Refactor duplicate code into DeconstructFkConstraintRow

My commit 3de241dba86f introduced some code (in tablecmds.c) to obtain
data from a pg_constraint row for a foreign key, that already existed in
ri_triggers.c.  Split it out into its own routine in pg_constraint.c,
where it naturally belongs.

No functional code changes, only code movement.

Backpatch to pg11, because a future bugfix is simpler after this.

diff --git a/src/backend/catalog/pg_constraint.c b/src/backend/catalog/pg_constraint.c
index f4057a9f15276c1d001966b3df72a1ab170002bb..6235729f69f220449983edd92af6150536fb42d3 100644 (file)
--- a/src/backend/catalog/pg_constraint.c
+++ b/src/backend/catalog/pg_constraint.c
@@ -450,14 +450,11 @@ static void
 clone_fk_constraints(Relation pg_constraint, Relation parentRel,
                                         Relation partRel, List *clone, List **cloned)
 {
-       TupleDesc       tupdesc;
        AttrNumber *attmap;
        List       *partFKs;
        List       *subclone = NIL;
        ListCell   *cell;
 
-       tupdesc = RelationGetDescr(pg_constraint);
-
        /*
         * The constraint key may differ, if the columns in the partition are
         * different.  This map is used to convert them.
@@ -487,9 +484,6 @@ clone_fk_constraints(Relation pg_constraint, Relation parentRel,
                int                     nelem;
                ListCell   *cell;
                int                     i;
-               ArrayType  *arr;
-               Datum           datum;
-               bool            isnull;
 
                tuple = SearchSysCache1(CONSTROID, parentConstrOid);
                if (!tuple)
@@ -506,93 +500,11 @@ clone_fk_constraints(Relation pg_constraint, Relation parentRel,
 
                ObjectAddressSet(parentAddr, ConstraintRelationId, parentConstrOid);
 
-               datum = fastgetattr(tuple, Anum_pg_constraint_conkey,
-                                                       tupdesc, &isnull);
-               if (isnull)
-                       elog(ERROR, "null conkey");
-               arr = DatumGetArrayTypeP(datum);
-               nelem = ARR_DIMS(arr)[0];
-               if (ARR_NDIM(arr) != 1 ||
-                       nelem < 1 ||
-                       nelem > INDEX_MAX_KEYS ||
-                       ARR_HASNULL(arr) ||
-                       ARR_ELEMTYPE(arr) != INT2OID)
-                       elog(ERROR, "conkey is not a 1-D smallint array");
-               memcpy(conkey, ARR_DATA_PTR(arr), nelem * sizeof(AttrNumber));
-
+               DeconstructFkConstraintRow(tuple, &nelem, conkey, confkey,
+                                                                  conpfeqop, conppeqop, conffeqop);
                for (i = 0; i < nelem; i++)
                        mapped_conkey[i] = attmap[conkey[i] - 1];
 
