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Diffstat (limited to 'src/backend/catalog/namespace.c')
| -rw-r--r-- | src/backend/catalog/namespace.c | 4614 |
1 files changed, 4614 insertions, 0 deletions
diff --git a/src/backend/catalog/namespace.c b/src/backend/catalog/namespace.c new file mode 100644 index 0000000..2ec2301 --- /dev/null +++ b/src/backend/catalog/namespace.c @@ -0,0 +1,4614 @@ +/*------------------------------------------------------------------------- + * + * namespace.c + * code to support accessing and searching namespaces + * + * This is separate from pg_namespace.c, which contains the routines that + * directly manipulate the pg_namespace system catalog. This module + * provides routines associated with defining a "namespace search path" + * and implementing search-path-controlled searches. + * + * + * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group + * Portions Copyright (c) 1994, Regents of the University of California + * + * IDENTIFICATION + * src/backend/catalog/namespace.c + * + *------------------------------------------------------------------------- + */ +#include "postgres.h" + +#include "access/htup_details.h" +#include "access/parallel.h" +#include "access/xact.h" +#include "access/xlog.h" +#include "catalog/dependency.h" +#include "catalog/objectaccess.h" +#include "catalog/pg_authid.h" +#include "catalog/pg_collation.h" +#include "catalog/pg_conversion.h" +#include "catalog/pg_namespace.h" +#include "catalog/pg_opclass.h" +#include "catalog/pg_operator.h" +#include "catalog/pg_opfamily.h" +#include "catalog/pg_proc.h" +#include "catalog/pg_statistic_ext.h" +#include "catalog/pg_ts_config.h" +#include "catalog/pg_ts_dict.h" +#include "catalog/pg_ts_parser.h" +#include "catalog/pg_ts_template.h" +#include "catalog/pg_type.h" +#include "commands/dbcommands.h" +#include "funcapi.h" +#include "mb/pg_wchar.h" +#include "miscadmin.h" +#include "nodes/makefuncs.h" +#include "parser/parse_func.h" +#include "storage/ipc.h" +#include "storage/lmgr.h" +#include "storage/sinvaladt.h" +#include "utils/acl.h" +#include "utils/builtins.h" +#include "utils/catcache.h" +#include "utils/guc.h" +#include "utils/inval.h" +#include "utils/lsyscache.h" +#include "utils/memutils.h" +#include "utils/syscache.h" +#include "utils/varlena.h" + + +/* + * The namespace search path is a possibly-empty list of namespace OIDs. + * In addition to the explicit list, implicitly-searched namespaces + * may be included: + * + * 1. If a TEMP table namespace has been initialized in this session, it + * is implicitly searched first. (The only time this doesn't happen is + * when we are obeying an override search path spec that says not to use the + * temp namespace, or the temp namespace is included in the explicit list.) + * + * 2. The system catalog namespace is always searched. If the system + * namespace is present in the explicit path then it will be searched in + * the specified order; otherwise it will be searched after TEMP tables and + * *before* the explicit list. (It might seem that the system namespace + * should be implicitly last, but this behavior appears to be required by + * SQL99. Also, this provides a way to search the system namespace first + * without thereby making it the default creation target namespace.) + * + * For security reasons, searches using the search path will ignore the temp + * namespace when searching for any object type other than relations and + * types. (We must allow types since temp tables have rowtypes.) + * + * The default creation target namespace is always the first element of the + * explicit list. If the explicit list is empty, there is no default target. + * + * The textual specification of search_path can include "$user" to refer to + * the namespace named the same as the current user, if any. (This is just + * ignored if there is no such namespace.) Also, it can include "pg_temp" + * to refer to the current backend's temp namespace. This is usually also + * ignorable if the temp namespace hasn't been set up, but there's a special + * case: if "pg_temp" appears first then it should be the default creation + * target. We kluge this case a little bit so that the temp namespace isn't + * set up until the first attempt to create something in it. (The reason for + * klugery is that we can't create the temp namespace outside a transaction, + * but initial GUC processing of search_path happens outside a transaction.) + * activeTempCreationPending is true if "pg_temp" appears first in the string + * but is not reflected in activeCreationNamespace because the namespace isn't + * set up yet. + * + * In bootstrap mode, the search path is set equal to "pg_catalog", so that + * the system namespace is the only one searched or inserted into. + * initdb is also careful to set search_path to "pg_catalog" for its + * post-bootstrap standalone backend runs. Otherwise the default search + * path is determined by GUC. The factory default path contains the PUBLIC + * namespace (if it exists), preceded by the user's personal namespace + * (if one exists). + * + * We support a stack of "override" search path settings for use within + * specific sections of backend code. namespace_search_path is ignored + * whenever the override stack is nonempty. activeSearchPath is always + * the actually active path; it points either to the search list of the + * topmost stack entry, or to baseSearchPath which is the list derived + * from namespace_search_path. + * + * If baseSearchPathValid is false, then baseSearchPath (and other + * derived variables) need to be recomputed from namespace_search_path. + * We mark it invalid upon an assignment to namespace_search_path or receipt + * of a syscache invalidation event for pg_namespace. The recomputation + * is done during the next non-overridden lookup attempt. Note that an + * override spec is never subject to recomputation. + * + * Any namespaces mentioned in namespace_search_path that are not readable + * by the current user ID are simply left out of baseSearchPath; so + * we have to be willing to recompute the path when current userid changes. + * namespaceUser is the userid the path has been computed for. + * + * Note: all data pointed to by these List variables is in TopMemoryContext. + * + * activePathGeneration is incremented whenever the effective values of + * activeSearchPath/activeCreationNamespace/activeTempCreationPending change. + * This can be used to quickly detect whether any change has happened since + * a previous examination of the search path state. + */ + +/* These variables define the actually active state: */ + +static List *activeSearchPath = NIL; + +/* default place to create stuff; if InvalidOid, no default */ +static Oid activeCreationNamespace = InvalidOid; + +/* if true, activeCreationNamespace is wrong, it should be temp namespace */ +static bool activeTempCreationPending = false; + +/* current generation counter; make sure this is never zero */ +static uint64 activePathGeneration = 1; + +/* These variables are the values last derived from namespace_search_path: */ + +static List *baseSearchPath = NIL; + +static Oid baseCreationNamespace = InvalidOid; + +static bool baseTempCreationPending = false; + +static Oid namespaceUser = InvalidOid; + +/* The above four values are valid only if baseSearchPathValid */ +static bool baseSearchPathValid = true; + +/* Override requests are remembered in a stack of OverrideStackEntry structs */ + +typedef struct +{ + List *searchPath; /* the desired search path */ + Oid creationNamespace; /* the desired creation namespace */ + int nestLevel; /* subtransaction nesting level */ +} OverrideStackEntry; + +static List *overrideStack = NIL; + +/* + * myTempNamespace is InvalidOid until and unless a TEMP namespace is set up + * in a particular backend session (this happens when a CREATE TEMP TABLE + * command is first executed). Thereafter it's the OID of the temp namespace. + * + * myTempToastNamespace is the OID of the namespace for my temp tables' toast + * tables. It is set when myTempNamespace is, and is InvalidOid before that. + * + * myTempNamespaceSubID shows whether we've created the TEMP namespace in the + * current subtransaction. The flag propagates up the subtransaction tree, + * so the main transaction will correctly recognize the flag if all + * intermediate subtransactions commit. When it is InvalidSubTransactionId, + * we either haven't made the TEMP namespace yet, or have successfully + * committed its creation, depending on whether myTempNamespace is valid. + */ +static Oid myTempNamespace = InvalidOid; + +static Oid myTempToastNamespace = InvalidOid; + +static SubTransactionId myTempNamespaceSubID = InvalidSubTransactionId; + +/* + * This is the user's textual search path specification --- it's the value + * of the GUC variable 'search_path'. + */ +char *namespace_search_path = NULL; + + +/* Local functions */ +static void recomputeNamespacePath(void); +static void AccessTempTableNamespace(bool force); +static void InitTempTableNamespace(void); +static void RemoveTempRelations(Oid tempNamespaceId); +static void RemoveTempRelationsCallback(int code, Datum arg); +static void NamespaceCallback(Datum arg, int cacheid, uint32 hashvalue); +static bool MatchNamedCall(HeapTuple proctup, int nargs, List *argnames, + int **argnumbers); + + +/* + * RangeVarGetRelidExtended + * Given a RangeVar describing an existing relation, + * select the proper namespace and look up the relation OID. + * + * If the schema or relation is not found, return InvalidOid if flags contains + * RVR_MISSING_OK, otherwise raise an error. + * + * If flags contains RVR_NOWAIT, throw an error if we'd have to wait for a + * lock. + * + * If flags contains RVR_SKIP_LOCKED, return InvalidOid if we'd have to wait + * for a lock. + * + * flags cannot contain both RVR_NOWAIT and RVR_SKIP_LOCKED. + * + * Note that if RVR_MISSING_OK and RVR_SKIP_LOCKED are both specified, a + * return value of InvalidOid could either mean the relation is missing or it + * could not be locked. + * + * Callback allows caller to check permissions or acquire additional locks + * prior to grabbing the relation lock. + */ +Oid +RangeVarGetRelidExtended(const RangeVar *relation, LOCKMODE lockmode, + uint32 flags, + RangeVarGetRelidCallback callback, void *callback_arg) +{ + uint64 inval_count; + Oid relId; + Oid oldRelId = InvalidOid; + bool retry = false; + bool missing_ok = (flags & RVR_MISSING_OK) != 0; + + /* verify that flags do no conflict */ + Assert(!((flags & RVR_NOWAIT) && (flags & RVR_SKIP_LOCKED))); + + /* + * We check the catalog name and then ignore it. + */ + if (relation->catalogname) + { + if (strcmp(relation->catalogname, get_database_name(MyDatabaseId)) != 0) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("cross-database references are not implemented: \"%s.%s.%s\"", + relation->catalogname, relation->schemaname, + relation->relname))); + } + + /* + * DDL operations can change the results of a name lookup. Since all such + * operations will generate invalidation messages, we keep track of + * whether any such messages show up while we're performing the operation, + * and retry until either (1) no more invalidation messages show up or (2) + * the answer doesn't change. + * + * But if lockmode = NoLock, then we assume that either the caller is OK + * with the answer changing under them, or that they already hold some + * appropriate lock, and therefore return the first answer we get without + * checking for invalidation messages. Also, if the requested lock is + * already held, LockRelationOid will not AcceptInvalidationMessages, so + * we may fail to notice a change. We could protect against that case by + * calling AcceptInvalidationMessages() before beginning this loop, but + * that would add a significant amount overhead, so for now we don't. + */ + for (;;) + { + /* + * Remember this value, so that, after looking up the relation name + * and locking its OID, we can check whether any invalidation messages + * have been processed that might require a do-over. + */ + inval_count = SharedInvalidMessageCounter; + + /* + * Some non-default relpersistence value may have been specified. The + * parser never generates such a RangeVar in simple DML, but it can + * happen in contexts such as "CREATE TEMP TABLE foo (f1 int PRIMARY + * KEY)". Such a command will generate an added CREATE INDEX + * operation, which must be careful to find the temp table, even when + * pg_temp is not first in the search path. + */ + if (relation->relpersistence == RELPERSISTENCE_TEMP) + { + if (!OidIsValid(myTempNamespace)) + relId = InvalidOid; /* this probably can't happen? */ + else + { + if (relation->schemaname) + { + Oid namespaceId; + + namespaceId = LookupExplicitNamespace(relation->schemaname, missing_ok); + + /* + * For missing_ok, allow a non-existent schema name to + * return InvalidOid. + */ + if (namespaceId != myTempNamespace) + ereport(ERROR, + (errcode(ERRCODE_INVALID_TABLE_DEFINITION), + errmsg("temporary tables cannot specify a schema name"))); + } + + relId = get_relname_relid(relation->relname, myTempNamespace); + } + } + else if (relation->schemaname) + { + Oid namespaceId; + + /* use exact schema given */ + namespaceId = LookupExplicitNamespace(relation->schemaname, missing_ok); + if (missing_ok && !OidIsValid(namespaceId)) + relId = InvalidOid; + else + relId = get_relname_relid(relation->relname, namespaceId); + } + else + { + /* search the namespace path */ + relId = RelnameGetRelid(relation->relname); + } + + /* + * Invoke caller-supplied callback, if any. + * + * This callback is a good place to check permissions: we haven't + * taken the table lock yet (and it's really best to check permissions + * before locking anything!), but we've gotten far enough to know what + * OID we think we should lock. Of course, concurrent DDL might + * change things while we're waiting for the lock, but in that case + * the callback will be invoked again for the new OID. + */ + if (callback) + callback(relation, relId, oldRelId, callback_arg); + + /* + * If no lock requested, we assume the caller knows what they're + * doing. They should have already acquired a heavyweight lock on + * this relation earlier in the processing of this same statement, so + * it wouldn't be appropriate to AcceptInvalidationMessages() here, as + * that might pull the rug out from under them. + */ + if (lockmode == NoLock) + break; + + /* + * If, upon retry, we get back the same OID we did last time, then the + * invalidation messages we processed did not change the final answer. + * So we're done. + * + * If we got a different OID, we've locked the relation that used to + * have this name rather than the one that does now. So release the + * lock. + */ + if (retry) + { + if (relId == oldRelId) + break; + if (OidIsValid(oldRelId)) + UnlockRelationOid(oldRelId, lockmode); + } + + /* + * Lock relation. This will also accept any pending invalidation + * messages. If we got back InvalidOid, indicating not found, then + * there's nothing to lock, but we accept invalidation messages + * anyway, to flush any negative catcache entries that may be + * lingering. + */ + if (!OidIsValid(relId)) + AcceptInvalidationMessages(); + else if (!