--- /dev/null
+/**********************************************************************
+ * 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 1.1 1998/08/24 01:38:05 momjian 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 "fmgr.h"
+
+
+/* ----------
+ * 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";
+
+
+/* ----------
+ * Global functions
+ * ----------
+ */
+text *pg_get_ruledef(NameData *rname);
+text *pg_get_viewdef(NameData *rname);
+
+
+/* ----------
+ * 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);
+static char *get_select_query_def(Query *query);
+static char *get_insert_query_def(Query *query);
+static char *get_update_query_def(Query *query);
+static char *get_delete_query_def(Query *query);
+static char *get_rule_expr(List *rtable, int rt_index, Node *node, bool varprefix);
+static char *get_func_expr(List *rtable, int rt_index, Expr *expr, bool varprefix);
+static char *get_tle_expr(List *rtable, int rt_index, TargetEntry *tle, bool varprefix);
+static char *get_const_expr(Const *constval);
+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;
+}
+
+
+/* ----------
+ * 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);
+ if (isnull) ev_qual = NULL;
+
+ fno = SPI_fnumber(rulettc, "ev_action");
+ ev_action = SPI_getvalue(ruletup, rulettc, fno);
+ if (isnull) ev_action = NULL;
+ 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));
+ if (ev_attr > 0) {
+ strcat(buf, ".");
+ strcat(buf, get_attribute_name(ev_class, ev_attr));
+ }
+
+ /* If the rule has an event qualification, add it */
+ if (ev_qual == NULL) ev_qual = "";
+ if (strlen(ev_qual) > 0) {
+ Node *qual;
+ Query *query;
+
+ qual = stringToNode(ev_qual);
+ query = (Query *)lfirst(actions);
+
+ strcat(buf, " WHERE ");
+ strcat(buf, get_rule_expr(query->rtable, 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));
+ 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));
+ 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);
+ if (isnull) ev_qual = "";
+
+ fno = SPI_fnumber(rulettc, "ev_action");
+ ev_action = SPI_getvalue(ruletup, rulettc, fno);
+ if (isnull) ev_action = NULL;
+ 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_select_query_def(query));
+ 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)
+{
+ switch (query->commandType) {
+ case CMD_SELECT:
+ return get_select_query_def(query);
+ break;
+
+ case CMD_UPDATE:
+ return get_update_query_def(query);
+ break;
+
+ case CMD_INSERT:
+ return get_insert_query_def(query);
+ break;
+
+ case CMD_DELETE:
+ return get_delete_query_def(query);
+ 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)
+{
+ 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(query->rtable, 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);
+ }
+ }
+
+ /* 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, rte->relname);
+ if (rt_numused > 1) {
+ strcat(buf, " ");
+ strcat(buf, rte->refname);
+ }
+ }
+ }
+ }
+
+ /* Add the WHERE clause if given */
+ if (query->qual != NULL) {
+ strcat(buf, " WHERE ");
+ strcat(buf, get_rule_expr(query->rtable, 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(query->rtable, 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)
+{
+ 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);
+
+ /* Add the target list */
+ sep = " (";
+ foreach (l, query->targetList) {
+ tle = (TargetEntry *)lfirst(l);
+
+ strcat(buf, sep); sep = ", ";
+ strcat(buf, tle->resdom->resname);
+ }
+ 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(query->rtable, 0, tle, (rt_numused > 1)));
+ }
+ strcat(buf, ")");
+ } else {
+ strcat(buf, get_select_query_def(query));
+ }
+
+ /* ----------
+ * 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)
+{
+ 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, tle->resdom->resname);
+ strcat(buf, " = ");
+ strcat(buf, get_tle_expr(query->rtable, query->resultRelation,
+ tle, TRUE));
+ }
+
+ /* Finally add a WHERE clause if given */
+ if (query->qual != NULL) {
+ strcat(buf, " WHERE ");
+ strcat(buf, get_rule_expr(query->rtable, 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)
+{
+ 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);
+
+ /* Add a WHERE clause if given */
+ if (query->qual != NULL) {
+ strcat(buf, " WHERE ");
+ strcat(buf, get_rule_expr(query->rtable, 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(List *rtable, 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(rtable, rt_index,
+ (Node *)(tle->expr), varprefix);
+ }
+ break;
+
+ case T_Aggreg:
+ {
+ Aggreg *agg = (Aggreg *)node;
+
+ strcat(buf, agg->aggname);
+ strcat(buf, "(");
+ strcat(buf, get_rule_expr(rtable, rt_index,
+ (Node *)(agg->target), varprefix));
+ strcat(buf, ")");
+ return pstrdup(buf);
+ }
+ break;
+
+ case T_GroupClause:
+ {
+ GroupClause *grp = (GroupClause *)node;
+
+ return get_rule_expr(rtable, 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(rtable, rt_index,
