Datum /* have to return HeapTuple to Executor */ timetravel(PG_FUNCTION_ARGS) { TriggerData *trigdata = (TriggerData *) fcinfo->context; Trigger *trigger; /* to get trigger name */ int argc; char **args; /* arguments */ int attnum[MaxAttrNum]; /* fnumbers of start/stop columns */ Datum oldtimeon, oldtimeoff; Datum newtimeon, newtimeoff, newuser, nulltext; Datum *cvals; /* column values */ char *cnulls; /* column nulls */ char *relname; /* triggered relation name */ Relation rel; /* triggered relation */ HeapTuple trigtuple; HeapTuple newtuple = NULL; HeapTuple rettuple; TupleDesc tupdesc; /* tuple description */ int natts; /* # of attributes */ EPlan *plan; /* prepared plan */ char ident[2 * NAMEDATALEN]; bool isnull; /* to know is some column NULL or not */ bool isinsert = false; int ret; int i; /* * Some checks first... */ /* Called by trigger manager ? */ if (!CALLED_AS_TRIGGER(fcinfo)) elog(ERROR, "timetravel: not fired by trigger manager"); /* Should be called for ROW trigger */ if (!TRIGGER_FIRED_FOR_ROW(trigdata->tg_event)) elog(ERROR, "timetravel: must be fired for row"); /* Should be called BEFORE */ if (!TRIGGER_FIRED_BEFORE(trigdata->tg_event)) elog(ERROR, "timetravel: must be fired before event"); /* INSERT ? */ if (TRIGGER_FIRED_BY_INSERT(trigdata->tg_event)) isinsert = true; if (TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event)) newtuple = trigdata->tg_newtuple; trigtuple = trigdata->tg_trigtuple; rel = trigdata->tg_relation; relname = SPI_getrelname(rel); /* check if TT is OFF for this relation */ if (0 == findTTStatus(relname)) { /* OFF - nothing to do */ pfree(relname); return PointerGetDatum((newtuple != NULL) ? newtuple : trigtuple); } trigger = trigdata->tg_trigger; argc = trigger->tgnargs; if (argc != MinAttrNum && argc != MaxAttrNum) elog(ERROR, "timetravel (%s): invalid (!= %d or %d) number of arguments %d", relname, MinAttrNum, MaxAttrNum, trigger->tgnargs); args = trigger->tgargs; tupdesc = rel->rd_att; natts = tupdesc->natts; for (i = 0; i < MinAttrNum; i++) { attnum[i] = SPI_fnumber(tupdesc, args[i]); if (attnum[i] <= 0) elog(ERROR, "timetravel (%s): there is no attribute %s", relname, args[i]); if (SPI_gettypeid(tupdesc, attnum[i]) != ABSTIMEOID) elog(ERROR, "timetravel (%s): attribute %s must be of abstime type", relname, args[i]); } for (; i < argc; i++) { attnum[i] = SPI_fnumber(tupdesc, args[i]); if (attnum[i] <= 0) elog(ERROR, "timetravel (%s): there is no attribute %s", relname, args[i]); if (SPI_gettypeid(tupdesc, attnum[i]) != TEXTOID) elog(ERROR, "timetravel (%s): attribute %s must be of text type", relname, args[i]); } /* create fields containing name */ newuser = CStringGetTextDatum(GetUserNameFromId(GetUserId(), false)); nulltext = (Datum) NULL; if (isinsert) { /* INSERT */ int chnattrs = 0; int chattrs[MaxAttrNum]; Datum newvals[MaxAttrNum]; bool newnulls[MaxAttrNum]; oldtimeon = SPI_getbinval(trigtuple, tupdesc, attnum[a_time_on], &isnull); if (isnull) { newvals[chnattrs] = GetCurrentAbsoluteTime(); newnulls[chnattrs] = false; chattrs[chnattrs] = attnum[a_time_on]; chnattrs++; } oldtimeoff = SPI_getbinval(trigtuple, tupdesc, attnum[a_time_off], &isnull); if (isnull) { if ((chnattrs == 0 && DatumGetInt32(oldtimeon) >= NOEND_ABSTIME) || (chnattrs > 0 && DatumGetInt32(newvals[a_time_on]) >= NOEND_ABSTIME)) elog(ERROR, "timetravel (%s): %s is infinity", relname, args[a_time_on]); newvals[chnattrs] = NOEND_ABSTIME; newnulls[chnattrs] = false; chattrs[chnattrs] = attnum[a_time_off]; chnattrs++; } else { if ((chnattrs == 0 && DatumGetInt32(oldtimeon) > DatumGetInt32(oldtimeoff)) || (chnattrs > 0 && DatumGetInt32(newvals[a_time_on]) > DatumGetInt32(oldtimeoff))) elog(ERROR, "timetravel (%s): %s gt %s", relname, args[a_time_on], args[a_time_off]); } pfree(relname); if (chnattrs <= 0) return PointerGetDatum(trigtuple); if (argc == MaxAttrNum) { /* clear update_user value */ newvals[chnattrs] = nulltext; newnulls[chnattrs] = true; chattrs[chnattrs] = attnum[a_upd_user]; chnattrs++; /* clear