/*
* 2PC processing routine for COMMIT PREPARED case.
*
* (We don't have to do anything for ROLLBACK PREPARED.)
*/
void
notify_twophase_postcommit(TransactionId xid, uint16 info,
void *recdata, uint32 len)
{
/*
* Set up to issue the NOTIFY at the end of my own current transaction.
* (XXX this has some issues if my own transaction later rolls back, or if
* there is any significant delay before I commit. OK for now because we
* disallow COMMIT PREPARED inside a transaction block.)
*/
Async_Notify((char *) recdata);
}
Datum
triggered_change_notification(PG_FUNCTION_ARGS)
{
TriggerData *trigdata = (TriggerData *) fcinfo->context;
Trigger *trigger;
int nargs;
HeapTuple trigtuple;
Relation rel;
TupleDesc tupdesc;
char *channel;
char operation;
StringInfo payload = makeStringInfo();
bool foundPK;
List *indexoidlist;
ListCell *indexoidscan;
/* make sure it's called as a trigger */
if (!CALLED_AS_TRIGGER(fcinfo))
ereport(ERROR,
(errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
errmsg("triggered_change_notification: must be called as trigger")));
/* and that it's called after the change */
if (!TRIGGER_FIRED_AFTER(trigdata->tg_event))
ereport(ERROR,
(errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
errmsg("triggered_change_notification: must be called after the change")));
/* and that it's called for each row */
if (!TRIGGER_FIRED_FOR_ROW(trigdata->tg_event))
ereport(ERROR,
(errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
errmsg("triggered_change_notification: must be called for each row")));
if (TRIGGER_FIRED_BY_INSERT(trigdata->tg_event))
operation = 'I';
else if (TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event))
operation = 'U';
else if (TRIGGER_FIRED_BY_DELETE(trigdata->tg_event))
operation = 'D';
else
{
elog(ERROR, "triggered_change_notification: trigger fired by unrecognized operation");
operation = 'X'; /* silence compiler warning */
}
trigger = trigdata->tg_trigger;
nargs = trigger->tgnargs;
if (nargs > 1)
ereport(ERROR,
(errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
errmsg("triggered_change_notification: must not be called with more than one parameter")));
if (nargs == 0)
channel = "tcn";
else
channel = trigger->tgargs[0];
/* get tuple data */
trigtuple = trigdata->tg_trigtuple;
rel = trigdata->tg_relation;
tupdesc = rel->rd_att;
foundPK = false;
/*
* Get the list of index OIDs for the table from the relcache, and look up
* each one in the pg_index syscache until we find one marked primary key
* (hopefully there isn't more than one such).
*/
indexoidlist = RelationGetIndexList(rel);
foreach(indexoidscan, indexoidlist)
{
Oid indexoid = lfirst_oid(indexoidscan);
HeapTuple indexTuple;
Form_pg_index index;
indexTuple = SearchSysCache1(INDEXRELID, ObjectIdGetDatum(indexoid));
if (!HeapTupleIsValid(indexTuple)) /* should not happen */
elog(ERROR, "cache lookup failed for index %u", indexoid);
index = (Form_pg_index) GETSTRUCT(indexTuple);
/* we're only interested if it is the primary key and valid */
if (index->indisprimary && IndexIsValid(index))
{
int numatts = index->indnatts;
if (numatts > 0)
{
int i;
foundPK = true;
strcpy_quoted(payload, RelationGetRelationName(rel), '"');
appendStringInfoCharMacro(payload, ',');
appendStringInfoCharMacro(payload, operation);
for (i = 0; i < numatts; i++)
{
int colno = index->indkey.values[i];
appendStringInfoCharMacro(payload, ',');
strcpy_quoted(payload, NameStr((tupdesc->attrs[colno - 1])->attname), '"');
appendStringInfoCharMacro(payload, '=');
strcpy_quoted(payload, SPI_getvalue(trigtuple, tupdesc, colno), '\'');
}
Async_Notify(channel, payload->data);
}
ReleaseSysCache(indexTuple);
break;
}
ReleaseSysCache(indexTuple);
}
