mirrors/postgres
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
postgres/src/backend/utils/adt/ri_triggers.c
Jan Wieck 34eb4f0a32 First real FOREIGN KEY constraint trigger functionality. 
Implemented now:

    FOREIGN KEY ... REFERENCES ... MATCH FULL
	FOREIGN KEY ... MATCH FULL ... ON DELETE CASCADE

Jan
1999-10-08 12:00:08 +00:00

1115 lines
26 KiB
C
Raw Blame History

/* ----------
* ri_triggers.c
*
* Generic trigger procedures for referential integrity constraint
* checks.
*
* 1999 Jan Wieck
*
* $Header: /cvsroot/pgsql/src/backend/utils/adt/ri_triggers.c,v 1.2 1999/10/08 12:00:08 wieck Exp $
*
* ----------
*/
#include "postgres.h"
#include "fmgr.h"
#include "access/heapam.h"
#include "catalog/pg_operator.h"
#include "catalog/catname.h"
#include "commands/trigger.h"
#include "executor/spi.h"
#include "utils/builtins.h"
#include "utils/mcxt.h"
#include "utils/syscache.h"
#include "lib/hasht.h"
/* ----------
* Local definitions
* ----------
*/
#define RI_CONSTRAINT_NAME_ARGNO 0
#define RI_FK_RELNAME_ARGNO 1
#define RI_PK_RELNAME_ARGNO 2
#define RI_MATCH_TYPE_ARGNO 3
#define RI_FIRST_ATTNAME_ARGNO 4
#define RI_MAX_NUMKEYS 16
#define RI_MAX_ARGUMENTS (RI_FIRST_ATTNAME_ARGNO + (RI_MAX_NUMKEYS * 2))
#define RI_KEYPAIR_FK_IDX 0
#define RI_KEYPAIR_PK_IDX 1
#define RI_INIT_QUERYHASHSIZE 128
#define RI_INIT_OPREQHASHSIZE 128
#define RI_MATCH_TYPE_UNSPECIFIED 0
#define RI_MATCH_TYPE_FULL 1
#define RI_MATCH_TYPE_PARTIAL 2
#define RI_KEYS_ALL_NULL 0
#define RI_KEYS_SOME_NULL 1
#define RI_KEYS_NONE_NULL 2
#define RI_PLAN_TYPE_CHECK_FULL 0
#define RI_PLAN_TYPE_CASCADE_DEL_FULL 1
/* ----------
* RI_QueryKey
*
* The key identifying a prepared SPI plan in our private hashtable
* ----------
*/
typedef struct RI_QueryKey {
int32 constr_type;
Oid constr_id;
int32 constr_queryno;
Oid fk_relid;
Oid pk_relid;
int32 nkeypairs;
int16 keypair[RI_MAX_NUMKEYS][2];
} RI_QueryKey;
/* ----------
* RI_QueryHashEntry
* ----------
*/
typedef struct RI_QueryHashEntry {
RI_QueryKey key;
void *plan;
} RI_QueryHashEntry;
typedef struct RI_OpreqHashEntry {
Oid typeid;
Oid oprfnid;
FmgrInfo oprfmgrinfo;
} RI_OpreqHashEntry;
/* ----------
* Local data
* ----------
*/
static HTAB *ri_query_cache = (HTAB *)NULL;
static HTAB *ri_opreq_cache = (HTAB *)NULL;
/* ----------
* Local function prototypes
* ----------
*/
static int ri_DetermineMatchType(char *str);
static int ri_NullCheck(Relation rel, HeapTuple tup,
RI_QueryKey *key, int pairidx);
static void ri_BuildQueryKeyFull(RI_QueryKey *key, Oid constr_id,
int32 constr_queryno,
Relation fk_rel, Relation pk_rel,
int argc, char **argv);
static bool ri_KeysEqual(Relation rel, HeapTuple oldtup, HeapTuple newtup,
RI_QueryKey *key, int pairidx);
static bool ri_AttributesEqual(Oid typeid, Datum oldvalue, Datum newvalue);
static void ri_InitHashTables(void);
static void *ri_FetchPreparedPlan(RI_QueryKey *key);
static void ri_HashPreparedPlan(RI_QueryKey *key, void *plan);
/* ----------
* RI_FKey_check -
*
* Check foreign key existance (combined for INSERT and UPDATE).