delete_user value */ newvals[chnattrs] = nulltext; newnulls[chnattrs] = true; chattrs[chnattrs] = attnum[a_del_user]; chnattrs++; /* set insert_user value */ newvals[chnattrs] = newuser; newnulls[chnattrs] = false; chattrs[chnattrs] = attnum[a_ins_user]; chnattrs++; } rettuple = heap_modify_tuple_by_cols(trigtuple, tupdesc, chnattrs, chattrs, newvals, newnulls); return PointerGetDatum(rettuple); /* end of INSERT */ } /* UPDATE/DELETE: */ oldtimeon = SPI_getbinval(trigtuple, tupdesc, attnum[a_time_on], &isnull); if (isnull) elog(ERROR, "timetravel (%s): %s must be NOT NULL", relname, args[a_time_on]); oldtimeoff = SPI_getbinval(trigtuple, tupdesc, attnum[a_time_off], &isnull); if (isnull) elog(ERROR, "timetravel (%s): %s must be NOT NULL", relname, args[a_time_off]); /* * If DELETE/UPDATE of tuple with stop_date neq INFINITY then say upper * Executor to skip operation for this tuple */ if (newtuple != NULL) { /* UPDATE */ newtimeon = SPI_getbinval(newtuple, tupdesc, attnum[a_time_on], &isnull); if (isnull) elog(ERROR, "timetravel (%s): %s must be NOT NULL", relname, args[a_time_on]); newtimeoff = SPI_getbinval(newtuple, tupdesc, attnum[a_time_off], &isnull); if (isnull) elog(ERROR, "timetravel (%s): %s must be NOT NULL", relname, args[a_time_off]); if (oldtimeon != newtimeon || oldtimeoff != newtimeoff) elog(ERROR, "timetravel (%s): you cannot change %s and/or %s columns (use set_timetravel)", relname, args[a_time_on], args[a_time_off]); } if (oldtimeoff != NOEND_ABSTIME) { /* current record is a deleted/updated record */ pfree(relname); return PointerGetDatum(NULL); } newtimeoff = GetCurrentAbsoluteTime(); /* Connect to SPI manager */ if ((ret = SPI_connect()) < 0) elog(ERROR, "timetravel (%s): SPI_connect returned %d", relname, ret); /* Fetch tuple values and nulls */ cvals = (Datum *) palloc(natts * sizeof(Datum)); cnulls = (char *) palloc(natts * sizeof(char)); for (i = 0; i < natts; i++) { cvals[i] = SPI_getbinval(trigtuple, tupdesc, i + 1, &isnull); cnulls[i] = (isnull) ? 'n' : ' '; } /* change date column(s) */ cvals[attnum[a_time_off] - 1] = newtimeoff; /* stop_date eq current date */ cnulls[attnum[a_time_off] - 1] = ' '; if (!newtuple) { /* DELETE */ if (argc == MaxAttrNum) { cvals[attnum[a_del_user] - 1] = newuser; /* set delete user */ cnulls[attnum[a_del_user] - 1] = ' '; } } /* * Construct ident string as TriggerName $ TriggeredRelationId and try to * find prepared execution plan. */ snprintf(ident, sizeof(ident), "%s$%u", trigger->tgname, rel->rd_id); plan = find_plan(ident, &Plans, &nPlans); /* if there is no plan ... */ if (plan->splan == NULL) { SPIPlanPtr pplan; Oid *ctypes; char sql[8192]; char separ = ' '; /* allocate ctypes for preparation */ ctypes = (Oid *) palloc(natts * sizeof(Oid)); /* * Construct query: INSERT INTO _relation_ VALUES ($1, ...) */ snprintf(sql, sizeof(sql), "INSERT INTO %s VALUES (", relname); for (i = 1; i <= natts; i++) { ctypes[i - 1] = SPI_gettypeid(tupdesc, i); if (!(tupdesc->attrs[i - 1]->attisdropped)) /* skip dropped columns */ { snprintf(sql + strlen(sql), sizeof(sql) - strlen(sql), "%c$%d", separ, i); separ = ','; } } snprintf(sql + strlen(sql), sizeof(sql) - strlen(sql), ")"); elog(DEBUG4, "timetravel (%s) update: sql: %s", relname, sql); /* Prepare plan for query */ pplan = SPI_prepare(sql, natts, ctypes); if (pplan == NULL) elog(ERROR, "timetravel (%s): SPI_prepare returned %d", relname, SPI_result); /* * Remember that SPI_prepare places plan in current memory context - * so, we have to save plan in Top memory context for later use. */ if (SPI_keepplan(pplan)) elog(ERROR, "timetravel (%s): SPI_keepplan failed", relname); plan->splan = pplan; } /* * Ok, execute prepared plan. */ ret = SPI_execp(plan->splan, cvals, cnulls, 0); if (ret < 0) elog(ERROR, "timetravel (%s): SPI_execp returned %d", relname, ret); /* Tuple to return to upper Executor ... */ if (newtuple) { /* UPDATE */ int chnattrs = 0; int chattrs[MaxAttrNum]; Datum newvals[MaxAttrNum]; char newnulls[MaxAttrNum]; newvals[chnattrs] = newtimeoff; newnulls[chnattrs] = ' '; chattrs[chnattrs] = attnum[a_time_on]; chnattrs++; newvals[chnattrs] = NOEND_ABSTIME; newnulls[chnattrs] = ' '; chattrs[chnattrs] = attnum[a_time_off]; chnattrs++; if (argc == MaxAttrNum) { /* set update_user value */ newvals[chnattrs] = newuser; newnulls[chnattrs] = ' '; chattrs[chnattrs] = attnum[a_upd_user]; chnattrs++; /* clear delete_user value */ newvals[chnattrs] = nulltext; newnulls[chnattrs] = 'n'; chattrs[chnattrs] = attnum[a_del_user]; chnattrs++; /* set insert_user value */ newvals[chnattrs] = nulltext; newnulls[chnattrs] = 'n'; chattrs[chnattrs] = attnum[a_ins_user]; chnattrs++; } /* * Use SPI_modifytuple() here because we are inside SPI environment * but rettuple must be allocated in caller's context. */ rettuple = SPI_modifytuple(rel, newtuple, chnattrs, chattrs, newvals, newnulls); } else /* DELETE case */ rettuple = trigtuple; SPI_finish(); /* don't forget say Bye to SPI mgr */ pfree(relname); return PointerGetDatum(rettuple); }
Datum autoinc(PG_FUNCTION_ARGS) { TriggerData *trigdata = (TriggerData *) fcinfo->context; Trigger *trigger; /* to get trigger name */ int nargs; /* # of arguments */ int *chattrs; /* attnums of attributes to change */ int chnattrs = 0; /* # of above */ Datum *newvals; /* vals of above */ bool *newnulls; /* null flags for above */ char **args; /* arguments */ char *relname; /* triggered relation name */ Relation rel; /* triggered relation */ HeapTuple rettuple = NULL; TupleDesc tupdesc; /* tuple description */ bool isnull; int i; if (!CALLED_AS_TRIGGER(fcinfo)) /* internal error */ elog(ERROR, "not fired by trigger manager"); if (!TRIGGER_FIRED_FOR_ROW(trigdata->tg_event)) /* internal error */ elog(ERROR, "must be fired for row"); if (!TRIGGER_FIRED_BEFORE(trigdata->tg_event)) /* internal error */ elog(ERROR, "must be fired before event"); if (TRIGGER_FIRED_BY_INSERT(trigdata->tg_event)) rettuple = trigdata->tg_trigtuple; else if (TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event)) rettuple = trigdata->tg_newtuple; else /* internal error */ elog(ERROR, "cannot process DELETE events"); rel = trigdata->tg_relation; relname = SPI_getrelname(rel); trigger = trigdata->tg_trigger; nargs = trigger->tgnargs; if (nargs <= 0 || nargs % 2 != 0) /* internal error */ elog(ERROR, "autoinc (%s): even number gt 0 of arguments was expected", relname); args = trigger->tgargs; tupdesc = rel->rd_att; chattrs = (int *) palloc(nargs / 2 * sizeof(int)); newvals = (Datum *) palloc(nargs / 2 * sizeof(Datum)); newnulls = (bool *) palloc(nargs / 2 * sizeof(bool)); for (i = 0; i < nargs;) { int attnum = SPI_fnumber(tupdesc, args[i]); int32 val; Datum seqname; if (attnum <= 0) ereport(ERROR, (errcode(ERRCODE_TRIGGERED_ACTION_EXCEPTION), errmsg("\"%s\" has no attribute \"%s\"", relname, args[i]))); if (SPI_gettypeid(tupdesc, attnum) != INT4OID) ereport(ERROR, (errcode(ERRCODE_TRIGGERED_ACTION_EXCEPTION), errmsg("attribute \"%s\" of \"%s\" must be type INT4", args[i], relname))); val = DatumGetInt32(SPI_getbinval(rettuple, tupdesc, attnum, &isnull)); if (!isnull && val != 0) { i += 2; continue; } i++; chattrs[chnattrs] = attnum; seqname = CStringGetTextDatum(args[i]); newvals[chnattrs] = DirectFunctionCall1(nextval, seqname); /* nextval now returns int64; coerce down to int32 */ newvals[chnattrs] = Int32GetDatum((int32) DatumGetInt64(newvals[chnattrs])); if (DatumGetInt32(newvals[chnattrs]) == 0) { newvals[chnattrs] = DirectFunctionCall1(nextval, seqname); newvals[chnattrs] = Int32GetDatum((int32) DatumGetInt64(newvals[chnattrs])); } newnulls[chnattrs] = false; pfree(DatumGetTextPP(seqname)); chnattrs++; i++; } if (chnattrs > 0) { rettuple = heap_modify_tuple_by_cols(rettuple, tupdesc, chnattrs, chattrs, newvals, newnulls); } pfree(relname); pfree(chattrs); pfree(newvals); pfree(newnulls); return PointerGetDatum(rettuple); }