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postgresql/src/backend/utils/adt/ruleutils.c

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/**********************************************************************
* get_ruledef.c - Function to get a rules definition text
* out of it's tuple
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/utils/adt/ruleutils.c,v 1.9 1999/04/29 15:52:01 wieck Exp $
*
* This software is copyrighted by Jan Wieck - Hamburg.
*
* The author hereby grants permission to use, copy, modify,
* distribute, and license this software and its documentation
* for any purpose, provided that existing copyright notices are
* retained in all copies and that this notice is included
* verbatim in any distributions. No written agreement, license,
* or royalty fee is required for any of the authorized uses.
* Modifications to this software may be copyrighted by their
* author and need not follow the licensing terms described
* here, provided that the new terms are clearly indicated on
* the first page of each file where they apply.
*
* IN NO EVENT SHALL THE AUTHOR OR DISTRIBUTORS BE LIABLE TO ANY
* PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR
* CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OF THIS
* SOFTWARE, ITS DOCUMENTATION, OR ANY DERIVATIVES THEREOF, EVEN
* IF THE AUTHOR HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE.
*
* THE AUTHOR AND DISTRIBUTORS SPECIFICALLY DISCLAIM ANY
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
* PURPOSE, AND NON-INFRINGEMENT. THIS SOFTWARE IS PROVIDED ON
* AN "AS IS" BASIS, AND THE AUTHOR AND DISTRIBUTORS HAVE NO
* OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES,
* ENHANCEMENTS, OR MODIFICATIONS.
*
**********************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include "executor/spi.h"
#include "commands/trigger.h"
#include "utils/elog.h"
#include "utils/builtins.h"
#include "nodes/nodes.h"
#include "optimizer/clauses.h"
#include "utils/syscache.h"
#include "utils/lsyscache.h"
#include "catalog/pg_class.h"
#include "catalog/pg_type.h"
#include "catalog/pg_shadow.h"
#include "catalog/pg_index.h"
#include "catalog/pg_opclass.h"
#include "fmgr.h"
/* ----------
* Local data types
* ----------
*/
typedef struct QryHier {
struct QryHier *parent;
Query *query;
} QryHier;
/* ----------
* Global data
* ----------
*/
static char *rulename;
static void *plan_getrule = NULL;
static char *query_getrule = "SELECT * FROM pg_rewrite WHERE rulename = $1";
static void *plan_getview = NULL;
static char *query_getview = "SELECT * FROM pg_rewrite WHERE rulename = $1 or rulename = $2";
static void *plan_getam = NULL;
static char *query_getam = "SELECT * FROM pg_am WHERE oid = $1";
static void *plan_getopclass = NULL;
static char *query_getopclass = "SELECT * FROM pg_opclass WHERE oid = $1";
/* ----------
* Global functions
* ----------
*/
text *pg_get_ruledef(NameData *rname);
text *pg_get_viewdef(NameData *rname);
text *pg_get_indexdef(Oid indexrelid);
NameData *pg_get_userbyid(int4 uid);
/* ----------
* Local functions
* ----------
*/
static char *make_ruledef(HeapTuple ruletup, TupleDesc rulettc);
static char *make_viewdef(HeapTuple ruletup, TupleDesc rulettc);
static char *get_query_def(Query *query, QryHier *parentqh);
static char *get_select_query_def(Query *query, QryHier *qh);
static char *get_insert_query_def(Query *query, QryHier *qh);
static char *get_update_query_def(Query *query, QryHier *qh);
static char *get_delete_query_def(Query *query, QryHier *qh);
static char *get_rule_expr(QryHier *qh, int rt_index, Node *node, bool varprefix);
static char *get_func_expr(QryHier *qh, int rt_index, Expr *expr, bool varprefix);
static char *get_tle_expr(QryHier *qh, int rt_index, TargetEntry *tle, bool varprefix);
static char *get_const_expr(Const *constval);
static char *get_sublink_expr(QryHier *qh, int rt_index, Node *node, bool varprefix);
static char *get_relation_name(Oid relid);
static char *get_attribute_name(Oid relid, int2 attnum);
static bool check_if_rte_used(int rt_index, Node *node, int sup);
/* ----------
* get_ruledef - Do it all and return a text
* that could be used as a statement
* to recreate the rule
* ----------
*/
text *
pg_get_ruledef(NameData *rname)
{
text *ruledef;
Datum args[1];
char nulls[2];
int spirc;
HeapTuple ruletup;
TupleDesc rulettc;
char *tmp;
int len;
/* ----------
* We need the rules name somewhere deep down
* ----------
*/
rulename = nameout(rname);
/* ----------
* Connect to SPI manager
* ----------
*/
if (SPI_connect() != SPI_OK_CONNECT)
elog(ERROR, "get_ruledef: cannot connect to SPI manager");
/* ----------
* On the first call prepare the plan to lookup pg_proc.
* We read pg_proc over the SPI manager instead of using
* the syscache to be checked for read access on pg_proc.
* ----------
*/
if (plan_getrule == NULL)
{
Oid argtypes[1];
void *plan;
argtypes[0] = NAMEOID;
plan = SPI_prepare(query_getrule, 1, argtypes);
if (plan == NULL)
elog(ERROR, "SPI_prepare() failed for \"%s\"", query_getrule);
plan_getrule = SPI_saveplan(plan);
}
/* ----------
* Get the pg_rewrite tuple for this rule
* ----------
*/
args[0] = PointerGetDatum(rulename);
nulls[0] = (rulename == NULL) ? 'n' : ' ';
nulls[1] = '\0';
spirc = SPI_execp(plan_getrule, args, nulls, 1);
if (spirc != SPI_OK_SELECT)
elog(ERROR, "failed to get pg_rewrite tuple for %s", rulename);
if (SPI_processed != 1)
{
if (SPI_finish() != SPI_OK_FINISH)
elog(ERROR, "get_ruledef: SPI_finish() failed");
ruledef = SPI_palloc(VARHDRSZ + 1);
VARSIZE(ruledef) = VARHDRSZ + 1;
VARDATA(ruledef)[0] = '-';
return ruledef;
}
ruletup = SPI_tuptable->vals[0];
rulettc = SPI_tuptable->tupdesc;
/* ----------
* Get the rules definition and put it into executors memory
* ----------
*/
tmp = make_ruledef(ruletup, rulettc);
len = strlen(tmp) + VARHDRSZ;
ruledef = SPI_palloc(len);
VARSIZE(ruledef) = len;
memcpy(VARDATA(ruledef), tmp, len - VARHDRSZ);
/* ----------
* Disconnect from SPI manager
* ----------
*/
if (SPI_finish() != SPI_OK_FINISH)
elog(ERROR, "get_ruledef: SPI_finish() failed");
/* ----------
* Easy - isn't it?