* ----------
*/
static HeapTuple
RI_FKey_check (FmgrInfo *proinfo)
{
TriggerData *trigdata;
int tgnargs;
char **tgargs;
Relation fk_rel;
Relation pk_rel;
HeapTuple new_row;
HeapTuple old_row;
RI_QueryKey qkey;
void *qplan;
Datum check_values[RI_MAX_NUMKEYS];
char check_nulls[RI_MAX_NUMKEYS + 1];
bool isnull;
int i;
trigdata = CurrentTriggerData;
CurrentTriggerData = NULL;
/* ----------
* Check that this is a valid trigger call on the right time and event.
* ----------
*/
if (trigdata == NULL)
elog(ERROR, "RI_FKey_check() not fired by trigger manager");
if (!TRIGGER_FIRED_AFTER(trigdata->tg_event) ||
!TRIGGER_FIRED_FOR_ROW(trigdata->tg_event))
elog(ERROR, "RI_FKey_check() must be fired AFTER ROW");
if (!TRIGGER_FIRED_BY_INSERT(trigdata->tg_event) &&
!TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event))
elog(ERROR, "RI_FKey_check() must be fired for INSERT or UPDATE");
/* ----------
* Check for the correct # of call arguments
* ----------
*/
tgnargs = trigdata->tg_trigger->tgnargs;
tgargs = trigdata->tg_trigger->tgargs;
if (tgnargs < 4 || (tgnargs % 2) != 0)
elog(ERROR, "wrong # of arguments in call to RI_FKey_check()");
if (tgnargs > RI_MAX_ARGUMENTS)
elog(ERROR, "too many keys (%d max) in call to RI_FKey_check()",
RI_MAX_NUMKEYS);
/* ----------
* Get the relation descriptors of the FK and PK tables and
* the new tuple.
* ----------
*/
fk_rel = trigdata->tg_relation;
pk_rel = heap_openr(tgargs[RI_PK_RELNAME_ARGNO], NoLock);
if (TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event))
{
old_row = trigdata->tg_trigtuple;
new_row = trigdata->tg_newtuple;
} else {
old_row = NULL;
new_row = trigdata->tg_trigtuple;
}
/* ----------
* SQL3 11.9 <referential constraint definition>
* Gereral rules 2) a):
* If Rf and Rt are empty (no columns to compare given)
* constraint is true if 0 < (SELECT COUNT(*) FROM T)
* ----------
*/
if (tgnargs == 4) {
ri_BuildQueryKeyFull(&qkey, trigdata->tg_trigger->tgoid, 1,
fk_rel, pk_rel,
tgnargs, tgargs);
if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
{
char querystr[8192];
/* ----------
* The query string built is
* SELECT oid FROM <pktable>
* ----------
*/
sprintf(querystr, "SELECT oid FROM \"%s\"",
tgargs[RI_PK_RELNAME_ARGNO]);
/* ----------
* Prepare, save and remember the new plan.
