estimated_extent() implemented for PG<80

git-svn-id: http://svn.osgeo.org/postgis/trunk@1303 b70326c6-7e19-0410-871a-916f4a2858ee

diff --git a/lwgeom/lwgeom_estimate.c b/lwgeom/lwgeom_estimate.c
index 4ea37d945cedb2213eb052bba12a2ad6c2f4f90d..68443f9ec724fe2c9a781ca518629bbcf9d21d1f 100644 (file)
--- a/lwgeom/lwgeom_estimate.c
+++ b/lwgeom/lwgeom_estimate.c
@@ -25,6 +25,8 @@
 #include "liblwgeom.h"
 #include "lwgeom_pg.h"
 
+//#define DEBUG_GEOMETRY_STATS 1
+
 
 #if USE_VERSION >= 80
 
@@ -44,8 +46,6 @@
  */
 #define STATISTIC_KIND_GEOMETRY 100
 
-//#define DEBUG_GEOMETRY_STATS 1
-
 /*
  * Define this if you want to use standard deviation based
  * histogram extent computation. If you do, you can also 
@@ -275,7 +275,7 @@ Datum create_lwhistogram2d(PG_FUNCTION_ARGS)
 
        size =  sizeof(LWHISTOGRAM2D) + (boxesPerSide*boxesPerSide-1)*4  ;
 
-       histo = (LWHISTOGRAM2D *) palloc(size);
+       histo = (LWHISTOGRAM2D *)palloc(size);
        histo->size = size;
 
        histo->xmin = bbox->xmin;
@@ -341,6 +341,11 @@ Datum build_lwhistogram2d(PG_FUNCTION_ARGS)
        xmax = histo->xmax;
        ymax = histo->ymax;
 
+#if DEBUG_GEOMETRY_STATS
+       elog(NOTICE, " build_histogram2d: histogram extent = %g %g, %g %g",
+               histo->xmin, histo->ymin, histo->xmax, histo->ymax);
+#endif
+
 
