Add support for binary i/o

h3/sql/install/00-type.sql

@@ -44,8 +44,20 @@ CREATE OR REPLACE FUNCTION
     h3index_out(h3index) RETURNS cstring
 AS 'h3' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
 
+--@ internal
+CREATE OR REPLACE FUNCTION
+    h3index_recv(internal) RETURNS h3index
+AS 'h3' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+--@ internal
+CREATE OR REPLACE FUNCTION
+    h3index_send(h3index) RETURNS bytea
+AS 'h3' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
 CREATE TYPE h3index (
   INPUT          = h3index_in,
   OUTPUT         = h3index_out,
+  RECEIVE        = h3index_recv,
+  SEND           = h3index_send,
   LIKE           = int8
 );

h3/sql/updates/h3--4.1.3--unreleased.sql

@@ -16,3 +16,18 @@
 
 -- complain if script is sourced in psql, rather than via CREATE EXTENSION
 \echo Use "ALTER EXTENSION h3 UPDATE TO 'unreleased'" to load this file. \quit
+
+--@ internal
+CREATE OR REPLACE FUNCTION
+    h3index_recv(internal) RETURNS h3index
+AS 'h3' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+--@ internal
+CREATE OR REPLACE FUNCTION
+    h3index_send(h3index) RETURNS byta
+AS 'h3' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+ALTER TYPE h3index SET (
+    RECEIVE        = h3index_recv,
+    SEND           = h3index_send
+    );

h3/src/type.c

@@ -18,13 +18,16 @@
 #include <h3api.h>
 
 #include <fmgr.h> // PG_FUNCTION_ARGS
+#include <libpq/pqformat.h> // needed for send/recv functions
 
 #include "error.h"
 #include "type.h"
 
 /* conversion */
 PGDLLEXPORT PG_FUNCTION_INFO_V1(h3index_in);
 PGDLLEXPORT PG_FUNCTION_INFO_V1(h3index_out);
+PGDLLEXPORT PG_FUNCTION_INFO_V1(h3index_send);
+PGDLLEXPORT PG_FUNCTION_INFO_V1(h3index_recv);
 PGDLLEXPORT PG_FUNCTION_INFO_V1(h3index_to_bigint);
 PGDLLEXPORT PG_FUNCTION_INFO_V1(bigint_to_h3index);
 
@@ -51,6 +54,33 @@ h3index_out(PG_FUNCTION_ARGS)
 	PG_RETURN_CSTRING(string);
 }
 
+Datum
+h3index_recv(PG_FUNCTION_ARGS)
+{
+	StringInfo	buf = (StringInfo) PG_GETARG_POINTER(0);
+	H3Index		h3;
+
+	const char *string = pq_getmsgstring(buf);
+	h3_assert(stringToH3(string, &h3));
+
+	PG_RETURN_POINTER(h3);
+}
+
+Datum
+h3index_send(PG_FUNCTION_ARGS)
+{
+	H3Index		h3 = PG_GETARG_H3INDEX(0);
+	char	   *string = palloc(17 * sizeof(char));
+
+	h3_assert(h3ToString(h3, string, 17));
+	StringInfoData buf;
+
+	pq_begintypsend(&buf);
+	pq_sendstring(&buf, string);
+
+	PG_RETURN_BYTEA_P(pq_endtypsend(&buf));
+}
+
 /* bigint conversion functions */
 Datum
 h3index_to_bigint(PG_FUNCTION_ARGS)

h3/test/expected/type.out

@@ -35,3 +35,12 @@ SELECT :asbigint = :hexagon::bigint;
 SELECT :hexagon = :asbigint::h3index;
  t
 
+--
+-- TEST binary io
+--
+COPY (SELECT :hexagon) TO '/tmp/test.bin' (FORMAT binary);
+CREATE TEMPORARY TABLE tmp (val h3index);
+COPY tmp FROM '/tmp/test.bin' (FORMAT binary);
+SELECT val = :hexagon FROM tmp WHERE val = :hexagon;
+ t
+

h3/test/sql/type.sql

@@ -22,3 +22,11 @@ SELECT bool_and(:pentagon @> c) FROM (
 SELECT :asbigint = :hexagon::bigint;
 
 SELECT :hexagon = :asbigint::h3index;
+
+--
+-- TEST binary io
+--
+COPY (SELECT :hexagon) TO '/tmp/test.bin' (FORMAT binary);
+CREATE TEMPORARY TABLE tmp (val h3index);
+COPY tmp FROM '/tmp/test.bin' (FORMAT binary);
+SELECT val = :hexagon FROM tmp WHERE val = :hexagon;