* ----------
*/
qplan = SPI_prepare(querystr, 0, NULL);
qplan = SPI_saveplan(qplan);
ri_HashPreparedPlan(&qkey, qplan);
}
heap_close(pk_rel, NoLock);
/* ----------
* Execute the plan
* ----------
*/
if (SPI_connect() != SPI_OK_CONNECT)
elog(NOTICE, "SPI_connect() failed in RI_FKey_check()");
if (SPI_execp(qplan, check_values, check_nulls, 1) != SPI_OK_SELECT)
elog(ERROR, "SPI_execp() failed in RI_FKey_check()");
if (SPI_processed == 0)
elog(ERROR, "%s referential integrity violation - "
"no rows found in %s",
tgargs[RI_CONSTRAINT_NAME_ARGNO],
tgargs[RI_PK_RELNAME_ARGNO]);
if (SPI_finish() != SPI_OK_FINISH)
elog(NOTICE, "SPI_finish() failed in RI_FKey_check()");
return NULL;
}
switch (ri_DetermineMatchType(tgargs[RI_MATCH_TYPE_ARGNO]))
{
/* ----------
* SQL3 11.9 <referential constraint definition>
* Gereral rules 2) b):
* <match type> is not specified
* ----------
*/
case RI_MATCH_TYPE_UNSPECIFIED:
elog(ERROR, "MATCH <unspecified> not yet supported");
return NULL;
/* ----------
* SQL3 11.9 <referential constraint definition>
* Gereral rules 2) c):
* MATCH PARTIAL
* ----------
*/
case RI_MATCH_TYPE_PARTIAL:
elog(ERROR, "MATCH PARTIAL not yet supported");
return NULL;
/* ----------
* SQL3 11.9 <referential constraint definition>
* Gereral rules 2) d):
* MATCH FULL
* ----------
*/
case RI_MATCH_TYPE_FULL:
ri_BuildQueryKeyFull(&qkey, trigdata->tg_trigger->tgoid, 2,
fk_rel, pk_rel,
tgnargs, tgargs);
switch (ri_NullCheck(fk_rel, new_row, &qkey, RI_KEYPAIR_FK_IDX))
{
case RI_KEYS_ALL_NULL:
/* ----------
* No check - if NULLs are allowed at all is
* already checked by NOT NULL constraint.
* ----------
*/
heap_close(pk_rel, NoLock);
return NULL;
case RI_KEYS_SOME_NULL:
/* ----------
* Not allowed - MATCH FULL says either all or none
* of the attributes can be NULLs
* ----------
*/
elog(ERROR, "%s referential integrity violation - "
"MATCH FULL doesn't allow mixing of NULL "
"and NON-NULL key values",
tgargs[RI_CONSTRAINT_NAME_ARGNO]);
break;
case RI_KEYS_NONE_NULL:
/* ----------
* Have a full qualified key - continue below
* ----------
*/
break;
}
heap_close(pk_rel, NoLock);
/* ----------
* If we're called on UPDATE, check if there was a change
* in the foreign key at all.
* ----------
*/
if (TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event))
{
if (ri_KeysEqual(fk_rel, old_row, new_row, &qkey,
RI_KEYPAIR_FK_IDX))
return NULL;
}
if (SPI_connect() != SPI_OK_CONNECT)
elog(NOTICE, "SPI_connect() failed in RI_FKey_check()");
/* ----------
* Fetch or prepare a saved plan for the real check
* ----------
*/
if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
{
char buf[256];
char querystr[8192];
char *querysep;
Oid queryoids[RI_MAX_NUMKEYS];
/* ----------
* The query string built is
* SELECT oid FROM <pktable> WHERE pkatt1 = $1 [AND ...]
* The type id's for the $ parameters are those of the
* corresponding FK attributes. Thus, SPI_prepare could
* eventually fail if the parser cannot identify some way
* how to compare these two types by '='.
* ----------
*/
sprintf(querystr, "SELECT oid FROM \"%s\"",
tgargs[RI_PK_RELNAME_ARGNO]);
querysep = "WHERE";
for (i = 0; i < qkey.nkeypairs; i++)
{
sprintf(buf, " %s \"%s\" = $%d", querysep,
tgargs[5 + i * 2], i + 1);
strcat(querystr, buf);
querysep = "AND";
queryoids[i] = SPI_gettypeid(fk_rel->rd_att,
qkey.keypair[i][RI_KEYPAIR_FK_IDX]);
}
/* ----------
* Prepare, save and remember the new plan.
* ----------
*/
qplan = SPI_prepare(querystr, qkey.nkeypairs, queryoids);
qplan = SPI_saveplan(qplan);
ri_HashPreparedPlan(&qkey, qplan);
}
/* ----------
* We have a plan now. Build up the arguments for SPI_execp()
* from the key values in the new FK tuple.
