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Add pretty formatting to pg_get_triggerdef #5

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293 changes: 293 additions & 0 deletions src/backend/utils/adt/ruleutils.c
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Original file line number Diff line number Diff line change
Expand Up @@ -353,6 +353,7 @@ static char *deparse_expression_pretty(Node *expr, List *dpcontext,
static char *pg_get_viewdef_worker(Oid viewoid,
int prettyFlags, int wrapColumn);
static char *pg_get_triggerdef_worker(Oid trigid, bool pretty);
static char *pg_get_triggerdef_worker_formatted(Oid trigid);
static int decompile_column_index_array(Datum column_index_array, Oid relId,
bool withPeriod, StringInfo buf);
static char *pg_get_ruledef_worker(Oid ruleoid, int prettyFlags);
Expand Down Expand Up @@ -1162,6 +1163,298 @@ pg_get_triggerdef_worker(Oid trigid, bool pretty)
return buf.data;
}

Datum
pg_get_triggerdef_formatted(PG_FUNCTION_ARGS)
{
Oid trigid = PG_GETARG_OID(0);
char *res;

res = pg_get_triggerdef_worker_formatted(trigid);

if (res == NULL)
PG_RETURN_NULL();

PG_RETURN_TEXT_P(string_to_text(res));
}

static char *
pg_get_triggerdef_worker_formatted(Oid trigid)
{
HeapTuple ht_trig;
Form_pg_trigger trigrec;
StringInfoData buf;
deparse_context context;
Relation tgrel;
ScanKeyData skey[1];
SysScanDesc tgscan;
int prettyFlags;
int findx = 0;
char *tgname;
char *tgoldtable;
char *tgnewtable;
Datum value;
bool isnull;

prettyFlags = GET_PRETTY_FLAGS(true);

/*
* Fetch the pg_trigger tuple by the Oid of the trigger
*/
tgrel = table_open(TriggerRelationId, AccessShareLock);

ScanKeyInit(&skey[0],
Anum_pg_trigger_oid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(trigid));

tgscan = systable_beginscan(tgrel, TriggerOidIndexId, true,
NULL, 1, skey);

ht_trig = systable_getnext(tgscan);

if (!HeapTupleIsValid(ht_trig))
{
systable_endscan(tgscan);
table_close(tgrel, AccessShareLock);
return NULL;
}

trigrec = (Form_pg_trigger) GETSTRUCT(ht_trig);

/*
* Start the trigger definition. Note that the trigger's name should never
* be schema-qualified, but the trigger rel's name may be.
*/
initStringInfo(&buf);

context.buf = &buf;
context.prettyFlags = prettyFlags;
context.wrapColumn = WRAP_COLUMN_DEFAULT;
context.indentLevel = 0;
context.colNamesVisible = true;

tgname = NameStr(trigrec->tgname);
appendStringInfo(&buf, "CREATE %sTRIGGER %s ",
OidIsValid(trigrec->tgconstraint) ? "CONSTRAINT " : "",
quote_identifier(tgname));

if (TRIGGER_FOR_BEFORE(trigrec->tgtype))
appendStringInfoString(&buf, "BEFORE");
else if (TRIGGER_FOR_AFTER(trigrec->tgtype))
appendStringInfoString(&buf, "AFTER");
else if (TRIGGER_FOR_INSTEAD(trigrec->tgtype))
appendStringInfoString(&buf, "INSTEAD OF");
else
elog(ERROR, "unexpected tgtype value: %d", trigrec->tgtype);

if (TRIGGER_FOR_INSERT(trigrec->tgtype))
{
appendStringInfoString(&buf, " INSERT");
findx++;
}
if (TRIGGER_FOR_DELETE(trigrec->tgtype))
{
if (findx > 0)
appendStringInfoString(&buf, " OR DELETE");
else
appendStringInfoString(&buf, " DELETE");
findx++;
}
if (TRIGGER_FOR_UPDATE(trigrec->tgtype))
{
if (findx > 0)
appendStringInfoString(&buf, " OR UPDATE");
else
appendStringInfoString(&buf, " UPDATE");
findx++;
/* tgattr is first var-width field, so OK to access directly */
if (trigrec->tgattr.dim1 > 0)
{
int i;

appendStringInfoString(&buf, " OF ");
for (i = 0; i < trigrec->tgattr.dim1; i++)
{
char *attname;

if (i > 0)
appendStringInfoString(&buf, ", ");
attname = get_attname(trigrec->tgrelid,
trigrec->tgattr.values[i], false);
appendStringInfoString(&buf, quote_identifier(attname));
}
}
}
if (TRIGGER_FOR_TRUNCATE(trigrec->tgtype))
{
if (findx > 0)
appendStringInfoString(&buf, " OR TRUNCATE");
else
appendStringInfoString(&buf, " TRUNCATE");
findx++;
}

appendContextKeyword(&context, " ON ", 0, 0, PRETTYINDENT_VAR - 1);
appendStringInfo(&buf, "%s",
generate_relation_name(trigrec->tgrelid, NIL));

if (OidIsValid(trigrec->tgconstraint))
{
if (OidIsValid(trigrec->tgconstrrelid))
{
appendContextKeyword(&context, " FROM ", 0, 0, PRETTYINDENT_VAR - 1);
appendStringInfoString(&buf, generate_relation_name(trigrec->tgconstrrelid, NIL));
}
if (!trigrec->tgdeferrable)
appendContextKeyword(&context, " NOT DEFERRABLE INITIALLY ", 0, 0, PRETTYINDENT_VAR - 1);
else
appendContextKeyword(&context, " DEFERRABLE INITIALLY ", 0, 0, PRETTYINDENT_VAR - 1);
if (trigrec->tginitdeferred)
appendStringInfoString(&buf, "DEFERRED");
else
appendStringInfoString(&buf, "IMMEDIATE");
}

