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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 12:15:05 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 12:15:05 +0000 |
commit | 46651ce6fe013220ed397add242004d764fc0153 (patch) | |
tree | 6e5299f990f88e60174a1d3ae6e48eedd2688b2b /contrib/spi/autoinc.c | |
parent | Initial commit. (diff) | |
download | postgresql-14-upstream.tar.xz postgresql-14-upstream.zip |
Adding upstream version 14.5.upstream/14.5upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'contrib/spi/autoinc.c')
-rw-r--r-- | contrib/spi/autoinc.c | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/contrib/spi/autoinc.c b/contrib/spi/autoinc.c new file mode 100644 index 0000000..8bf7422 --- /dev/null +++ b/contrib/spi/autoinc.c @@ -0,0 +1,127 @@ +/* + * contrib/spi/autoinc.c + */ +#include "postgres.h" + +#include "access/htup_details.h" +#include "catalog/pg_type.h" +#include "commands/sequence.h" +#include "commands/trigger.h" +#include "executor/spi.h" +#include "utils/builtins.h" +#include "utils/rel.h" + +PG_MODULE_MAGIC; + +PG_FUNCTION_INFO_V1(autoinc); + +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); +} |