* ----------
*/
for (i = 0; i < qkey.nkeypairs; i++)
{
check_values[i] = SPI_getbinval(new_row,
fk_rel->rd_att,
qkey.keypair[i][RI_KEYPAIR_FK_IDX],
&isnull);
if (isnull)
check_nulls[i] = 'n';
else
check_nulls[i] = ' ';
}
check_nulls[RI_MAX_NUMKEYS] = '\0';
/* ----------
* Now check that foreign key exists in PK table
* ----------
*/
if (SPI_execp(qplan, check_values, check_nulls, 1) != SPI_OK_SELECT)
elog(ERROR, "SPI_execp() failed in RI_FKey_check()");
if (SPI_processed == 0)
elog(ERROR, "%s referential integrity violation - "
"key referenced from %s not found in %s",
tgargs[RI_CONSTRAINT_NAME_ARGNO],
tgargs[RI_FK_RELNAME_ARGNO],
tgargs[RI_PK_RELNAME_ARGNO]);
if (SPI_finish() != SPI_OK_FINISH)
elog(NOTICE, "SPI_finish() failed in RI_FKey_check()");
return NULL;
}
/* ----------
* Never reached
* ----------
*/
elog(ERROR, "internal error #1 in ri_triggers.c");
return NULL;
}
/* ----------
* RI_FKey_check_ins -
*
* Check foreign key existance at insert event on FK table.
* ----------
*/
HeapTuple
RI_FKey_check_ins (FmgrInfo *proinfo)
{
return RI_FKey_check(proinfo);
}
/* ----------
* RI_FKey_check_upd -
*
* Check foreign key existance at update event on FK table.
* ----------
*/
HeapTuple
RI_FKey_check_upd (FmgrInfo *proinfo)
{
return RI_FKey_check(proinfo);
}
/* ----------
* RI_FKey_cascade_del -
*
* Cascaded delete foreign key references at delete event on PK table.
* ----------
*/
HeapTuple
RI_FKey_cascade_del (FmgrInfo *proinfo)
{
TriggerData *trigdata;
int tgnargs;
char **tgargs;
Relation fk_rel;
Relation pk_rel;
HeapTuple old_row;
RI_QueryKey qkey;
void *qplan;
Datum del_values[RI_MAX_NUMKEYS];
char del_nulls[RI_MAX_NUMKEYS + 1];
bool isnull;
int i;
trigdata = CurrentTriggerData;
CurrentTriggerData = NULL;
/* ----------
* Check that this is a valid trigger call on the right time and event.
* ----------
*/
if (trigdata == NULL)
elog(ERROR, "RI_FKey_cascade_del() not fired by trigger manager");
if (!TRIGGER_FIRED_AFTER(trigdata->tg_event) ||
!TRIGGER_FIRED_FOR_ROW(trigdata->tg_event))
elog(ERROR, "RI_FKey_cascade_del() must be fired AFTER ROW");
if (!TRIGGER_FIRED_BY_DELETE(trigdata->tg_event))
elog(ERROR, "RI_FKey_cascade_del() must be fired for DELETE");
/* ----------
* Check for the correct # of call arguments
* ----------
*/
tgnargs = trigdata->tg_trigger->tgnargs;
tgargs = trigdata->tg_trigger->tgargs;
if (tgnargs < 4 || (tgnargs % 2) != 0)
elog(ERROR, "wrong # of arguments in call to RI_FKey_cascade_del()");
if (tgnargs > RI_MAX_ARGUMENTS)
elog(ERROR, "too many keys (%d max) in call to RI_FKey_cascade_del()",
RI_MAX_NUMKEYS);
/* ----------
* Nothing to do if no column names to compare given
* ----------
*/
if (tgnargs == 4)
return NULL;
/* ----------
* Get the relation descriptors of the FK and PK tables and
* the old tuple.