(flags & (RVR_NOWAIT | RVR_SKIP_LOCKED))) + LockRelationOid(relId, lockmode); + else if (!ConditionalLockRelationOid(relId, lockmode)) + { + int elevel = (flags & RVR_SKIP_LOCKED) ? DEBUG1 : ERROR; + + if (relation->schemaname) + ereport(elevel, + (errcode(ERRCODE_LOCK_NOT_AVAILABLE), + errmsg("could not obtain lock on relation \"%s.%s\"", + relation->schemaname, relation->relname))); + else + ereport(elevel, + (errcode(ERRCODE_LOCK_NOT_AVAILABLE), + errmsg("could not obtain lock on relation \"%s\"", + relation->relname))); + + return InvalidOid; + } + + /* + * If no invalidation message were processed, we're done! + */ + if (inval_count == SharedInvalidMessageCounter) + break; + + /* + * Something may have changed. Let's repeat the name lookup, to make + * sure this name still references the same relation it did + * previously. + */ + retry = true; + oldRelId = relId; + } + + if (!OidIsValid(relId)) + { + int elevel = missing_ok ? DEBUG1 : ERROR; + + if (relation->schemaname) + ereport(elevel, + (errcode(ERRCODE_UNDEFINED_TABLE), + errmsg("relation \"%s.%s\" does not exist", + relation->schemaname, relation->relname))); + else + ereport(elevel, + (errcode(ERRCODE_UNDEFINED_TABLE), + errmsg("relation \"%s\" does not exist", + relation->relname))); + } + return relId; +} + +/* + * RangeVarGetCreationNamespace + * Given a RangeVar describing a to-be-created relation, + * choose which namespace to create it in. + * + * Note: calling this may result in a CommandCounterIncrement operation. + * That will happen on the first request for a temp table in any particular + * backend run; we will need to either create or clean out the temp schema. + */ +Oid +RangeVarGetCreationNamespace(const RangeVar *newRelation) +{ + Oid namespaceId; + + /* + * We check the catalog name and then ignore it. + */ + if (newRelation->catalogname) + { + if (strcmp(newRelation->catalogname, get_database_name(MyDatabaseId)) != 0) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("cross-database references are not implemented: \"%s.%s.%s\"", + newRelation->catalogname, newRelation->schemaname, + newRelation->relname))); + } + + if (newRelation->schemaname) + { + /* check for pg_temp alias */ + if (strcmp(newRelation->schemaname, "pg_temp") == 0) + { + /* Initialize temp namespace */ + AccessTempTableNamespace(false); + return myTempNamespace; + } + /* use exact schema given */ + namespaceId = get_namespace_oid(newRelation->schemaname, false); + /* we do not check for USAGE rights here! */ + } + else if (newRelation->relpersistence == RELPERSISTENCE_TEMP) + { + /* Initialize temp namespace */ + AccessTempTableNamespace(false); + return myTempNamespace; + } + else + { + /* use the default creation namespace */ + recomputeNamespacePath(); + if (activeTempCreationPending) + { + /* Need to initialize temp namespace */ + AccessTempTableNamespace(true); + return myTempNamespace; + } + namespaceId = activeCreationNamespace; + if (!OidIsValid(namespaceId)) + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_SCHEMA), + errmsg("no schema has been selected to create in"))); + } + + /* Note: callers will check for CREATE rights when appropriate */ + + return namespaceId; +} + +/* + * RangeVarGetAndCheckCreationNamespace + * + * This function returns the OID of the namespace in which a new relation + * with a given name should be created. If the user does not have CREATE + * permission on the target namespace, this function will instead signal + * an ERROR. + * + * If non-NULL, *existing_relation_id is set to the OID of any existing relation + * with the same name which already exists in that namespace, or to InvalidOid + * if no such relation exists. + * + * If lockmode != NoLock, the specified lock mode is acquired on the existing + * relation, if any, provided that the current user owns the target relation. + * However, if lockmode != NoLock and the user does not own the target + * relation, we throw an ERROR, as we must not try to lock relations the + * user does not have permissions on. + * + * As a side effect, this function acquires AccessShareLock on the target + * namespace. Without this, the namespace could be dropped before our + * transaction commits, leaving behind relations with relnamespace pointing + * to a no-longer-existent namespace. + * + * As a further side-effect, if the selected namespace is a temporary namespace, + * we mark the RangeVar as RELPERSISTENCE_TEMP. + */ +Oid +RangeVarGetAndCheckCreationNamespace(RangeVar *relation, + LOCKMODE lockmode, + Oid *existing_relation_id) +{ + uint64 inval_count; + Oid relid; + Oid oldrelid = InvalidOid; + Oid nspid; + Oid oldnspid = InvalidOid; + bool retry = false; + + /* + * We check the catalog name and then ignore it. + */ + if (relation->catalogname) + { + if (strcmp(relation->catalogname, get_database_name(MyDatabaseId)) != 0) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("cross-database references are not implemented: \"%s.%s.%s\"", + relation->catalogname, relation->schemaname, + relation->relname))); + } + + /* + * As in RangeVarGetRelidExtended(), we guard against concurrent DDL + * operations by tracking whether any invalidation messages are processed + * while we're doing the name lookups and acquiring locks. See comments + * in that function for a more detailed explanation of this logic. + */ + for (;;) + { + AclResult aclresult; + + inval_count = SharedInvalidMessageCounter; + + /* Look up creation namespace and check for existing relation. */ + nspid = RangeVarGetCreationNamespace(relation); + Assert(OidIsValid(nspid)); + if (existing_relation_id != NULL) + relid = get_relname_relid(relation->relname, nspid); + else + relid = InvalidOid; + + /* + * In bootstrap processing mode, we don't bother with permissions or + * locking. Permissions might not be working yet, and locking is + * unnecessary. + */ + if (IsBootstrapProcessingMode()) + break; + + /* Check namespace permissions. */ + aclresult = pg_namespace_aclcheck(nspid, GetUserId(), ACL_CREATE); + if (aclresult != ACLCHECK_OK) + aclcheck_error(aclresult, OBJECT_SCHEMA, + get_namespace_name(nspid)); + + if (retry) + { + /* If nothing changed, we're done. */ + if (relid == oldrelid && nspid == oldnspid) + break; + /* If creation namespace has changed, give up old lock. */ + if (nspid != oldnspid) + UnlockDatabaseObject(NamespaceRelationId, oldnspid, 0, + AccessShareLock); + /* If name points to something different, give up old lock. */ + if (relid != oldrelid && OidIsValid(oldrelid) && lockmode != NoLock) + UnlockRelationOid(oldrelid, lockmode); + } + + /* Lock namespace. */ + if (nspid != oldnspid) + LockDatabaseObject(NamespaceRelationId, nspid, 0, AccessShareLock); + + /* Lock relation, if required if and we have permission. */ + if (lockmode != NoLock && OidIsValid(relid)) + { + if (!pg_class_ownercheck(relid, GetUserId())) + aclcheck_error(ACLCHECK_NOT_OWNER, get_relkind_objtype(get_rel_relkind(relid)), + relation->relname); + if (relid != oldrelid) + LockRelationOid(relid, lockmode); + } + + /* If no invalidation message were processed, we're done! */ + if (inval_count == SharedInvalidMessageCounter) + break; + + /* Something may have changed, so recheck our work. */ + retry = true; + oldrelid = relid; + oldnspid = nspid; + } + + RangeVarAdjustRelationPersistence(relation, nspid); + if (existing_relation_id != NULL) + *existing_relation_id = relid; + return nspid; +} + +/* + * Adjust the relpersistence for an about-to-be-created relation based on the + * creation namespace, and throw an error for invalid combinations. + */ +void +RangeVarAdjustRelationPersistence(RangeVar *newRelation, Oid nspid) +{ + switch (newRelation->relpersistence) + { + case RELPERSISTENCE_TEMP: + if (!isTempOrTempToastNamespace(nspid)) + { + if (isAnyTempNamespace(nspid)) + ereport(ERROR, + (errcode(ERRCODE_INVALID_TABLE_DEFINITION), + errmsg("cannot create relations in temporary schemas of other sessions"))); + else + ereport(ERROR, + (errcode(ERRCODE_INVALID_TABLE_DEFINITION), + errmsg("cannot create temporary relation in non-temporary schema"))); + } + break; + case RELPERSISTENCE_PERMANENT: + if (isTempOrTempToastNamespace(nspid)) + newRelation->relpersistence = RELPERSISTENCE_TEMP; + else if (isAnyTempNamespace(nspid)) + ereport(ERROR, + (errcode(ERRCODE_INVALID_TABLE_DEFINITION), + errmsg("cannot create relations in temporary schemas of other sessions"))); + break; + default: + if (isAnyTempNamespace(nspid)) + ereport(ERROR, + (errcode(ERRCODE_INVALID_TABLE_DEFINITION), + errmsg("only temporary relations may be created in temporary schemas"))); + } +} + +/* + * RelnameGetRelid + * Try to resolve an unqualified relation name. + * Returns OID if relation found in search path, else InvalidOid. + */ +Oid +RelnameGetRelid(const char *relname) +{ + Oid relid; + ListCell *l; + + recomputeNamespacePath(); + + foreach(l, activeSearchPath) + { + Oid namespaceId = lfirst_oid(l); + + relid = get_relname_relid(relname, namespaceId); + if (OidIsValid(relid)) + return relid; + } + + /* Not found in path */ + return InvalidOid; +} + + +/* + * RelationIsVisible + * Determine whether a relation (identified by OID) is visible in the + * current search path. Visible means "would be found by searching + * for the unqualified relation name". + */ +bool +RelationIsVisible(Oid relid) +{ + HeapTuple reltup; + Form_pg_class relform; + Oid relnamespace; + bool visible; + + reltup = SearchSysCache1(RELOID, ObjectIdGetDatum(relid)); + if (!HeapTupleIsValid(reltup)) + elog(ERROR, "cache lookup failed for relation %u", relid); + relform = (Form_pg_class) GETSTRUCT(reltup); + + recomputeNamespacePath(); + + /* + * Quick check: if it ain't in the path at all, it ain't visible. Items in + * the system namespace are surely in the path and so we needn't even do + * list_member_oid() for them. + */ + relnamespace = relform->relnamespace; + if (relnamespace != PG_CATALOG_NAMESPACE && + !list_member_oid(activeSearchPath, relnamespace)) + visible = false; + else + { + /* + * If it is in the path, it might still not be visible; it could be + * hidden by another relation of the same name earlier in the path. So + * we must do a slow check for conflicting relations. + */ + char *relname = NameStr(relform->relname); + ListCell *l; + + visible = false; + foreach(l, activeSearchPath) + { + Oid namespaceId = lfirst_oid(l); + + if (namespaceId == relnamespace) + { + /* Found it first in path */ + visible = true; + break; + } + if (OidIsValid(get_relname_relid(relname, namespaceId))) + { + /* Found something else first in path */ + break; + } + } + } + + ReleaseSysCache(reltup); + + return visible; +} + + +/* + * TypenameGetTypid + * Wrapper for binary compatibility. + */ +Oid +TypenameGetTypid(const char *typname) +{ + return TypenameGetTypidExtended(typname, true); +} + +/* + * TypenameGetTypidExtended + * Try to resolve an unqualified datatype name. + * Returns OID if type found in search path, else InvalidOid. + * + * This is essentially the same as RelnameGetRelid. + */ +Oid +TypenameGetTypidExtended(const char *typname, bool temp_ok) +{ + Oid typid; + ListCell *l; + + recomputeNamespacePath(); + + foreach(l, activeSearchPath) + { + Oid namespaceId = lfirst_oid(l); + + if (!temp_ok && namespaceId == myTempNamespace) + continue; /* do not look in temp namespace */ + + typid = GetSysCacheOid2(TYPENAMENSP, Anum_pg_type_oid, + PointerGetDatum(typname), + ObjectIdGetDatum(namespaceId)); + if (OidIsValid(typid)) + return typid; + } + + /* Not found in path */ + return InvalidOid; +} + +/* + * TypeIsVisible + * Determine whether a type (identified by OID) is visible in the + * current search path. Visible means "would be found by searching + * for the unqualified type name". + */ +bool +TypeIsVisible(Oid typid) +{ + HeapTuple typtup; + Form_pg_type typform; + Oid typnamespace; + bool visible; + + typtup = SearchSysCache1(TYPEOID, ObjectIdGetDatum(typid)); + if (!HeapTupleIsValid(typtup)) + elog(ERROR, "cache lookup failed for type %u", typid); + typform = (Form_pg_type) GETSTRUCT(typtup); + + recomputeNamespacePath(); + + /* + * Quick check: if it ain't in the path at all, it ain't visible. Items in + * the system namespace are surely in the path and so we needn't even do + * list_member_oid() for them. + */ + typnamespace = typform->typnamespace; + if (typnamespace != PG_CATALOG_NAMESPACE && + !list_member_oid(activeSearchPath, typnamespace)) + visible = false; + else + { + /* + * If it is in the path, it might still not be visible; it could be + * hidden by another type of the same name earlier in the path. So we + * must do a slow check for conflicting types. + */ + char *typname = NameStr(typform->typname); + ListCell *l; + + visible = false; + foreach(l, activeSearchPath) + { + Oid namespaceId = lfirst_oid(l); + + if (namespaceId == typnamespace) + { + /* Found it first in path */ + visible = true; + break; + } + if (SearchSysCacheExists2(TYPENAMENSP, + PointerGetDatum(typname), + ObjectIdGetDatum(namespaceId))) + { + /* Found something else first in path */ + break; + } + } + } + + ReleaseSysCache(typtup); + + return visible; +} + + +/* + * FuncnameGetCandidates + * Given a possibly-qualified function name and argument count, + * retrieve a list of the possible matches. + * + * If nargs is -1, we return all functions matching the given name, + * regardless of argument count. (argnames must be NIL, and expand_variadic + * and expand_defaults must be false, in this case.) + * + * If argnames isn't NIL, we are considering a named- or mixed-notation call, + * and only functions having all the listed argument names will be returned. + * (We assume that length(argnames) <= nargs and all the passed-in names are + * distinct.) The returned structs will include an argnumbers array showing + * the actual argument index for each logical argument position. + * + * If expand_variadic is true, then variadic functions having the same number + * or fewer arguments will be retrieved, with the variadic argument and any + * additional argument positions filled with the variadic element type. + * nvargs in the returned struct is set to the number of such arguments. + * If expand_variadic is false, variadic arguments are not treated specially, + * and the returned nvargs will always be zero. + * + * If expand_defaults is true, functions that could match after insertion of + * default argument values will also be retrieved. In this case the returned + * structs could have nargs > passed-in nargs, and ndargs is set to the number + * of additional args (which can be retrieved from the function's + * proargdefaults entry). + * + * It is not possible for nvargs and ndargs to both be nonzero in the same + * list entry, since default insertion allows matches to functions with more + * than nargs arguments while the variadic transformation requires the same + * number or less. + * + * When argnames isn't NIL, the returned args[] type arrays are not ordered + * according to the functions' declarations, but rather according to the call: + * first any positional arguments, then the named arguments, then defaulted + * arguments (if needed and allowed by expand_defaults). The argnumbers[] + * array can be used to map this back to the catalog information. + * argnumbers[k] is set to the proargtypes index of the k'th call argument. + * + * We search a single namespace if the function name is qualified, else + * all namespaces in the search path. In the multiple-namespace case, + * we arrange for entries in earlier namespaces to mask identical entries in + * later namespaces. + * + * When expanding variadics, we arrange for non-variadic functions to mask + * variadic ones if the expanded argument list is the same. It is still + * possible for there to be conflicts between different variadic functions, + * however. + * + * It is guaranteed that the return list will never contain multiple entries + * with identical argument lists. When expand_defaults is true, the entries + * could have more than nargs positions, but we still guarantee that they are + * distinct in the first nargs positions. However, if argnames isn't NIL or + * either expand_variadic or expand_defaults is true, there might be multiple + * candidate functions that expand to identical argument lists. Rather than + * throw error here, we report such situations by returning a single entry + * with oid = 0 that represents a set of such conflicting candidates. + * The caller might end up discarding such an entry anyway, but if it selects + * such an entry it should react as though the call were ambiguous. + * + * If missing_ok is true, an empty list (NULL) is returned if the name was + * schema- qualified with a schema that does not exist. Likewise if no + * candidate is found for other reasons. + */ +FuncCandidateList +FuncnameGetCandidates(List *names, int nargs, List *argnames, + bool expand_variadic, bool expand_defaults, + bool missing_ok) +{ + FuncCandidateList resultList = NULL; + bool any_special = false; + char *schemaname; + char *funcname; + Oid namespaceId; + CatCList *catlist; + int i; + + /* check for caller error */ + Assert(nargs >= 0 || !