+ (Node *)get_leftop(expr),
+ varprefix));
+ strcat(buf, " ");
+ strcat(buf, get_opname(((Oper *)expr->oper)->opno));
+ strcat(buf, " ");
+ strcat(buf, get_rule_expr(rtable, rt_index,
+ (Node *)get_rightop(expr),
+ varprefix));
+ return pstrdup(buf);
+ break;
+
+ case OR_EXPR:
+ strcat(buf, "(");
+ strcat(buf, get_rule_expr(rtable, rt_index,
+ (Node *)get_leftop(expr),
+ varprefix));
+ strcat(buf, ") OR (");
+ strcat(buf, get_rule_expr(rtable, rt_index,
+ (Node *)get_rightop(expr),
+ varprefix));
+ strcat(buf, ")");
+ return pstrdup(buf);
+ break;
+
+ case AND_EXPR:
+ strcat(buf, "(");
+ strcat(buf, get_rule_expr(rtable, rt_index,
+ (Node *)get_leftop(expr),
+ varprefix));
+ strcat(buf, ") AND (");
+ strcat(buf, get_rule_expr(rtable, rt_index,
+ (Node *)get_rightop(expr),
+ varprefix));
+ strcat(buf, ")");
+ return pstrdup(buf);
+ break;
+
+ case NOT_EXPR:
+ strcat(buf, "NOT (");
+ strcat(buf, get_rule_expr(rtable, rt_index,
+ (Node *)get_leftop(expr),
+ varprefix));
+ strcat(buf, ")");
+ return pstrdup(buf);
+ break;
+
+ case FUNC_EXPR:
+ return get_func_expr(rtable, 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 = (RangeTblEntry *)nth(var->varno - 1, rtable);
+
+ if (!strcmp(rte->refname, "*NEW*")) {
+ strcat(buf, "new.");
+ } else {
+ if (!strcmp(rte->refname, "*CURRENT*")) {
+ strcat(buf, "current.");
+ } else {
+ if (varprefix && var->varno != rt_index) {
+ strcat(buf, rte->refname);
+ strcat(buf, ".");
+ }
+ }
+ }
+ strcat(buf, get_attribute_name(rte->relid, var->varattno));
+
+ return pstrdup(buf);
+ }
+ break;
+
+ case T_List:
+ {
+ printf("\n%s\n", nodeToString(node));
+ elog(ERROR, "List not yet supported");
+ }
+ break;
+
+ case T_SubLink:
+ {
+ SubLink *sublink = (SubLink *)node;
+ Query *query = (Query *)(sublink->subselect);
+ List *l;
+ char *sep;
+
+ if (sublink->lefthand != NULL) {
+ strcat(buf, "(");
+ sep = "";
+ foreach (l, sublink->lefthand) {
+ strcat(buf, sep); sep = ", ";
+ strcat(buf, get_rule_expr(rtable, rt_index,
+ lfirst(l), varprefix));
+ }
+ strcat(buf, ") IN ");
+ }
+
+ strcat(buf, "(");
+ strcat(buf, get_query_def(query));
+ strcat(buf, ")");
+
+ return pstrdup(buf);
+ }
+ 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(List *rtable, 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(rtable, rt_index, lfirst(expr->args),
+ varprefix));
+ strcat(buf, ") ISNULL");
+ return pstrdup(buf);
+ }
+ if (!strcmp(proname, "nonnullvalue")) {
+ strcpy(buf, "(");
+ strcat(buf, get_rule_expr(rtable, rt_index, lfirst(expr->args),
+ varprefix));
+ strcat(buf, ") NOTNULL");
+ return pstrdup(buf);
+ }
+ }
+
+ /* ----------
+ * Build a string of proname(args)
+ * ----------
+ */
+ strcpy(buf, proname);
+ strcat(buf, "(");
+ sep = "";
+ foreach (l, expr->args) {
+ strcat(buf, sep); sep = ", ";
+ strcat(buf, get_rule_expr(rtable, 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(List *rtable, 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(rtable, rt_index, tle->expr, varprefix);
+ }
+ if (nodeTag(tle->expr) != T_Expr) {
+ return get_rule_expr(rtable, rt_index, tle->expr, varprefix);
+ }
+ expr = (Expr *)(tle->expr);
+ if (expr->opType != FUNC_EXPR) {
+ return get_rule_expr(rtable, 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(rtable, rt_index, tle->expr, varprefix);
+ }
+ if (procStruct->prorettype != procStruct->proargtypes[0]) {
+ return get_rule_expr(rtable, rt_index, tle->expr, varprefix);
+ }
+ if (procStruct->proargtypes[1] != INT4OID) {
+ return get_rule_expr(rtable, 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(rtable, rt_index, tle->expr, varprefix);
+ }
+ if ((int4)(second_arg->constvalue) != tle->resdom->restypmod) {
+ return get_rule_expr(rtable, rt_index, tle->expr, varprefix);
+ }
+
+ /* ----------
+ * Whow - got it. Now get rid of the padding function
+ * ----------
+ */
+ return get_rule_expr(rtable, rt_index, lfirst(expr->args), varprefix);
+}
+
+
+/* ----------
+ * get_const_expr - Make a string representation
+ * with the type cast out of a Const
+ * ----------
+ */
+char *
+get_const_expr(Const *constval)
+{
+ HeapTuple typetup;
+ TypeTupleForm typeStruct;
+ FmgrInfo finfo_output;
+ char *extval;
+ bool isnull = FALSE;
+ char buf[8192];
+
+ 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 = (TypeTupleForm) GETSTRUCT(typetup);
+
+ fmgr_info(typeStruct->typoutput, &finfo_output);
+ extval = (char *)(*fmgr_faddr(&finfo_output))(constval->constvalue,
+ &isnull, -1);
+
+ sprintf(buf, "'%s'::%s", extval, nameout(&(typeStruct->typname)));
+ 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;
+ AttributeTupleForm 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 = (AttributeTupleForm) 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_Aggreg:
+ {
+ Aggreg *agg = (Aggreg *)node;
+ return check_if_rte_used(rt_index,
+ (Node *)(agg->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;
+}
+
+
projects / postgresql / commitdiff