* ----------
*/
return ruledef;
}
/* ----------
* get_viewdef - Mainly the same thing, but we
* only return the SELECT part of a view
* ----------
*/
text *
pg_get_viewdef(NameData *rname)
{
text *ruledef;
Datum args[2];
char nulls[3];
int spirc;
HeapTuple ruletup;
TupleDesc rulettc;
char *tmp;
int len;
char name1[NAMEDATALEN + 5];
char name2[NAMEDATALEN + 5];
/* ----------
* We need the rules name somewhere deep down
* ----------
*/
rulename = nameout(rname);
/* ----------
* Connect to SPI manager
* ----------
*/
if (SPI_connect() != SPI_OK_CONNECT)
elog(ERROR, "get_viewdef: cannot connect to SPI manager");
/* ----------
* On the first call prepare the plan to lookup pg_proc.
* We read pg_proc over the SPI manager instead of using
* the syscache to be checked for read access on pg_proc.
* ----------
*/
if (plan_getview == NULL)
{
Oid argtypes[2];
void *plan;
argtypes[0] = NAMEOID;
argtypes[1] = NAMEOID;
plan = SPI_prepare(query_getview, 2, argtypes);
if (plan == NULL)
elog(ERROR, "SPI_prepare() failed for \"%s\"", query_getview);
plan_getview = SPI_saveplan(plan);
}
/* ----------
* Get the pg_rewrite tuple for this rule
* ----------
*/
sprintf(name1, "_RET%s", rulename);
sprintf(name2, "_ret%s", rulename);
args[0] = PointerGetDatum(name1);
args[1] = PointerGetDatum(name2);
nulls[0] = ' ';
nulls[1] = ' ';
nulls[2] = '\0';
spirc = SPI_execp(plan_getview, args, nulls, 1);
if (spirc != SPI_OK_SELECT)
elog(ERROR, "failed to get pg_rewrite tuple for view %s", rulename);
if (SPI_processed != 1)
tmp = "Not a view";
else
{
/* ----------
* Get the rules definition and put it into executors memory
* ----------
*/
ruletup = SPI_tuptable->vals[0];
rulettc = SPI_tuptable->tupdesc;
tmp = make_viewdef(ruletup, rulettc);
}
len = strlen(tmp) + VARHDRSZ;
ruledef = SPI_palloc(len);
VARSIZE(ruledef) = len;
memcpy(VARDATA(ruledef), tmp, len - VARHDRSZ);
/* ----------
* Disconnect from SPI manager
* ----------
*/
if (SPI_finish() != SPI_OK_FINISH)
elog(ERROR, "get_viewdef: SPI_finish() failed");
/* ----------
* Easy - isn't it?
* ----------
*/
return ruledef;
}
/* ----------
* get_viewdef - Mainly the same thing, but we
* only return the SELECT part of a view
* ----------
*/
text *
pg_get_indexdef(Oid indexrelid)
{
text *indexdef;
HeapTuple ht_idx;
HeapTuple ht_idxrel;
HeapTuple ht_indrel;
HeapTuple spi_tup;
TupleDesc spi_ttc;
int spi_fno;
Form_pg_index idxrec;
Form_pg_class idxrelrec;
Form_pg_class indrelrec;
Datum spi_args[1];
char spi_nulls[2];
int spirc;
int len;
int keyno;
char buf[8192];
char keybuf[8192];
char *sep;
/* ----------
* Connect to SPI manager
* ----------
*/
if (SPI_connect() != SPI_OK_CONNECT)
elog(ERROR, "get_indexdef: cannot connect to SPI manager");
/* ----------
* On the first call prepare the plans to lookup pg_am
* and pg_opclass.