-               datum = fastgetattr(tuple, Anum_pg_constraint_confkey,
-                                                       tupdesc, &isnull);
-               if (isnull)
-                       elog(ERROR, "null confkey");
-               arr = DatumGetArrayTypeP(datum);
-               nelem = ARR_DIMS(arr)[0];
-               if (ARR_NDIM(arr) != 1 ||
-                       nelem < 1 ||
-                       nelem > INDEX_MAX_KEYS ||
-                       ARR_HASNULL(arr) ||
-                       ARR_ELEMTYPE(arr) != INT2OID)
-                       elog(ERROR, "confkey is not a 1-D smallint array");
-               memcpy(confkey, ARR_DATA_PTR(arr), nelem * sizeof(AttrNumber));
-
-               datum = fastgetattr(tuple, Anum_pg_constraint_conpfeqop,
-                                                       tupdesc, &isnull);
-               if (isnull)
-                       elog(ERROR, "null conpfeqop");
-               arr = DatumGetArrayTypeP(datum);
-               nelem = ARR_DIMS(arr)[0];
-               if (ARR_NDIM(arr) != 1 ||
-                       nelem < 1 ||
-                       nelem > INDEX_MAX_KEYS ||
-                       ARR_HASNULL(arr) ||
-                       ARR_ELEMTYPE(arr) != OIDOID)
-                       elog(ERROR, "conpfeqop is not a 1-D OID array");
-               memcpy(conpfeqop, ARR_DATA_PTR(arr), nelem * sizeof(Oid));
-
-               datum = fastgetattr(tuple, Anum_pg_constraint_conpfeqop,
-                                                       tupdesc, &isnull);
-               if (isnull)
-                       elog(ERROR, "null conpfeqop");
-               arr = DatumGetArrayTypeP(datum);
-               nelem = ARR_DIMS(arr)[0];
-               if (ARR_NDIM(arr) != 1 ||
-                       nelem < 1 ||
-                       nelem > INDEX_MAX_KEYS ||
-                       ARR_HASNULL(arr) ||
-                       ARR_ELEMTYPE(arr) != OIDOID)
-                       elog(ERROR, "conpfeqop is not a 1-D OID array");
-               memcpy(conpfeqop, ARR_DATA_PTR(arr), nelem * sizeof(Oid));
-
-               datum = fastgetattr(tuple, Anum_pg_constraint_conppeqop,
-                                                       tupdesc, &isnull);
-               if (isnull)
-                       elog(ERROR, "null conppeqop");
-               arr = DatumGetArrayTypeP(datum);
-               nelem = ARR_DIMS(arr)[0];
-               if (ARR_NDIM(arr) != 1 ||
-                       nelem < 1 ||
-                       nelem > INDEX_MAX_KEYS ||
-                       ARR_HASNULL(arr) ||
-                       ARR_ELEMTYPE(arr) != OIDOID)
-                       elog(ERROR, "conppeqop is not a 1-D OID array");
-               memcpy(conppeqop, ARR_DATA_PTR(arr), nelem * sizeof(Oid));
-
-               datum = fastgetattr(tuple, Anum_pg_constraint_conffeqop,
-                                                       tupdesc, &isnull);
-               if (isnull)
-                       elog(ERROR, "null conffeqop");
-               arr = DatumGetArrayTypeP(datum);
-               nelem = ARR_DIMS(arr)[0];
-               if (ARR_NDIM(arr) != 1 ||
-                       nelem < 1 ||
-                       nelem > INDEX_MAX_KEYS ||
-                       ARR_HASNULL(arr) ||
-                       ARR_ELEMTYPE(arr) != OIDOID)
-                       elog(ERROR, "conffeqop is not a 1-D OID array");
-               memcpy(conffeqop, ARR_DATA_PTR(arr), nelem * sizeof(Oid));
-
                /*
                 * Before creating a new constraint, see whether any existing FKs are
                 * fit for the purpose.  If one is, attach the parent constraint to it,
@@ -1536,6 +1448,113 @@ get_primary_key_attnos(Oid relid, bool deferrableOk, Oid *constraintOid)
        return pkattnos;
 }
 