(expand_variadic | expand_defaults)); + + /* deconstruct the name list */ + DeconstructQualifiedName(names, &schemaname, &funcname); + + if (schemaname) + { + /* use exact schema given */ + namespaceId = LookupExplicitNamespace(schemaname, missing_ok); + if (!OidIsValid(namespaceId)) + return NULL; + } + else + { + /* flag to indicate we need namespace search */ + namespaceId = InvalidOid; + recomputeNamespacePath(); + } + + /* Search syscache by name only */ + catlist = SearchSysCacheList1(PROCNAMEARGSNSP, CStringGetDatum(funcname)); + + for (i = 0; i < catlist->n_members; i++) + { + HeapTuple proctup = &catlist->members[i]->tuple; + Form_pg_proc procform = (Form_pg_proc) GETSTRUCT(proctup); + int pronargs = procform->pronargs; + int effective_nargs; + int pathpos = 0; + bool variadic; + bool use_defaults; + Oid va_elem_type; + int *argnumbers = NULL; + FuncCandidateList newResult; + + if (OidIsValid(namespaceId)) + { + /* Consider only procs in specified namespace */ + if (procform->pronamespace != namespaceId) + continue; + } + else + { + /* + * Consider only procs that are in the search path and are not in + * the temp namespace. + */ + ListCell *nsp; + + foreach(nsp, activeSearchPath) + { + if (procform->pronamespace == lfirst_oid(nsp) && + procform->pronamespace != myTempNamespace) + break; + pathpos++; + } + if (nsp == NULL) + continue; /* proc is not in search path */ + } + + if (argnames != NIL) + { + /* + * Call uses named or mixed notation + * + * Named or mixed notation can match a variadic function only if + * expand_variadic is off; otherwise there is no way to match the + * presumed-nameless parameters expanded from the variadic array. + */ + if (OidIsValid(procform->provariadic) && expand_variadic) + continue; + va_elem_type = InvalidOid; + variadic = false; + + /* + * Check argument count. + */ + Assert(nargs >= 0); /* -1 not supported with argnames */ + + if (pronargs > nargs && expand_defaults) + { + /* Ignore if not enough default expressions */ + if (nargs + procform->pronargdefaults < pronargs) + continue; + use_defaults = true; + } + else + use_defaults = false; + + /* Ignore if it doesn't match requested argument count */ + if (pronargs != nargs && !use_defaults) + continue; + + /* Check for argument name match, generate positional mapping */ + if (!MatchNamedCall(proctup, nargs, argnames, + &argnumbers)) + continue; + + /* Named argument matching is always "special" */ + any_special = true; + } + else + { + /* + * Call uses positional notation + * + * Check if function is variadic, and get variadic element type if + * so. If expand_variadic is false, we should just ignore + * variadic-ness. + */ + if (pronargs <= nargs && expand_variadic) + { + va_elem_type = procform->provariadic; + variadic = OidIsValid(va_elem_type); + any_special |= variadic; + } + else + { + va_elem_type = InvalidOid; + variadic = false; + } + + /* + * Check if function can match by using parameter defaults. + */ + if (pronargs > nargs && expand_defaults) + { + /* Ignore if not enough default expressions */ + if (nargs + procform->pronargdefaults < pronargs) + continue; + use_defaults = true; + any_special = true; + } + else + use_defaults = false; + + /* Ignore if it doesn't match requested argument count */ + if (nargs >= 0 && pronargs != nargs && !variadic && !use_defaults) + continue; + } + + /* + * We must compute the effective argument list so that we can easily + * compare it to earlier results. We waste a palloc cycle if it gets + * masked by an earlier result, but really that's a pretty infrequent + * case so it's not worth worrying about. + */ + effective_nargs = Max(pronargs, nargs); + newResult = (FuncCandidateList) + palloc(offsetof(struct _FuncCandidateList, args) + + effective_nargs * sizeof(Oid)); + newResult->pathpos = pathpos; + newResult->oid = procform->oid; + newResult->nargs = effective_nargs; + newResult->argnumbers = argnumbers; + if (argnumbers) + { + /* Re-order the argument types into call's logical order */ + Oid *proargtypes = procform->proargtypes.values; + int i; + + for (i = 0; i < pronargs; i++) + newResult->args[i] = proargtypes[argnumbers[i]]; + } + else + { + /* Simple positional case, just copy proargtypes as-is */ + memcpy(newResult->args, procform->proargtypes.values, + pronargs * sizeof(Oid)); + } + if (variadic) + { + int i; + + newResult->nvargs = effective_nargs - pronargs + 1; + /* Expand variadic argument into N copies of element type */ + for (i = pronargs - 1; i < effective_nargs; i++) + newResult->args[i] = va_elem_type; + } + else + newResult->nvargs = 0; + newResult->ndargs = use_defaults ? pronargs - nargs : 0; + + /* + * Does it have the same arguments as something we already accepted? + * If so, decide what to do to avoid returning duplicate argument + * lists. We can skip this check for the single-namespace case if no + * special (named, variadic or defaults) match has been made, since + * then the unique index on pg_proc guarantees all the matches have + * different argument lists. + */ + if (resultList != NULL && + (any_special || !OidIsValid(namespaceId))) + { + /* + * If we have an ordered list from SearchSysCacheList (the normal + * case), then any conflicting proc must immediately adjoin this + * one in the list, so we only need to look at the newest result + * item. If we have an unordered list, we have to scan the whole + * result list. Also, if either the current candidate or any + * previous candidate is a special match, we can't assume that + * conflicts are adjacent. + * + * We ignore defaulted arguments in deciding what is a match. + */ + FuncCandidateList prevResult; + + if (catlist->ordered && !any_special) + { + /* ndargs must be 0 if !any_special */ + if (effective_nargs == resultList->nargs && + memcmp(newResult->args, + resultList->args, + effective_nargs * sizeof(Oid)) == 0) + prevResult = resultList; + else + prevResult = NULL; + } + else + { + int cmp_nargs = newResult->nargs - newResult->ndargs; + + for (prevResult = resultList; + prevResult; + prevResult = prevResult->next) + { + if (cmp_nargs == prevResult->nargs - prevResult->ndargs && + memcmp(newResult->args, + prevResult->args, + cmp_nargs * sizeof(Oid)) == 0) + break; + } + } + + if (prevResult) + { + /* + * We have a match with a previous result. Decide which one + * to keep, or mark it ambiguous if we can't decide. The + * logic here is preference > 0 means prefer the old result, + * preference < 0 means prefer the new, preference = 0 means + * ambiguous. + */ + int preference; + + if (pathpos != prevResult->pathpos) + { + /* + * Prefer the one that's earlier in the search path. + */ + preference = pathpos - prevResult->pathpos; + } + else if (variadic && prevResult->nvargs == 0) + { + /* + * With variadic functions we could have, for example, + * both foo(numeric) and foo(variadic numeric[]) in the + * same namespace; if so we prefer the non-variadic match + * on efficiency grounds. + */ + preference = 1; + } + else if (!variadic && prevResult->nvargs > 0) + { + preference = -1; + } + else + { + /*---------- + * We can't decide. This can happen with, for example, + * both foo(numeric, variadic numeric[]) and + * foo(variadic numeric[]) in the same namespace, or + * both foo(int) and foo (int, int default something) + * in the same namespace, or both foo(a int, b text) + * and foo(b text, a int) in the same namespace. + *---------- + */ + preference = 0; + } + + if (preference > 0) + { + /* keep previous result */ + pfree(newResult); + continue; + } + else if (preference < 0) + { + /* remove previous result from the list */ + if (prevResult == resultList) + resultList = prevResult->next; + else + { + FuncCandidateList prevPrevResult; + + for (prevPrevResult = resultList; + prevPrevResult; + prevPrevResult = prevPrevResult->next) + { + if (prevResult == prevPrevResult->next) + { + prevPrevResult->next = prevResult->next; + break; + } + } + Assert(prevPrevResult); /* assert we found it */ + } + pfree(prevResult); + /* fall through to add newResult to list */ + } + else + { + /* mark old result as ambiguous, discard new */ + prevResult->oid = InvalidOid; + pfree(newResult); + continue; + } + } + } + + /* + * Okay to add it to result list + */ + newResult->next = resultList; + resultList = newResult; + } + + ReleaseSysCacheList(catlist); + + return resultList; +} + +/* + * MatchNamedCall + * Given a pg_proc heap tuple and a call's list of argument names, + * check whether the function could match the call. + * + * The call could match if all supplied argument names are accepted by + * the function, in positions after the last positional argument, and there + * are defaults for all unsupplied arguments. + * + * The number of positional arguments is nargs - list_length(argnames). + * Note caller has already done basic checks on argument count. + * + * On match, return true and fill *argnumbers with a palloc'd array showing + * the mapping from call argument positions to actual function argument + * numbers. Defaulted arguments are included in this map, at positions + * after the last supplied argument. + */ +static bool +MatchNamedCall(HeapTuple proctup, int nargs, List *argnames, + int **argnumbers) +{ + Form_pg_proc procform = (Form_pg_proc) GETSTRUCT(proctup); + int pronargs = procform->pronargs; + int numposargs = nargs - list_length(argnames); + int pronallargs; + Oid *p_argtypes; + char **p_argnames; + char *p_argmodes; + bool arggiven[FUNC_MAX_ARGS]; + bool isnull; + int ap; /* call args position */ + int pp; /* proargs position */ + ListCell *lc; + + Assert(argnames != NIL); + Assert(numposargs >= 0); + Assert(nargs <= pronargs); + + /* Ignore this function if its proargnames is null */ + (void) SysCacheGetAttr(PROCOID, proctup, Anum_pg_proc_proargnames, + &isnull); + if (isnull) + return false; + + /* OK, let's extract the argument names and types */ + pronallargs = get_func_arg_info(proctup, + &p_argtypes, &p_argnames, &p_argmodes); + Assert(p_argnames != NULL); + + /* initialize state for matching */ + *argnumbers = (int *) palloc(pronargs * sizeof(int)); + memset(arggiven, false, pronargs * sizeof(bool)); + + /* there are numposargs positional args before the named args */ + for (ap = 0; ap < numposargs; ap++) + { + (*argnumbers)[ap] = ap; + arggiven[ap] = true; + } + + /* now examine the named args */ + foreach(lc, argnames) + { + char *argname = (char *) lfirst(lc); + bool found; + int i; + + pp = 0; + found = false; + for (i = 0; i < pronallargs; i++) + { + /* consider only input parameters */ + if (p_argmodes && + (p_argmodes[i] != FUNC_PARAM_IN && + p_argmodes[i] != FUNC_PARAM_INOUT && + p_argmodes[i] != FUNC_PARAM_VARIADIC)) + continue; + if (p_argnames[i] && strcmp(p_argnames[i], argname) == 0) + { + /* fail if argname matches a positional argument */ + if (arggiven[pp]) + return false; + arggiven[pp] = true; + (*argnumbers)[ap] = pp; + found = true; + break; + } + /* increase pp only for input parameters */ + pp++; + } + /* if name isn't in proargnames, fail */ + if (!found) + return false; + ap++; + } + + Assert(ap == nargs); /* processed all actual parameters */ + + /* Check for default arguments */ + if (nargs < pronargs) + { + int first_arg_with_default = pronargs - procform->pronargdefaults; + + for (pp = numposargs; pp < pronargs; pp++) + { + if (arggiven[pp]) + continue; + /* fail if arg not given and no default available */ + if (pp < first_arg_with_default) + return false; + (*argnumbers)[ap++] = pp; + } + } + + Assert(ap == pronargs); /* processed all function parameters */ + + return true; +} + +/* + * FunctionIsVisible + * Determine whether a function (identified by OID) is visible in the + * current search path. Visible means "would be found by searching + * for the unqualified function name with exact argument matches". + */ +bool +FunctionIsVisible(Oid funcid) +{ + HeapTuple proctup; + Form_pg_proc procform; + Oid pronamespace; + bool visible; + + proctup = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcid)); + if (!HeapTupleIsValid(proctup)) + elog(ERROR, "cache lookup failed for function %u", funcid); + procform = (Form_pg_proc) GETSTRUCT(proctup); + + recomputeNamespacePath(); + + /* + * Quick check: if it ain't in the path at all, it ain't visible. Items in + * the system namespace are surely in the path and so we needn't even do + * list_member_oid() for them. + */ + pronamespace = procform->pronamespace; + if (pronamespace != PG_CATALOG_NAMESPACE && + !list_member_oid(activeSearchPath, pronamespace)) + visible = false; + else + { + /* + * If it is in the path, it might still not be visible; it could be + * hidden by another proc of the same name and arguments earlier in + * the path. So we must do a slow check to see if this is the same + * proc that would be found by FuncnameGetCandidates. + */ + char *proname = NameStr(procform->proname); + int nargs = procform->pronargs; + FuncCandidateList clist; + + visible = false; + + clist = FuncnameGetCandidates(list_make1(makeString(proname)), + nargs, NIL, false, false, false); + + for (; clist; clist = clist->next) + { + if (memcmp(clist->args, procform->proargtypes.values, + nargs * sizeof(Oid)) == 0) + { + /* Found the expected entry; is it the right proc? */ + visible = (clist->oid == funcid); + break; + } + } + } + + ReleaseSysCache(proctup); + + return visible; +} + + +/* + * OpernameGetOprid + * Given a possibly-qualified operator name and exact input datatypes, + * look up the operator. Returns InvalidOid if not found. + * + * Pass oprleft = InvalidOid for a prefix op, oprright = InvalidOid for + * a postfix op. + * + * If the operator name is not schema-qualified, it is sought in the current + * namespace search path. If the name is schema-qualified and the given + * schema does not exist, InvalidOid is returned. + */ +Oid +OpernameGetOprid(List *names, Oid oprleft, Oid oprright) +{ + char *schemaname; + char *opername; + CatCList *catlist; + ListCell *l; + + /* deconstruct the name list */ + DeconstructQualifiedName(names, &schemaname, &opername); + + if (schemaname) + { + /* search only in exact schema given */ + Oid namespaceId; + + namespaceId = LookupExplicitNamespace(schemaname, true); + if (OidIsValid(namespaceId)) + { + HeapTuple opertup; + + opertup = SearchSysCache4(OPERNAMENSP, + CStringGetDatum(opername), + ObjectIdGetDatum(oprleft), + ObjectIdGetDatum(oprright), + ObjectIdGetDatum(namespaceId)); + if (HeapTupleIsValid(opertup)) + { + Form_pg_operator operclass = (Form_pg_operator) GETSTRUCT(opertup); + Oid result = operclass->oid; + + ReleaseSysCache(opertup); + return result; + } + } + + return InvalidOid; + } + + /* Search syscache by name and argument types */ + catlist = SearchSysCacheList3(OPERNAMENSP, + CStringGetDatum(opername), + ObjectIdGetDatum(oprleft), + ObjectIdGetDatum(oprright)); + + if (catlist->n_members == 0) + { + /* no hope, fall out early */ + ReleaseSysCacheList(catlist); + return InvalidOid; + } + + /* + * We have to find the list member that is first in the search path, if + * there's more than one. This doubly-nested loop looks ugly, but in + * practice there should usually be few catlist members. + */ + recomputeNamespacePath(); + + foreach(l, activeSearchPath) + { + Oid namespaceId = lfirst_oid(l); + int i; + + if (namespaceId == myTempNamespace) + continue; /* do not look in temp namespace */ + + for (i = 0; i < catlist->n_members; i++) + { + HeapTuple opertup = &catlist->members[i]->tuple; + Form_pg_operator operform = (Form_pg_operator) GETSTRUCT(opertup); + + if (operform->oprnamespace == namespaceId) + { + Oid result = operform->oid; + + ReleaseSysCacheList(catlist); + return result; + } + } + } + + ReleaseSysCacheList(catlist); + return InvalidOid; +} + +/* + * OpernameGetCandidates + * Given a possibly-qualified operator name and operator kind, + * retrieve a list of the possible matches. + * + * If oprkind is '\0', we return all operators matching the given name, + * regardless of arguments. + * + * We search a single namespace if the operator name is qualified, else + * all namespaces in the search path. The return list will never contain + * multiple entries with identical argument lists --- in the multiple- + * namespace case, we arrange for entries in earlier namespaces to mask + * identical entries in later namespaces. + * + * The returned items always have two args[] entries --- one or the other + * will be InvalidOid for a prefix or postfix oprkind. nargs is 2, too. + */ +FuncCandidateList +OpernameGetCandidates(List *names, char oprkind, bool missing_schema_ok) +{ + FuncCandidateList resultList = NULL; + char *resultSpace = NULL; + int nextResult = 0; + char *schemaname; + char *opername; + Oid namespaceId; + CatCList *catlist; + int i; + + /* deconstruct the name list */ + DeconstructQualifiedName(names, &schemaname, &opername); + + if (schemaname) + { + /* use exact schema given */ + namespaceId = LookupExplicitNamespace(schemaname, missing_schema_ok); + if (missing_schema_ok && !OidIsValid(namespaceId)) + return NULL; + } + else + { + /* flag to indicate we need namespace search */ + namespaceId = InvalidOid; + recomputeNamespacePath(); + } + + /* Search syscache by name only */ + catlist = SearchSysCacheList1(OPERNAMENSP, CStringGetDatum(opername)); + + /* + * In typical scenarios, most if not all of the operators found by the + * catcache search will end up getting returned; and there can be quite a + * few, for common operator names such as '=' or '+'. To reduce the time + * spent in palloc, we allocate the result space as an array large enough + * to hold all the operators. The original coding of this routine did a + * separate palloc for each operator, but profiling revealed that the + * pallocs used an unreasonably large fraction of parsing time. + */ +#define SPACE_PER_OP MAXALIGN(offsetof(struct _FuncCandidateList, args) + \ + 2 * sizeof(Oid)) + + if (catlist->n_members > 0) + resultSpace = palloc(catlist->n_members * SPACE_PER_OP); + + for (i = 0; i < catlist->n_members; i++) + { + HeapTuple opertup = &catlist->members[i]->tuple; + Form_pg_operator operform = (Form_pg_operator) GETSTRUCT(opertup); + int pathpos = 0; + FuncCandidateList newResult; + + /* Ignore operators of wrong kind, if specific kind requested */ + if (oprkind && operform->oprkind != oprkind) + continue; + + if (OidIsValid(namespaceId)) + { + /* Consider only opers in specified namespace */ + if (operform->oprnamespace != namespaceId) + continue; + /* No need to check args, they must all be different */ + } + else + { + /* + * Consider only opers that are in the search path and are not in + * the temp namespace. + */ + ListCell *nsp; + + foreach(nsp, activeSearchPath) + { + if (operform->oprnamespace == lfirst_oid(nsp) && + operform->oprnamespace != myTempNamespace) + break; + pathpos++; + } + if (nsp == NULL) + continue; /* oper is not in search path */ + + /* + * Okay, it's in the search path, but does it have the same + * arguments as something we already accepted? If so, keep only + * the one that appears earlier in the search path. + * + * If we have an ordered list from SearchSysCacheList (the normal + * case), then any conflicting oper must immediately adjoin this + * one in the list, so we only need to look at the newest result + * item. If we have an unordered list, we have to scan the whole + * result list. + */ + if (resultList) + { + FuncCandidateList prevResult; + + if (catlist->ordered) + { + if (operform->oprleft == resultList->args[0] && + operform->oprright == resultList->args[1]) + prevResult = resultList; + else + prevResult = NULL; + } + else + { + for (prevResult = resultList; + prevResult; + prevResult = prevResult->next) + { + if (operform->oprleft == prevResult->args[0] && + operform->oprright == prevResult->args[1]) + break; + } + } + if (prevResult) + { + /* We have a match with a previous result */ + Assert(pathpos != prevResult->pathpos); + if (pathpos > prevResult->pathpos) + continue; /* keep previous result */ + /* replace previous result */ + prevResult->pathpos = pathpos; + prevResult->oid = operform->oid; + continue; /* args are same, of course */ + } + } + } + + /* + * Okay to add it to result list + */ + newResult = (FuncCandidateList) (resultSpace + nextResult); + nextResult += SPACE_PER_OP; + + newResult->pathpos = pathpos; + newResult->oid = operform->oid; + newResult->nargs = 2; + newResult->nvargs = 0; + newResult->ndargs = 0; + newResult->argnumbers = NULL; + newResult->args[0] = operform->oprleft; + newResult->args[1] = operform->oprright; + newResult->next = resultList; + resultList = newResult; + } + + ReleaseSysCacheList(catlist); + + return resultList; +} + +/* + * OperatorIsVisible + * Determine whether an operator (identified by OID) is visible in the + * current search path. Visible means "would be found by searching + * for the unqualified operator name with exact argument matches". + */ +bool +OperatorIsVisible(Oid oprid) +{ + HeapTuple oprtup; + Form_pg_operator oprform; + Oid oprnamespace; + bool visible; + + oprtup = SearchSysCache1(OPEROID, ObjectIdGetDatum(oprid)); + if (!HeapTupleIsValid(oprtup)) + elog(ERROR, "cache lookup failed for operator %u", oprid); + oprform = (Form_pg_operator) GETSTRUCT(oprtup); + + recomputeNamespacePath(); + + /* + * Quick check: if it ain't in the path at all, it ain't visible. Items in + * the system namespace are surely in the path and so we needn't even do + * list_member_oid() for them. + */ + oprnamespace = oprform->oprnamespace; + if (oprnamespace != PG_CATALOG_NAMESPACE && + !list_member_oid(activeSearchPath, oprnamespace)) + visible = false; + else + { + /* + * If it is in the path, it might still not be visible; it could be + * hidden by another operator of the same name and arguments earlier + * in the path. So we must do a slow check to see if this is the same + * operator that would be found by OpernameGetOprid. + */ + char *oprname = NameStr(oprform->oprname); + + visible = (OpernameGetOprid(list_make1(makeString(oprname)), + oprform->oprleft, oprform->oprright) + == oprid); + } + + ReleaseSysCache(oprtup); + + return visible; +} + + +/* + * OpclassnameGetOpcid + * Try to resolve an unqualified index opclass name. + * Returns OID if opclass found in search path, else InvalidOid. + * + * This is essentially the same as TypenameGetTypid, but we have to have + * an extra argument for the index AM OID. + */ +Oid +OpclassnameGetOpcid(Oid amid, const char *opcname) +{ + Oid opcid; + ListCell *l; + + recomputeNamespacePath(); + + foreach(l, activeSearchPath) + { + Oid namespaceId = lfirst_oid(l); + + if (namespaceId == myTempNamespace) + continue; /* do not look in temp namespace */ + + opcid = GetSysCacheOid3(CLAAMNAMENSP, Anum_pg_opclass_oid, + ObjectIdGetDatum(amid), + PointerGetDatum(opcname), + ObjectIdGetDatum(namespaceId)); + if (OidIsValid(opcid)) + return opcid; + } + + /* Not found in path */ + return InvalidOid; +} + +/* + * OpclassIsVisible + * Determine whether an opclass (identified by OID) is visible in the + * current search path. Visible means "would be found by searching + * for the unqualified opclass name". + */ +bool +OpclassIsVisible(Oid opcid) +{ + HeapTuple opctup; + Form_pg_opclass opcform; + Oid opcnamespace; + bool visible; + + opctup = SearchSysCache1(CLAOID, ObjectIdGetDatum(opcid)); + if (!HeapTupleIsValid(opctup)) + elog(ERROR, "cache lookup failed for opclass %u", opcid); + opcform = (Form_pg_opclass) GETSTRUCT(opctup); + + recomputeNamespacePath(); + + /* + * Quick check: if it ain't in the path at all, it ain't visible. Items in + * the system namespace are surely in the path and so we needn't even do + * list_member_oid() for them. + */ + opcnamespace = opcform->opcnamespace; + if (opcnamespace != PG_CATALOG_NAMESPACE && + !list_member_oid(activeSearchPath, opcnamespace)) + visible = false; + else + { + /* + * If it is in the path, it might still not be visible; it could be + * hidden by another opclass of the same name earlier in the path. So + * we must do a slow check to see if this opclass would be found by + * OpclassnameGetOpcid. + */ + char *opcname = NameStr(opcform->opcname); + + visible = (OpclassnameGetOpcid(opcform->opcmethod, opcname) == opcid); + } + + ReleaseSysCache(opctup); + + return visible; +} + +/* + * OpfamilynameGetOpfid + * Try to resolve an unqualified index opfamily name. + * Returns OID if opfamily found in search path, else InvalidOid. + * + * This is essentially the same as TypenameGetTypid, but we have to have + * an extra argument for the index AM OID. + */ +Oid +OpfamilynameGetOpfid(Oid amid, const char *opfname) +{ + Oid opfid; + ListCell *l; + + recomputeNamespacePath(); + + foreach(l, activeSearchPath) + { + Oid namespaceId = lfirst_oid(l); + + if (namespaceId == myTempNamespace) + continue; /* do not look in temp namespace */ + + opfid = GetSysCacheOid3(OPFAMILYAMNAMENSP, Anum_pg_opfamily_oid, + ObjectIdGetDatum(amid), + PointerGetDatum(opfname), + ObjectIdGetDatum(namespaceId)); + if (OidIsValid(opfid)) + return opfid; + } + + /* Not found in path */ + return InvalidOid; +} + +/* + * OpfamilyIsVisible + * Determine whether an opfamily (identified by OID) is visible in the + * current search path. Visible means "would be found by searching + * for the unqualified opfamily name". + */ +bool +OpfamilyIsVisible(Oid opfid) +{ + HeapTuple opftup; + Form_pg_opfamily opfform; + Oid opfnamespace; + bool visible; + + opftup = SearchSysCache1(OPFAMILYOID, ObjectIdGetDatum(opfid)); + if (!HeapTupleIsValid(opftup)) + elog(ERROR, "cache lookup failed for opfamily %u", opfid); + opfform = (Form_pg_opfamily) GETSTRUCT(opftup); + + recomputeNamespacePath(); + + /* + * Quick check: if it ain't in the path at all, it ain't visible. Items in + * the system namespace are surely in the path and so we needn't even do + * list_member_oid() for them. + */ + opfnamespace = opfform->opfnamespace; + if (opfnamespace != PG_CATALOG_NAMESPACE && + !list_member_oid(activeSearchPath, opfnamespace)) + visible = false; + else + { + /* + * If it is in the path, it might still not be visible; it could be + * hidden by another opfamily of the same name earlier in the path. So + * we must do a slow check to see if this opfamily would be found by + * OpfamilynameGetOpfid. + */ + char *opfname = NameStr(opfform->opfname); + + visible = (OpfamilynameGetOpfid(opfform->opfmethod, opfname) == opfid); + } + + ReleaseSysCache(opftup); + + return visible; +} + +/* + * lookup_collation + * If there's a collation of the given name/namespace, and it works + * with the given encoding, return its OID. Else return InvalidOid. + */ +static Oid +lookup_collation(const char *collname, Oid collnamespace, int32 encoding) +{ + Oid collid; + HeapTuple colltup; + Form_pg_collation collform; + + /* Check for encoding-specific entry (exact match) */ + collid = GetSysCacheOid3(COLLNAMEENCNSP, Anum_pg_collation_oid, + PointerGetDatum(collname), + Int32GetDatum(encoding), + ObjectIdGetDatum(collnamespace)); + if (OidIsValid(collid)) + return collid; + + /* + * Check for any-encoding entry. This takes a bit more work: while libc + * collations with collencoding = -1 do work with all encodings, ICU + * collations only work with certain encodings, so we have to check that + * aspect before deciding it's a match. + */ + colltup = SearchSysCache3(COLLNAMEENCNSP, + PointerGetDatum(collname), + Int32GetDatum(-1), + ObjectIdGetDatum(collnamespace)); + if (!HeapTupleIsValid(colltup)) + return InvalidOid; + collform = (Form_pg_collation) GETSTRUCT(colltup); + if (collform->collprovider == COLLPROVIDER_ICU) + { + if (is_encoding_supported_by_icu(encoding)) + collid = collform->oid; + else + collid = InvalidOid; + } + else + { + collid = collform->oid; + } + ReleaseSysCache(colltup); + return collid; +} + +/* + * CollationGetCollid + * Try to resolve an unqualified collation name. + * Returns OID if collation found in search path, else InvalidOid. + * + * Note that this will only find collations that work with the current + * database's encoding. + */ +Oid +CollationGetCollid(const char *collname) +{ + int32 dbencoding = GetDatabaseEncoding(); + ListCell *l; + + recomputeNamespacePath(); + + foreach(l, activeSearchPath) + { + Oid