* ----------
*/
if (plan_getam == NULL)
{
Oid argtypes[1];
void *plan;
argtypes[0] = OIDOID;
plan = SPI_prepare(query_getam, 1, argtypes);
if (plan == NULL)
elog(ERROR, "SPI_prepare() failed for \"%s\"", query_getam);
plan_getam = SPI_saveplan(plan);
argtypes[0] = OIDOID;
plan = SPI_prepare(query_getopclass, 1, argtypes);
if (plan == NULL)
elog(ERROR, "SPI_prepare() failed for \"%s\"", query_getopclass);
plan_getopclass = SPI_saveplan(plan);
}
/* ----------
* Fetch the pg_index tuple by the Oid of the index
* ----------
*/
ht_idx = SearchSysCacheTuple(INDEXRELID,
ObjectIdGetDatum(indexrelid), 0, 0, 0);
if (!HeapTupleIsValid(ht_idx))
elog(ERROR, "syscache lookup for index %d failed", indexrelid);
idxrec = (Form_pg_index)GETSTRUCT(ht_idx);
/* ----------
* Fetch the pg_class tuple of the index relation
* ----------
*/
ht_idxrel = SearchSysCacheTuple(RELOID,
ObjectIdGetDatum(idxrec->indexrelid), 0, 0, 0);
if (!HeapTupleIsValid(ht_idxrel))
elog(ERROR, "syscache lookup for relid %d failed", idxrec->indexrelid);
idxrelrec = (Form_pg_class)GETSTRUCT(ht_idxrel);
/* ----------
* Fetch the pg_class tuple of the indexed relation
* ----------
*/
ht_indrel = SearchSysCacheTuple(RELOID,
ObjectIdGetDatum(idxrec->indrelid), 0, 0, 0);
if (!HeapTupleIsValid(ht_indrel))
elog(ERROR, "syscache lookup for relid %d failed", idxrec->indrelid);
indrelrec = (Form_pg_class)GETSTRUCT(ht_indrel);
/* ----------
* Get the am name for the index relation
* ----------
*/
spi_args[0] = ObjectIdGetDatum(idxrelrec->relam);
spi_nulls[0] = ' ';
spi_nulls[1] = '\0';
spirc = SPI_execp(plan_getam, spi_args, spi_nulls, 1);
if (spirc != SPI_OK_SELECT)
elog(ERROR, "failed to get pg_am tuple for index %s", nameout(&(idxrelrec->relname)));
if (SPI_processed != 1)
elog(ERROR, "failed to get pg_am tuple for index %s", nameout(&(idxrelrec->relname)));
spi_tup = SPI_tuptable->vals[0];
spi_ttc = SPI_tuptable->tupdesc;
spi_fno = SPI_fnumber(spi_ttc, "amname");
/* ----------
* Start the index definition
* ----------
*/
sprintf(buf, "CREATE %sINDEX \"%s\" ON \"%s\" USING %s (",
idxrec->indisunique ? "UNIQUE " : "",
nameout(&(idxrelrec->relname)),
nameout(&(indrelrec->relname)),
SPI_getvalue(spi_tup, spi_ttc, spi_fno));
/* ----------
* Collect the indexed attributes
* ----------
*/
sep = "";
keybuf[0] = '\0';
for (keyno = 0; keyno < INDEX_MAX_KEYS; keyno++)
{
if (idxrec->indkey[keyno] == InvalidAttrNumber)
break;
strcat(keybuf, sep);
sep = ", ";
/* ----------
* Add the indexed field name
* ----------
*/
strcat(keybuf, "\"");
if (idxrec->indkey[keyno] == ObjectIdAttributeNumber - 1)
strcat(keybuf, "oid");
else
strcat(keybuf, get_attribute_name(idxrec->indrelid,
idxrec->indkey[keyno]));
strcat(keybuf, "\"");
/* ----------
* If not a functional index, add the operator class name
* ----------
*/
if (idxrec->indproc == InvalidOid)
{
spi_args[0] = ObjectIdGetDatum(idxrec->indclass[keyno]);
spi_nulls[0] = ' ';
spi_nulls[1] = '\0';
spirc = SPI_execp(plan_getopclass, spi_args, spi_nulls, 1);
if (spirc != SPI_OK_SELECT)
elog(ERROR, "failed to get pg_opclass tuple %d", idxrec->indclass[keyno]);
if (SPI_processed != 1)
elog(ERROR, "failed to get pg_opclass tuple %d", idxrec->indclass[keyno]);
spi_tup = SPI_tuptable->vals[0];
spi_ttc = SPI_tuptable->tupdesc;
spi_fno = SPI_fnumber(spi_ttc, "opcname");
strcat(keybuf, " \"");
strcat(keybuf, SPI_getvalue(spi_tup, spi_ttc, spi_fno));
strcat(keybuf, "\"");
}
}
/* ----------
* For functional index say 'func (attrs) opclass'
* ----------
*/
if (idxrec->indproc != InvalidOid)
{
HeapTuple proctup;
Form_pg_proc procStruct;
proctup = SearchSysCacheTuple(PROOID,
ObjectIdGetDatum(idxrec->indproc), 0, 0, 0);
if (!HeapTupleIsValid(proctup))
elog(ERROR, "cache lookup for proc %d failed", idxrec->indproc);
procStruct = (Form_pg_proc) GETSTRUCT(proctup);
strcat(buf, "\"");
strcat(buf, nameout(&(procStruct->proname)));
strcat(buf, "\" (");
strcat(buf, keybuf);
strcat(buf, ") ");
spi_args[0] = ObjectIdGetDatum(idxrec->indclass[0]);
spi_nulls[0] = ' ';
spi_nulls[1] = '\0';
spirc = SPI_execp(plan_getopclass, spi_args, spi_nulls, 1);
if (spirc != SPI_OK_SELECT)
elog(ERROR, "failed to get pg_opclass tuple %d", idxrec->indclass[0]);
if (SPI_processed != 1)
elog(ERROR, "failed to get pg_opclass tuple %d", idxrec->indclass[0]);
spi_tup = SPI_tuptable->vals[0];
spi_ttc = SPI_tuptable->tupdesc;
spi_fno = SPI_fnumber(spi_ttc, "opcname");
strcat(buf, "\"");
strcat(buf, SPI_getvalue(spi_tup, spi_ttc, spi_fno));
strcat(buf, "\"");
}
else
/* ----------
* For the others say 'attr opclass [, ...]'