+/*
+ * Extract data from the pg_constraint tuple of a foreign-key constraint.
+ *
+ * All arguments save the first are output arguments; the last three of them
+ * can be passed as NULL if caller doesn't need them.
+ */
+void
+DeconstructFkConstraintRow(HeapTuple tuple, int *numfks,
+                                                  AttrNumber *conkey, AttrNumber *confkey,
+                                                  Oid *pf_eq_oprs, Oid *pp_eq_oprs, Oid *ff_eq_oprs)
+{
+       Oid                     constrId = HeapTupleGetOid(tuple);
+       Datum           adatum;
+       bool            isNull;
+       ArrayType  *arr;
+       int                     numkeys;
+
+       /*
+        * We expect the arrays to be 1-D arrays of the right types; verify that.
+        * We don't need to use deconstruct_array() since the array data is just
+        * going to look like a C array of values.
+        */
+       adatum = SysCacheGetAttr(CONSTROID, tuple,
+                                                        Anum_pg_constraint_conkey, &isNull);
+       if (isNull)
+               elog(ERROR, "null conkey for constraint %u", constrId);
+       arr = DatumGetArrayTypeP(adatum);       /* ensure not toasted */
+       if (ARR_NDIM(arr) != 1 ||
+               ARR_HASNULL(arr) ||
+               ARR_ELEMTYPE(arr) != INT2OID)
+               elog(ERROR, "conkey is not a 1-D smallint array");
+       numkeys = ARR_DIMS(arr)[0];
+       if (numkeys <= 0 || numkeys > INDEX_MAX_KEYS)
+               elog(ERROR, "foreign key constraint cannot have %d columns", numkeys);
+       memcpy(conkey, ARR_DATA_PTR(arr), numkeys * sizeof(int16));
+       if ((Pointer) arr != DatumGetPointer(adatum))
+               pfree(arr);                             /* free de-toasted copy, if any */
+
+       adatum = SysCacheGetAttr(CONSTROID, tuple,
+                                                        Anum_pg_constraint_confkey, &isNull);
+       if (isNull)
+               elog(ERROR, "null confkey for constraint %u", constrId);
+       arr = DatumGetArrayTypeP(adatum);       /* ensure not toasted */
+       if (ARR_NDIM(arr) != 1 ||
+               ARR_DIMS(arr)[0] != numkeys ||
+               ARR_HASNULL(arr) ||
+               ARR_ELEMTYPE(arr) != INT2OID)
+               elog(ERROR, "confkey is not a 1-D smallint array");
+       memcpy(confkey, ARR_DATA_PTR(arr), numkeys * sizeof(int16));
+       if ((Pointer) arr != DatumGetPointer(adatum))
+               pfree(arr);                             /* free de-toasted copy, if any */
+
+       if (pf_eq_oprs)
+       {
+               adatum = SysCacheGetAttr(CONSTROID, tuple,
+                                                                Anum_pg_constraint_conpfeqop, &isNull);
+               if (isNull)
+                       elog(ERROR, "null conpfeqop for constraint %u", constrId);
+               arr = DatumGetArrayTypeP(adatum);       /* ensure not toasted */
+               /* see TryReuseForeignKey if you change the test below */
+               if (ARR_NDIM(arr) != 1 ||
+                       ARR_DIMS(arr)[0] != numkeys ||
+                       ARR_HASNULL(arr) ||
+                       ARR_ELEMTYPE(arr) != OIDOID)
+                       elog(ERROR, "conpfeqop is not a 1-D Oid array");
+               memcpy(pf_eq_oprs, ARR_DATA_PTR(arr), numkeys * sizeof(Oid));
+               if ((Pointer) arr != DatumGetPointer(adatum))
+                       pfree(arr);                     /* free de-toasted copy, if any */
+       }
+
+       if (pp_eq_oprs)
+       {
+               adatum = SysCacheGetAttr(CONSTROID, tuple,
+                                                                Anum_pg_constraint_conppeqop, &isNull);
+               if (isNull)
+                       elog(ERROR, "null conppeqop for constraint %u", constrId);
+               arr = DatumGetArrayTypeP(adatum);       /* ensure not toasted */
+               if (ARR_NDIM(arr) != 1 ||
+                       ARR_DIMS(arr)[0] != numkeys ||
+                       ARR_HASNULL(arr) ||
+                       ARR_ELEMTYPE(arr) != OIDOID)
+                       elog(ERROR, "conppeqop is not a 1-D Oid array");
+               memcpy(pp_eq_oprs, ARR_DATA_PTR(arr), numkeys * sizeof(Oid));
+               if ((Pointer) arr != DatumGetPointer(adatum))
+                       pfree(arr);                     /* free de-toasted copy, if any */
+       }
+
+       if (ff_eq_oprs)
+       {
+               adatum = SysCacheGetAttr(CONSTROID, tuple,
+                                                                Anum_pg_constraint_conffeqop, &isNull);
+               if (isNull)
+                       elog(ERROR, "null conffeqop for constraint %u", constrId);
+               arr = DatumGetArrayTypeP(adatum);       /* ensure not toasted */
+               if (ARR_NDIM(arr) != 1 ||
+                       ARR_DIMS(arr)[0] != numkeys ||
+                       ARR_HASNULL(arr) ||
+                       ARR_ELEMTYPE(arr) != OIDOID)
+                       elog(ERROR, "conffeqop is not a 1-D Oid array");
+               memcpy(ff_eq_oprs, ARR_DATA_PTR(arr), numkeys * sizeof(Oid));
+               if ((Pointer) arr != DatumGetPointer(adatum))
+                       pfree(arr);                     /* free de-toasted copy, if any */
+       }
+
+       *numfks = numkeys;
+}
+
 /*
  * Determine whether a relation can be proven functionally dependent on
  * a set of grouping columns.  If so, return true and add the pg_constraint

