Hi,
I wanted to do some transformation on an inet value from
an SPI-using function. The inet Datum passed from SPI_getbinval()
to the values array in heap_form_tuple() obviously gives good data
to the frontend. When I use DatumGetInetP() on the Datum,
the structure passed to me is corrupt:
zozo=# select * from inet_test() as (id integer, i1 inet, i2 inet);
NOTICE: i1 family=CORRUPTED
NOTICE: i1 family=CORRUPTED
NOTICE: i1 family=CORRUPTED
id | i1 | i2
----+-------------+---------------
1 | 192.168.0.1 | 192.168.0.101
2 | 192.168.0.2 | 192.168.0.102
3 | 192.168.0.3 | 192.168.0.103
(3 rows)
I looked at utils/inet.h and DatumGetInetP() uses PG_DETOAST_DATUM_PACKED().
fmgr.h warns about PG_DETOAST_DATUM_PACKED() that it may give you
an unaligned pointer. Indeed, using PG_DETOAST_DATUM() instead of the
_PACKED variant on the Datum give me a well formed inet structure:
zozo=# select * from inet_test() as (id integer, i1 inet, i2 inet);
NOTICE: i1 family=AF_INET
NOTICE: i1 netmask=32 bits
NOTICE: i1 address=192.168.0.1
NOTICE: i1 family=AF_INET
NOTICE: i1 netmask=32 bits
NOTICE: i1 address=192.168.0.2
NOTICE: i1 family=AF_INET
NOTICE: i1 netmask=32 bits
NOTICE: i1 address=192.168.0.3
id | i1 | i2
----+-------------+---------------
1 | 192.168.0.1 | 192.168.0.101
2 | 192.168.0.2 | 192.168.0.102
3 | 192.168.0.3 | 192.168.0.103
(3 rows)
System is Fedora 16/x86_64, PostgreSQL 9.1.1 as provided by the OS.
The same error occurs on PostgreSQL 9.0.4 on another system
which is also Linux/x86_64
Example code is attached, the tables used by the code are:
create table t1 (id serial primary key, i1 inet);
create table t2 (id serial primary key, id2 integer references t1(id), i2 inet);
insert into t1 (i1) values ('192.168.0.1');
insert into t1 (i1) values ('192.168.0.2');
insert into t1 (i1) values ('192.168.0.3');
insert into t2 (id2, i2) values (1, '192.168.0.101');
insert into t2 (id2, i2) values (2, '192.168.0.102');
insert into t2 (id2, i2) values (3, '192.168.0.103');
Best regards,
Zoltán Böszörményi
--
----------------------------------
Zoltán Böszörményi
Cybertec Schönig & Schönig GmbH
Gröhrmühlgasse 26
A-2700 Wiener Neustadt, Austria
Web: http://www.postgresql-support.de
http://www.postgresql.at/