/*
** GetPrepGeomCache
**
** Pull the current prepared geometry from the cache or make
** one if there is not one available. Only prepare geometry
** if we are seeing a key for the second time. That way rapidly
** cycling keys don't cause too much preparing.
*/
PrepGeomCache*
GetPrepGeomCache(FunctionCallInfoData *fcinfo, GSERIALIZED *pg_geom1, GSERIALIZED *pg_geom2)
{
MemoryContext old_context;
PrepGeomCache* cache = fcinfo->flinfo->fn_extra;
int copy_keys = 1;
size_t pg_geom1_size = 0;
size_t pg_geom2_size = 0;
/* Make sure this isn't someone else's cache object. */
if ( cache && cache->type != 2 ) cache = NULL;
if (!PrepGeomHash)
CreatePrepGeomHash();
if ( pg_geom1 )
pg_geom1_size = VARSIZE(pg_geom1) + VARHDRSZ;
if ( pg_geom2 )
pg_geom2_size = VARSIZE(pg_geom2) + VARHDRSZ;
if ( cache == NULL)
{
/*
** Cache requested, but the cache isn't set up yet.
** Set it up, but don't prepare the geometry yet.
** That way if the next call is a cache miss we haven't
** wasted time preparing a geometry we don't need.
*/
PrepGeomHashEntry pghe;
old_context = MemoryContextSwitchTo(fcinfo->flinfo->fn_mcxt);
cache = palloc(sizeof(PrepGeomCache));
MemoryContextSwitchTo(old_context);
cache->type = 2;
cache->prepared_geom = 0;
cache->geom = 0;
cache->argnum = 0;
cache->pg_geom1 = 0;
cache->pg_geom2 = 0;
cache->pg_geom1_size = 0;
cache->pg_geom2_size = 0;
cache->context = MemoryContextCreate(T_AllocSetContext, 8192,
&PreparedCacheContextMethods,
fcinfo->flinfo->fn_mcxt,
"PostGIS Prepared Geometry Context");
POSTGIS_DEBUGF(3, "GetPrepGeomCache: creating cache: %p", cache);
pghe.context = cache->context;
pghe.geom = 0;
pghe.prepared_geom = 0;
AddPrepGeomHashEntry( pghe );
fcinfo->flinfo->fn_extra = cache;
POSTGIS_DEBUGF(3, "GetPrepGeomCache: adding context to hash: %p", cache);
}
else if ( pg_geom1 &&
cache->argnum != 2 &&
cache->pg_geom1_size == pg_geom1_size &&
memcmp(cache->pg_geom1, pg_geom1, pg_geom1_size) == 0)
{
if ( !cache->prepared_geom )
{
/*
** Cache hit, but we haven't prepared our geometry yet.
** Prepare it.
*/
PrepGeomHashEntry* pghe;
cache->geom = POSTGIS2GEOS( pg_geom1 );
cache->prepared_geom = GEOSPrepare( cache->geom );
cache->argnum = 1;
POSTGIS_DEBUG(3, "GetPrepGeomCache: preparing obj in argument 1");
pghe = GetPrepGeomHashEntry(cache->context);
pghe->geom = cache->geom;
pghe->prepared_geom = cache->prepared_geom;
POSTGIS_DEBUG(3, "GetPrepGeomCache: storing references to prepared obj in argument 1");
}
else
{
/*
** Cache hit, and we're good to go. Do nothing.
*/
POSTGIS_DEBUG(3, "GetPrepGeomCache: cache hit, argument 1");
}
/* We don't need new keys until we have a cache miss */
copy_keys = 0;
}
else if ( pg_geom2 &&
cache->argnum != 1 &&
cache->pg_geom2_size == pg_geom2_size &&
memcmp(cache->pg_geom2, pg_geom2, pg_geom2_size) == 0)
{
if ( !cache->prepared_geom )
{
/*
** Cache hit on arg2, but we haven't prepared our geometry yet.
** Prepare it.
*/
PrepGeomHashEntry* pghe;
cache->geom = POSTGIS2GEOS( pg_geom2 );
cache->prepared_geom = GEOSPrepare( cache->geom );
cache->argnum = 2;
POSTGIS_DEBUG(3, "GetPrepGeomCache: preparing obj in argument 2");
pghe = GetPrepGeomHashEntry(cache->context);
pghe->geom = cache->geom;
pghe->prepared_geom = cache->prepared_geom;
POSTGIS_DEBUG(3, "GetPrepGeomCache: storing references to prepared obj in argument 2");
}
else
{
/*
** Cache hit, and we're good to go. Do nothing.
*/
POSTGIS_DEBUG(3, "GetPrepGeomCache: cache hit, argument 2");
}
/* We don't need new keys until we have a cache miss */
copy_keys = 0;
}
else if ( cache->prepared_geom )
