CREATE EXTENSION bytea_plphp CASCADE;
NOTICE:  installing required extension "plphp"
-- A bytea argument arrives as a raw PHP string; a returned string becomes
-- bytea verbatim. Round-trip an ordinary value.
CREATE FUNCTION roundtrip(val bytea) RETURNS bytea
LANGUAGE plphp TRANSFORM FOR TYPE bytea AS $$
	return $args[0];
$$;
SELECT roundtrip('\x00ff01'::bytea);
 roundtrip 
-----------
 \x00ff01
(1 row)

SELECT roundtrip('hello'::bytea);
  roundtrip   
--------------
 \x68656c6c6f
(1 row)

-- empty bytea
SELECT roundtrip(''::bytea);
 roundtrip 
-----------
 \x
(1 row)

-- Binary-safe: embedded NUL bytes survive both directions (the default text
-- path would truncate them). strlen sees the true byte count.
CREATE FUNCTION bytelen(val bytea) RETURNS int
LANGUAGE plphp TRANSFORM FOR TYPE bytea AS $$
	return strlen($args[0]);
$$;
SELECT bytelen('\x00010200'::bytea);
 bytelen 
---------
       4
(1 row)

SELECT length(roundtrip('\x00010200'::bytea));
 length 
--------
      4
(1 row)

-- What PHP sees really is bytes, not the "\x..." text form: index into them.
CREATE FUNCTION byteat(val bytea, idx int) RETURNS int
LANGUAGE plphp TRANSFORM FOR TYPE bytea AS $$
	return ord($args[0][$args[1]]);
$$;
SELECT byteat('\xdeadbeef'::bytea, 0);
 byteat 
--------
    222
(1 row)

SELECT byteat('\xdeadbeef'::bytea, 3);
 byteat 
--------
    239
(1 row)

-- Build a bytea from raw bytes in PHP.
CREATE FUNCTION make_bytes() RETURNS bytea
LANGUAGE plphp TRANSFORM FOR TYPE bytea AS $$
	return chr(0) . chr(255) . chr(16);
$$;
SELECT make_bytes();
 make_bytes 
------------
 \x00ff10
(1 row)

-- NULL passes through as SQL NULL (the transform is STRICT / null-safe).
SELECT roundtrip(NULL::bytea) IS NULL AS is_null;
 is_null 
---------
 t
(1 row)

-- Nested context: a bytea column inside a composite result also gets the
-- transform (the #30 nested-transform machinery), so PHP works with raw bytes
-- when building the row.
CREATE TYPE blob_row AS (tag text, data bytea);
CREATE FUNCTION make_row(t text, d bytea) RETURNS blob_row
LANGUAGE plphp TRANSFORM FOR TYPE bytea AS $$
	// $args[1] is raw bytes; prepend a byte and return the row
	return array('tag' => $args[0], 'data' => chr(1) . $args[1]);
$$;
SELECT (make_row('x', '\xaabb'::bytea)).*;
 tag |   data   
-----+----------
 x   | \x01aabb
(1 row)

-- Returning a non-string PHP value for bytea is an error.
CREATE FUNCTION bad_return() RETURNS bytea
LANGUAGE plphp TRANSFORM FOR TYPE bytea AS $$
	return array(1, 2, 3);
$$;
SELECT bad_return();
ERROR:  cannot transform this PHP value to bytea
DETAIL:  Only a PHP string maps to bytea; got PHP type 7.
CONTEXT:  PL/php function "bad_return"
DROP TYPE blob_row CASCADE;
NOTICE:  drop cascades to function make_row(text,bytea)