* ----------
*/
fk_rel = heap_openr(tgargs[RI_FK_RELNAME_ARGNO], NoLock);
pk_rel = trigdata->tg_relation;
old_row = trigdata->tg_trigtuple;
switch (ri_DetermineMatchType(tgargs[RI_MATCH_TYPE_ARGNO]))
{
/* ----------
* SQL3 11.9 <referential constraint definition>
* Gereral rules 6) a) i):
* MATCH <unspecified> or MATCH FULL
* ... ON DELETE CASCADE
* ----------
*/
case RI_MATCH_TYPE_UNSPECIFIED:
case RI_MATCH_TYPE_FULL:
ri_BuildQueryKeyFull(&qkey, trigdata->tg_trigger->tgoid, 1,
fk_rel, pk_rel,
tgnargs, tgargs);
switch (ri_NullCheck(pk_rel, old_row, &qkey, RI_KEYPAIR_PK_IDX))
{
case RI_KEYS_ALL_NULL:
case RI_KEYS_SOME_NULL:
/* ----------
* No check - MATCH FULL means there cannot be any
* reference to old key if it contains NULL
* ----------
*/
heap_close(fk_rel, NoLock);
return NULL;
case RI_KEYS_NONE_NULL:
/* ----------
* Have a full qualified key - continue below
* ----------
*/
break;
}
heap_close(fk_rel, NoLock);
if (SPI_connect() != SPI_OK_CONNECT)
elog(NOTICE, "SPI_connect() failed in RI_FKey_check()");
/* ----------
* Fetch or prepare a saved plan for the cascaded delete
* ----------
*/
if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
{
char buf[256];
char querystr[8192];
char *querysep;
Oid queryoids[RI_MAX_NUMKEYS];
/* ----------
* The query string built is
* DELETE FROM <fktable> WHERE fkatt1 = $1 [AND ...]
* The type id's for the $ parameters are those of the
* corresponding PK attributes. Thus, SPI_prepare could
* eventually fail if the parser cannot identify some way
* how to compare these two types by '='.
* ----------
*/
sprintf(querystr, "DELETE FROM \"%s\"",
tgargs[RI_FK_RELNAME_ARGNO]);
querysep = "WHERE";
for (i = 0; i < qkey.nkeypairs; i++)
{
sprintf(buf, " %s \"%s\" = $%d", querysep,
tgargs[4 + i * 2], i + 1);
strcat(querystr, buf);
querysep = "AND";
queryoids[i] = SPI_gettypeid(pk_rel->rd_att,
qkey.keypair[i][RI_KEYPAIR_PK_IDX]);
}
/* ----------
* Prepare, save and remember the new plan.
* ----------
*/
qplan = SPI_prepare(querystr, qkey.nkeypairs, queryoids);
qplan = SPI_saveplan(qplan);
ri_HashPreparedPlan(&qkey, qplan);
}
/* ----------
* We have a plan now. Build up the arguments for SPI_execp()
* from the key values in the deleted PK tuple.
* ----------
*/
for (i = 0; i < qkey.nkeypairs; i++)
{
del_values[i] = SPI_getbinval(old_row,
pk_rel->rd_att,
qkey.keypair[i][RI_KEYPAIR_PK_IDX],
&isnull);
if (isnull)
del_nulls[i] = 'n';
else
del_nulls[i] = ' ';
}
del_nulls[RI_MAX_NUMKEYS] = '\0';
/* ----------
* Now delete constraint
* ----------
*/
if (SPI_execp(qplan, del_values, del_nulls, 1) != SPI_OK_DELETE)
elog(ERROR, "SPI_execp() failed in RI_FKey_cascade_del()");
if (SPI_finish() != SPI_OK_FINISH)
elog(NOTICE, "SPI_finish() failed in RI_FKey_cascade_del()");
return NULL;
/* ----------
* Handle MATCH PARTIAL cascaded delete.
* ----------
*/
case RI_MATCH_TYPE_PARTIAL:
elog(ERROR, "MATCH PARTIAL not yet supported");
return NULL;
}
/* ----------
* Never reached
* ----------
*/
elog(ERROR, "internal error #2 in ri_triggers.c");
return NULL;
}
/* ----------
* RI_FKey_cascade_upd -
*
* Cascaded update/delete foreign key references at update event on PK table.
* ----------
*/
HeapTuple
RI_FKey_cascade_upd (FmgrInfo *proinfo)
{
TriggerData *trigdata;
trigdata = CurrentTriggerData;
CurrentTriggerData = NULL;
elog(NOTICE, "RI_FKey_cascade_upd() called\n");
return NULL;
}
/* ----------
* RI_FKey_restrict_del -
*
* Restrict delete from PK table to rows unreferenced by foreign key.