diff --git a/src/backend/utils/adt/ri_triggers.c b/src/backend/utils/adt/ri_triggers.c
index fc034ce601929e0ea40b0b1dcad6371665961872..cfc25c55dfa99070805a27b84c0011aa39b4786c 100644 (file)
--- a/src/backend/utils/adt/ri_triggers.c
+++ b/src/backend/utils/adt/ri_triggers.c
@@ -2334,10 +2334,6 @@ ri_LoadConstraintInfo(Oid constraintOid)
        bool            found;
        HeapTuple       tup;
        Form_pg_constraint conForm;
-       Datum           adatum;
-       bool            isNull;
-       ArrayType  *arr;
-       int                     numkeys;
 
        /*
         * On the first call initialize the hashtable
@@ -2379,84 +2375,13 @@ ri_LoadConstraintInfo(Oid constraintOid)
        riinfo->confdeltype = conForm->confdeltype;
        riinfo->confmatchtype = conForm->confmatchtype;
 
-       /*
-        * We expect the arrays to be 1-D arrays of the right types; verify that.
-        * We don't need to use deconstruct_array() since the array data is just
-        * going to look like a C array of values.
-        */
-       adatum = SysCacheGetAttr(CONSTROID, tup,
-                                                        Anum_pg_constraint_conkey, &isNull);
-       if (isNull)
-               elog(ERROR, "null conkey for constraint %u", constraintOid);
-       arr = DatumGetArrayTypeP(adatum);       /* ensure not toasted */
-       if (ARR_NDIM(arr) != 1 ||
-               ARR_HASNULL(arr) ||
-               ARR_ELEMTYPE(arr) != INT2OID)
-               elog(ERROR, "conkey is not a 1-D smallint array");
-       numkeys = ARR_DIMS(arr)[0];
-       if (numkeys <= 0 || numkeys > RI_MAX_NUMKEYS)
-               elog(ERROR, "foreign key constraint cannot have %d columns", numkeys);
-       riinfo->nkeys = numkeys;
-       memcpy(riinfo->fk_attnums, ARR_DATA_PTR(arr), numkeys * sizeof(int16));
-       if ((Pointer) arr != DatumGetPointer(adatum))
-               pfree(arr);                             /* free de-toasted copy, if any */
-
-       adatum = SysCacheGetAttr(CONSTROID, tup,
-                                                        Anum_pg_constraint_confkey, &isNull);
-       if (isNull)
-               elog(ERROR, "null confkey for constraint %u", constraintOid);
-       arr = DatumGetArrayTypeP(adatum);       /* ensure not toasted */
-       if (ARR_NDIM(arr) != 1 ||
-               ARR_DIMS(arr)[0] != numkeys ||
-               ARR_HASNULL(arr) ||
-               ARR_ELEMTYPE(arr) != INT2OID)
-               elog(ERROR, "confkey is not a 1-D smallint array");
-       memcpy(riinfo->pk_attnums, ARR_DATA_PTR(arr), numkeys * sizeof(int16));
-       if ((Pointer) arr != DatumGetPointer(adatum))
-               pfree(arr);                             /* free de-toasted copy, if any */
-
-       adatum = SysCacheGetAttr(CONSTROID, tup,
-                                                        Anum_pg_constraint_conpfeqop, &isNull);
-       if (isNull)
-               elog(ERROR, "null conpfeqop for constraint %u", constraintOid);
-       arr = DatumGetArrayTypeP(adatum);       /* ensure not toasted */
-       /* see TryReuseForeignKey if you change the test below */
-       if (ARR_NDIM(arr) != 1 ||
-               ARR_DIMS(arr)[0] != numkeys ||
-               ARR_HASNULL(arr) ||
-               ARR_ELEMTYPE(arr) != OIDOID)