namespaceId = lfirst_oid(l); + Oid collid; + + if (namespaceId == myTempNamespace) + continue; /* do not look in temp namespace */ + + collid = lookup_collation(collname, namespaceId, dbencoding); + if (OidIsValid(collid)) + return collid; + } + + /* Not found in path */ + return InvalidOid; +} + +/* + * CollationIsVisible + * Determine whether a collation (identified by OID) is visible in the + * current search path. Visible means "would be found by searching + * for the unqualified collation name". + * + * Note that only collations that work with the current database's encoding + * will be considered visible. + */ +bool +CollationIsVisible(Oid collid) +{ + HeapTuple colltup; + Form_pg_collation collform; + Oid collnamespace; + bool visible; + + colltup = SearchSysCache1(COLLOID, ObjectIdGetDatum(collid)); + if (!HeapTupleIsValid(colltup)) + elog(ERROR, "cache lookup failed for collation %u", collid); + collform = (Form_pg_collation) GETSTRUCT(colltup); + + recomputeNamespacePath(); + + /* + * Quick check: if it ain't in the path at all, it ain't visible. Items in + * the system namespace are surely in the path and so we needn't even do + * list_member_oid() for them. + */ + collnamespace = collform->collnamespace; + if (collnamespace != PG_CATALOG_NAMESPACE && + !list_member_oid(activeSearchPath, collnamespace)) + visible = false; + else + { + /* + * If it is in the path, it might still not be visible; it could be + * hidden by another collation of the same name earlier in the path, + * or it might not work with the current DB encoding. So we must do a + * slow check to see if this collation would be found by + * CollationGetCollid. + */ + char *collname = NameStr(collform->collname); + + visible = (CollationGetCollid(collname) == collid); + } + + ReleaseSysCache(colltup); + + return visible; +} + + +/* + * ConversionGetConid + * Try to resolve an unqualified conversion name. + * Returns OID if conversion found in search path, else InvalidOid. + * + * This is essentially the same as RelnameGetRelid. + */ +Oid +ConversionGetConid(const char *conname) +{ + Oid conid; + ListCell *l; + + recomputeNamespacePath(); + + foreach(l, activeSearchPath) + { + Oid namespaceId = lfirst_oid(l); + + if (namespaceId == myTempNamespace) + continue; /* do not look in temp namespace */ + + conid = GetSysCacheOid2(CONNAMENSP, Anum_pg_conversion_oid, + PointerGetDatum(conname), + ObjectIdGetDatum(namespaceId)); + if (OidIsValid(conid)) + return conid; + } + + /* Not found in path */ + return InvalidOid; +} + +/* + * ConversionIsVisible + * Determine whether a conversion (identified by OID) is visible in the + * current search path. Visible means "would be found by searching + * for the unqualified conversion name". + */ +bool +ConversionIsVisible(Oid conid) +{ + HeapTuple contup; + Form_pg_conversion conform; + Oid connamespace; + bool visible; + + contup = SearchSysCache1(CONVOID, ObjectIdGetDatum(conid)); + if (!HeapTupleIsValid(contup)) + elog(ERROR, "cache lookup failed for conversion %u", conid); + conform = (Form_pg_conversion) GETSTRUCT(contup); + + recomputeNamespacePath(); + + /* + * Quick check: if it ain't in the path at all, it ain't visible. Items in + * the system namespace are surely in the path and so we needn't even do + * list_member_oid() for them. + */ + connamespace = conform->connamespace; + if (connamespace != PG_CATALOG_NAMESPACE && + !list_member_oid(activeSearchPath, connamespace)) + visible = false; + else + { + /* + * If it is in the path, it might still not be visible; it could be + * hidden by another conversion of the same name earlier in the path. + * So we must do a slow check to see if this conversion would be found + * by ConversionGetConid. + */ + char *conname = NameStr(conform->conname); + + visible = (ConversionGetConid(conname) == conid); + } + + ReleaseSysCache(contup); + + return visible; +} + +/* + * get_statistics_object_oid - find a statistics object by possibly qualified name + * + * If not found, returns InvalidOid if missing_ok, else throws error + */ +Oid +get_statistics_object_oid(List *names, bool missing_ok) +{ + char *schemaname; + char *stats_name; + Oid namespaceId; + Oid stats_oid = InvalidOid; + ListCell *l; + + /* deconstruct the name list */ + DeconstructQualifiedName(names, &schemaname, &stats_name); + + if (schemaname) + { + /* use exact schema given */ + namespaceId = LookupExplicitNamespace(schemaname, missing_ok); + if (missing_ok && !OidIsValid(namespaceId)) + stats_oid = InvalidOid; + else + stats_oid = GetSysCacheOid2(STATEXTNAMENSP, Anum_pg_statistic_ext_oid, + PointerGetDatum(stats_name), + ObjectIdGetDatum(namespaceId)); + } + else + { + /* search for it in search path */ + recomputeNamespacePath(); + + foreach(l, activeSearchPath) + { + namespaceId = lfirst_oid(l); + + if (namespaceId == myTempNamespace) + continue; /* do not look in temp namespace */ + stats_oid = GetSysCacheOid2(STATEXTNAMENSP, Anum_pg_statistic_ext_oid, + PointerGetDatum(stats_name), + ObjectIdGetDatum(namespaceId)); + if (OidIsValid(stats_oid)) + break; + } + } + + if (!OidIsValid(stats_oid) && !missing_ok) + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_OBJECT), + errmsg("statistics object \"%s\" does not exist", + NameListToString(names)))); + + return stats_oid; +} + +/* + * StatisticsObjIsVisible + * Determine whether a statistics object (identified by OID) is visible in + * the current search path. Visible means "would be found by searching + * for the unqualified statistics object name". + */ +bool +StatisticsObjIsVisible(Oid relid) +{ + HeapTuple stxtup; + Form_pg_statistic_ext stxform; + Oid stxnamespace; + bool visible; + + stxtup = SearchSysCache1(STATEXTOID, ObjectIdGetDatum(relid)); + if (!HeapTupleIsValid(stxtup)) + elog(ERROR, "cache lookup failed for statistics object %u", relid); + stxform = (Form_pg_statistic_ext) GETSTRUCT(stxtup); + + recomputeNamespacePath(); + + /* + * Quick check: if it ain't in the path at all, it ain't visible. Items in + * the system namespace are surely in the path and so we needn't even do + * list_member_oid() for them. + */ + stxnamespace = stxform->stxnamespace; + if (stxnamespace != PG_CATALOG_NAMESPACE && + !list_member_oid(activeSearchPath, stxnamespace)) + visible = false; + else + { + /* + * If it is in the path, it might still not be visible; it could be + * hidden by another statistics object of the same name earlier in the + * path. So we must do a slow check for conflicting objects. + */ + char *stxname = NameStr(stxform->stxname); + ListCell *l; + + visible = false; + foreach(l, activeSearchPath) + { + Oid namespaceId = lfirst_oid(l); + + if (namespaceId == stxnamespace) + { + /* Found it first in path */ + visible = true; + break; + } + if (SearchSysCacheExists2(STATEXTNAMENSP, + PointerGetDatum(stxname), + ObjectIdGetDatum(namespaceId))) + { + /* Found something else first in path */ + break; + } + } + } + + ReleaseSysCache(stxtup); + + return visible; +} + +/* + * get_ts_parser_oid - find a TS parser by possibly qualified name + * + * If not found, returns InvalidOid if missing_ok, else throws error + */ +Oid +get_ts_parser_oid(List *names, bool missing_ok) +{ + char *schemaname; + char *parser_name; + Oid namespaceId; + Oid prsoid = InvalidOid; + ListCell *l; + + /* deconstruct the name list */ + DeconstructQualifiedName(names, &schemaname, &parser_name); + + if (schemaname) + { + /* use exact schema given */ + namespaceId = LookupExplicitNamespace(schemaname, missing_ok); + if (missing_ok && !OidIsValid(namespaceId)) + prsoid = InvalidOid; + else + prsoid = GetSysCacheOid2(TSPARSERNAMENSP, Anum_pg_ts_parser_oid, + PointerGetDatum(parser_name), + ObjectIdGetDatum(namespaceId)); + } + else + { + /* search for it in search path */ + recomputeNamespacePath(); + + foreach(l, activeSearchPath) + { + namespaceId = lfirst_oid(l); + + if (namespaceId == myTempNamespace) + continue; /* do not look in temp namespace */ + + prsoid = GetSysCacheOid2(TSPARSERNAMENSP, Anum_pg_ts_parser_oid, + PointerGetDatum(parser_name), + ObjectIdGetDatum(namespaceId)); + if (OidIsValid(prsoid)) + break; + } + } + + if (!OidIsValid(prsoid) && !missing_ok) + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_OBJECT), + errmsg("text search parser \"%s\" does not exist", + NameListToString(names)))); + + return prsoid; +} + +/* + * TSParserIsVisible + * Determine whether a parser (identified by OID) is visible in the + * current search path. Visible means "would be found by searching + * for the unqualified parser name". + */ +bool +TSParserIsVisible(Oid prsId) +{ + HeapTuple tup; + Form_pg_ts_parser form; + Oid namespace; + bool visible; + + tup = SearchSysCache1(TSPARSEROID, ObjectIdGetDatum(prsId)); + if (!HeapTupleIsValid(tup)) + elog(ERROR, "cache lookup failed for text search parser %u", prsId); + form = (Form_pg_ts_parser) GETSTRUCT(tup); + + recomputeNamespacePath(); + + /* + * Quick check: if it ain't in the path at all, it ain't visible. Items in + * the system namespace are surely in the path and so we needn't even do + * list_member_oid() for them. + */ + namespace = form->prsnamespace; + if (namespace != PG_CATALOG_NAMESPACE && + !list_member_oid(activeSearchPath, namespace)) + visible = false; + else + { + /* + * If it is in the path, it might still not be visible; it could be + * hidden by another parser of the same name earlier in the path. So + * we must do a slow check for conflicting parsers. + */ + char *name = NameStr(form->prsname); + ListCell *l; + + visible = false; + foreach(l, activeSearchPath) + { + Oid namespaceId = lfirst_oid(l); + + if (namespaceId == myTempNamespace) + continue; /* do not look in temp namespace */ + + if (namespaceId == namespace) + { + /* Found it first in path */ + visible = true; + break; + } + if (SearchSysCacheExists2(TSPARSERNAMENSP, + PointerGetDatum(name), + ObjectIdGetDatum(namespaceId))) + { + /* Found something else first in path */ + break; + } + } + } + + ReleaseSysCache(tup); + + return visible; +} + +/* + * get_ts_dict_oid - find a TS dictionary by possibly qualified name + * + * If not found, returns InvalidOid if missing_ok, else throws error + */ +Oid +get_ts_dict_oid(List *names, bool missing_ok) +{ + char *schemaname; + char *dict_name; + Oid namespaceId; + Oid dictoid = InvalidOid; + ListCell *l; + + /* deconstruct the name list */ + DeconstructQualifiedName(names, &schemaname, &dict_name); + + if (schemaname) + { + /* use exact schema given */ + namespaceId = LookupExplicitNamespace(schemaname, missing_ok); + if (missing_ok && !OidIsValid(namespaceId)) + dictoid = InvalidOid; + else + dictoid = GetSysCacheOid2(TSDICTNAMENSP, Anum_pg_ts_dict_oid, + PointerGetDatum(dict_name), + ObjectIdGetDatum(namespaceId)); + } + else + { + /* search for it in search path */ + recomputeNamespacePath(); + + foreach(l, activeSearchPath) + { + namespaceId = lfirst_oid(l); + + if (namespaceId == myTempNamespace) + continue; /* do not look in temp namespace */ + + dictoid = GetSysCacheOid2(TSDICTNAMENSP, Anum_pg_ts_dict_oid, + PointerGetDatum(dict_name), + ObjectIdGetDatum(namespaceId)); + if (OidIsValid(dictoid)) + break; + } + } + + if (!OidIsValid(dictoid) && !missing_ok) + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_OBJECT), + errmsg("text search dictionary \"%s\" does not exist", + NameListToString(names)))); + + return dictoid; +} + +/* + * TSDictionaryIsVisible + * Determine whether a dictionary (identified by OID) is visible in the + * current search path. Visible means "would be found by searching + * for the unqualified dictionary name". + */ +bool +TSDictionaryIsVisible(Oid dictId) +{ + HeapTuple tup; + Form_pg_ts_dict form; + Oid namespace; + bool visible; + + tup = SearchSysCache1(TSDICTOID, ObjectIdGetDatum(dictId)); + if (!HeapTupleIsValid(tup)) + elog(ERROR, "cache lookup failed for text search dictionary %u", + dictId); + form = (Form_pg_ts_dict) GETSTRUCT(tup); + + recomputeNamespacePath(); + + /* + * Quick check: if it ain't in the path at all, it ain't visible. Items in + * the system namespace are surely in the path and so we needn't even do + * list_member_oid() for them. + */ + namespace = form->dictnamespace; + if (namespace != PG_CATALOG_NAMESPACE && + !list_member_oid(activeSearchPath, namespace)) + visible = false; + else + { + /* + * If it is in the path, it might still not be visible; it could be + * hidden by another dictionary of the same name earlier in the path. + * So we must do a slow check for conflicting dictionaries. + */ + char *name = NameStr(form->dictname); + ListCell *l; + + visible = false; + foreach(l, activeSearchPath) + { + Oid namespaceId = lfirst_oid(l); + + if (namespaceId == myTempNamespace) + continue; /* do not look in temp namespace */ + + if (namespaceId == namespace) + { + /* Found it first in path */ + visible = true; + break; + } + if (SearchSysCacheExists2(TSDICTNAMENSP, + PointerGetDatum(name), + ObjectIdGetDatum(namespaceId))) + { + /* Found something else first in path */ + break; + } + } + } + + ReleaseSysCache(tup); + + return visible; +} + +/* + * get_ts_template_oid - find a TS template by possibly qualified name + * + * If not found, returns InvalidOid if missing_ok, else throws error + */ +Oid +get_ts_template_oid(List *names, bool missing_ok) +{ + char *schemaname; + char *template_name; + Oid namespaceId; + Oid tmploid = InvalidOid; + ListCell *l; + + /* deconstruct the name list */ + DeconstructQualifiedName(names, &schemaname, &template_name); + + if (schemaname) + { + /* use exact schema given */ + namespaceId = LookupExplicitNamespace(schemaname, missing_ok); + if (missing_ok && !OidIsValid(namespaceId)) + tmploid = InvalidOid; + else + tmploid = GetSysCacheOid2(TSTEMPLATENAMENSP, Anum_pg_ts_template_oid, + PointerGetDatum(template_name), + ObjectIdGetDatum(namespaceId)); + } + else + { + /* search for it in search path */ + recomputeNamespacePath(); + + foreach(l, activeSearchPath) + { + namespaceId = lfirst_oid(l); + + if (namespaceId == myTempNamespace) + continue; /* do not look in temp namespace */ + + tmploid = GetSysCacheOid2(TSTEMPLATENAMENSP, Anum_pg_ts_template_oid, + PointerGetDatum(template_name), + ObjectIdGetDatum(namespaceId)); + if (OidIsValid(tmploid)) + break; + } + } + + if (!OidIsValid(tmploid) && !missing_ok) + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_OBJECT), + errmsg("text search template \"%s\" does not exist", + NameListToString(names)))); + + return tmploid; +} + +/* + * TSTemplateIsVisible + * Determine whether a template (identified by OID) is visible in the + * current search path. Visible means "would be found by searching + * for the unqualified template name". + */ +bool +TSTemplateIsVisible(Oid tmplId) +{ + HeapTuple tup; + Form_pg_ts_template form; + Oid namespace; + bool visible; + + tup = SearchSysCache1(TSTEMPLATEOID, ObjectIdGetDatum(tmplId)); + if (!HeapTupleIsValid(tup)) + elog(ERROR, "cache lookup failed for text search template %u", tmplId); + form = (Form_pg_ts_template) GETSTRUCT(tup); + + recomputeNamespacePath(); + + /* + * Quick check: if it ain't in the path at all, it ain't visible. Items in + * the