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220db7ccd8
strings. This patch introduces four support functions cstring_to_text, cstring_to_text_with_len, text_to_cstring, and text_to_cstring_buffer, and two macros CStringGetTextDatum and TextDatumGetCString. A number of existing macros that provided variants on these themes were removed. Most of the places that need to make such conversions now require just one function or macro call, in place of the multiple notational layers that used to be needed. There are no longer any direct calls of textout or textin, and we got most of the places that were using handmade conversions via memcpy (there may be a few still lurking, though). This commit doesn't make any serious effort to eliminate transient memory leaks caused by detoasting toasted text objects before they reach text_to_cstring. We changed PG_GETARG_TEXT_P to PG_GETARG_TEXT_PP in a few places where it was easy, but much more could be done. Brendan Jurd and Tom Lane
120 lines
3.2 KiB
C
120 lines
3.2 KiB
C
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#include "executor/spi.h" /* this is what you need to work with SPI */
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#include "commands/trigger.h" /* -"- and triggers */
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#include "commands/sequence.h" /* for nextval() */
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PG_MODULE_MAGIC;
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extern Datum autoinc(PG_FUNCTION_ARGS);
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PG_FUNCTION_INFO_V1(autoinc);
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Datum
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autoinc(PG_FUNCTION_ARGS)
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{
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TriggerData *trigdata = (TriggerData *) fcinfo->context;
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Trigger *trigger; /* to get trigger name */
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int nargs; /* # of arguments */
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int *chattrs; /* attnums of attributes to change */
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int chnattrs = 0; /* # of above */
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Datum *newvals; /* vals of above */
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char **args; /* arguments */
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char *relname; /* triggered relation name */
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Relation rel; /* triggered relation */
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HeapTuple rettuple = NULL;
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TupleDesc tupdesc; /* tuple description */
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bool isnull;
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int i;
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if (!CALLED_AS_TRIGGER(fcinfo))
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/* internal error */
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elog(ERROR, "not fired by trigger manager");
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if (TRIGGER_FIRED_FOR_STATEMENT(trigdata->tg_event))
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/* internal error */
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elog(ERROR, "cannot process STATEMENT events");
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if (TRIGGER_FIRED_AFTER(trigdata->tg_event))
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/* internal error */
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elog(ERROR, "must be fired before event");
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if (TRIGGER_FIRED_BY_INSERT(trigdata->tg_event))
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rettuple = trigdata->tg_trigtuple;
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else if (TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event))
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rettuple = trigdata->tg_newtuple;
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else
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/* internal error */
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elog(ERROR, "cannot process DELETE events");
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rel = trigdata->tg_relation;
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relname = SPI_getrelname(rel);
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trigger = trigdata->tg_trigger;
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nargs = trigger->tgnargs;
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if (nargs <= 0 || nargs % 2 != 0)
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/* internal error */
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elog(ERROR, "autoinc (%s): even number gt 0 of arguments was expected", relname);
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args = trigger->tgargs;
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tupdesc = rel->rd_att;
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chattrs = (int *) palloc(nargs / 2 * sizeof(int));
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newvals = (Datum *) palloc(nargs / 2 * sizeof(Datum));
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for (i = 0; i < nargs;)
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{
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int attnum = SPI_fnumber(tupdesc, args[i]);
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int32 val;
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Datum seqname;
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if (attnum < 0)
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ereport(ERROR,
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(errcode(ERRCODE_TRIGGERED_ACTION_EXCEPTION),
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errmsg("\"%s\" has no attribute \"%s\"",
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relname, args[i])));
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if (SPI_gettypeid(tupdesc, attnum) != INT4OID)
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ereport(ERROR,
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(errcode(ERRCODE_TRIGGERED_ACTION_EXCEPTION),
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errmsg("attribute \"%s\" of \"%s\" must be type INT4",
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args[i], relname)));
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val = DatumGetInt32(SPI_getbinval(rettuple, tupdesc, attnum, &isnull));
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if (!isnull && val != 0)
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{
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i += 2;
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continue;
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}
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i++;
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chattrs[chnattrs] = attnum;
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seqname = CStringGetTextDatum(args[i]);
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newvals[chnattrs] = DirectFunctionCall1(nextval, seqname);
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/* nextval now returns int64; coerce down to int32 */
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newvals[chnattrs] = Int32GetDatum((int32) DatumGetInt64(newvals[chnattrs]));
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if (DatumGetInt32(newvals[chnattrs]) == 0)
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{
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newvals[chnattrs] = DirectFunctionCall1(nextval, seqname);
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newvals[chnattrs] = Int32GetDatum((int32) DatumGetInt64(newvals[chnattrs]));
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}
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pfree(DatumGetTextP(seqname));
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chnattrs++;
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i++;
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}
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if (chnattrs > 0)
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{
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rettuple = SPI_modifytuple(rel, rettuple, chnattrs, chattrs, newvals, NULL);
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if (rettuple == NULL)
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/* internal error */
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elog(ERROR, "autoinc (%s): %d returned by SPI_modifytuple",
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relname, SPI_result);
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}
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pfree(relname);
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pfree(chattrs);
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pfree(newvals);
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return PointerGetDatum(rettuple);
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}
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