Add PC_Get sql function and PCPoint type

pgsql/Makefile

@@ -5,6 +5,7 @@ include ../config.mk
 MODULE_big = pointcloud
 OBJS = \
 	pc_inout.o \
+	pc_access.o \
 	pc_pgsql.o
 
 EXTENSION = pointcloud

pgsql/pc_access.c

@@ -0,0 +1,37 @@
+
+#include "pc_pgsql.h"      /* Common PgSQL support for our type */
+#include "utils/numeric.h"
+
+/* Other SQL functions */
+Datum PC_Get(PG_FUNCTION_ARGS);
+
+
+
+/**
+* Read a named dimension from a PCPOINT
+*/
+PG_FUNCTION_INFO_V1(PC_Get);
+Datum PC_Get(PG_FUNCTION_ARGS)
+{
+	SERIALIZED_POINT *serpt = PG_GETARG_SERPOINT_P(0);
+	text *dim_name = PG_GETARG_TEXT_P(1);
+	char *dim_str;
+	float8 double_result;
+
+	PCPOINT *pt = pc_point_deserialize(serpt);
+	if ( ! pt ) 
+		PG_RETURN_NULL();	
+	
+	dim_str = text_to_cstring(dim_name);
+	if ( ! pc_schema_get_dimension_by_name(pt->schema, dim_str) )
+	{
+		pc_point_free(pt);
+		elog(ERROR, "dimension \"%s\" does not exist in schema", dim_str);
+	}
+	
+	double_result = pc_point_get_double_by_name(pt, dim_str);
+	pfree(dim_str);
+	pc_point_free(pt);
+	PG_RETURN_DATUM(DirectFunctionCall1(float8_numeric, Float8GetDatum(double_result)));
+}
+

pgsql/pc_pgsql.c

@@ -162,7 +162,7 @@ hexbytes_from_bytes(const uint8_t *bytebuf, size_t bytesize)
 	
 	for ( i = 0; i < bytesize; i++ )
 	{
-		int incr = snprintf(ptr, 2, "%X", bytebuf[i]);
+		int incr = snprintf(ptr, 3, "%02X", bytebuf[i]);
 		if ( incr < 0 )
 		{
 			pcerror("write failure in hexbytes_from_bytes");
@@ -331,7 +331,7 @@ pc_schema_get_by_id(uint32_t pcid)
 	if (SPI_processed <= 0)
 	{
 		SPI_finish();
-		elog(ERROR, "no entry in \"%s\" for PCID (%d)", POINTCLOUD_FORMATS, pcid);
+		elog(ERROR, "no entry in \"%s\" for pcid = %d", POINTCLOUD_FORMATS, pcid);
 		return NULL;
 	}
 

pgsql/pc_pgsql.h

@@ -13,6 +13,8 @@
 #define POINTCLOUD_FORMATS_XML "schema"
 #define POINTCLOUD_FORMATS_SRID "srid"
 
+#define PG_GETARG_SERPOINT_P(datum) (SERIALIZED_POINT*)PG_DETOAST_DATUM(PG_GETARG_DATUM(datum))
+
 typedef struct 
 {
 	uint32_t size;

pgsql/pointcloud--1.0.sql

@@ -3,6 +3,10 @@
 \echo Use "CREATE EXTENSION pointcloud" to load this file. \quit
 
 
+-------------------------------------------------------------------
+--  METADATA and SCHEMA
+-------------------------------------------------------------------
+
 -- Confirm the XML representation of a schema has everything we need
 CREATE OR REPLACE FUNCTION PC_SchemaIsValid(xml text)
 	RETURNS boolean AS 'MODULE_PATHNAME','PC_SchemaIsValid'
@@ -24,6 +28,38 @@ CREATE OR REPLACE FUNCTION PC_SchemaGetNDims(pcid integer)
     LANGUAGE 'c' IMMUTABLE STRICT;
 
 
+
+-------------------------------------------------------------------
+--  PCPOINT
+-------------------------------------------------------------------
+
+CREATE OR REPLACE FUNCTION pcpoint_in(cstring)
+	RETURNS pcpoint AS 'MODULE_PATHNAME', 'pcpoint_in'
+	LANGUAGE 'c' IMMUTABLE STRICT;
+
+CREATE OR REPLACE FUNCTION pcpoint_out(pcpoint)
+	RETURNS cstring AS 'MODULE_PATHNAME', 'pcpoint_out'
+	LANGUAGE 'c' IMMUTABLE STRICT;
+	
+CREATE TYPE pcpoint (
+	internallength = variable,
+	input = pcpoint_in,
+	output = pcpoint_out,
+	-- send = geometry_send,
+	-- receive = geometry_recv,
+	-- typmod_in = geometry_typmod_in,
+	-- typmod_out = geometry_typmod_out,
+	-- delimiter = ':',
+	-- alignment = double,
+	-- analyze = geometry_analyze,
+	storage = main
+);
+
+CREATE OR REPLACE FUNCTION PC_Get(point pcpoint, dimname text)
+	RETURNS numeric AS 'MODULE_PATHNAME', 'PC_Get'
+    LANGUAGE 'c' IMMUTABLE STRICT;
+
+
 -- Sample data
 INSERT INTO pointcloud_formats (pcid, srid, schema) VALUES (1, 4326, '<?xml version="1.0" encoding="UTF-8"?>
 <pc:PointCloudSchema xmlns:pc="http://pointcloud.org/schemas/PC/1.1" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">