* ----------
*/
HeapTuple
RI_FKey_restrict_del (FmgrInfo *proinfo)
{
TriggerData *trigdata;
trigdata = CurrentTriggerData;
CurrentTriggerData = NULL;
elog(NOTICE, "RI_FKey_restrict_del() called\n");
return NULL;
}
/* ----------
* RI_FKey_restrict_upd -
*
* Restrict update of PK to rows unreferenced by foreign key.
* ----------
*/
HeapTuple
RI_FKey_restrict_upd (FmgrInfo *proinfo)
{
TriggerData *trigdata;
trigdata = CurrentTriggerData;
CurrentTriggerData = NULL;
elog(NOTICE, "RI_FKey_restrict_upd() called\n");
return NULL;
}
/* ----------
* RI_FKey_setnull_del -
*
* Set foreign key references to NULL values at delete event on PK table.
* ----------
*/
HeapTuple
RI_FKey_setnull_del (FmgrInfo *proinfo)
{
TriggerData *trigdata;
trigdata = CurrentTriggerData;
CurrentTriggerData = NULL;
elog(NOTICE, "RI_FKey_setnull_del() called\n");
return NULL;
}
/* ----------
* RI_FKey_setnull_upd -
*
* Set foreign key references to NULL at update event on PK table.
* ----------
*/
HeapTuple
RI_FKey_setnull_upd (FmgrInfo *proinfo)
{
TriggerData *trigdata;
trigdata = CurrentTriggerData;
CurrentTriggerData = NULL;
elog(NOTICE, "RI_FKey_setnull_upd() called\n");
return NULL;
}
/* ----------
* RI_FKey_setdefault_del -
*
* Set foreign key references to defaults at delete event on PK table.
* ----------
*/
HeapTuple
RI_FKey_setdefault_del (FmgrInfo *proinfo)
{
TriggerData *trigdata;
trigdata = CurrentTriggerData;
CurrentTriggerData = NULL;
elog(NOTICE, "RI_FKey_setdefault_del() called\n");
return NULL;
}
/* ----------
* RI_FKey_setdefault_upd -
*
* Set foreign key references to defaults at update event on PK table.
* ----------
*/
HeapTuple
RI_FKey_setdefault_upd (FmgrInfo *proinfo)
{
TriggerData *trigdata;
trigdata = CurrentTriggerData;
CurrentTriggerData = NULL;
elog(NOTICE, "RI_FKey_setdefault_upd() called\n");
return NULL;
}
/* ----------
* Local functions below
* ----------
*/
/* ----------
* ri_DetermineMatchType -
*
* Convert the MATCH TYPE string into a switchable int
* ----------
*/
static int
ri_DetermineMatchType(char *str)
{
if (!strcmp(str, "UNSPECIFIED"))
return RI_MATCH_TYPE_UNSPECIFIED;
if (!strcmp(str, "FULL"))
return RI_MATCH_TYPE_FULL;
if (!strcmp(str, "PARTIAL"))
return RI_MATCH_TYPE_PARTIAL;
elog(ERROR, "unrecognized referential integrity MATCH type '%s'", str);
return 0;
}
/* ----------
* ri_BuildQueryKeyFull -
*
* Build up a new hashtable key for a prepared SPI plan of a
* constraint trigger of MATCH FULL. The key consists of:
*
* constr_type is FULL
* constr_id is the OID of the pg_trigger row that invoked us
* constr_queryno is an internal number of the query inside the proc
* fk_relid is the OID of referencing relation
* pk_relid is the OID of referenced relation
* nkeypairs is the number of keypairs
* following are the attribute number keypairs of the trigger invocation
*
* At least for MATCH FULL this builds a unique key per plan.