* ----------
*/
{
strcat(buf, keybuf);
}
/* ----------
* Finish
* ----------
*/
strcat(buf, ")");
/* ----------
* Create the result in upper executor memory
* ----------
*/
len = strlen(buf) + VARHDRSZ;
indexdef = SPI_palloc(len);
VARSIZE(indexdef) = len;
memcpy(VARDATA(indexdef), buf, len - VARHDRSZ);
/* ----------
* Disconnect from SPI manager
* ----------
*/
if (SPI_finish() != SPI_OK_FINISH)
elog(ERROR, "get_viewdef: SPI_finish() failed");
return indexdef;
}
/* ----------
* get_userbyid - Get a user name by usesysid and
* fallback to 'unknown (UID=n)'
* ----------
*/
NameData *
pg_get_userbyid(int4 uid)
{
HeapTuple usertup;
Form_pg_shadow user_rec;
NameData *result;
/* ----------
* Allocate space for the result
* ----------
*/
result = (NameData *) palloc(NAMEDATALEN);
memset(result->data, 0, NAMEDATALEN);
/* ----------
* Get the pg_shadow entry and print the result
* ----------
*/
usertup = SearchSysCacheTuple(USESYSID,
ObjectIdGetDatum(uid), 0, 0, 0);
if (HeapTupleIsValid(usertup))
{
user_rec = (Form_pg_shadow)GETSTRUCT(usertup);
StrNCpy(result->data, (&(user_rec->usename))->data, NAMEDATALEN);
}
else
{
sprintf((char *)result, "unknown (UID=%d)", uid);
}
return result;
}
/* ----------
* make_ruledef - reconstruct the CREATE RULE command
* for a given pg_rewrite tuple
* ----------
*/
static char *
make_ruledef(HeapTuple ruletup, TupleDesc rulettc)
{
char *buf;
char ev_type;
Oid ev_class;
int2 ev_attr;
bool is_instead;
char *ev_qual;
char *ev_action;
List *actions = NIL;
int fno;
bool isnull;
/* ----------
* Allocate space for the returned rule definition text
* ----------
*/
buf = palloc(8192);
/* ----------
* Get the attribute values from the rules tuple
* ----------
*/
fno = SPI_fnumber(rulettc, "ev_type");
ev_type = (char) SPI_getbinval(ruletup, rulettc, fno, &isnull);
fno = SPI_fnumber(rulettc, "ev_class");
ev_class = (Oid) SPI_getbinval(ruletup, rulettc, fno, &isnull);
fno = SPI_fnumber(rulettc, "ev_attr");
ev_attr = (int2) SPI_getbinval(ruletup, rulettc, fno, &isnull);
fno = SPI_fnumber(rulettc, "is_instead");
is_instead = (bool) SPI_getbinval(ruletup, rulettc, fno, &isnull);
fno = SPI_fnumber(rulettc, "ev_qual");
ev_qual = SPI_getvalue(ruletup, rulettc, fno);
fno = SPI_fnumber(rulettc, "ev_action");
ev_action = SPI_getvalue(ruletup, rulettc, fno);
if (ev_action != NULL)
actions = (List *) stringToNode(ev_action);
/* ----------
* Build the rules definition text
* ----------
*/
strcpy(buf, "CREATE RULE \"");
/* The rule name */
strcat(buf, rulename);
strcat(buf, "\" AS ON ");
/* The event the rule is fired for */
switch (ev_type)
{
case '1':
strcat(buf, "SELECT TO \"");
break;
case '2':
strcat(buf, "UPDATE TO \"");
break;
case '3':
strcat(buf, "INSERT TO \"");
break;
case '4':
strcat(buf, "DELETE TO \"");
break;
default:
elog(ERROR, "get_ruledef: rule %s has unsupported event type %d",
rulename, ev_type);
break;
}
/* The relation the rule is fired on */
strcat(buf, get_relation_name(ev_class));
strcat(buf, "\"");
if (ev_attr > 0)
{
strcat(buf, ".\"");
strcat(buf, get_attribute_name(ev_class, ev_attr));
strcat(buf, "\"");
}
/* If the rule has an event qualification, add it */
if (ev_qual == NULL)
ev_qual = "";
if (strlen(ev_qual) > 0)
{
Node *qual;
Query *query;
QryHier qh;
qual = stringToNode(ev_qual);
query = (Query *) lfirst(actions);
qh.parent = NULL;
qh.query = query;
strcat(buf, " WHERE ");
strcat(buf, get_rule_expr(&qh, 0, qual, TRUE));
}
strcat(buf, " DO ");
/* The INSTEAD keyword (if so) */
if (is_instead)
strcat(buf, "INSTEAD ");
/* Finally the rules actions */
if (length(actions) > 1)
{
List *action;
Query *query;
strcat(buf, "(");
foreach(action, actions)
{
query = (Query *) lfirst(action);
strcat(buf, get_query_def(query, NULL));
strcat(buf, "; ");
}
strcat(buf, ");");
}
else
{
if (length(actions) == 0)
{
strcat(buf, "NOTHING;");
}
else
{
Query *query;
query = (Query *) lfirst(actions);
strcat(buf, get_query_def(query, NULL));
strcat(buf, ";");
}
}
/* ----------
* That's it
* ----------
*/
return buf;
}
/* ----------
* make_viewdef - reconstruct the SELECT part of a
* view rewrite rule
* ----------
*/
static char *
make_viewdef(HeapTuple ruletup, TupleDesc rulettc)
{
char buf[8192];
Query *query;
char ev_type;
Oid ev_class;
int2 ev_attr;
bool is_instead;
char *ev_qual;
char *ev_action;
List *actions = NIL;
int fno;
bool isnull;
/* ----------
* Get the attribute values from the rules tuple
* ----------
*/
fno = SPI_fnumber(rulettc, "ev_type");
ev_type = (char) SPI_getbinval(ruletup, rulettc, fno, &isnull);
fno = SPI_fnumber(rulettc, "ev_class");
ev_class = (Oid) SPI_getbinval(ruletup, rulettc, fno, &isnull);
fno = SPI_fnumber(rulettc, "ev_attr");
ev_attr = (int2) SPI_getbinval(ruletup, rulettc, fno, &isnull);
fno = SPI_fnumber(rulettc, "is_instead");
is_instead = (bool) SPI_getbinval(ruletup, rulettc, fno, &isnull);
fno = SPI_fnumber(rulettc, "ev_qual");
ev_qual = SPI_getvalue(ruletup, rulettc, fno);
fno = SPI_fnumber(rulettc, "ev_action");
ev_action = SPI_getvalue(ruletup, rulettc, fno);
if (ev_action != NULL)
actions = (List *) stringToNode(ev_action);
if (length(actions) != 1)
return "Not a view";
query = (Query *) lfirst(actions);
if (ev_type != '1' || ev_attr >= 0 || !is_instead || strcmp(ev_qual, ""))
return "Not a view";
strcpy(buf, get_query_def(query, NULL));
strcat(buf, ";");
/* ----------
* That's it
* ----------
*/
return pstrdup(buf);
}
/* ----------
* get_query_def - Parse back one action from
* the parsetree in the actions
* list
* ----------
*/
static char *
get_query_def(Query *query, QryHier *parentqh)
{
QryHier qh;
qh.parent = parentqh;
qh.query = query;
switch (query->commandType)
{
case CMD_SELECT:
return get_select_query_def(query, &qh);
break;
case CMD_UPDATE:
return get_update_query_def(query, &qh);
break;
case CMD_INSERT:
return get_insert_query_def(query, &qh);
break;
case CMD_DELETE:
return get_delete_query_def(query, &qh);
break;
case CMD_NOTHING:
return "NOTHING";
break;
default:
elog(ERROR, "get_ruledef of %s: query command type %d not implemented yet",
rulename, query->commandType);
break;
}
return NULL;
}
/* ----------
* get_select_query_def - Parse back a SELECT parsetree
* ----------
*/
static char *
get_select_query_def(Query *query, QryHier *qh)
{
char buf[8192];
char *sep;
TargetEntry *tle;
RangeTblEntry *rte;
bool *rt_used;
int rt_length;
int rt_numused = 0;
bool rt_constonly = TRUE;
int i;
List *l;
/* ----------
* First we need need to know which and how many of the
* range table entries in the query are used in the target list
* or queries qualification
* ----------
*/
rt_length = length(query->rtable);
rt_used = palloc(sizeof(bool) * rt_length);
for (i = 0; i < rt_length; i++)
{
if (check_if_rte_used(i + 1, (Node *) (query->targetList), 0))
{
rt_used[i] = TRUE;
rt_numused++;
}
else
{
if (check_if_rte_used(i + 1, (Node *) (query->qual), 0))
{
rt_used[i] = TRUE;
rt_numused++;
}
else
rt_used[i] = FALSE;
}
}
/* ----------
* Now check if any of the used rangetable entries is different
* from *NEW* and *CURRENT*. If so we must omit the FROM clause
* later.
