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Merge near-duplicate code in RI triggers

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Merge ri_setnull and ri_setdefault into one function ri_set.  These
functions were to a large part identical.

This is a continuation in spirit of
4797f9b519.

Author: Corey Huinker <corey.huinker@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/0ccdd3e1-10b0-dd05-d8a7-183507c11eb1%402ndquadrant.com
pull/39/head
Peter Eisentraut 7 years ago
parent c94fb8e8ac
commit 3f61999cc9
1 changed files with 40 additions and 141 deletions
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  1. 181
      src/backend/utils/adt/ri_triggers.c

181
src/backend/utils/adt/ri_triggers.c
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@ -176,8 +176,7 @@ static bool ri_Check_Pk_Match(Relation pk_rel, Relation fk_rel,
TupleTableSlot *oldslot,
const RI_ConstraintInfo *riinfo);
static Datum ri_restrict(TriggerData *trigdata, bool is_no_action);
static Datum ri_setnull(TriggerData *trigdata);
static Datum ri_setdefault(TriggerData *trigdata);
static Datum ri_set(TriggerData *trigdata, bool is_set_null);
static void quoteOneName(char *buffer, const char *name);
static void quoteRelationName(char *buffer, Relation rel);
static void ri_GenerateQual(StringInfo buf,
@ -960,7 +959,7 @@ RI_FKey_setnull_del(PG_FUNCTION_ARGS)
ri_CheckTrigger(fcinfo, "RI_FKey_setnull_del", RI_TRIGTYPE_DELETE);
/* Share code with UPDATE case */
return ri_setnull((TriggerData *) fcinfo->context);
return ri_set((TriggerData *) fcinfo->context, true);
}
/*
@ -975,119 +974,9 @@ RI_FKey_setnull_upd(PG_FUNCTION_ARGS)
ri_CheckTrigger(fcinfo, "RI_FKey_setnull_upd", RI_TRIGTYPE_UPDATE);
/* Share code with DELETE case */
return ri_setnull((TriggerData *) fcinfo->context);
return ri_set((TriggerData *) fcinfo->context, true);
}
/*
* ri_setnull -
*
* Common code for ON DELETE SET NULL and ON UPDATE SET NULL
*/
static Datum
ri_setnull(TriggerData *trigdata)
{
const RI_ConstraintInfo *riinfo;
Relation fk_rel;
Relation pk_rel;
TupleTableSlot *oldslot;
RI_QueryKey qkey;
SPIPlanPtr qplan;
riinfo = ri_FetchConstraintInfo(trigdata->tg_trigger,
trigdata->tg_relation, true);
/*
* Get the relation descriptors of the FK and PK tables and the old tuple.
*
* fk_rel is opened in RowExclusiveLock mode since that's what our
* eventual UPDATE will get on it.
*/
fk_rel = table_open(riinfo->fk_relid, RowExclusiveLock);
pk_rel = trigdata->tg_relation;
oldslot = trigdata->tg_trigslot;
if (SPI_connect() != SPI_OK_CONNECT)
elog(ERROR, "SPI_connect failed");
/*
* Fetch or prepare a saved plan for the set null operation (it's
* the same query for delete and update cases)
*/
ri_BuildQueryKey(&qkey, riinfo, RI_PLAN_SETNULL_DOUPDATE);
if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
{
StringInfoData querybuf;
StringInfoData qualbuf;
char fkrelname[MAX_QUOTED_REL_NAME_LEN];
char attname[MAX_QUOTED_NAME_LEN];
char paramname[16];
const char *querysep;
const char *qualsep;
const char *fk_only;
Oid queryoids[RI_MAX_NUMKEYS];
/* ----------
* The query string built is
* UPDATE [ONLY] <fktable> SET fkatt1 = NULL [, ...]
* WHERE $1 = fkatt1 [AND ...]
* The type id's for the $ parameters are those of the
* corresponding PK attributes.
* ----------
*/
initStringInfo(&querybuf);
initStringInfo(&qualbuf);
fk_only = fk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
"" : "ONLY ";
quoteRelationName(fkrelname, fk_rel);
appendStringInfo(&querybuf, "UPDATE %s%s SET",
fk_only, fkrelname);
querysep = "";
qualsep = "WHERE";
for (int i = 0; i < riinfo->nkeys; i++)
{
Oid pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
Oid fk_type = RIAttType(fk_rel, riinfo->fk_attnums[i]);
quoteOneName(attname,
RIAttName(fk_rel, riinfo->fk_attnums[i]));
appendStringInfo(&querybuf,
"%s %s = NULL",
querysep, attname);
sprintf(paramname, "$%d", i + 1);
ri_GenerateQual(&qualbuf, qualsep,
paramname, pk_type,
riinfo->pf_eq_oprs[i],
attname, fk_type);
querysep = ",";
qualsep = "AND";
queryoids[i] = pk_type;
}
appendStringInfoString(&querybuf, qualbuf.data);
/* Prepare and save the plan */
qplan = ri_PlanCheck(querybuf.data, riinfo->nkeys, queryoids,
&qkey, fk_rel, pk_rel, true);
}
/*
* We have a plan now. Run it to update the existing references.
*/
ri_PerformCheck(riinfo, &qkey, qplan,
fk_rel, pk_rel,
oldslot, NULL,
true, /* must detect new rows */
SPI_OK_UPDATE);
if (SPI_finish() != SPI_OK_FINISH)