* ----------
*/
static void
ri_BuildQueryKeyFull(RI_QueryKey *key, Oid constr_id, int32 constr_queryno,
Relation fk_rel, Relation pk_rel,
int argc, char **argv)
{
int i;
int j;
int fno;
/* ----------
* Initialize the key and fill in type, oid's and number of keypairs
* ----------
*/
memset ((void *)key, 0, sizeof(RI_QueryKey));
key->constr_type = RI_MATCH_TYPE_FULL;
key->constr_id = constr_id;
key->constr_queryno = constr_queryno;
key->fk_relid = fk_rel->rd_id;
key->pk_relid = pk_rel->rd_id;
key->nkeypairs = (argc - RI_FIRST_ATTNAME_ARGNO) / 2;
/* ----------
* Lookup the attribute numbers of the arguments to the trigger call
* and fill in the keypairs.
* ----------
*/
for (i = 0, j = RI_FIRST_ATTNAME_ARGNO; j < argc; i++, j += 2)
{
fno = SPI_fnumber(fk_rel->rd_att, argv[j]);
if (fno == SPI_ERROR_NOATTRIBUTE)
elog(ERROR, "constraint %s: table %s does not have an attribute %s",
argv[RI_CONSTRAINT_NAME_ARGNO],
argv[RI_FK_RELNAME_ARGNO],
argv[j]);
key->keypair[i][RI_KEYPAIR_FK_IDX] = fno;
fno = SPI_fnumber(pk_rel->rd_att, argv[j + 1]);
if (fno == SPI_ERROR_NOATTRIBUTE)
elog(ERROR, "constraint %s: table %s does not have an attribute %s",
argv[RI_CONSTRAINT_NAME_ARGNO],
argv[RI_PK_RELNAME_ARGNO],
argv[j + 1]);
key->keypair[i][RI_KEYPAIR_PK_IDX] = fno;
}
return;
}
/* ----------
* ri_NullCheck -
*
* Determine the NULL state of all key values in a tuple
*
* Returns one of RI_KEYS_ALL_NULL, RI_KEYS_NONE_NULL or RI_KEYS_SOME_NULL.
* ----------
*/
static int
ri_NullCheck(Relation rel, HeapTuple tup, RI_QueryKey *key, int pairidx)
{
int i;
bool isnull;
bool allnull = true;
bool nonenull = true;
for (i = 0; i < key->nkeypairs; i++)
{
isnull = false;
SPI_getbinval(tup, rel->rd_att, key->keypair[i][pairidx], &isnull);
if (isnull)
nonenull = false;
else
allnull = false;
}
if (allnull)
return RI_KEYS_ALL_NULL;
if (nonenull)
return RI_KEYS_NONE_NULL;
return RI_KEYS_SOME_NULL;
}
/* ----------
* ri_InitHashTables -
*
* Initialize our internal hash tables for prepared
* query plans and equal operators.
* ----------
*/
static void
ri_InitHashTables(void)
{
HASHCTL ctl;
memset(&ctl, 0, sizeof(ctl));
ctl.keysize = sizeof(RI_QueryKey);
ctl.datasize = sizeof(void *);
ri_query_cache = hash_create(RI_INIT_QUERYHASHSIZE, &ctl, HASH_ELEM);
memset(&ctl, 0, sizeof(ctl));
ctl.keysize = sizeof(Oid);
ctl.datasize = sizeof(Oid) + sizeof(FmgrInfo);
ctl.hash = tag_hash;
ri_opreq_cache = hash_create(RI_INIT_OPREQHASHSIZE, &ctl,
HASH_ELEM | HASH_FUNCTION);
}
/* ----------
* ri_FetchPreparedPlan -
*
* Lookup for a query key in our private hash table of prepared
* and saved SPI execution plans. Return the plan if found or NULL.
* ----------
*/
static void *
ri_FetchPreparedPlan(RI_QueryKey *key)
{
RI_QueryHashEntry *entry;
bool found;
/* ----------
* On the first call initialize the hashtable
* ----------
*/
if (!ri_query_cache)
ri_InitHashTables();
/* ----------
* Lookup for the key
* ----------
*/
entry = (RI_QueryHashEntry *)hash_search(ri_query_cache,
(char *)key, HASH_FIND, &found);
if (entry == NULL)
elog(FATAL, "error in RI plan cache");
if (!found)
return NULL;
return entry->plan;
}
/* ----------
* ri_HashPreparedPlan -
*
* Add another plan to our private SPI query plan hashtable.