value = fastgetattr(ht_trig, Anum_pg_trigger_tgoldtable,
tgrel->rd_att, &isnull);
if (!isnull)
tgoldtable = NameStr(*DatumGetName(value));
else
tgoldtable = NULL;
value = fastgetattr(ht_trig, Anum_pg_trigger_tgnewtable,
tgrel->rd_att, &isnull);
if (!isnull)
tgnewtable = NameStr(*DatumGetName(value));
else
tgnewtable = NULL;
if (tgoldtable != NULL || tgnewtable != NULL)
{
appendContextKeyword(&context, " REFERENCING", 0, 0, PRETTYINDENT_VAR - 1);
if (tgoldtable != NULL)
appendStringInfo(&buf, " OLD TABLE AS %s",
quote_identifier(tgoldtable));
if (tgnewtable != NULL)
appendStringInfo(&buf, " NEW TABLE AS %s",
quote_identifier(tgnewtable));
}

appendContextKeyword(&context, " FOR EACH ", 0, 0, PRETTYINDENT_VAR - 1);

if (TRIGGER_FOR_ROW(trigrec->tgtype))
appendStringInfoString(&buf, "ROW");
else
appendStringInfoString(&buf, "STATEMENT");

/* If the trigger has a WHEN qualification, add that */
value = fastgetattr(ht_trig, Anum_pg_trigger_tgqual,
tgrel->rd_att, &isnull);
if (!isnull)
{
Node *qual;
char relkind;
deparse_context whenContext;
deparse_namespace dpns;
RangeTblEntry *oldrte;
RangeTblEntry *newrte;

appendContextKeyword(&context, " WHEN (", 0, 0, PRETTYINDENT_VAR - 1);

qual = stringToNode(TextDatumGetCString(value));

relkind = get_rel_relkind(trigrec->tgrelid);

/* Build minimal OLD and NEW RTEs for the rel */
oldrte = makeNode(RangeTblEntry);
oldrte->rtekind = RTE_RELATION;
oldrte->relid = trigrec->tgrelid;
oldrte->relkind = relkind;
oldrte->rellockmode = AccessShareLock;
oldrte->alias = makeAlias("old", NIL);
oldrte->eref = oldrte->alias;
oldrte->lateral = false;
oldrte->inh = false;
oldrte->inFromCl = true;

newrte = makeNode(RangeTblEntry);
newrte->rtekind = RTE_RELATION;
newrte->relid = trigrec->tgrelid;
newrte->relkind = relkind;
newrte->rellockmode = AccessShareLock;
newrte->alias = makeAlias("new", NIL);
newrte->eref = newrte->alias;
newrte->lateral = false;
newrte->inh = false;
newrte->inFromCl = true;

/* Build two-element rtable */
memset(&dpns, 0, sizeof(dpns));
dpns.rtable = list_make2(oldrte, newrte);
dpns.subplans = NIL;
dpns.ctes = NIL;
dpns.appendrels = NULL;
set_rtable_names(&dpns, NIL, NULL);
set_simple_column_names(&dpns);

/* Set up context with one-deep namespace stack */
whenContext.buf = &buf;
whenContext.namespaces = list_make1(&dpns);
whenContext.resultDesc = NULL;
whenContext.targetList = NIL;
whenContext.windowClause = NIL;
whenContext.varprefix = true;
whenContext.wrapColumn = WRAP_COLUMN_DEFAULT;
whenContext.indentLevel = PRETTYINDENT_STD;
whenContext.colNamesVisible = true;
whenContext.inGroupBy = false;
whenContext.varInOrderBy = false;
whenContext.appendparents = NULL;

get_rule_expr(qual, &whenContext, false);

appendStringInfoChar(&buf, ')');
}

appendContextKeyword(&context, " EXECUTE FUNCTION ", 0, 0, PRETTYINDENT_VAR - 1);
appendStringInfo(&buf, "%s(",
generate_function_name(trigrec->tgfoid, 0,
NIL, NULL,
false, NULL, false));

if (trigrec->tgnargs > 0)
{
char *p;
int i;

value = fastgetattr(ht_trig, Anum_pg_trigger_tgargs,
tgrel->rd_att, &isnull);
if (isnull)
elog(ERROR, "tgargs is null for trigger %u", trigid);
p = (char *) VARDATA_ANY(DatumGetByteaPP(value));
for (i = 0; i < trigrec->tgnargs; i++)
{
if (i > 0)
appendStringInfoString(&buf, ", ");
simple_quote_literal(&buf, p);
/* advance p to next string embedded in tgargs */
while (*p)
p++;
p++;
}
}

/* We deliberately do not put semi-colon at end */
appendStringInfoChar(&buf, ')');

/* Clean up */
systable_endscan(tgscan);

table_close(tgrel, AccessShareLock);

return buf.data;
}



/* ----------
* pg_get_indexdef - Get the definition of an index
*
Expand Down
3 changes: 3 additions & 0 deletions src/include/catalog/pg_proc.dat
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Original file line number Diff line number Diff line change
Expand Up @@ -8555,6 +8555,9 @@
{ oid => '2730', descr => 'trigger description with pretty-print option',
proname => 'pg_get_triggerdef', provolatile => 's', prorettype => 'text',
proargtypes => 'oid bool', prosrc => 'pg_get_triggerdef_ext' },
{ oid => '9750', descr => 'trigger description in a pretty-printed format',
proname => 'pg_get_triggerdef_formatted', provolatile => 's', prorettype => 'text',
proargtypes => 'oid', prosrc => 'pg_get_triggerdef_formatted' },

# asynchronous notifications
{ oid => '3035',
Expand Down