Added lwexploded_findlength

git-svn-id: http://svn.osgeo.org/postgis/trunk@861 b70326c6-7e19-0410-871a-916f4a2858ee

diff --git a/lwgeom/lwgeom.h b/lwgeom/lwgeom.h
index 0b4828bef8494004048c84027a67b4a5c8a7f0d9..9ec39cfa44b5ffcacaafa5cf723af1ae3ef01840 100644 (file)
--- a/lwgeom/lwgeom.h
+++ b/lwgeom/lwgeom.h
@@ -398,11 +398,11 @@ typedef struct
 {
        int SRID;
        int ndims;
-       int npoints;
+       uint32 npoints;
        char **points;
-       int nlines;
+       uint32 nlines;
        char **lines;
-       int npolys;
+       uint32 npolys;
        char **polys;
 } LWGEOM_EXPLODED;
 
@@ -416,7 +416,13 @@ LWGEOM_EXPLODED * lwexploded_sum(LWGEOM_EXPLODED *exp1, LWGEOM_EXPLODED *exp2);
  * This function recursively scan the given serialized geometry
  * and returns a list of _all_ subgeoms in it (deep-first)
  */
-LWGEOM_EXPLODED *lwgeom_explode(char *serialized);
+extern LWGEOM_EXPLODED *lwgeom_explode(char *serialized);
+
+/*
+ * Return the length of the serialized form corresponding
+ * to this exploded structure.
+ */
+extern uint32 lwexploded_findlength(LWGEOM_EXPLODED *exp, int wantbbox);
 
 // Serialize an LWGEOM_EXPLODED object.
 // SRID and ndims will be taken from exploded structure.

diff --git a/lwgeom/lwgeom_api.c b/lwgeom/lwgeom_api.c
index 14787367aeb4c3f7e0edb97c957b02d3f9942160..0a62b0a35d5123c135343bc146e37f8e56c90a38 100644 (file)
--- a/lwgeom/lwgeom_api.c
+++ b/lwgeom/lwgeom_api.c
@@ -17,13 +17,16 @@
 #include "lwgeom.h"
 
 
+//#define DEBUG 1
+//#define DEBUG_EXPLODED 1
+
 // This is an implementation of the functions defined in lwgeom.h
 
 //forward decs
-
-
-
 extern  BOX3D *lw_geom_getBB_simple(char *serialized_form);
+#ifdef DEBUG_EXPLODED
+void checkexplodedsize(char *srl, LWGEOM_EXPLODED *exploded, int alloced, char wantbbox);
+#endif
 
 
 // this will change to NaN when I figure out how to
@@ -31,7 +34,6 @@ extern  BOX3D *lw_geom_getBB_simple(char *serialized_form);
 
 #define NO_Z_VALUE 0.0
 
-//#define DEBUG 1
 
 //*********************************************************************
 // BOX routines
@@ -3122,12 +3124,6 @@ lwexploded_serialize(LWGEOM_EXPLODED *exploded, int wantbbox)
        elog(NOTICE, " computed outtype: %d, ngeoms: %d", outtype, ngeoms);
 #endif
 
-       if ( ! ngeoms )
-       {
-               return lwgeom_constructempty(exploded->SRID, exploded->ndims);
-       }
-
-
        // For a single geometry just set SRID and BBOX (if requested)
        if ( ngeoms < 2 )
        {
@@ -3167,10 +3163,16 @@ lwexploded_serialize(LWGEOM_EXPLODED *exploded, int wantbbox)
                        loc += sizeof(BOX2DFLOAT4);
                        memcpy(loc, (ser+1), size-1);
                        pfree(ser);
+#ifdef DEBUG_EXPLODED
+checkexplodedsize(result, exploded, size+4, wantbbox);
+#endif
                        return result;
                }
                else
                {
+#ifdef DEBUG_EXPLODED
+checkexplodedsize(ser, exploded, -1, wantbbox);
+#endif
                        return ser;
                }
        }
@@ -3320,7 +3322,106 @@ lwexploded_serialize(LWGEOM_EXPLODED *exploded, int wantbbox)
        }
        elog(NOTICE, " numgeoms: %d", lwgeom_getnumgeometries(result));
 #endif
-               
+
+#ifdef DEBUG_EXPLODED
+checkexplodedsize(result, exploded, size*2, wantbbox);
+#endif
+
        return result;
 }
 
+#ifdef DEBUG_EXPLODED
+void
+checkexplodedsize(char *srl, LWGEOM_EXPLODED *exp, int alloced, char wantbbox)
+{
+       elog(NOTICE, "exploded len: serialized:%d computed:%d alloced:%d",
+               lwgeom_seralizedformlength_simple(srl),
+               lwexploded_findlength(exp, wantbbox),
+               alloced);
+}
+#endif
+
+uint32
+lwexploded_findlength(LWGEOM_EXPLODED *exploded, int wantbbox)
+{
+       uint32 size=0;
+       char ntypes=0;
+       uint32 i;
+       
+
+       // find sum of sizes of all geoms.
+       // substract size of eventually embedded SRID and BBOXes
+       if ( exploded->npoints )
+       {
+               ntypes++;
+               for (i=0; i<exploded->npoints; i++)
+               {
+                       size += lwpoint_findlength(exploded->points[i]);
+                       if ( lwgeom_hasBBOX(exploded->points[i][0]) )
+                               size -= sizeof(BOX2DFLOAT4);
+                       if ( lwgeom_hasSRID(exploded->points[i][0]) )
+                               size -= 4;
+               }
+               // add multigeom header size
+               if ( exploded->npoints > 1 )
+               {
+                       size += 1; // type
+                       size += 4; // numgeometries
+               }
+       }
+       if ( exploded->nlines )
+       {
+               ntypes++;
+               for (i=0; i<exploded->nlines; i++)
+               {
+                       size += lwline_findlength(exploded->lines[i]);
+                       if ( lwgeom_hasBBOX(exploded->lines[i][0]) )
+                               size -= sizeof(BOX2DFLOAT4);
+                       if ( lwgeom_hasSRID(exploded->lines[i][0]) )
+                               size -= 4;
+               }
+               // add multigeom header size
+               if ( exploded->nlines > 1 )
+               {
+                       size += 1; // type
+                       size += 4; // numgeometries
+               }
+       }
+       if ( exploded->npolys )
+       {
+               ntypes++;
+               for (i=0; i<exploded->npolys; i++)
+               {
+                       size += lwpoly_findlength(exploded->polys[i]);
+                       if ( lwgeom_hasBBOX(exploded->polys[i][0]) )
+                               size -= sizeof(BOX2DFLOAT4);
+                       if ( lwgeom_hasSRID(exploded->polys[i][0]) )
+                               size -= 4;
+               }
+               // add multigeom header size
+               if ( exploded->npolys > 1 )
+               {
+                       size += 1; // type
+                       size += 4; // numgeometries
+               }
+       }
+
+       /* structure is empty */
+       if ( ! ntypes ) return 0;
+
+       /* multi-typed geom (collection), add collection header */
+       if ( ntypes > 1 )
+       {
+               size += 1; // type
+               size += 4; // numgeometries
+       }
+
+       /*
+        * Add BBOX and SRID if required
+        */
+       if ( exploded->SRID != -1 ) size += 4;
+       if ( wantbbox ) size += sizeof(BOX2DFLOAT4);
+
+       return size;
+}
+