[postgis-devel] [PostGIS] #837: [raster] ST_MapAlgebra -- I think we have a memory leak

[PostGIS]

#837: [raster] ST_MapAlgebra -- I think we have a memory leak
----------------------------+-----------------------------------------------
 Reporter:  robe            |       Owner:  jorgearevalo 
     Type:  defect          |      Status:  assigned     
 Priority:  blocker         |   Milestone:  PostGIS 2.0.0
Component:  postgis raster  |     Version:  trunk        
 Keywords:                  |  
----------------------------+-----------------------------------------------

Comment(by pracine):

 My first attemp at the C implementation of ST_MapAlgebra ever:

 {{{
 CREATE TYPE geomvalxy AS (
     geom geometry,
     val double precision,
     x int,
     y int
 );

 CREATE OR REPLACE FUNCTION ST_PixelAsPolygons(rast raster, band integer)
     RETURNS SETOF geomvalxy AS
     $$
     DECLARE
         rast alias for $1;
         w integer;
         h integer;
         x integer;
         y integer;
         result geomvalxy;
     BEGIN
         SELECT st_width(rast), st_height(rast)
         INTO w, h;
         FOR x IN 1..w LOOP
              FOR y IN 1..h LOOP
                  SELECT ST_PixelAsPolygon(rast, band, x, y),
 ST_Value(rast, band, x, y), x, y INTO result;
             RETURN NEXT result;
          END LOOP;
         END LOOP;
         RETURN;
     END;
     $$
     LANGUAGE 'plpgsql';

 -- This query works
 SELECT ST_MapAlgebra(ST_AddBand(ST_MakeEmptyRaster(5, 5, 0, 0, 1, 1, 0, 0,
 -1), '8BUI'::text, 0, -1), 'rast + 1')

 -- This query crashes (certainly because SPI_finish was not done)
 SELECT ST_PixelAsPolygons(ST_MapAlgebra(ST_AddBand(ST_MakeEmptyRaster(5,
 5, 0, 0, 1, 1, 0, 0, -1), '8BUI'::text, 0, -1), 'rast + 1'))
 }}}

 with

 {{{
 ERROR:  SPI_connect failed: SPI_ERROR_CONNECT
 CONTEXT:  SQL function "st_pixelaspolygons" statement 1

 ********** Error **********

 ERROR: SPI_connect failed: SPI_ERROR_CONNECT
 SQL state: XX000
 Context: SQL function "st_pixelaspolygons" statement 1

 }}}

-- 
Ticket URL: <http://trac.osgeo.org/postgis/ticket/837#comment:14>
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