/*
* Set the state of a slot.
*
* This doesn't maintain the non-persistent state at all,
* but since the slot isn't in use that's OK.
*
* There's intentionally no check to prevent slots going backwards
* because they can actually go backwards if the master crashes when
* it hasn't yet flushed slot state to disk then we copy the older
* slot state after recovery.
*
* There's no checking done for xmin or catalog xmin either, since
* we can't really do anything useful that accounts for xid wrap-around.
*
* Note that this is test harness code. You shouldn't expose slot internals
* to SQL like this for any real world usage. See the README.
*/
Datum
test_slot_timelines_advance_logical_slot(PG_FUNCTION_ARGS)
{
char *slotname = text_to_cstring(PG_GETARG_TEXT_P(0));
TransactionId new_xmin = (TransactionId) PG_GETARG_INT64(1);
TransactionId new_catalog_xmin = (TransactionId) PG_GETARG_INT64(2);
XLogRecPtr restart_lsn = PG_GETARG_LSN(3);
XLogRecPtr confirmed_lsn = PG_GETARG_LSN(4);
CheckSlotRequirements();
ReplicationSlotAcquire(slotname);
if (MyReplicationSlot->data.database != MyDatabaseId)
elog(ERROR, "Trying to update a slot on a different database");
MyReplicationSlot->data.xmin = new_xmin;
MyReplicationSlot->data.catalog_xmin = new_catalog_xmin;
MyReplicationSlot->data.restart_lsn = restart_lsn;
MyReplicationSlot->data.confirmed_flush = confirmed_lsn;
clear_slot_transient_state();
ReplicationSlotMarkDirty();
ReplicationSlotSave();
ReplicationSlotRelease();
ReplicationSlotsComputeRequiredXmin(false);
ReplicationSlotsComputeRequiredLSN();
PG_RETURN_VOID();
}
/*
* SQL function for creating a new physical (streaming replication)
* replication slot.
*/
Datum
pg_create_physical_replication_slot(PG_FUNCTION_ARGS)
{
Name name = PG_GETARG_NAME(0);
bool immediately_reserve = PG_GETARG_BOOL(1);
Datum values[2];
bool nulls[2];
TupleDesc tupdesc;
HeapTuple tuple;
Datum result;
Assert(!MyReplicationSlot);
if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
elog(ERROR, "return type must be a row type");
check_permissions();
CheckSlotRequirements();
/* acquire replication slot, this will check for conflicting names */
ReplicationSlotCreate(NameStr(*name), false, RS_PERSISTENT);
values[0] = NameGetDatum(&MyReplicationSlot->data.name);
nulls[0] = false;
if (immediately_reserve)
{
/* Reserve WAL as the user asked for it */
ReplicationSlotReserveWal();
/* Write this slot to disk */
ReplicationSlotMarkDirty();
ReplicationSlotSave();
values[1] = LSNGetDatum(MyReplicationSlot->data.restart_lsn);
nulls[1] = false;
}
else
{
values[0] = NameGetDatum(&MyReplicationSlot->data.name);
nulls[1] = true;
}
tuple = heap_form_tuple(tupdesc, values, nulls);
result = HeapTupleGetDatum(tuple);
ReplicationSlotRelease();
PG_RETURN_DATUM(result);
}
/*
* Convert a slot that's marked as RS_EPHEMERAL to a RS_PERSISTENT slot,
* guaranteeing it will be there after an eventual crash.
*/
void
ReplicationSlotPersist(void)
{
ReplicationSlot *slot = MyReplicationSlot;
Assert(slot != NULL);
Assert(slot->data.persistency != RS_PERSISTENT);
SpinLockAcquire(&slot->mutex);
slot->data.persistency = RS_PERSISTENT;
SpinLockRelease(&slot->mutex);
ReplicationSlotMarkDirty();
ReplicationSlotSave();
}