From 85bce43a2b41ea61b552a16591b318fc1a617101 Mon Sep 17 00:00:00 2001
From: Sandro Santilli <strk@keybit.net>
Date: Fri, 7 Jan 2005 00:58:13 +0000
Subject: [PATCH] Initial import

git-svn-id: http://svn.osgeo.org/postgis/trunk@1238 b70326c6-7e19-0410-871a-916f4a2858ee
---
 lwgeom/lwgeom_dump.c | 210 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 210 insertions(+)
 create mode 100644 lwgeom/lwgeom_dump.c

diff --git a/lwgeom/lwgeom_dump.c b/lwgeom/lwgeom_dump.c
new file mode 100644
index 000000000..ea4588c41
--- /dev/null
+++ b/lwgeom/lwgeom_dump.c
@@ -0,0 +1,210 @@
+/*
+
+-- To enable the dump() function copy this SQL into lwpostgis.sql.in
+-- and run make, then open lwpostgis.sql and feed the corresponding
+-- queries to your spatial db
+--
+-- Also, add lwgeom_dump.o to OBJS variable in Makefile
+
+CREATE TYPE geometry_dump AS (path integer[], geom geometry);
+
+CREATEFUNCTION dump(geometry)
+	RETURNS SETOF geometry_dump
+	AS '@MODULE_FILENAME@', 'LWGEOM_dump'
+	LANGUAGE 'C' WITH (isstrict,iscachable);
+
+*/
+
+#include <math.h>
+#include <float.h>
+#include <string.h>
+#include <stdio.h>
+#include <errno.h>
+
+#include "postgres.h"
+#include "fmgr.h"
+#include "utils/elog.h"
+#include "utils/array.h"
+#include "utils/geo_decls.h"
+#include "funcapi.h"
+
+#include "liblwgeom.h"
+#include "lwgeom_pg.h"
+#include "profile.h"
+#include "wktparse.h"
+
+typedef struct GEOMDUMPNODE_T {
+	int idx;
+	LWCOLLECTION *geom;
+} GEOMDUMPNODE;
+
+#define MAXDEPTH 32
+typedef struct GEOMDUMPSTATE {
+	int stacklen;
+	GEOMDUMPNODE *stack[MAXDEPTH];
+	LWGEOM *root;
+	LWGEOM *geom;
+} GEOMDUMPSTATE;
+
+#define PUSH(x,y) ((x)->stack[(x)->stacklen++]=(y))
+#define LAST(x) ((x)->stack[(x)->stacklen-1])
+#define POP(x) (--((x)->stacklen))
+
+PG_FUNCTION_INFO_V1(LWGEOM_dump);
+Datum LWGEOM_dump(PG_FUNCTION_ARGS)
+{
+	PG_LWGEOM *pglwgeom;
+	LWCOLLECTION *lwcoll;
+	LWGEOM *lwgeom;
+	FuncCallContext *funcctx;
+	GEOMDUMPSTATE *state;
+	GEOMDUMPNODE *node;
+	TupleDesc tupdesc;
+	TupleTableSlot *slot;
+	HeapTuple tuple;
+	AttInMetadata *attinmeta;
+	MemoryContext oldcontext;
+	Datum result;
+	char address[256];
+	char *ptr;
+	unsigned int i;
+	char *values[2];
+
+	if (SRF_IS_FIRSTCALL())
+	{
+		funcctx = SRF_FIRSTCALL_INIT();
+
+		oldcontext = MemoryContextSwitchTo(
+			funcctx->multi_call_memory_ctx);
+
+		pglwgeom = (PG_LWGEOM *)PG_DETOAST_DATUM_COPY(PG_GETARG_DATUM(0));
+		if ( TYPE_GETTYPE(pglwgeom->type) < MULTIPOINTTYPE )
+		{
+			lwgeom = lwgeom_deserialize(
+				SERIALIZED_FORM(pglwgeom));
+			/*
+			 * Write state the user context
+			 */
+			state = lwalloc(sizeof(GEOMDUMPSTATE));
+			state->stacklen=0;
+			state->root = lwgeom;
+			funcctx->user_fctx = state;
+		}
+		else
+		{
+			lwcoll = lwcollection_deserialize(
+				SERIALIZED_FORM(pglwgeom));