* ----------
*/
i = 0;
foreach(l, query->rtable)
{
if (!rt_used[i++])
continue;
rte = (RangeTblEntry *) lfirst(l);
if (!strcmp(rte->refname, "*NEW*"))
continue;
if (!strcmp(rte->refname, "*CURRENT*"))
continue;
rt_constonly = FALSE;
break;
}
/* ----------
* Build up the query string - first we say SELECT
* ----------
*/
strcpy(buf, "SELECT");
/* Then we tell what to select (the targetlist) */
sep = " ";
foreach(l, query->targetList)
{
bool tell_as = FALSE;
tle = (TargetEntry *) lfirst(l);
strcat(buf, sep);
sep = ", ";
strcat(buf, get_tle_expr(qh, 0, tle, (rt_numused > 1)));
/* Check if we must say AS ... */
if (nodeTag(tle->expr) != T_Var)
tell_as = strcmp(tle->resdom->resname, "?column?");
else
{
Var *var = (Var *) (tle->expr);
char *attname;
rte = (RangeTblEntry *) nth(var->varno - 1, query->rtable);
attname = get_attribute_name(rte->relid, var->varattno);
if (strcmp(attname, tle->resdom->resname))
tell_as = TRUE;
}
/* and do if so */
if (tell_as)
{
strcat(buf, " AS \"");
strcat(buf, tle->resdom->resname);
strcat(buf, "\"");
}
}
/* If we need other tables that *NEW* or *CURRENT* add the FROM clause */
if (!rt_constonly && rt_numused > 0)
{
strcat(buf, " FROM");
i = 0;
sep = " ";
foreach(l, query->rtable)
{
if (rt_used[i++])
{
rte = (RangeTblEntry *) lfirst(l);
if (!strcmp(rte->refname, "*NEW*"))
continue;
if (!strcmp(rte->refname, "*CURRENT*"))
continue;
strcat(buf, sep);
sep = ", ";
strcat(buf, "\"");
strcat(buf, rte->relname);
strcat(buf, "\"");
if (strcmp(rte->relname, rte->refname) != 0)
{
strcat(buf, " \"");
strcat(buf, rte->refname);
strcat(buf, "\"");
}
}
}
}
/* Add the WHERE clause if given */
if (query->qual != NULL)
{
strcat(buf, " WHERE ");
strcat(buf, get_rule_expr(qh, 0, query->qual, (rt_numused > 1)));
}
/* Add the GROUP BY CLAUSE */
if (query->groupClause != NULL)
{
strcat(buf, " GROUP BY ");
sep = "";
foreach(l, query->groupClause)
{
strcat(buf, sep);
sep = ", ";
strcat(buf, get_rule_expr(qh, 0, lfirst(l), (rt_numused > 1)));
}
}
/* ----------
* Copy the query string into allocated space and return it
* ----------
*/
return pstrdup(buf);
}
/* ----------
* get_insert_query_def - Parse back an INSERT parsetree
* ----------
*/
static char *
get_insert_query_def(Query *query, QryHier *qh)
{
char buf[8192];
char *sep;
TargetEntry *tle;
RangeTblEntry *rte;
bool *rt_used;
int rt_length;
int rt_numused = 0;
bool rt_constonly = TRUE;
int i;
List *l;
/* ----------
* We need to know if other tables than *NEW* or *CURRENT*
* are used in the query. If not, it's an INSERT ... VALUES,
* otherwise an INSERT ... SELECT.