system namespace are surely in the path and so we needn't even do + * list_member_oid() for them. + */ + namespace = form->tmplnamespace; + if (namespace != PG_CATALOG_NAMESPACE && + !list_member_oid(activeSearchPath, namespace)) + visible = false; + else + { + /* + * If it is in the path, it might still not be visible; it could be + * hidden by another template of the same name earlier in the path. So + * we must do a slow check for conflicting templates. + */ + char *name = NameStr(form->tmplname); + ListCell *l; + + visible = false; + foreach(l, activeSearchPath) + { + Oid namespaceId = lfirst_oid(l); + + if (namespaceId == myTempNamespace) + continue; /* do not look in temp namespace */ + + if (namespaceId == namespace) + { + /* Found it first in path */ + visible = true; + break; + } + if (SearchSysCacheExists2(TSTEMPLATENAMENSP, + PointerGetDatum(name), + ObjectIdGetDatum(namespaceId))) + { + /* Found something else first in path */ + break; + } + } + } + + ReleaseSysCache(tup); + + return visible; +} + +/* + * get_ts_config_oid - find a TS config by possibly qualified name + * + * If not found, returns InvalidOid if missing_ok, else throws error + */ +Oid +get_ts_config_oid(List *names, bool missing_ok) +{ + char *schemaname; + char *config_name; + Oid namespaceId; + Oid cfgoid = InvalidOid; + ListCell *l; + + /* deconstruct the name list */ + DeconstructQualifiedName(names, &schemaname, &config_name); + + if (schemaname) + { + /* use exact schema given */ + namespaceId = LookupExplicitNamespace(schemaname, missing_ok); + if (missing_ok && !OidIsValid(namespaceId)) + cfgoid = InvalidOid; + else + cfgoid = GetSysCacheOid2(TSCONFIGNAMENSP, Anum_pg_ts_config_oid, + PointerGetDatum(config_name), + ObjectIdGetDatum(namespaceId)); + } + else + { + /* search for it in search path */ + recomputeNamespacePath(); + + foreach(l, activeSearchPath) + { + namespaceId = lfirst_oid(l); + + if (namespaceId == myTempNamespace) + continue; /* do not look in temp namespace */ + + cfgoid = GetSysCacheOid2(TSCONFIGNAMENSP, Anum_pg_ts_config_oid, + PointerGetDatum(config_name), + ObjectIdGetDatum(namespaceId)); + if (OidIsValid(cfgoid)) + break; + } + } + + if (!OidIsValid(cfgoid) && !missing_ok) + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_OBJECT), + errmsg("text search configuration \"%s\" does not exist", + NameListToString(names)))); + + return cfgoid; +} + +/* + * TSConfigIsVisible + * Determine whether a text search configuration (identified by OID) + * is visible in the current search path. Visible means "would be found + * by searching for the unqualified text search configuration name". + */ +bool +TSConfigIsVisible(Oid cfgid) +{ + HeapTuple tup; + Form_pg_ts_config form; + Oid namespace; + bool visible; + + tup = SearchSysCache1(TSCONFIGOID, ObjectIdGetDatum(cfgid)); + if (!HeapTupleIsValid(tup)) + elog(ERROR, "cache lookup failed for text search configuration %u", + cfgid); + form = (Form_pg_ts_config) GETSTRUCT(tup); + + recomputeNamespacePath(); + + /* + * Quick check: if it ain't in the path at all, it ain't visible. Items in + * the system namespace are surely in the path and so we needn't even do + * list_member_oid() for them. + */ + namespace = form->cfgnamespace; + if (namespace != PG_CATALOG_NAMESPACE && + !list_member_oid(activeSearchPath, namespace)) + visible = false; + else + { + /* + * If it is in the path, it might still not be visible; it could be + * hidden by another configuration of the same name earlier in the + * path. So we must do a slow check for conflicting configurations. + */ + char *name = NameStr(form->cfgname); + ListCell *l; + + visible = false; + foreach(l, activeSearchPath) + { + Oid namespaceId = lfirst_oid(l); + + if (namespaceId == myTempNamespace) + continue; /* do not look in temp namespace */ + + if (namespaceId == namespace) + { + /* Found it first in path */ + visible = true; + break; + } + if (SearchSysCacheExists2(TSCONFIGNAMENSP, + PointerGetDatum(name), + ObjectIdGetDatum(namespaceId))) + { + /* Found something else first in path */ + break; + } + } + } + + ReleaseSysCache(tup); + + return visible; +} + + +/* + * DeconstructQualifiedName + * Given a possibly-qualified name expressed as a list of String nodes, + * extract the schema name and object name. + * + * *nspname_p is set to NULL if there is no explicit schema name. + */ +void +DeconstructQualifiedName(List *names, + char **nspname_p, + char **objname_p) +{ + char *catalogname; + char *schemaname = NULL; + char *objname = NULL; + + switch (list_length(names)) + { + case 1: + objname = strVal(linitial(names)); + break; + case 2: + schemaname = strVal(linitial(names)); + objname = strVal(lsecond(names)); + break; + case 3: + catalogname = strVal(linitial(names)); + schemaname = strVal(lsecond(names)); + objname = strVal(lthird(names)); + + /* + * We check the catalog name and then ignore it. + */ + if (strcmp(catalogname, get_database_name(MyDatabaseId)) != 0) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("cross-database references are not implemented: %s", + NameListToString(names)))); + break; + default: + ereport(ERROR, + (errcode(ERRCODE_SYNTAX_ERROR), + errmsg("improper qualified name (too many dotted names): %s", + NameListToString(names)))); + break; + } + + *nspname_p = schemaname; + *objname_p = objname; +} + +/* + * LookupNamespaceNoError + * Look up a schema name. + * + * Returns the namespace OID, or InvalidOid if not found. + * + * Note this does NOT perform any permissions check --- callers are + * responsible for being sure that an appropriate check is made. + * In the majority of cases LookupExplicitNamespace is preferable. + */ +Oid +LookupNamespaceNoError(const char *nspname) +{ + /* check for pg_temp alias */ + if (strcmp(nspname, "pg_temp") == 0) + { + if (OidIsValid(myTempNamespace)) + { + InvokeNamespaceSearchHook(myTempNamespace, true); + return myTempNamespace; + } + + /* + * Since this is used only for looking up existing objects, there is + * no point in trying to initialize the temp namespace here; and doing + * so might create problems for some callers. Just report "not found". + */ + return InvalidOid; + } + + return get_namespace_oid(nspname, true); +} + +/* + * LookupExplicitNamespace + * Process an explicitly-specified schema name: look up the schema + * and verify we have USAGE (lookup) rights in it. + * + * Returns the namespace OID + */ +Oid +LookupExplicitNamespace(const char *nspname, bool missing_ok) +{ + Oid namespaceId; + AclResult aclresult; + + /* check for pg_temp alias */ + if (strcmp(nspname, "pg_temp") == 0) + { + if (OidIsValid(myTempNamespace)) + return myTempNamespace; + + /* + * Since this is used only for looking up existing objects, there is + * no point in trying to initialize the temp namespace here; and doing + * so might create problems for some callers --- just fall through. + */ + } + + namespaceId = get_namespace_oid(nspname, missing_ok); + if (missing_ok && !OidIsValid(namespaceId)) + return InvalidOid; + + aclresult = pg_namespace_aclcheck(namespaceId, GetUserId(), ACL_USAGE); + if (aclresult != ACLCHECK_OK) + aclcheck_error(aclresult, OBJECT_SCHEMA, + nspname); + /* Schema search hook for this lookup */ + InvokeNamespaceSearchHook(namespaceId, true); + + return namespaceId; +} + +/* + * LookupCreationNamespace + * Look up the schema and verify we have CREATE rights on it. + * + * This is just like LookupExplicitNamespace except for the different + * permission check, and that we are willing to create pg_temp if needed. + * + * Note: calling this may result in a CommandCounterIncrement operation, + * if we have to create or clean out the temp namespace. + */ +Oid +LookupCreationNamespace(const char *nspname) +{ + Oid namespaceId; + AclResult aclresult; + + /* check for pg_temp alias */ + if (strcmp(nspname, "pg_temp") == 0) + { + /* Initialize temp namespace */ + AccessTempTableNamespace(false); + return myTempNamespace; + } + + namespaceId = get_namespace_oid(nspname, false); + + aclresult = pg_namespace_aclcheck(namespaceId, GetUserId(), ACL_CREATE); + if (aclresult != ACLCHECK_OK) + aclcheck_error(aclresult, OBJECT_SCHEMA, + nspname); + + return namespaceId; +} + +/* + * Common checks on switching namespaces. + * + * We complain if either the old or new namespaces is a temporary schema + * (or temporary toast schema), or if either the old or new namespaces is the + * TOAST schema. + */ +void +CheckSetNamespace(Oid oldNspOid, Oid nspOid) +{ + /* disallow renaming into or out of temp schemas */ + if (isAnyTempNamespace(nspOid) || isAnyTempNamespace(oldNspOid)) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("cannot move objects into or out of temporary schemas"))); + + /* same for TOAST schema */ + if (nspOid == PG_TOAST_NAMESPACE || oldNspOid == PG_TOAST_NAMESPACE) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("cannot move objects into or out of TOAST schema"))); +} + +/* + * QualifiedNameGetCreationNamespace + * Given a possibly-qualified name for an object (in List-of-Values + * format), determine what namespace the object should be created in. + * Also extract and return the object name (last component of list). + * + * Note: this does not apply any permissions check. Callers must check + * for CREATE rights on the selected namespace when appropriate. + * + * Note: calling this may result in a CommandCounterIncrement operation, + * if we have to create or clean out the temp namespace. + */ +Oid +QualifiedNameGetCreationNamespace(List *names, char **objname_p) +{ + char *schemaname; + Oid namespaceId; + + /* deconstruct the name list */ + DeconstructQualifiedName(names, &schemaname, objname_p); + + if (schemaname) + { + /* check for pg_temp alias */ + if (strcmp(schemaname, "pg_temp") == 0) + { + /* Initialize temp namespace */ + AccessTempTableNamespace(false); + return myTempNamespace; + } + /* use exact schema given */ + namespaceId = get_namespace_oid(schemaname, false); + /* we do not check for USAGE rights here! */ + } + else + { + /* use the default creation namespace */ + recomputeNamespacePath(); + if (activeTempCreationPending) + { + /* Need to initialize temp namespace */ + AccessTempTableNamespace(true); + return myTempNamespace; + } + namespaceId = activeCreationNamespace; + if (!OidIsValid(namespaceId)) + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_SCHEMA), + errmsg("no schema has been selected to create in"))); + } + + return namespaceId; +} + +/* + * get_namespace_oid - given a namespace name, look up the OID + * + * If missing_ok is false, throw an error if namespace name not found. If + * true, just return InvalidOid. + */ +Oid +get_namespace_oid(const char *nspname, bool missing_ok) +{ + Oid oid; + + oid = GetSysCacheOid1(NAMESPACENAME, Anum_pg_namespace_oid, + CStringGetDatum(nspname)); + if (!OidIsValid(oid) && !missing_ok) + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_SCHEMA), + errmsg("schema \"%s\" does not exist", nspname))); + + return oid; +} + +/* + * makeRangeVarFromNameList + * Utility routine to convert a qualified-name list into RangeVar form. + */ +RangeVar * +makeRangeVarFromNameList(List *names) +{ + RangeVar *rel = makeRangeVar(NULL, NULL, -1); + + switch (list_length(names)) + { + case 1: + rel->relname = strVal(linitial(names)); + break; + case 2: + rel->schemaname = strVal(linitial(names)); + rel->relname = strVal(lsecond(names)); + break; + case 3: + rel->catalogname = strVal(linitial(names)); + rel->schemaname = strVal(lsecond(names)); + rel->relname = strVal(lthird(names)); + break; + default: + ereport(ERROR, + (errcode(ERRCODE_SYNTAX_ERROR), + errmsg("improper relation name (too many dotted names): %s", + NameListToString(names)))); + break; + } + + return rel; +} + +/* + * NameListToString + * Utility routine to convert a qualified-name list into a string. + * + * This is used primarily to form error messages, and so we do not quote + * the list elements, for the sake of legibility. + * + * In most scenarios the list elements should always be Value strings, + * but we also allow A_Star for the convenience of ColumnRef processing. + */ +char * +NameListToString(List *names) +{ + StringInfoData string; + ListCell *l; + + initStringInfo(&string); + + foreach(l, names) + { + Node *name = (Node *) lfirst(l); + + if (l != list_head(names)) + appendStringInfoChar(&string, '.'); + + if (IsA(name, String)) + appendStringInfoString(&string, strVal(name)); + else if (IsA(name, A_Star)) + appendStringInfoChar(&string, '*'); + else + elog(ERROR, "unexpected node type in name list: %d", + (int) nodeTag(name)); + } + + return string.data; +} + +/* + * NameListToQuotedString + * Utility routine to convert a qualified-name list into a string. + * + * Same as above except that names will be double-quoted where necessary, + * so the string could be re-parsed (eg, by textToQualifiedNameList). + */ +char * +NameListToQuotedString(List *names) +{ + StringInfoData string; + ListCell *l; + + initStringInfo(&string); + + foreach(l, names) + { + if (l != list_head(names)) + appendStringInfoChar(&string, '.'); + appendStringInfoString(&string, quote_identifier(strVal(lfirst(l)))); + } + + return string.data; +} + +/* + * isTempNamespace - is the given namespace my temporary-table namespace? + */ +bool +isTempNamespace(Oid namespaceId) +{ + if (OidIsValid(myTempNamespace) && myTempNamespace == namespaceId) + return true; + return false; +} + +/* + * isTempToastNamespace - is the given namespace my temporary-toast-table + * namespace? + */ +bool +isTempToastNamespace(Oid namespaceId) +{ + if (OidIsValid(myTempToastNamespace) && myTempToastNamespace == namespaceId) + return true; + return false; +} + +/* + * isTempOrTempToastNamespace - is the given namespace my temporary-table + * namespace or my temporary-toast-table namespace? + */ +bool +isTempOrTempToastNamespace(Oid namespaceId) +{ + if (OidIsValid(myTempNamespace) && + (myTempNamespace == namespaceId || myTempToastNamespace == namespaceId)) + return true; + return false; +} + +/* + * isAnyTempNamespace - is the given namespace a temporary-table namespace + * (either my own, or another backend's)? Temporary-toast-table namespaces + * are included, too. + */ +bool +isAnyTempNamespace(Oid namespaceId) +{ + bool result; + char *nspname; + + /* True if the namespace name starts with "pg_temp_" or "pg_toast_temp_" */ + nspname = get_namespace_name(namespaceId); + if (!nspname) + return false; /* no such namespace? */ + result = (strncmp(nspname, "pg_temp_", 8) == 0) || + (strncmp(nspname, "pg_toast_temp_", 14) == 0); + pfree(nspname); + return result; +} + +/* + * isOtherTempNamespace - is the given namespace some other backend's + * temporary-table namespace (including temporary-toast-table namespaces)? + * + * Note: for most purposes in the C code, this function is obsolete. Use + * RELATION_IS_OTHER_TEMP() instead to detect non-local temp relations. + */ +bool +isOtherTempNamespace(Oid namespaceId) +{ + /* If it's my own temp namespace, say "false" */ + if (isTempOrTempToastNamespace(namespaceId)) + return false; + /* Else, if it's any temp namespace, say "true" */ + return