------------------------------------------------------------------- */
/* Add all the shapeids at this node to our list. */
/* -------------------------------------------------------------------- */
if(numshapes > 0)
{
if( *pnResultCount + numshapes > *pnBufferMax )
{
*pnBufferMax = (int) ((*pnResultCount + numshapes + 100) * 1.25);
*ppanResultBuffer = (int *)
SfRealloc( *ppanResultBuffer, *pnBufferMax * sizeof(int) );
}
fread( *ppanResultBuffer + *pnResultCount,
sizeof(int), numshapes, fp );
if (bNeedSwap )
{
for( i=0; i<numshapes; i++ )
SwapWord( 4, *ppanResultBuffer + *pnResultCount + i );
}
*pnResultCount += numshapes;
}
/* -------------------------------------------------------------------- */
/* Process the subnodes. */
/* -------------------------------------------------------------------- */
fread( &numsubnodes, 4, 1, fp );
if ( bNeedSwap ) SwapWord ( 4, &numsubnodes );
for(i=0; i<numsubnodes; i++)
{
if( !SHPSearchDiskTreeNode( fp, padfBoundsMin, padfBoundsMax,
ppanResultBuffer, pnBufferMax,
pnResultCount, bNeedSwap ) )
return FALSE;
}
return TRUE;
}
static int
SHPSearchDiskTreeNode( SHPTreeDiskHandle hDiskTree, double *padfBoundsMin, double *padfBoundsMax,
int **ppanResultBuffer, int *pnBufferMax,
int *pnResultCount, int bNeedSwap, int nRecLevel )
{
unsigned int i;
unsigned int offset;
unsigned int numshapes, numsubnodes;
double adfNodeBoundsMin[2], adfNodeBoundsMax[2];
int nFReadAcc;
/* -------------------------------------------------------------------- */
/* Read and unswap first part of node info. */
/* -------------------------------------------------------------------- */
nFReadAcc = (int)hDiskTree->sHooks.FRead( &offset, 4, 1, hDiskTree->fpQIX );
if ( bNeedSwap ) SwapWord ( 4, &offset );
nFReadAcc += (int)hDiskTree->sHooks.FRead( adfNodeBoundsMin, sizeof(double), 2, hDiskTree->fpQIX );
nFReadAcc += (int)hDiskTree->sHooks.FRead( adfNodeBoundsMax, sizeof(double), 2, hDiskTree->fpQIX );
if ( bNeedSwap )
{
SwapWord( 8, adfNodeBoundsMin + 0 );
SwapWord( 8, adfNodeBoundsMin + 1 );
SwapWord( 8, adfNodeBoundsMax + 0 );
SwapWord( 8, adfNodeBoundsMax + 1 );
}
nFReadAcc += (int)hDiskTree->sHooks.FRead( &numshapes, 4, 1, hDiskTree->fpQIX );
if ( bNeedSwap ) SwapWord ( 4, &numshapes );
/* Check that we could read all previous values */
if( nFReadAcc != 1 + 2 + 2 + 1 )
{
hDiskTree->sHooks.Error("I/O error");
return FALSE;
}
/* Sanity checks to avoid int overflows in later computation */
if( offset > INT_MAX - sizeof(int) )
{
hDiskTree->sHooks.Error("Invalid value for offset");
return FALSE;
}
if( numshapes > (INT_MAX - offset - sizeof(int)) / sizeof(int) ||
numshapes > INT_MAX / sizeof(int) - *pnResultCount )
{
hDiskTree->sHooks.Error("Invalid value for numshapes");
return FALSE;
}
/* -------------------------------------------------------------------- */
/* If we don't overlap this node at all, we can just fseek() */
/* pass this node info and all subnodes. */
/* -------------------------------------------------------------------- */
if( !SHPCheckBoundsOverlap( adfNodeBoundsMin, adfNodeBoundsMax,
padfBoundsMin, padfBoundsMax, 2 ) )
{
offset += numshapes*sizeof(int) + sizeof(int);
hDiskTree->sHooks.FSeek(hDiskTree->fpQIX, offset, SEEK_CUR);
return TRUE;
}
/* -------------------------------------------------------------------- */
/* Add all the shapeids at this node to our list. */
/* -------------------------------------------------------------------- */
if(numshapes > 0)
{
if( *pnResultCount + numshapes > *pnBufferMax )
{
int* pNewBuffer;
*pnBufferMax = (*pnResultCount + numshapes + 100) * 5 / 4;
if( *pnBufferMax > INT_MAX / sizeof(int) )
*pnBufferMax = *pnResultCount + numshapes;
pNewBuffer = (int *)
SfRealloc( *ppanResultBuffer, *pnBufferMax * sizeof(int) );
if( pNewBuffer == NULL )
{
hDiskTree->sHooks.Error("Out of memory error");
return FALSE;
}
*ppanResultBuffer = pNewBuffer;
}
if( hDiskTree->sHooks.FRead( *ppanResultBuffer + *pnResultCount,
sizeof(int), numshapes, hDiskTree->fpQIX ) != numshapes )
{
hDiskTree->sHooks.Error("I/O error");
return FALSE;
}
if (bNeedSwap )
{
for( i=0; i<numshapes; i++ )
SwapWord( 4, *ppanResultBuffer + *pnResultCount + i );
}
*pnResultCount += numshapes;
}
/* -------------------------------------------------------------------- */
/* Process the subnodes. */
/* -------------------------------------------------------------------- */
if( hDiskTree->sHooks.FRead( &numsubnodes, 4, 1, hDiskTree->fpQIX ) != 1 )
{
hDiskTree->sHooks.Error("I/O error");
return FALSE;
}
if ( bNeedSwap ) SwapWord ( 4, &numsubnodes );
if( numsubnodes > 0 && nRecLevel == 32 )
{
hDiskTree->sHooks.Error("Shape tree is too deep");
return FALSE;
}
for(i=0; i<numsubnodes; i++)
{
if( !SHPSearchDiskTreeNode( hDiskTree, padfBoundsMin, padfBoundsMax,
ppanResultBuffer, pnBufferMax,
pnResultCount, bNeedSwap, nRecLevel + 1 ) )
return FALSE;
}
return TRUE;
}