* ----------
*/
rt_length = length(query->rtable);
rt_used = palloc(sizeof(bool) * rt_length);
for (i = 0; i < rt_length; i++)
{
if (check_if_rte_used(i + 1, (Node *) (query->targetList), 0))
{
rt_used[i] = TRUE;
rt_numused++;
}
else
{
if (check_if_rte_used(i + 1, (Node *) (query->qual), 0))
{
rt_used[i] = TRUE;
rt_numused++;
}
else
rt_used[i] = FALSE;
}
}
i = 0;
foreach(l, query->rtable)
{
if (!rt_used[i++])
continue;
rte = (RangeTblEntry *) lfirst(l);
if (!strcmp(rte->refname, "*NEW*"))
continue;
if (!strcmp(rte->refname, "*CURRENT*"))
continue;
rt_constonly = FALSE;
break;
}
/* ----------
* Start the query with INSERT INTO relname
* ----------
*/
rte = (RangeTblEntry *) nth(query->resultRelation - 1, query->rtable);
strcpy(buf, "INSERT INTO \"");
strcat(buf, rte->relname);
strcat(buf, "\"");
/* Add the target list */
sep = " (";
foreach(l, query->targetList)
{
tle = (TargetEntry *) lfirst(l);
strcat(buf, sep);
sep = ", ";
strcat(buf, "\"");
strcat(buf, tle->resdom->resname);
strcat(buf, "\"");
}
strcat(buf, ") ");
/* Add the VALUES or the SELECT */
if (rt_constonly && query->qual == NULL)
{
strcat(buf, "VALUES (");
sep = "";
foreach(l, query->targetList)
{
tle = (TargetEntry *) lfirst(l);
strcat(buf, sep);
sep = ", ";
strcat(buf, get_tle_expr(qh, 0, tle, (rt_numused > 1)));
}
strcat(buf, ")");
}
else
strcat(buf, get_select_query_def(query, qh));
/* ----------
* Copy the query string into allocated space and return it
* ----------
*/
return pstrdup(buf);
}
/* ----------
* get_update_query_def - Parse back an UPDATE parsetree
* ----------
*/
static char *
get_update_query_def(Query *query, QryHier *qh)
{
char buf[8192];
char *sep;
TargetEntry *tle;
RangeTblEntry *rte;
List *l;
/* ----------
* Start the query with UPDATE relname SET
* ----------
*/
rte = (RangeTblEntry *) nth(query->resultRelation - 1, query->rtable);
strcpy(buf, "UPDATE ");
strcat(buf, rte->relname);
strcat(buf, " SET ");
/* Add the comma separated list of 'attname = value' */
sep = "";
foreach(l, query->targetList)
{
tle = (TargetEntry *) lfirst(l);
strcat(buf, sep);
sep = ", ";
strcat(buf, "\"");
strcat(buf, tle->resdom->resname);
strcat(buf, "\" = ");
strcat(buf, get_tle_expr(qh, query->resultRelation,
tle, TRUE));
}
/* Finally add a WHERE clause if given */
if (query->qual != NULL)
{
strcat(buf, " WHERE ");
strcat(buf, get_rule_expr(qh, query->resultRelation,
query->qual, TRUE));
}
/* ----------
* Copy the query string into allocated space and return it
* ----------
*/
return pstrdup(buf);
}
/* ----------
* get_delete_query_def - Parse back a DELETE parsetree
* ----------
*/
static char *
get_delete_query_def(Query *query, QryHier *qh)
{
char buf[8192];
RangeTblEntry *rte;
/* ----------
* Start the query with DELETE FROM relname
* ----------
*/
rte = (RangeTblEntry *) nth(query->resultRelation - 1, query->rtable);
strcpy(buf, "DELETE FROM \"");
strcat(buf, rte->relname);
strcat(buf, "\"");
/* Add a WHERE clause if given */
if (query->qual != NULL)
{
strcat(buf, " WHERE ");
strcat(buf, get_rule_expr(qh, 0, query->qual, FALSE));
}
/* ----------
* Copy the query string into allocated space and return it
* ----------
*/
return pstrdup(buf);
}
/* ----------
* get_rule_expr - Parse back an expression
* ----------
*/
static char *
get_rule_expr(QryHier *qh, int rt_index, Node *node, bool varprefix)
{
char buf[8192];
if (node == NULL)
return pstrdup("");
buf[0] = '\0';
/* ----------
* Up to now I don't know if all the node types below
* can really occur in rules actions and qualifications.
* There might be some work left.
* ----------
*/
switch (nodeTag(node))
{
case T_TargetEntry:
{
TargetEntry *tle = (TargetEntry *) node;
return get_rule_expr(qh, rt_index,
(Node *) (tle->expr), varprefix);
}
break;
case T_Aggref:
{
Aggref *aggref = (Aggref *) node;
strcat(buf, "\"");
strcat(buf, aggref->aggname);
strcat(buf, "\"(");
strcat(buf, get_rule_expr(qh, rt_index,
(Node *) (aggref->target), varprefix));
strcat(buf, ")");
return pstrdup(buf);
}
break;
case T_GroupClause:
{
GroupClause *grp = (GroupClause *) node;
return get_rule_expr(qh, rt_index,
(Node *) (grp->entry), varprefix);
}
break;
case T_Expr:
{
Expr *expr = (Expr *) node;
/* ----------
* Expr nodes have to be handled a bit detailed
* ----------
*/
switch (expr->opType)
{
case OP_EXPR:
strcat(buf, get_rule_expr(qh, rt_index,
(Node *) get_leftop(expr),
varprefix));
strcat(buf, " ");
strcat(buf, get_opname(((Oper *) expr->oper)->opno));
strcat(buf, " ");
strcat(buf, get_rule_expr(qh, rt_index,
(Node *) get_rightop(expr),
varprefix));
return pstrdup(buf);
break;
case OR_EXPR:
strcat(buf, "(");
strcat(buf, get_rule_expr(qh, rt_index,
(Node *) get_leftop(expr),
varprefix));
strcat(buf, ") OR (");
strcat(buf, get_rule_expr(qh, rt_index,
(Node *) get_rightop(expr),
varprefix));
strcat(buf, ")");
return pstrdup(buf);
break;
case AND_EXPR:
strcat(buf, "(");