        result = (LWHISTOGRAM2D *) malloc(histo->size);
        memcpy(result,histo,histo->size);
@@ -1179,8 +1184,143 @@ Datum LWGEOM_gist_sel(PG_FUNCTION_ARGS)
 PG_FUNCTION_INFO_V1(LWGEOM_estimated_extent);
 Datum LWGEOM_estimated_extent(PG_FUNCTION_ARGS)
 {
-       elog(ERROR, "estimated_extent() not implemented yet for PG<80");
-       PG_RETURN_NULL();
+       text *txnsp = NULL;
+       text *txtbl = NULL;
+       text *txcol = NULL;
+       char *nsp = NULL;
+       char *tbl = NULL;
+       char *col = NULL;
+       char *query;
+       size_t querysize;
+       SPITupleTable *tuptable;
+       TupleDesc tupdesc ;
+       HeapTuple tuple ;
+       LWHISTOGRAM2D *histo;
+       Datum datum;
+       int SPIcode;
+       bool isnull;
+       BOX2DFLOAT4 *box;
+
+       if ( PG_NARGS() == 3 )
+       {
+               txnsp = PG_GETARG_TEXT_P(0);
+               nsp = palloc(VARSIZE(txnsp)+1);
+               memcpy(nsp, VARATT_DATA(txnsp), VARSIZE(txnsp)-VARHDRSZ);
+               nsp[VARSIZE(txnsp)-VARHDRSZ]='\0';
+
+               txtbl = PG_GETARG_TEXT_P(1);
+               txcol = PG_GETARG_TEXT_P(2);
+       }
+       else if ( PG_NARGS() == 2 )
+       {
+               txtbl = PG_GETARG_TEXT_P(0);
+               txcol = PG_GETARG_TEXT_P(1);
+       }
+       else
+       {
+               elog(ERROR, "estimated_extent() called with wrong number of arguments");
+               PG_RETURN_NULL();
+       }
+
+       tbl = palloc(VARSIZE(txtbl)+1);
+       memcpy(tbl, VARATT_DATA(txtbl), VARSIZE(txtbl)-VARHDRSZ);
+       tbl[VARSIZE(txtbl)-VARHDRSZ]='\0';
+
+       col = palloc(VARSIZE(txcol)+1);
+       memcpy(col, VARATT_DATA(txcol), VARSIZE(txcol)-VARHDRSZ);
+       col[VARSIZE(txcol)-VARHDRSZ]='\0';
+
+#if DEBUG_GEOMETRY_STATS
+       elog(NOTICE, "LWGEOM_estimated_extent called");
+#endif
+
+       /* Connect to SPI manager */
+       SPIcode = SPI_connect();
+       if (SPIcode != SPI_OK_CONNECT)
+       {
+               elog(ERROR, "LWGEOM_estimated_extent: couldnt open a connection to SPI");
+               PG_RETURN_NULL() ;
+       }
+
+       querysize = strlen(tbl)+strlen(col)+256;
+       if ( nsp )
+       {
+               querysize += strlen(nsp)+32;
+               query = palloc(querysize);
+               sprintf(query, "SELECT stats FROM geometry_columns WHERE f_table_schema = '%s' AND f_table_name = '%s' AND f_geometry_column = '%s'", nsp, tbl, col);
+       } 
+       else
+       {
+               query = palloc(querysize);
+               sprintf(query, "SELECT stats FROM geometry_columns WHERE f_table_name = '%s' AND f_geometry_column = '%s'", tbl, col);
+       }
+
+#if DEBUG_GEOMETRY_STATS > 1
+       elog(NOTICE, " query: %s", query);
+#endif
+
+       SPIcode = SPI_exec(query, 1);
+       if (SPIcode != SPI_OK_SELECT )
+       {
+               SPI_finish();
+               elog(ERROR,"LWGEOM_estimated_extent: couldnt execute sql via SPI");
+               PG_RETURN_NULL();
+       }
+       if (SPI_processed > 1)
+       {
+               SPI_finish();
+               elog(NOTICE, " More then a single row (%d) in geometry_columns matches given schema/table/column specs", SPI_processed);
+               PG_RETURN_NULL() ;
+       }
+       if (SPI_processed == 0)
+       {
+               SPI_finish();
+#if DEBUG_GEOMETRY_STATS
+               elog(NOTICE, " %d stat rows", SPI_processed);
+#endif
+               PG_RETURN_NULL() ;
+       }
+
+       tuptable = SPI_tuptable;
+       tupdesc = SPI_tuptable->tupdesc;
+       tuple = tuptable->vals[0];
+       datum = SPI_getbinval(tuple, tupdesc, 1, &isnull);
+       if (isnull)
+       {
+               SPI_finish();
+#if DEBUG_GEOMETRY_STATS
+               elog(NOTICE, " stats are NULL");
+#endif
+               PG_RETURN_NULL();
+       }
+
+       histo = (LWHISTOGRAM2D *)PG_DETOAST_DATUM(datum);
+
+#if DEBUG_GEOMETRY_STATS
+       elog(NOTICE, " histogram extent = %g %g, %g %g", histo->xmin,
+               histo->ymin, histo->xmax, histo->ymax);
+#endif
+
+       /* Construct box2dfloat4 */
+       box = palloc(sizeof(BOX2DFLOAT4));
+
+       box->xmin = histo->xmin;
+       box->ymin = histo->ymin;
+       box->xmax = histo->xmax;
+       box->ymax = histo->ymax;
+
+#if DEBUG_GEOMETRY_STATS
+       elog(NOTICE, " histogram extent = %f %f, %f %f", box->xmin,
+               box->ymin, box->xmax, box->ymax);
+#endif
+
+       SPIcode = SPI_finish();
+       if (SPIcode != SPI_OK_FINISH )
+       {
+               elog(ERROR, "LWGEOM_estimated_extent: couldnt disconnect from SPI");
+       }
+
+       PG_RETURN_POINTER(box);
 }
 
 #else // USE_VERSION >= 80
@@ -2313,6 +2453,9 @@ Datum LWGEOM_estimated_extent(PG_FUNCTION_ARGS)
 
 /**********************************************************************
  * $Log$
+ * Revision 1.22  2005/01/13 18:26:49  strk
+ * estimated_extent() implemented for PG<80
+ *
  * Revision 1.21  2005/01/13 17:41:40  strk
  * estimated_extent() prepared for future expansion (support of pre-800 PGSQL)
  *