-               elog(ERROR, "conpfeqop is not a 1-D Oid array");
-       memcpy(riinfo->pf_eq_oprs, ARR_DATA_PTR(arr), numkeys * sizeof(Oid));
-       if ((Pointer) arr != DatumGetPointer(adatum))
-               pfree(arr);                             /* free de-toasted copy, if any */
-
-       adatum = SysCacheGetAttr(CONSTROID, tup,
-                                                        Anum_pg_constraint_conppeqop, &isNull);
-       if (isNull)
-               elog(ERROR, "null conppeqop for constraint %u", constraintOid);
-       arr = DatumGetArrayTypeP(adatum);       /* ensure not toasted */
-       if (ARR_NDIM(arr) != 1 ||
-               ARR_DIMS(arr)[0] != numkeys ||
-               ARR_HASNULL(arr) ||
-               ARR_ELEMTYPE(arr) != OIDOID)
-               elog(ERROR, "conppeqop is not a 1-D Oid array");
-       memcpy(riinfo->pp_eq_oprs, ARR_DATA_PTR(arr), numkeys * sizeof(Oid));
-       if ((Pointer) arr != DatumGetPointer(adatum))
-               pfree(arr);                             /* free de-toasted copy, if any */
-
-       adatum = SysCacheGetAttr(CONSTROID, tup,
-                                                        Anum_pg_constraint_conffeqop, &isNull);
-       if (isNull)
-               elog(ERROR, "null conffeqop for constraint %u", constraintOid);
-       arr = DatumGetArrayTypeP(adatum);       /* ensure not toasted */
-       if (ARR_NDIM(arr) != 1 ||
-               ARR_DIMS(arr)[0] != numkeys ||
-               ARR_HASNULL(arr) ||
-               ARR_ELEMTYPE(arr) != OIDOID)
-               elog(ERROR, "conffeqop is not a 1-D Oid array");
-       memcpy(riinfo->ff_eq_oprs, ARR_DATA_PTR(arr), numkeys * sizeof(Oid));
-       if ((Pointer) arr != DatumGetPointer(adatum))
-               pfree(arr);                             /* free de-toasted copy, if any */
+       DeconstructFkConstraintRow(tup,
+                                                          &riinfo->nkeys,
+                                                          riinfo->fk_attnums,
+                                                          riinfo->pk_attnums,
+                                                          riinfo->pf_eq_oprs,
+                                                          riinfo->pp_eq_oprs,
+                                                          riinfo->ff_eq_oprs);
 
        ReleaseSysCache(tup);
 

diff --git a/src/backend/utils/cache/relcache.c b/src/backend/utils/cache/relcache.c
index aecbd4a943711a102a4a5a5aaca698f0999e8ab0..e21ec620db105318bec6e438bbd6f87d6f811bf8 100644 (file)
--- a/src/backend/utils/cache/relcache.c
+++ b/src/backend/utils/cache/relcache.c
@@ -4135,10 +4135,6 @@ RelationGetFKeyList(Relation relation)
        {
                Form_pg_constraint constraint = (Form_pg_constraint) GETSTRUCT(htup);
                ForeignKeyCacheInfo *info;
-               Datum           adatum;
-               bool            isnull;
-               ArrayType  *arr;
-               int                     nelem;
 
                /* consider only foreign keys */
                if (constraint->contype != CONSTRAINT_FOREIGN)
@@ -4149,58 +4145,11 @@ RelationGetFKeyList(Relation relation)
                info->conrelid = constraint->conrelid;
                info->confrelid = constraint->confrelid;
 