+
+			/*
+			 * Write state the user context
+			 */
+			node = lwalloc(sizeof(GEOMDUMPNODE));
+			node->idx=0;
+			node->geom = lwcoll;
+			state = lwalloc(sizeof(GEOMDUMPSTATE));
+			state->root = (LWGEOM *)lwcoll;
+			state->stacklen=0;
+			PUSH(state, node);
+			funcctx->user_fctx = state;
+		}
+
+		/*
+		 * Build a tuple description for an
+		 * geometry_dump tuple
+		 */
+		tupdesc = RelationNameGetTupleDesc("geometry_dump");
+
+		/* allocate a slot for a tuple with this tupdesc */
+		slot = TupleDescGetSlot(tupdesc);
+
+		/* allocate a slot for a tuple with this tupdesc */
+		slot = TupleDescGetSlot(tupdesc);
+
+		/* assign slot to function context */
+		funcctx->slot = slot;
+
+		/*
+		 * generate attribute metadata needed later to produce tuples from
+		 * raw C strings
+		 */
+		attinmeta = TupleDescGetAttInMetadata(tupdesc);
+		funcctx->attinmeta = attinmeta;
+
+		MemoryContextSwitchTo(oldcontext);
+	}
+
+	/* stuff done on every call of the function */
+	funcctx = SRF_PERCALL_SETUP();
+
+	/* get state */
+	state = funcctx->user_fctx;
+
+	/* Handled simple geometries */
+	if ( ! state->root ) SRF_RETURN_DONE(funcctx);
+	if ( TYPE_GETTYPE(state->root->type) < MULTIPOINTTYPE )
+	{
+		values[0] = "{}";
+		values[1] = lwgeom_to_hexwkb(lwgeom, -1);
+		tuple = BuildTupleFromCStrings(funcctx->attinmeta, values);
+		result = TupleGetDatum(funcctx->slot, tuple);
+
+		//lwnotice("%s", address);
+		//pglwgeom = pglwgeom_serialize(lwgeom);
+		//result = PointerGetDatum(pglwgeom);
+		state->root = NULL;
+		SRF_RETURN_NEXT(funcctx, result);
+	}
+
+	while (1)
+	{
+		node = LAST(state);
+		lwcoll = node->geom;
+
+		if ( node->idx < lwcoll->ngeoms )
+		{
+			lwgeom = lwcoll->geoms[node->idx];
+			if ( TYPE_GETTYPE(lwgeom->type) < MULTIPOINTTYPE )
+			{
+	/* write address of current geom */
+	ptr=address; *ptr++='{';
+	for (i=0; i<state->stacklen; i++)
+	{
+		if ( i ) ptr += sprintf(ptr, ",");
+		ptr += sprintf(ptr, "%d", state->stack[i]->idx+1);
+	}
+	*ptr++='}'; *ptr='\0';
+
+				break;
+			}
+
+			/*
+			 * It's a collection, increment index
+			 * of current node, push a new one on the
+			 * stack
+			 */
+			node->idx;
+			node = lwalloc(sizeof(GEOMDUMPNODE));
+			node->idx=0;
+			node->geom = (LWCOLLECTION *)lwgeom;
+			PUSH(state, node);
+			continue;
+		}
+
+		if ( ! POP(state) ) SRF_RETURN_DONE(funcctx);
+		LAST(state)->idx++;
+	}
+
+	lwgeom->SRID = state->root->SRID;
+
+	//pglwgeom = pglwgeom_serialize(lwgeom);
+	//result = PointerGetDatum(pglwgeom);
+	//lwnotice("%s", address);
+	values[0] = address;
+	values[1] = lwgeom_to_hexwkb(lwgeom, -1);
+	tuple = BuildTupleFromCStrings(funcctx->attinmeta, values);
+	result = TupleGetDatum(funcctx->slot, tuple);
+	node->idx++;
+	SRF_RETURN_NEXT(funcctx, result);
+}
+
+
-- 
2.40.0