* ----------
*/
static void
ri_HashPreparedPlan(RI_QueryKey *key, void *plan)
{
RI_QueryHashEntry *entry;
bool found;
/* ----------
* On the first call initialize the hashtable
* ----------
*/
if (!ri_query_cache)
ri_InitHashTables();
/* ----------
* Add the new plan.
* ----------
*/
entry = (RI_QueryHashEntry *)hash_search(ri_query_cache,
(char *)key, HASH_ENTER, &found);
if (entry == NULL)
elog(FATAL, "can't insert into RI plan cache");
entry->plan = plan;
}
/* ----------
* ri_KeysEqual -
*
* Check if all key values in OLD and NEW are equal.
* ----------
*/
static bool
ri_KeysEqual(Relation rel, HeapTuple oldtup, HeapTuple newtup,
RI_QueryKey *key, int pairidx)
{
int i;
Oid typeid;
Datum oldvalue;
Datum newvalue;
bool isnull;
for (i = 0; i < key->nkeypairs; i++)
{
/* ----------
* Get one attributes oldvalue. If it is NULL - they're not equal.
* ----------
*/
oldvalue = SPI_getbinval(oldtup, rel->rd_att,
key->keypair[i][pairidx], &isnull);
if (isnull)
return false;
/* ----------
* Get one attributes oldvalue. If it is NULL - they're not equal.
* ----------
*/
newvalue = SPI_getbinval(newtup, rel->rd_att,
key->keypair[i][pairidx], &isnull);
if (isnull)
return false;
/* ----------
* Get the attributes type OID and call the '=' operator
* to compare the values.
* ----------
*/
typeid = SPI_gettypeid(rel->rd_att, key->keypair[i][pairidx]);
if (!ri_AttributesEqual(typeid, oldvalue, newvalue))
return false;
}
return true;
}
/* ----------
* ri_AttributesEqual -
*
* Call the type specific '=' operator comparision function
* for two values.
* ----------
*/
static bool
ri_AttributesEqual(Oid typeid, Datum oldvalue, Datum newvalue)
{
RI_OpreqHashEntry *entry;
bool found;
Datum result;
/* ----------
* On the first call initialize the hashtable
* ----------
*/
if (!ri_query_cache)
ri_InitHashTables();
/* ----------
* Try to find the '=' operator for this type in our cache
* ----------
*/
entry = (RI_OpreqHashEntry *)hash_search(ri_opreq_cache,
(char *)&typeid, HASH_FIND, &found);
if (entry == NULL)
elog(FATAL, "error in RI operator cache");
/* ----------
* If not found, lookup the OPRNAME system cache for it
* and remember that info.
* ----------
*/
if (!found)
{
HeapTuple opr_tup;
Form_pg_operator opr_struct;
opr_tup = SearchSysCacheTuple(OPRNAME,
PointerGetDatum("="),
ObjectIdGetDatum(typeid),
ObjectIdGetDatum(typeid),
CharGetDatum('b'));
if (!HeapTupleIsValid(opr_tup))
elog(ERROR, "ri_AttributesEqual(): cannot find '=' operator "
"for type %d", typeid);
opr_struct = (Form_pg_operator) GETSTRUCT(opr_tup);
entry = (RI_OpreqHashEntry *)hash_search(ri_opreq_cache,
(char *)&typeid, HASH_ENTER, &found);
if (entry == NULL)
elog(FATAL, "can't insert into RI operator cache");
entry->oprfnid = opr_struct->oprcode;
memset(&(entry->oprfmgrinfo), 0, sizeof(FmgrInfo));
}
/* ----------
* Call the type specific '=' function
* ----------
*/
fmgr_info(entry->oprfnid, &(entry->oprfmgrinfo));
result = (Datum)(*fmgr_faddr(&(entry->oprfmgrinfo)))(oldvalue, newvalue);
return (bool)result;
}
Reference in New Issue View Git Blame Copy Permalink