strcat(buf, get_rule_expr(qh, rt_index,
(Node *) get_leftop(expr),
varprefix));
strcat(buf, ") AND (");
strcat(buf, get_rule_expr(qh, rt_index,
(Node *) get_rightop(expr),
varprefix));
strcat(buf, ")");
return pstrdup(buf);
break;
case NOT_EXPR:
strcat(buf, "NOT (");
strcat(buf, get_rule_expr(qh, rt_index,
(Node *) get_leftop(expr),
varprefix));
strcat(buf, ")");
return pstrdup(buf);
break;
case FUNC_EXPR:
return get_func_expr(qh, rt_index,
(Expr *) node,
varprefix);
break;
default:
printf("\n%s\n", nodeToString(node));
elog(ERROR, "Expr not yet supported");
}
}
break;
case T_Var:
{
Var *var = (Var *) node;
RangeTblEntry *rte;
int sup = var->varlevelsup;
while(sup-- > 0) qh = qh->parent;
rte = (RangeTblEntry *) nth(var->varno - 1, qh->query->rtable);
if (!strcmp(rte->refname, "*NEW*"))
strcat(buf, "new.");
else
{
if (!strcmp(rte->refname, "*CURRENT*"))
strcat(buf, "current.");
else
{
if (strcmp(rte->relname, rte->refname) != 0)
{
strcat(buf, "\"");
strcat(buf, rte->refname);
strcat(buf, "\".");
}
}
}
strcat(buf, "\"");
strcat(buf, get_attribute_name(rte->relid, var->varattno));
strcat(buf, "\"");
return pstrdup(buf);
}
break;
case T_List:
{
printf("\n%s\n", nodeToString(node));
elog(ERROR, "List not yet supported");
}
break;
case T_SubLink:
{
return get_sublink_expr(qh, rt_index, node, varprefix);
}
break;
case T_Const:
return get_const_expr((Const *) node);
break;
default:
printf("\n%s\n", nodeToString(node));
elog(ERROR, "get_ruledef of %s: unknown node type %d get_rule_expr()",
rulename, nodeTag(node));
break;
}
return FALSE;
}
/* ----------
* get_func_expr - Parse back a Func node
* ----------
*/
static char *
get_func_expr(QryHier *qh, int rt_index, Expr *expr, bool varprefix)
{
char buf[8192];
HeapTuple proctup;
Form_pg_proc procStruct;
List *l;
char *sep;
Func *func = (Func *) (expr->oper);
char *proname;
/* ----------
* Get the functions pg_proc tuple
* ----------
*/
proctup = SearchSysCacheTuple(PROOID,
ObjectIdGetDatum(func->funcid), 0, 0, 0);
if (!HeapTupleIsValid(proctup))
elog(ERROR, "cache lookup for proc %d failed", func->funcid);
procStruct = (Form_pg_proc) GETSTRUCT(proctup);
proname = nameout(&(procStruct->proname));
if (procStruct->pronargs == 1 && procStruct->proargtypes[0] == InvalidOid)
{
if (!strcmp(proname, "nullvalue"))
{
strcpy(buf, "(");
strcat(buf, get_rule_expr(qh, rt_index, lfirst(expr->args),
varprefix));
strcat(buf, ") ISNULL");
return pstrdup(buf);
}
if (!strcmp(proname, "nonnullvalue"))
{
strcpy(buf, "(");
strcat(buf, get_rule_expr(qh, rt_index, lfirst(expr->args),
varprefix));
strcat(buf, ") NOTNULL");
return pstrdup(buf);
}
}
/* ----------
* Build a string of proname(args)
* ----------
*/
strcpy(buf, "\"");
strcat(buf, proname);
strcat(buf, "\"(");
sep = "";
foreach(l, expr->args)
{
strcat(buf, sep);
sep = ", ";
strcat(buf, get_rule_expr(qh, rt_index, lfirst(l), varprefix));
}
strcat(buf, ")");
/* ----------
* Copy the function call string into allocated space and return it
* ----------
*/
return pstrdup(buf);
}
/* ----------
* get_tle_expr - A target list expression is a bit
* different from a normal expression.
* If the target column has an
* an atttypmod, the parser usually
* puts a padding-/cut-function call
* around the expression itself. We
* we must get rid of it, otherwise
* dump/reload/dump... would blow up
* the expressions.
* ----------
*/
static char *
get_tle_expr(QryHier *qh, int rt_index, TargetEntry *tle, bool varprefix)
{
HeapTuple proctup;
Form_pg_proc procStruct;
Expr *expr;
Func *func;
Const *second_arg;
/* ----------
* Check if the result has an atttypmod and if the
* expression in the targetlist entry is a function call
* ----------
*/
if (tle->resdom->restypmod < 0)
return get_rule_expr(qh, rt_index, tle->expr, varprefix);
if (nodeTag(tle->expr) != T_Expr)
return get_rule_expr(qh, rt_index, tle->expr, varprefix);
expr = (Expr *) (tle->expr);
if (expr->opType != FUNC_EXPR)
return get_rule_expr(qh, rt_index, tle->expr, varprefix);
func = (Func *) (expr->oper);
/* ----------
* Get the functions pg_proc tuple
* ----------
*/
proctup = SearchSysCacheTuple(PROOID,
ObjectIdGetDatum(func->funcid), 0, 0, 0);
if (!HeapTupleIsValid(proctup))
elog(ERROR, "cache lookup for proc %d failed", func->funcid);
procStruct = (Form_pg_proc) GETSTRUCT(proctup);
/* ----------
* It must be a function with two arguments where the first
* is of the same type as the return value and the second is
* an int4.
* ----------
*/
if (procStruct->pronargs != 2)
return get_rule_expr(qh, rt_index, tle->expr, varprefix);
if (procStruct->prorettype != procStruct->proargtypes[0])
return get_rule_expr(qh, rt_index, tle->expr, varprefix);
if (procStruct->proargtypes[1] != INT4OID)
return get_rule_expr(qh, rt_index, tle->expr, varprefix);
/* ----------
* Finally (to be totally safe) the second argument must be a
* const and match the value in the results atttypmod.
