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Diffstat (limited to 'src/backend/rewrite/rewriteDefine.c')
| -rw-r--r-- | src/backend/rewrite/rewriteDefine.c | 461 |
1 files changed, 0 insertions, 461 deletions
diff --git a/src/backend/rewrite/rewriteDefine.c b/src/backend/rewrite/rewriteDefine.c deleted file mode 100644 index 43f8ffd6f1f..00000000000 --- a/src/backend/rewrite/rewriteDefine.c +++ /dev/null @@ -1,461 +0,0 @@ -/*------------------------------------------------------------------------- - * - * rewriteDefine.c - * routines for defining a rewrite rule - * - * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group - * Portions Copyright (c) 1994, Regents of the University of California - * - * - * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteDefine.c,v 1.73 2002/06/20 20:29:33 momjian Exp $ - * - *------------------------------------------------------------------------- - */ -#include "postgres.h" - -#include "access/heapam.h" -#include "catalog/catname.h" -#include "catalog/indexing.h" -#include "catalog/pg_rewrite.h" -#include "commands/view.h" -#include "miscadmin.h" -#include "optimizer/clauses.h" -#include "parser/parse_relation.h" -#include "rewrite/rewriteDefine.h" -#include "rewrite/rewriteManip.h" -#include "rewrite/rewriteSupport.h" -#include "storage/smgr.h" -#include "utils/acl.h" -#include "utils/builtins.h" -#include "utils/syscache.h" - - -static void setRuleCheckAsUser(Query *qry, Oid userid); -static bool setRuleCheckAsUser_walker(Node *node, Oid *context); - - -/* - * InsertRule - - * takes the arguments and inserts them as a row into the system - * relation "pg_rewrite" - */ -static Oid -InsertRule(char *rulname, - int evtype, - Oid eventrel_oid, - AttrNumber evslot_index, - bool evinstead, - char *evqual, - char *actiontree) -{ - int i; - Datum values[Natts_pg_rewrite]; - char nulls[Natts_pg_rewrite]; - NameData rname; - Relation pg_rewrite_desc; - TupleDesc tupDesc; - HeapTuple tup; - Oid rewriteObjectId; - - if (IsDefinedRewriteRule(eventrel_oid, rulname)) - elog(ERROR, "Attempt to insert rule \"%s\" failed: already exists", - rulname); - - /* - * Set up *nulls and *values arrays - */ - MemSet(nulls, ' ', sizeof(nulls)); - - i = 0; - namestrcpy(&rname, rulname); - values[i++] = NameGetDatum(&rname); /* rulename */ - values[i++] = ObjectIdGetDatum(eventrel_oid); /* ev_class */ - values[i++] = Int16GetDatum(evslot_index); /* ev_attr */ - values[i++] = CharGetDatum(evtype + '0'); /* ev_type */ - values[i++] = BoolGetDatum(evinstead); /* is_instead */ - values[i++] = DirectFunctionCall1(textin, CStringGetDatum(evqual)); /* ev_qual */ - values[i++] = DirectFunctionCall1(textin, CStringGetDatum(actiontree)); /* ev_action */ - - /* - * create a new pg_rewrite tuple - */ - pg_rewrite_desc = heap_openr(RewriteRelationName, RowExclusiveLock); - - tupDesc = pg_rewrite_desc->rd_att; - - tup = heap_formtuple(tupDesc, - values, - nulls); - - rewriteObjectId = simple_heap_insert(pg_rewrite_desc, tup); - - if (RelationGetForm(pg_rewrite_desc)->relhasindex) - { - Relation idescs[Num_pg_rewrite_indices]; - - CatalogOpenIndices(Num_pg_rewrite_indices, Name_pg_rewrite_indices, - idescs); - CatalogIndexInsert(idescs, Num_pg_rewrite_indices, pg_rewrite_desc, - tup); - CatalogCloseIndices(Num_pg_rewrite_indices, idescs); - } - - heap_freetuple(tup); - - heap_close(pg_rewrite_desc, RowExclusiveLock); - - return rewriteObjectId; -} - -void -DefineQueryRewrite(RuleStmt *stmt) -{ - RangeVar *event_obj = stmt->relation; - Node *event_qual = stmt->whereClause; - CmdType event_type = stmt->event; - bool is_instead = stmt->instead; - List *action = stmt->actions; - Relation event_relation; - Oid ev_relid; - Oid ruleId; - int event_attno; - Oid event_attype; - char *actionP, - *event_qualP; - List *l; - Query *query; - AclResult aclresult; - bool RelisBecomingView = false; - - /* - * If we are installing an ON SELECT rule, we had better grab - * AccessExclusiveLock to ensure no SELECTs are currently running on - * the event relation. For other types of rules, it might be - * sufficient to grab ShareLock to lock out insert/update/delete - * actions. But for now, let's just grab AccessExclusiveLock all the - * time. - */ - event_relation = heap_openrv(event_obj, AccessExclusiveLock); - ev_relid = RelationGetRelid(event_relation); - - /* - * Check user has permission to apply rules to this relation. - */ - aclresult = pg_class_aclcheck(ev_relid, GetUserId(), ACL_RULE); - if (aclresult != ACLCHECK_OK) - aclcheck_error(aclresult, RelationGetRelationName(event_relation)); - - /* - * No rule actions that modify OLD or NEW - */ - foreach(l, action) - { - query = (Query *) lfirst(l); - if (query->resultRelation == 0) - continue; - /* Don't be fooled by INSERT/SELECT */ - if (query != getInsertSelectQuery(query, NULL)) - continue; - if (query->resultRelation == PRS2_OLD_VARNO) - elog(ERROR, "rule actions on OLD currently not supported" - "\n\tuse views or triggers instead"); - if (query->resultRelation == PRS2_NEW_VARNO) - elog(ERROR, "rule actions on NEW currently not supported" - "\n\tuse triggers instead"); - } - - /* - * Rules ON SELECT are restricted to view definitions - */ - if (event_type == CMD_SELECT) - { - List *tllist; - int i; - - /* - * So there cannot be INSTEAD NOTHING, ... - */ - if (length(action) == 0) - { - elog(ERROR, "instead nothing rules on select currently not supported" - "\n\tuse views instead"); - } - - /* - * ... there cannot be multiple actions, ... - */ - if (length(action) > 1) - elog(ERROR, "multiple action rules on select currently not supported"); - - /* - * ... the one action must be a SELECT, ... - */ - query = (Query *) lfirst(action); - if (!is_instead || query->commandType != CMD_SELECT) - elog(ERROR, "only instead-select rules currently supported on select"); - - /* - * ... there can be no rule qual, ... - */ - if (event_qual != NULL) - elog(ERROR, "event qualifications not supported for rules on select"); - - /* - * ... the targetlist of the SELECT action must exactly match the - * event relation, ... - */ - i = 0; - foreach(tllist, query->targetList) - { - TargetEntry *tle = (TargetEntry *) lfirst(tllist); - Resdom *resdom = tle->resdom; - Form_pg_attribute attr; - char *attname; - - if (resdom->resjunk) - continue; - i++; - if (i > event_relation->rd_att->natts) - elog(ERROR, "select rule's target list has too many entries"); - - attr = event_relation->rd_att->attrs[i - 1]; - attname = NameStr(attr->attname); - - if (strcmp(resdom->resname, attname) != 0) - elog(ERROR, "select rule's target entry %d has different column name from %s", i, attname); - - if (attr->atttypid != resdom->restype) - elog(ERROR, "select rule's target entry %d has different type from attribute %s", i, attname); - - /* - * Allow typmods to be different only if one of them is -1, - * ie, "unspecified". This is necessary for cases like - * "numeric", where the table will have a filled-in default - * length but the select rule's expression will probably have - * typmod = -1. - */ - if (attr->atttypmod != resdom->restypmod && - attr->atttypmod != -1 && resdom->restypmod != -1) - elog(ERROR, "select rule's target entry %d has different size from attribute %s", i, attname); - } - - if (i != event_relation->rd_att->natts) - elog(ERROR, "select rule's target list has too few entries"); - - /* - * ... there must not be another ON SELECT rule already ... - */ - if (event_relation->rd_rules != NULL) - { - for (i = 0; i < event_relation->rd_rules->numLocks; i++) - { - RewriteRule *rule; - - rule = event_relation->rd_rules->rules[i]; - if (rule->event == CMD_SELECT) - elog(ERROR, "\"%s\" is already a view", - RelationGetRelationName(event_relation)); - } - } - - /* - * ... and finally the rule must be named _RETURN. - */ - if (strcmp(stmt->rulename, ViewSelectRuleName) != 0) - { - /* - * In versions before 7.3, the expected name was _RETviewname. - * For backwards compatibility with old pg_dump output, accept - * that and silently change it to _RETURN. Since this is just - * a quick backwards-compatibility hack, limit the number of - * characters checked to a few less than NAMEDATALEN; this - * saves having to worry about where a multibyte character might - * have gotten truncated. - */ - if (strncmp(stmt->rulename, "_RET", 4) != 0 || - strncmp(stmt->rulename + 4, event_obj->relname, - NAMEDATALEN - 4 - 4) != 0) - elog(ERROR, "view rule for \"%s\" must be named \"%s\"", - event_obj->relname, ViewSelectRuleName); - stmt->rulename = pstrdup(ViewSelectRuleName); - } - - /* - * Are we converting a relation to a view? - * - * If so, check that the relation is empty because the storage for - * the relation is going to be deleted. - */ - if (event_relation->rd_rel->relkind != RELKIND_VIEW) - { - HeapScanDesc scanDesc; - - scanDesc = heap_beginscan(event_relation, SnapshotNow, 0, NULL); - if (heap_getnext(scanDesc, ForwardScanDirection) != NULL) - elog(ERROR, "Relation \"%s\" is not empty. Cannot convert it to view", - event_obj->relname); - heap_endscan(scanDesc); - - RelisBecomingView = true; - } - } - - /* - * This rule is allowed - prepare to install it. - */ - event_attno = -1; - event_attype = InvalidOid; - - /* - * We want the rule's table references to be checked as though by the - * rule owner, not the user referencing the rule. Therefore, scan - * through the rule's rtables and set the checkAsUser field on all - * rtable entries. - */ - foreach(l, action) - { - query = (Query *) lfirst(l); - setRuleCheckAsUser(query, GetUserId()); - } - - /* discard rule if it's null action and not INSTEAD; it's a no-op */ - if (action != NIL || is_instead) - { - event_qualP = nodeToString(event_qual); - actionP = nodeToString(action); - - ruleId = InsertRule(stmt->rulename, - event_type, - ev_relid, - event_attno, - is_instead, - event_qualP, - actionP); - - /* - * Set pg_class 'relhasrules' field TRUE for event relation. If - * appropriate, also modify the 'relkind' field to show that the - * relation is now a view. - * - * Important side effect: an SI notice is broadcast to force all - * backends (including me!) to update relcache entries with the - * new rule. - */ - SetRelationRuleStatus(ev_relid, true, RelisBecomingView); - } - - /* - * IF the relation is becoming a view, delete the storage files - * associated with it. NB: we had better have AccessExclusiveLock to - * do this ... - */ - if (RelisBecomingView) - smgrunlink(DEFAULT_SMGR, event_relation); - - /* Close rel, but keep lock till commit... */ - heap_close(event_relation, NoLock); -} - -/* - * setRuleCheckAsUser - * Recursively scan a query and set the checkAsUser field to the - * given userid in all rtable entries. - * - * Note: for a view (ON SELECT rule), the checkAsUser field of the *OLD* - * RTE entry will be overridden when the view rule is expanded, and the - * checkAsUser field of the *NEW* entry is irrelevant because that entry's - * checkFor bits will never be set. However, for other types of rules it's - * important to set these fields to match the rule owner. So we just set - * them always. - */ -static void -setRuleCheckAsUser(Query *qry, Oid userid) -{ - List *l; - - /* Set all the RTEs in this query node */ - foreach(l, qry->rtable) - { - RangeTblEntry *rte = (RangeTblEntry *) lfirst(l); - - if (rte->rtekind == RTE_SUBQUERY) - { - /* Recurse into subquery in FROM */ - setRuleCheckAsUser(rte->subquery, userid); - } - else - rte->checkAsUser = userid; - } - - /* If there are sublinks, search for them and process their RTEs */ - if (qry->hasSubLinks) - query_tree_walker(qry, setRuleCheckAsUser_walker, (void *) &userid, - false /* already did the ones in rtable */ ); -} - -/* - * Expression-tree walker to find sublink queries - */ -static bool -setRuleCheckAsUser_walker(Node *node, Oid *context) -{ - if (node == NULL) - return false; - if (IsA(node, Query)) - { - Query *qry = (Query *) node; - - setRuleCheckAsUser(qry, *context); - return false; - } - return expression_tree_walker(node, setRuleCheckAsUser_walker, - (void *) context); -} - - -/* - * Rename an existing rewrite rule. - * - * This is unused code at the moment. - */ -void -RenameRewriteRule(Oid owningRel, const char *oldName, - const char *newName) -{ - Relation pg_rewrite_desc; - HeapTuple ruletup; - - pg_rewrite_desc = heap_openr(RewriteRelationName, RowExclusiveLock); - - ruletup = SearchSysCacheCopy(RULERELNAME, - ObjectIdGetDatum(owningRel), - PointerGetDatum(oldName), - 0, 0); - if (!HeapTupleIsValid(ruletup)) - elog(ERROR, "RenameRewriteRule: rule \"%s\" does not exist", oldName); - - /* should not already exist */ - if (IsDefinedRewriteRule(owningRel, newName)) - elog(ERROR, "Attempt to rename rule \"%s\" failed: \"%s\" already exists", - oldName, newName); - - namestrcpy(&(((Form_pg_rewrite) GETSTRUCT(ruletup))->rulename), newName); - - simple_heap_update(pg_rewrite_desc, &ruletup->t_self, ruletup); - - /* keep system catalog indices current */ - if (RelationGetForm(pg_rewrite_desc)->relhasindex) - { - Relation idescs[Num_pg_rewrite_indices]; - - CatalogOpenIndices(Num_pg_rewrite_indices, Name_pg_rewrite_indices, - idescs); - CatalogIndexInsert(idescs, Num_pg_rewrite_indices, pg_rewrite_desc, - ruletup); - CatalogCloseIndices(Num_pg_rewrite_indices, idescs); - } - - heap_freetuple(ruletup); - heap_close(pg_rewrite_desc, RowExclusiveLock); -} |