-               /* Extract data from conkey field */
-               adatum = fastgetattr(htup, Anum_pg_constraint_conkey,
-                                                        conrel->rd_att, &isnull);
-               if (isnull)
-                       elog(ERROR, "null conkey for rel %s",
-                                RelationGetRelationName(relation));
-
-               arr = DatumGetArrayTypeP(adatum);       /* ensure not toasted */
-               nelem = ARR_DIMS(arr)[0];
-               if (ARR_NDIM(arr) != 1 ||
-                       nelem < 1 ||
-                       nelem > INDEX_MAX_KEYS ||
-                       ARR_HASNULL(arr) ||
-                       ARR_ELEMTYPE(arr) != INT2OID)
-                       elog(ERROR, "conkey is not a 1-D smallint array");
-
-               info->nkeys = nelem;
-               memcpy(info->conkey, ARR_DATA_PTR(arr), nelem * sizeof(AttrNumber));
-
-               /* Likewise for confkey */
-               adatum = fastgetattr(htup, Anum_pg_constraint_confkey,
-                                                        conrel->rd_att, &isnull);
-               if (isnull)
-                       elog(ERROR, "null confkey for rel %s",
-                                RelationGetRelationName(relation));
-
-               arr = DatumGetArrayTypeP(adatum);       /* ensure not toasted */
-               nelem = ARR_DIMS(arr)[0];
-               if (ARR_NDIM(arr) != 1 ||
-                       nelem != info->nkeys ||
-                       ARR_HASNULL(arr) ||
-                       ARR_ELEMTYPE(arr) != INT2OID)
-                       elog(ERROR, "confkey is not a 1-D smallint array");
-
-               memcpy(info->confkey, ARR_DATA_PTR(arr), nelem * sizeof(AttrNumber));
-
-               /* Likewise for conpfeqop */
-               adatum = fastgetattr(htup, Anum_pg_constraint_conpfeqop,
-                                                        conrel->rd_att, &isnull);
-               if (isnull)
-                       elog(ERROR, "null conpfeqop for rel %s",
-                                RelationGetRelationName(relation));
-
-               arr = DatumGetArrayTypeP(adatum);       /* ensure not toasted */
-               nelem = ARR_DIMS(arr)[0];
-               if (ARR_NDIM(arr) != 1 ||
-                       nelem != info->nkeys ||
-                       ARR_HASNULL(arr) ||
-                       ARR_ELEMTYPE(arr) != OIDOID)
-                       elog(ERROR, "conpfeqop is not a 1-D OID array");
-
-               memcpy(info->conpfeqop, ARR_DATA_PTR(arr), nelem * sizeof(Oid));
+               DeconstructFkConstraintRow(htup, &info->nkeys,
+                                                                  info->conkey,
+                                                                  info->confkey,
+                                                                  info->conpfeqop,
+                                                                  NULL, NULL);
 
                /* Add FK's node to the result list */
                result = lappend(result, info);

diff --git a/src/include/catalog/pg_constraint.h b/src/include/catalog/pg_constraint.h
index 66b3f13f74abf3b91d9c3174538a4b170a98d073..028e11a795a7dd6351324d932a959883c522f440 100644 (file)
--- a/src/include/catalog/pg_constraint.h
+++ b/src/include/catalog/pg_constraint.h
@@ -255,6 +255,9 @@ extern Oid  get_relation_idx_constraint_oid(Oid relationId, Oid indexId);
 
 extern Bitmapset *get_primary_key_attnos(Oid relid, bool deferrableOk,
                                           Oid *constraintOid);
+extern void DeconstructFkConstraintRow(HeapTuple tuple, int *numfks,
+                                                  AttrNumber *conkey, AttrNumber *confkey,
+                                                  Oid *pf_eq_oprs, Oid *pp_eq_oprs, Oid *ff_eq_oprs);
 
 extern bool check_functional_grouping(Oid relid,
                                                  Index varno, Index varlevelsup,