elog(ERROR, "SPI_finish failed");
table_close(fk_rel, RowExclusiveLock);
return PointerGetDatum(NULL);
}
/*
* RI_FKey_setdefault_del -
*
@ -1100,7 +989,7 @@ RI_FKey_setdefault_del(PG_FUNCTION_ARGS)
ri_CheckTrigger(fcinfo, "RI_FKey_setdefault_del", RI_TRIGTYPE_DELETE);
/* Share code with UPDATE case */
return ri_setdefault((TriggerData *) fcinfo->context);
return ri_set((TriggerData *) fcinfo->context, false);
}
/*
@ -1115,16 +1004,17 @@ RI_FKey_setdefault_upd(PG_FUNCTION_ARGS)
ri_CheckTrigger(fcinfo, "RI_FKey_setdefault_upd", RI_TRIGTYPE_UPDATE);
/* Share code with DELETE case */
return ri_setdefault((TriggerData *) fcinfo->context);
return ri_set((TriggerData *) fcinfo->context, false);
}
/*
* ri_setdefault -
* ri_set -
*
* Common code for ON DELETE SET DEFAULT and ON UPDATE SET DEFAULT
* Common code for ON DELETE SET NULL, ON DELETE SET DEFAULT, ON UPDATE SET
* NULL, and ON UPDATE SET DEFAULT.
*/
static Datum
ri_setdefault(TriggerData *trigdata)
ri_set(TriggerData *trigdata, bool is_set_null)
{
const RI_ConstraintInfo *riinfo;
Relation fk_rel;
@ -1150,10 +1040,13 @@ ri_setdefault(TriggerData *trigdata)
elog(ERROR, "SPI_connect failed");
/*
* Fetch or prepare a saved plan for the set default operation
* (it's the same query for delete and update cases)
* Fetch or prepare a saved plan for the set null/default operation (it's
* the same query for delete and update cases)
*/
ri_BuildQueryKey(&qkey, riinfo, RI_PLAN_SETDEFAULT_DOUPDATE);
ri_BuildQueryKey(&qkey, riinfo,
(is_set_null
? RI_PLAN_SETNULL_DOUPDATE
: RI_PLAN_SETDEFAULT_DOUPDATE));
if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
{
@ -1169,7 +1062,7 @@ ri_setdefault(TriggerData *trigdata)
/* ----------
* The query string built is
* UPDATE [ONLY] <fktable> SET fkatt1 = DEFAULT [, ...]
* UPDATE [ONLY] <fktable> SET fkatt1 = {NULL|DEFAULT} [, ...]
* WHERE $1 = fkatt1 [AND ...]
* The type id's for the $ parameters are those of the
* corresponding PK attributes.
@ -1177,9 +1070,9 @@ ri_setdefault(TriggerData *trigdata)
*/
initStringInfo(&querybuf);
initStringInfo(&qualbuf);
quoteRelationName(fkrelname, fk_rel);
fk_only = fk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
"" : "ONLY ";
quoteRelationName(fkrelname, fk_rel);
appendStringInfo(&querybuf, "UPDATE %s%s SET",
fk_only, fkrelname);
querysep = "";
@ -1192,8 +1085,9 @@ ri_setdefault(TriggerData *trigdata)
quoteOneName(attname,
RIAttName(fk_rel, riinfo->fk_attnums[i]));
appendStringInfo(&querybuf,
"%s %s = DEFAULT",
querysep, attname);
"%s %s = %s",
querysep, attname,
is_set_null ? "NULL" : "DEFAULT");
sprintf(paramname, "$%d", i + 1);
ri_GenerateQual(&qualbuf, qualsep,
paramname, pk_type,
@ -1224,21 +1118,26 @@ ri_setdefault(TriggerData *trigdata)
table_close(fk_rel, RowExclusiveLock);
/*
* If we just deleted or updated the PK row whose key was equal to
* the FK columns' default values, and a referencing row exists in
* the FK table, we would have updated that row to the same values
* it already had --- and RI_FKey_fk_upd_check_required would
* hence believe no check is necessary. So we need to do another
* lookup now and in case a reference still exists, abort the
* operation. That is already implemented in the NO ACTION
* trigger, so just run it. (This recheck is only needed in the
* SET DEFAULT case, since CASCADE would remove such rows in case
* of a DELETE operation or would change the FK key values in case
* of an UPDATE, while SET NULL is certain to result in rows that
* satisfy the FK constraint.)
*/
return ri_restrict(trigdata, true);
if (is_set_null)
return PointerGetDatum(NULL);
else
{
/*
* If we just deleted or updated the PK row whose key was equal to
* the FK columns' default values, and a referencing row exists in
* the FK table, we would have updated that row to the same values
* it already had --- and RI_FKey_fk_upd_check_required would
* hence believe no check is necessary. So we need to do another
* lookup now and in case a reference still exists, abort the
* operation. That is already implemented in the NO ACTION
* trigger, so just run it. (This recheck is only needed in the
* SET DEFAULT case, since CASCADE would remove such rows in case
* of a DELETE operation or would change the FK key values in case
* of an UPDATE, while SET NULL is certain to result in rows that
* satisfy the FK constraint.)
*/
return ri_restrict(trigdata, true);
}
}

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