* ----------
*/
second_arg = (Const *) nth(1, expr->args);
if (nodeTag((Node *) second_arg) != T_Const)
return get_rule_expr(qh, rt_index, tle->expr, varprefix);
if ((int4) (second_arg->constvalue) != tle->resdom->restypmod)
return get_rule_expr(qh, rt_index, tle->expr, varprefix);
/* ----------
* Whow - got it. Now get rid of the padding function
* ----------
*/
return get_rule_expr(qh, rt_index, lfirst(expr->args), varprefix);
}
/* ----------
* get_const_expr - Make a string representation
* with the type cast out of a Const
* ----------
*/
static char *
get_const_expr(Const *constval)
{
HeapTuple typetup;
Form_pg_type typeStruct;
FmgrInfo finfo_output;
char *extval;
bool isnull = FALSE;
char buf[8192];
char namebuf[64];
if (constval->constisnull)
return "NULL";
typetup = SearchSysCacheTuple(TYPOID,
ObjectIdGetDatum(constval->consttype), 0, 0, 0);
if (!HeapTupleIsValid(typetup))
elog(ERROR, "cache lookup of type %d failed", constval->consttype);
typeStruct = (Form_pg_type) GETSTRUCT(typetup);
fmgr_info(typeStruct->typoutput, &finfo_output);
extval = (char *) (*fmgr_faddr(&finfo_output)) (constval->constvalue,
&isnull, -1);
sprintf(namebuf, "::\"%s\"", nameout(&(typeStruct->typname)));
if (strcmp(namebuf, "::unknown") == 0)
namebuf[0] = '\0';
sprintf(buf, "'%s'%s", extval, namebuf);
return pstrdup(buf);
}
/* ----------
* get_sublink_expr - Parse back a sublink
* ----------
*/
static char *
get_sublink_expr(QryHier *qh, int rt_index, Node *node, bool varprefix)
{
SubLink *sublink = (SubLink *) node;
Query *query = (Query *) (sublink->subselect);
Expr *expr;
List *l;
char *sep;
char buf[8192];
buf[0] = '\0';
if (sublink->lefthand != NULL)
{
if (length(sublink->lefthand) > 1)
strcat(buf, "(");
sep = "";
foreach(l, sublink->lefthand)
{
strcat(buf, sep);
sep = ", ";
strcat(buf, get_rule_expr(qh, rt_index,
lfirst(l), varprefix));
}
if (length(sublink->lefthand) > 1)
strcat(buf, ") ");
else
strcat(buf, " ");
}
switch (sublink->subLinkType) {
case EXISTS_SUBLINK:
strcat(buf, "EXISTS ");
break;
case ANY_SUBLINK:
expr = (Expr *)lfirst(sublink->oper);
strcat(buf, get_opname(((Oper *) (expr->oper))->opno));
strcat(buf, " ANY ");
break;
case ALL_SUBLINK:
expr = (Expr *)lfirst(sublink->oper);
strcat(buf, get_opname(((Oper *) (expr->oper))->opno));
strcat(buf, " ALL ");
break;
case EXPR_SUBLINK:
expr = (Expr *)lfirst(sublink->oper);
strcat(buf, get_opname(((Oper *) (expr->oper))->opno));
strcat(buf, " ");
break;
default:
elog(ERROR, "unupported sublink type %d",
sublink->subLinkType);
break;
}
strcat(buf, "(");
strcat(buf, get_query_def(query, qh));
strcat(buf, ")");
return pstrdup(buf);
}
/* ----------
* get_relation_name - Get a relation name by Oid
* ----------
*/
static char *
get_relation_name(Oid relid)
{
HeapTuple classtup;
Form_pg_class classStruct;
classtup = SearchSysCacheTuple(RELOID,
ObjectIdGetDatum(relid), 0, 0, 0);
if (!HeapTupleIsValid(classtup))
elog(ERROR, "cache lookup of relation %d failed", relid);
classStruct = (Form_pg_class) GETSTRUCT(classtup);
return nameout(&(classStruct->relname));
}
/* ----------
* get_attribute_name - Get an attribute name by it's
* relations Oid and it's attnum
* ----------
*/
static char *
get_attribute_name(Oid relid, int2 attnum)
{
HeapTuple atttup;
Form_pg_attribute attStruct;
atttup = SearchSysCacheTuple(ATTNUM,
ObjectIdGetDatum(relid), (Datum) attnum, 0, 0);
if (!HeapTupleIsValid(atttup))
elog(ERROR, "cache lookup of attribute %d in relation %d failed",
attnum, relid);
attStruct = (Form_pg_attribute) GETSTRUCT(atttup);
return nameout(&(attStruct->attname));
}
/* ----------
* check_if_rte_used - Check a targetlist or qual
* if a given rangetable entry
* is used in it
* ----------
*/
static bool
check_if_rte_used(int rt_index, Node *node, int sup)
{
if (node == NULL)
return FALSE;
switch (nodeTag(node))
{
case T_TargetEntry:
{
TargetEntry *tle = (TargetEntry *) node;
return check_if_rte_used(rt_index,
(Node *) (tle->expr), sup);
}
break;
case T_Aggref:
{
Aggref *aggref = (Aggref *) node;
return check_if_rte_used(rt_index,
(Node *) (aggref->target), sup);
}
break;
case T_GroupClause:
{
GroupClause *grp = (GroupClause *) node;
return check_if_rte_used(rt_index,
(Node *) (grp->entry), sup);
}
break;
case T_Expr:
{
Expr *expr = (Expr *) node;
return check_if_rte_used(rt_index,
(Node *) (expr->args), sup);
}
break;
case T_Var:
{
Var *var = (Var *) node;
return var->varno == rt_index && var->varlevelsup == sup;
}
break;
case T_List:
{
List *l;
foreach(l, (List *) node)
{
if (check_if_rte_used(rt_index, lfirst(l), sup))
return TRUE;
}
return FALSE;
}
break;
case T_SubLink:
{
SubLink *sublink = (SubLink *) node;
Query *query = (Query *) sublink->subselect;
if (check_if_rte_used(rt_index, (Node *) (query->qual), sup + 1))
return TRUE;
if (check_if_rte_used(rt_index, (Node *) (sublink->lefthand), sup))
return TRUE;
return FALSE;
}
break;
case T_Const:
return FALSE;
break;
default:
elog(ERROR, "get_ruledef of %s: unknown node type %d in check_if_rte_used()",
rulename, nodeTag(node));
break;
}
return FALSE;
}
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