{
/*
** No cache hits, so this must be a miss.
** Destroy the GEOS objects, empty the cache.
*/
PrepGeomHashEntry* pghe;
pghe = GetPrepGeomHashEntry(cache->context);
pghe->geom = 0;
pghe->prepared_geom = 0;
POSTGIS_DEBUGF(3, "GetPrepGeomCache: cache miss, argument %d", cache->argnum);
GEOSPreparedGeom_destroy( cache->prepared_geom );
GEOSGeom_destroy( (GEOSGeometry *)cache->geom );
cache->prepared_geom = 0;
cache->geom = 0;
cache->argnum = 0;
}
if ( copy_keys && pg_geom1 )
{
/*
** If this is a new key (cache miss) we flip into the function
** manager memory context and make a copy. We can't just store a pointer
** because this copy will be pfree'd at the end of this function
** call.
*/
POSTGIS_DEBUG(3, "GetPrepGeomCache: copying pg_geom1 into cache");
old_context = MemoryContextSwitchTo(fcinfo->flinfo->fn_mcxt);
if ( cache->pg_geom1 )
pfree(cache->pg_geom1);
cache->pg_geom1 = palloc(pg_geom1_size);
MemoryContextSwitchTo(old_context);
memcpy(cache->pg_geom1, pg_geom1, pg_geom1_size);
cache->pg_geom1_size = pg_geom1_size;
}
if ( copy_keys && pg_geom2 )
{
POSTGIS_DEBUG(3, "GetPrepGeomCache: copying pg_geom2 into cache");
old_context = MemoryContextSwitchTo(fcinfo->flinfo->fn_mcxt);
if ( cache->pg_geom2 )
pfree(cache->pg_geom2);
cache->pg_geom2 = palloc(pg_geom2_size);
MemoryContextSwitchTo(old_context);
memcpy(cache->pg_geom2, pg_geom2, pg_geom2_size);
cache->pg_geom2_size = pg_geom2_size;
}
return cache;
}
Datum intersectsPrepared(PG_FUNCTION_ARGS)
{
#ifndef PREPARED_GEOM
elog(ERROR,"Not implemented in this version!");
PG_RETURN_NULL(); /* never get here */
#else
PG_LWGEOM * geom1;
PG_LWGEOM * geom2;
bool result;
BOX2DFLOAT4 box1, box2;
PrepGeomCache * prep_cache;
int32 key1, key2;
geom1 = (PG_LWGEOM *) PG_DETOAST_DATUM(PG_GETARG_DATUM(0));
geom2 = (PG_LWGEOM *) PG_DETOAST_DATUM(PG_GETARG_DATUM(1));
key1 = PG_GETARG_INT32(2);
key2 = PG_GETARG_INT32(3);
errorIfGeometryCollection(geom1,geom2);
errorIfSRIDMismatch(pglwgeom_getSRID(geom1), pglwgeom_getSRID(geom2));
/*
* short-circuit 1: if geom2 bounding box does not overlap
* geom1 bounding box we can prematurely return FALSE.
* Do the test IFF BOUNDING BOX AVAILABLE.
*/
if ( getbox2d_p(SERIALIZED_FORM(geom1), &box1) &&
getbox2d_p(SERIALIZED_FORM(geom2), &box2) )
{
if (( box2.xmax < box1.xmin ) || ( box2.xmin > box1.xmax ) ||
( box2.ymax < box1.ymin ) || ( box2.ymin > box1.ymax ))
PG_RETURN_BOOL(FALSE);
}
prep_cache = GetPrepGeomCache( fcinfo, geom1, geom2 );
initGEOS(lwnotice, lwnotice);
if ( prep_cache && prep_cache->prepared_geom )
{
if ( prep_cache->argnum == 1 )
{
GEOSGeom g = POSTGIS2GEOS(geom2);
result = GEOSPreparedIntersects( prep_cache->prepared_geom, g);
GEOSGeom_destroy(g);
}
else
{
GEOSGeom g = POSTGIS2GEOS(geom1);
result = GEOSPreparedIntersects( prep_cache->prepared_geom, g);
GEOSGeom_destroy(g);
}
}
else
{
GEOSGeom g1 = POSTGIS2GEOS(geom1);
GEOSGeom g2 = POSTGIS2GEOS(geom2);
result = GEOSIntersects( g1, g2);
GEOSGeom_destroy(g1);
GEOSGeom_destroy(g2);
}
if (result == 2)
{
elog(ERROR,"GEOS contains() threw an error!");
PG_RETURN_NULL(); /* never get here */
}
PG_FREE_IF_COPY(geom1, 0);
PG_FREE_IF_COPY(geom2, 1);
PG_RETURN_BOOL(result);
#endif /* PREPARED_GEOM */
}