isAnyTempNamespace(namespaceId); +} + +/* + * checkTempNamespaceStatus - is the given namespace owned and actively used + * by a backend? + * + * Note: this can be used while scanning relations in pg_class to detect + * orphaned temporary tables or namespaces with a backend connected to a + * given database. The result may be out of date quickly, so the caller + * must be careful how to handle this information. + */ +TempNamespaceStatus +checkTempNamespaceStatus(Oid namespaceId) +{ + PGPROC *proc; + int backendId; + + Assert(OidIsValid(MyDatabaseId)); + + backendId = GetTempNamespaceBackendId(namespaceId); + + /* No such namespace, or its name shows it's not temp? */ + if (backendId == InvalidBackendId) + return TEMP_NAMESPACE_NOT_TEMP; + + /* Is the backend alive? */ + proc = BackendIdGetProc(backendId); + if (proc == NULL) + return TEMP_NAMESPACE_IDLE; + + /* Is the backend connected to the same database we are looking at? */ + if (proc->databaseId != MyDatabaseId) + return TEMP_NAMESPACE_IDLE; + + /* Does the backend own the temporary namespace? */ + if (proc->tempNamespaceId != namespaceId) + return TEMP_NAMESPACE_IDLE; + + /* Yup, so namespace is busy */ + return TEMP_NAMESPACE_IN_USE; +} + +/* + * GetTempNamespaceBackendId - if the given namespace is a temporary-table + * namespace (either my own, or another backend's), return the BackendId + * that owns it. Temporary-toast-table namespaces are included, too. + * If it isn't a temp namespace, return InvalidBackendId. + */ +int +GetTempNamespaceBackendId(Oid namespaceId) +{ + int result; + char *nspname; + + /* See if the namespace name starts with "pg_temp_" or "pg_toast_temp_" */ + nspname = get_namespace_name(namespaceId); + if (!nspname) + return InvalidBackendId; /* no such namespace? */ + if (strncmp(nspname, "pg_temp_", 8) == 0) + result = atoi(nspname + 8); + else if (strncmp(nspname, "pg_toast_temp_", 14) == 0) + result = atoi(nspname + 14); + else + result = InvalidBackendId; + pfree(nspname); + return result; +} + +/* + * GetTempToastNamespace - get the OID of my temporary-toast-table namespace, + * which must already be assigned. (This is only used when creating a toast + * table for a temp table, so we must have already done InitTempTableNamespace) + */ +Oid +GetTempToastNamespace(void) +{ + Assert(OidIsValid(myTempToastNamespace)); + return myTempToastNamespace; +} + + +/* + * GetTempNamespaceState - fetch status of session's temporary namespace + * + * This is used for conveying state to a parallel worker, and is not meant + * for general-purpose access. + */ +void +GetTempNamespaceState(Oid *tempNamespaceId, Oid *tempToastNamespaceId) +{ + /* Return namespace OIDs, or 0 if session has not created temp namespace */ + *tempNamespaceId = myTempNamespace; + *tempToastNamespaceId = myTempToastNamespace; +} + +/* + * SetTempNamespaceState - set status of session's temporary namespace + * + * This is used for conveying state to a parallel worker, and is not meant for + * general-purpose access. By transferring these namespace OIDs to workers, + * we ensure they will have the same notion of the search path as their leader + * does. + */ +void +SetTempNamespaceState(Oid tempNamespaceId, Oid tempToastNamespaceId) +{ + /* Worker should not have created its own namespaces ... */ + Assert(myTempNamespace == InvalidOid); + Assert(myTempToastNamespace == InvalidOid); + Assert(myTempNamespaceSubID == InvalidSubTransactionId); + + /* Assign same namespace OIDs that leader has */ + myTempNamespace = tempNamespaceId; + myTempToastNamespace = tempToastNamespaceId; + + /* + * It's fine to leave myTempNamespaceSubID == InvalidSubTransactionId. + * Even if the namespace is new so far as the leader is concerned, it's + * not new to the worker, and we certainly wouldn't want the worker trying + * to destroy it. + */ + + baseSearchPathValid = false; /* may need to rebuild list */ +} + + +/* + * GetOverrideSearchPath - fetch current search path definition in form + * used by PushOverrideSearchPath. + * + * The result structure is allocated in the specified memory context + * (which might or might not be equal to CurrentMemoryContext); but any + * junk created by revalidation calculations will be in CurrentMemoryContext. + */ +OverrideSearchPath * +GetOverrideSearchPath(MemoryContext context) +{ + OverrideSearchPath *result; + List *schemas; + MemoryContext oldcxt; + + recomputeNamespacePath(); + + oldcxt = MemoryContextSwitchTo(context); + + result = (OverrideSearchPath *) palloc0(sizeof(OverrideSearchPath)); + schemas = list_copy(activeSearchPath); + while (schemas && linitial_oid(schemas) != activeCreationNamespace) + { + if (linitial_oid(schemas) == myTempNamespace) + result->addTemp = true; + else + { + Assert(linitial_oid(schemas) == PG_CATALOG_NAMESPACE); + result->addCatalog = true; + } + schemas = list_delete_first(schemas); + } + result->schemas = schemas; + result->generation = activePathGeneration; + + MemoryContextSwitchTo(oldcxt); + + return result; +} + +/* + * CopyOverrideSearchPath - copy the specified OverrideSearchPath. + * + * The result structure is allocated in CurrentMemoryContext. + */ +OverrideSearchPath * +CopyOverrideSearchPath(OverrideSearchPath *path) +{ + OverrideSearchPath *result; + + result = (OverrideSearchPath *) palloc(sizeof(OverrideSearchPath)); + result->schemas = list_copy(path->schemas); + result->addCatalog = path->addCatalog; + result->addTemp = path->addTemp; + result->generation = path->generation; + + return result; +} + +/* + * OverrideSearchPathMatchesCurrent - does path match current setting? + * + * This is tested over and over in some common code paths, and in the typical + * scenario where the active search path seldom changes, it'll always succeed. + * We make that case fast by keeping a generation counter that is advanced + * whenever the active search path changes. + */ +bool +OverrideSearchPathMatchesCurrent(OverrideSearchPath *path) +{ + ListCell *lc, + *lcp; + + recomputeNamespacePath(); + + /* Quick out if already known equal to active path. */ + if (path->generation == activePathGeneration) + return true; + + /* We scan down the activeSearchPath to see if it matches the input. */ + lc = list_head(activeSearchPath); + + /* If path->addTemp, first item should be my temp namespace. */ + if (path->addTemp) + { + if (lc && lfirst_oid(lc) == myTempNamespace) + lc = lnext(activeSearchPath, lc); + else + return false; + } + /* If path->addCatalog, next item should be pg_catalog. */ + if (path->addCatalog) + { + if (lc && lfirst_oid(lc) == PG_CATALOG_NAMESPACE) + lc = lnext(activeSearchPath, lc); + else + return false; + } + /* We should now be looking at the activeCreationNamespace. */ + if (activeCreationNamespace != (lc ? lfirst_oid(lc) : InvalidOid)) + return false; + /* The remainder of activeSearchPath should match path->schemas. */ + foreach(lcp, path->schemas) + { + if (lc && lfirst_oid(lc) == lfirst_oid(lcp)) + lc = lnext(activeSearchPath, lc); + else + return false; + } + if (lc) + return false; + + /* + * Update path->generation so that future tests will return quickly, so + * long as the active search path doesn't change. + */ + path->generation = activePathGeneration; + + return true; +} + +/* + * PushOverrideSearchPath - temporarily override the search path + * + * We allow nested overrides, hence the push/pop terminology. The GUC + * search_path variable is ignored while an override is active. + * + * It's possible that newpath->useTemp is set but there is no longer any + * active temp namespace, if the path was saved during a transaction that + * created a temp namespace and was later rolled back. In that case we just + * ignore useTemp. A plausible alternative would be to create a new temp + * namespace, but for existing callers that's not necessary because an empty + * temp namespace wouldn't affect their results anyway. + * + * It's also worth noting that other schemas listed in newpath might not + * exist anymore either. We don't worry about this because OIDs that match + * no existing namespace will simply not produce any hits during searches. + */ +void +PushOverrideSearchPath(OverrideSearchPath *newpath) +{ + OverrideStackEntry *entry; + List *oidlist; + Oid firstNS; + MemoryContext oldcxt; + + /* + * Copy the list for safekeeping, and insert implicitly-searched + * namespaces as needed. This code should track recomputeNamespacePath. + */ + oldcxt = MemoryContextSwitchTo(TopMemoryContext); + + oidlist = list_copy(newpath->schemas); + + /* + * Remember the first member of the explicit list. + */ + if (oidlist == NIL) + firstNS = InvalidOid; + else + firstNS = linitial_oid(oidlist); + + /* + * Add any implicitly-searched namespaces to the list. Note these go on + * the front, not the back; also notice that we do not check USAGE + * permissions for these. + */ + if (newpath->addCatalog) + oidlist = lcons_oid(PG_CATALOG_NAMESPACE, oidlist); + + if (newpath->addTemp && OidIsValid(myTempNamespace)) + oidlist = lcons_oid(myTempNamespace, oidlist); + + /* + * Build the new stack entry, then insert it at the head of the list. + */ + entry = (OverrideStackEntry *) palloc(sizeof(OverrideStackEntry)); + entry->searchPath = oidlist; + entry->creationNamespace = firstNS; + entry->nestLevel = GetCurrentTransactionNestLevel(); + + overrideStack = lcons(entry, overrideStack); + + /* And make it active. */ + activeSearchPath = entry->searchPath; + activeCreationNamespace = entry->creationNamespace; + activeTempCreationPending = false; /* XXX is this OK? */ + + /* + * We always increment activePathGeneration when pushing/popping an + * override path. In current usage, these actions always change the + * effective path state, so there's no value in checking to see if it + * didn't change. + */ + activePathGeneration++; + + MemoryContextSwitchTo(oldcxt); +} + +/* + * PopOverrideSearchPath - undo a previous PushOverrideSearchPath + * + * Any push during a (sub)transaction will be popped automatically at abort. + * But it's caller error if a push isn't popped in normal control flow. + */ +void +PopOverrideSearchPath(void) +{ + OverrideStackEntry *entry; + + /* Sanity checks. */ + if (overrideStack == NIL) + elog(ERROR, "bogus PopOverrideSearchPath call"); + entry = (OverrideStackEntry *) linitial(overrideStack); + if (entry->nestLevel != GetCurrentTransactionNestLevel()) + elog(ERROR, "bogus PopOverrideSearchPath call"); + + /* Pop the stack and free storage. */ + overrideStack = list_delete_first(overrideStack); + list_free(entry->searchPath); + pfree(entry); + + /* Activate the next level down. */ + if (overrideStack) + { + entry = (OverrideStackEntry *) linitial(overrideStack); + activeSearchPath = entry->searchPath; + activeCreationNamespace = entry->creationNamespace; + activeTempCreationPending = false; /* XXX is this OK? */ + } + else + { + /* If not baseSearchPathValid, this is useless but harmless */ + activeSearchPath = baseSearchPath; + activeCreationNamespace = baseCreationNamespace; + activeTempCreationPending = baseTempCreationPending; + } + + /* As above, the generation always increments. */ + activePathGeneration++; +} + + +/* + * get_collation_oid - find a collation by possibly qualified name + * + * Note that this will only find collations that work with the current + * database's encoding. + */ +Oid +get_collation_oid(List *name, bool missing_ok) +{ + char *schemaname; + char *collation_name; + int32 dbencoding = GetDatabaseEncoding(); + Oid namespaceId; + Oid colloid; + ListCell *l; + + /* deconstruct the name list */ + DeconstructQualifiedName(name, &schemaname, &collation_name); + + if (schemaname) + { + /* use exact schema given */ + namespaceId = LookupExplicitNamespace(schemaname, missing_ok); + if (missing_ok && !OidIsValid(namespaceId)) + return InvalidOid; + + colloid = lookup_collation(collation_name, namespaceId, dbencoding); + if (OidIsValid(colloid)) + return colloid; + } + else + { + /* search for it in search path */ + recomputeNamespacePath(); + + foreach(l, activeSearchPath) + { + namespaceId = lfirst_oid(l); + + if (namespaceId == myTempNamespace) + continue; /* do not look in temp namespace */ + + colloid = lookup_collation(collation_name, namespaceId, dbencoding); + if (OidIsValid(colloid)) + return colloid; + } + } + + /* Not found in path */ + if (!missing_ok) + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_OBJECT), + errmsg("collation \"%s\" for encoding \"%s\" does not exist", + NameListToString(name), GetDatabaseEncodingName()))); + return InvalidOid; +} + +/* + * get_conversion_oid - find a conversion by possibly qualified name + */ +Oid +get_conversion_oid(List *name, bool missing_ok) +{ + char *schemaname; + char *conversion_name; + Oid namespaceId; + Oid conoid = InvalidOid; + ListCell *l; + + /* deconstruct the name list */ + DeconstructQualifiedName(name, &schemaname, &conversion_name); + + if (schemaname) + { + /* use exact schema given */ + namespaceId = LookupExplicitNamespace(schemaname, missing_ok); + if (missing_ok && !OidIsValid(namespaceId)) + conoid = InvalidOid; + else + conoid = GetSysCacheOid2(CONNAMENSP, Anum_pg_conversion_oid, + PointerGetDatum(conversion_name), + ObjectIdGetDatum(namespaceId)); + } + else + { + /* search for it in search path */ + recomputeNamespacePath(); + + foreach(l, activeSearchPath) + { + namespaceId = lfirst_oid(l); + + if (namespaceId == myTempNamespace) + continue; /* do not look in temp namespace */ + + conoid = GetSysCacheOid2(CONNAMENSP, Anum_pg_conversion_oid, + PointerGetDatum(conversion_name), + ObjectIdGetDatum(namespaceId)); + if (OidIsValid(conoid)) + return conoid; + } + } + + /* Not found in path */ + if (!OidIsValid(conoid) && !missing_ok) + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_OBJECT), + errmsg("conversion \"%s\" does not exist", + NameListToString(name)))); + return conoid; +} + +/* + * FindDefaultConversionProc - find default encoding conversion proc + */ +Oid +FindDefaultConversionProc(int32 for_encoding, int32 to_encoding) +{ + Oid proc; + ListCell *l; + + recomputeNamespacePath(); + + foreach(l, activeSearchPath) + { + Oid namespaceId = lfirst_oid(l); + + if (namespaceId == myTempNamespace) + continue; /* do not look in temp namespace */ + + proc = FindDefaultConversion(namespaceId, for_encoding, to_encoding); + if (OidIsValid(proc)) + return proc; + } + + /* Not found in path */ + return InvalidOid; +} + +/* + * recomputeNamespacePath - recompute path derived variables if needed. + */ +static void +recomputeNamespacePath(void) +{ + Oid roleid = GetUserId(); + char *rawname; + List *namelist; + List *oidlist; + List *newpath; + ListCell *l; + bool temp_missing; + Oid firstNS; + bool pathChanged; + MemoryContext oldcxt; + + /* Do nothing if an override search spec is active. */ + if (overrideStack) + return; + + /* Do nothing if path is already valid. */ + if (baseSearchPathValid && namespaceUser == roleid) + return; + + /* Need a modifiable copy of namespace_search_path string */ + rawname = pstrdup(namespace_search_path); + + /* Parse string into list of identifiers */ + if (!SplitIdentifierString(rawname, ',', &namelist)) + { + /* syntax error in name list */ + /* this should not happen if GUC checked check_search_path */ + elog(ERROR, "invalid list syntax"); + } + + /* + * Convert the list of names to a list of OIDs. If any names are not + * recognizable or we don't have read access, just leave them out of the + * list. (We can't raise an error, since the search_path setting has + * already been accepted.) Don't make duplicate entries, either. + */ + oidlist = NIL; + temp_missing = false; + foreach(l, namelist) + { + char *curname = (char *) lfirst(l); + Oid namespaceId; + + if (strcmp(curname, "$user") == 0) + { + /* $user --- substitute namespace matching user name, if any */ + HeapTuple tuple; + + tuple = SearchSysCache1(AUTHOID, ObjectIdGetDatum(roleid)); + if (HeapTupleIsValid(tuple)) + { + char *rname; + + rname = NameStr(((Form_pg_authid) GETSTRUCT(tuple))->rolname); + namespaceId = get_namespace_oid(rname, true); + ReleaseSysCache(tuple); + if (OidIsValid(namespaceId) && + !list_member_oid(oidlist, namespaceId) && + pg_namespace_aclcheck(namespaceId, roleid, + ACL_USAGE) == ACLCHECK_OK && + InvokeNamespaceSearchHook(namespaceId, false)) + oidlist = lappend_oid(oidlist, namespaceId); + } + } + else if (strcmp(curname, "pg_temp") == 0) + { + /* pg_temp --- substitute temp namespace, if any */ + if (OidIsValid(myTempNamespace)) + { + if (!list_member_oid(oidlist, myTempNamespace) && + InvokeNamespaceSearchHook(myTempNamespace, false)) + oidlist = lappend_oid(oidlist, myTempNamespace); + } + else + { + /* If it ought to be the creation namespace, set flag */ + if (oidlist == NIL) + temp_missing = true; + } + } + else + { + /* normal namespace reference */ + namespaceId = get_namespace_oid(curname, true); + if (OidIsValid(namespaceId) && + !list_member_oid(oidlist, namespaceId) && + pg_namespace_aclcheck(namespaceId, roleid, + ACL_USAGE) == ACLCHECK_OK && + InvokeNamespaceSearchHook(namespaceId, false)) + oidlist = lappend_oid(oidlist, namespaceId); + } + } + + /* + * Remember the first member of the explicit list. (Note: this is + * nominally wrong if temp_missing, but we need it anyway to distinguish + * explicit from implicit mention of pg_catalog.) + */ + if (oidlist == NIL) + firstNS = InvalidOid; + else + firstNS = linitial_oid(oidlist); + + /* + * Add any implicitly-searched namespaces to the list. Note these go on + * the front, not the back; also notice that we do not check USAGE + * permissions for these. + */ + if (!list_member_oid(oidlist, PG_CATALOG_NAMESPACE)) + oidlist = lcons_oid(PG_CATALOG_NAMESPACE, oidlist); + + if (OidIsValid(myTempNamespace) && + !list_member_oid(oidlist, myTempNamespace)) + oidlist = lcons_oid(myTempNamespace, oidlist); + + /* + * We want to detect the case where the effective value of the base search + * path variables didn't change. As long as we're doing so, we can avoid + * copying the OID list unncessarily. + */ + if (baseCreationNamespace == firstNS && + baseTempCreationPending == temp_missing && + equal(oidlist, baseSearchPath)) + { + pathChanged = false; + } + else + { + pathChanged = true; + + /* Must save OID list in permanent storage. */ + oldcxt = MemoryContextSwitchTo(TopMemoryContext); + newpath = list_copy(oidlist); + MemoryContextSwitchTo(oldcxt); + + /* Now safe to assign to state variables. */ + list_free(baseSearchPath); + baseSearchPath = newpath; + baseCreationNamespace = firstNS; + baseTempCreationPending = temp_missing; + } + + /* Mark the path valid. */ + baseSearchPathValid = true; + namespaceUser = roleid; + + /* And make it active. */ + activeSearchPath = baseSearchPath; + activeCreationNamespace = baseCreationNamespace; + activeTempCreationPending = baseTempCreationPending; + + /* + * Bump the generation only if something actually changed. (Notice that + * what we compared to was the old state of the base path variables; so + * this does not deal with the situation where we have just popped an + * override path and restored the prior state of the base path. Instead + * we rely on the override-popping logic to have bumped the generation.) + */ + if (pathChanged) + activePathGeneration++; + + /* Clean up. */ + pfree(rawname); + list_free(namelist); + list_free(oidlist); +} + +/* + * AccessTempTableNamespace + * Provide access to a temporary namespace, potentially creating it + * if not present yet. This routine registers if the namespace gets + * in use in this transaction. 'force' can be set to true to allow + * the caller to enforce the creation of the temporary namespace for + * use in this backend, which happens if its creation is pending. + */ +static void +AccessTempTableNamespace(bool force) +{ + /* + * Make note that this temporary namespace has been accessed in this + * transaction. + */ + MyXactFlags |= XACT_FLAGS_ACCESSEDTEMPNAMESPACE; + + /* + * If the caller attempting to access a temporary schema expects the + * creation of the namespace to be pending and should be enforced, then go + * through the creation. + */ + if (!force && OidIsValid(myTempNamespace)) + return; + + /* + * The temporary tablespace does not exist yet and is wanted, so + * initialize it. + */ + InitTempTableNamespace(); +} + +/* + * InitTempTableNamespace + * Initialize temp table namespace on first use in a particular backend + */ +static void +InitTempTableNamespace(void) +{ + char namespaceName[NAMEDATALEN]; + Oid namespaceId; + Oid toastspaceId; + + Assert(!OidIsValid(myTempNamespace)); + + /* + * First, do permission check to see if we are authorized to make temp + * tables. We use a nonstandard error message here since "databasename: + * permission denied" might be a tad cryptic. + * + * Note that ACL_CREATE_TEMP rights are rechecked in pg_namespace_aclmask; + * that's necessary since current user ID could change during the session. + * But there's no need to make the namespace in the first place until a + * temp table creation request is made by someone with appropriate rights. + */ + if (pg_database_aclcheck(MyDatabaseId, GetUserId(), + ACL_CREATE_TEMP) != ACLCHECK_OK) + ereport(ERROR, + (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), + errmsg("permission denied to create temporary tables in database \"%s\"", + get_database_name(MyDatabaseId)))); + + /* + * Do not allow a Hot Standby session to make temp tables. Aside from + * problems with modifying the system catalogs, there is a naming + * conflict: pg_temp_N belongs to the session with BackendId N on the + * master, not to a hot standby session with the same BackendId. We + * should not be able to get here anyway due to XactReadOnly checks, but + * let's just make real sure. Note that this also backstops various + * operations that allow XactReadOnly transactions to modify temp tables; + * they'd need RecoveryInProgress checks if not for this. + */ + if (RecoveryInProgress()) + ereport(ERROR, + (errcode(ERRCODE_READ_ONLY_SQL_TRANSACTION), + errmsg("cannot create temporary tables during recovery"))); + + /* Parallel workers can't create temporary tables, either. */ + if (IsParallelWorker()) + ereport(ERROR, + (errcode(ERRCODE_READ_ONLY_SQL_TRANSACTION), + errmsg("cannot create temporary tables during a parallel operation"))); + + snprintf(namespaceName, sizeof(namespaceName), "pg_temp_%d", MyBackendId); + + namespaceId = get_namespace_oid(namespaceName, true); + if (!OidIsValid(namespaceId)) + { + /* + * First use of this temp namespace in this database; create it. The + * temp namespaces are always owned by the superuser. We leave their + * permissions at default --- i.e., no access except to superuser --- + * to ensure that unprivileged users can't peek at other backends' + * temp tables. This works because the places that access the temp + * namespace for my own backend skip permissions checks on it. + */ + namespaceId = NamespaceCreate(namespaceName, BOOTSTRAP_SUPERUSERID, + true); + /* Advance command counter to make namespace visible */ + CommandCounterIncrement(); + } + else + { + /* + * If the namespace already exists, clean it out (in case the former + * owner crashed without doing so). + */ + RemoveTempRelations(namespaceId); + } + + /* + * If the corresponding toast-table namespace doesn't exist yet, create + * it. (We assume there is no need to clean it out if it does exist, since + * dropping a parent table should make its toast table go away.) + */ + snprintf(namespaceName, sizeof(namespaceName), "pg_toast_temp_%d", + MyBackendId); + + toastspaceId = get_namespace_oid(namespaceName, true); + if (!OidIsValid(toastspaceId)) + { + toastspaceId = NamespaceCreate(namespaceName, BOOTSTRAP_SUPERUSERID, + true); + /* Advance command counter to make namespace visible */ + CommandCounterIncrement(); + } + + /* + * Okay, we've prepared the temp namespace ... but it's not committed yet, + * so all our work could be undone by transaction rollback. Set flag for + * AtEOXact_Namespace to know what to do. + */ + myTempNamespace = namespaceId; + myTempToastNamespace = toastspaceId; + + /* + * Mark MyProc as owning this namespace which other processes can use to + * decide if a temporary namespace is in use or not. We assume that + * assignment of namespaceId is an atomic operation. Even if it is not, + * the temporary relation which resulted in the creation of this temporary + * namespace is still locked until the current transaction commits, and + * its pg_namespace row is not visible yet. However it does not matter: + * this flag makes the namespace as being in use, so no objects created on + * it would be removed concurrently. + */ + MyProc->tempNamespaceId = namespaceId; + + /* It should not be done already. */ + AssertState(myTempNamespaceSubID == InvalidSubTransactionId); + myTempNamespaceSubID = GetCurrentSubTransactionId(); + + baseSearchPathValid = false; /* need to rebuild list */ +} + +/* + * End-of-transaction cleanup for namespaces. + */ +void +AtEOXact_Namespace(bool isCommit, bool parallel) +{ + /* + * If we abort the transaction in which a temp namespace was selected, + * we'll have to do any creation or cleanout work over again. So, just + * forget the namespace entirely until next time. On the other hand, if + * we commit then register an exit callback to clean out the temp tables + * at backend shutdown. (We only want to register the callback once per + * session, so this is a good place to do it.) + */ + if (myTempNamespaceSubID != InvalidSubTransactionId && !parallel) + { + if (isCommit) + before_shmem_exit(RemoveTempRelationsCallback, 0); + else + { + myTempNamespace = InvalidOid; + myTempToastNamespace = InvalidOid; + baseSearchPathValid = false; /* need to rebuild list */ + + /* + * Reset the temporary namespace flag in MyProc. We assume that + * this operation is atomic. + * + * Because this transaction is aborting, the pg_namespace row is + * not visible to anyone else anyway, but that doesn't matter: + * it's not a problem if objects contained in this namespace are + * removed concurrently. + */ + MyProc->tempNamespaceId = InvalidOid; + } + myTempNamespaceSubID = InvalidSubTransactionId; + } + + /* + * Clean up if someone failed to do PopOverrideSearchPath + */ + if (overrideStack) + { + if (isCommit) + elog(WARNING, "leaked override search path"); + while (overrideStack) + { + OverrideStackEntry *entry; + + entry = (OverrideStackEntry *) linitial(overrideStack); + overrideStack = list_delete_first(overrideStack); + list_free(entry->searchPath); + pfree(entry); + } + /* If not baseSearchPathValid, this is useless but harmless */ + activeSearchPath = baseSearchPath; + activeCreationNamespace = baseCreationNamespace; + activeTempCreationPending = baseTempCreationPending; + /* Always bump generation --- see note in recomputeNamespacePath */ + activePathGeneration++; + } +} + +/* + * AtEOSubXact_Namespace + * + * At subtransaction commit, propagate the temp-namespace-creation + * flag to the parent subtransaction. + * + * At subtransaction abort, forget the flag if we set it up. + */ +void +AtEOSubXact_Namespace(bool isCommit, SubTransactionId mySubid, + SubTransactionId parentSubid) +{ + OverrideStackEntry *entry; + + if (myTempNamespaceSubID == mySubid) + { + if (isCommit) + myTempNamespaceSubID = parentSubid; + else + { + myTempNamespaceSubID = InvalidSubTransactionId; + /* TEMP namespace creation failed, so reset state */ + myTempNamespace = InvalidOid; + myTempToastNamespace = InvalidOid; + baseSearchPathValid = false; /* need to rebuild list */ + + /* + * Reset the temporary namespace flag in MyProc. We assume that + * this operation is atomic. + * + * Because this subtransaction is aborting, the pg_namespace row + * is not visible to anyone else anyway, but that doesn't matter: + * it's not a problem if objects contained in this namespace are + * removed concurrently. + */ + MyProc->tempNamespaceId = InvalidOid; + } + } + + /* + * Clean up if someone failed to do PopOverrideSearchPath + */ + while (overrideStack) + { + entry = (OverrideStackEntry *) linitial(overrideStack); + if (entry->nestLevel < GetCurrentTransactionNestLevel()) + break; + if (isCommit) + elog(WARNING, "leaked override search path"); + overrideStack = list_delete_first(overrideStack); + list_free(entry->searchPath); + pfree(entry); + /* Always bump generation --- see note in recomputeNamespacePath */ + activePathGeneration++; + } + + /* Activate the next level down. */ + if (overrideStack) + { + entry = (OverrideStackEntry *) linitial(overrideStack); + activeSearchPath = entry->searchPath; + activeCreationNamespace = entry->creationNamespace; + activeTempCreationPending = false; /* XXX is this OK? */ + + /* + * It's probably unnecessary to bump generation here, but this should + * not be a performance-critical case, so better to be over-cautious. + */ + activePathGeneration++; + } + else + { + /* If not baseSearchPathValid, this is useless but harmless */ + activeSearchPath = baseSearchPath; + activeCreationNamespace = baseCreationNamespace; + activeTempCreationPending = baseTempCreationPending; + + /* + * If we popped an override stack entry, then we already bumped the + * generation above. If we did not, then the above assignments did + * nothing and we need not bump the generation. + */ + } +} + +/* + * Remove all relations in the specified temp namespace. + * + * This is called at backend shutdown (if we made any temp relations). + * It is also called when we begin using a pre-existing temp namespace, + * in order to clean out any relations that might have been created by + * a crashed backend. + */ +static void +RemoveTempRelations(Oid tempNamespaceId) +{ + ObjectAddress object; + + /* + * We want to get rid of everything in the target namespace, but not the + * namespace itself (deleting it only to recreate it later would be a + * waste of cycles). Hence, specify SKIP_ORIGINAL. It's also an INTERNAL + * deletion, and we want to not drop any extensions that might happen to + * own temp objects. + */ + object.classId = NamespaceRelationId; + object.objectId = tempNamespaceId; + object.objectSubId = 0; + + performDeletion(&object, DROP_CASCADE, + PERFORM_DELETION_INTERNAL | + PERFORM_DELETION_QUIETLY | + PERFORM_DELETION_SKIP_ORIGINAL | + PERFORM_DELETION_SKIP_EXTENSIONS); +} + +/* + * Callback to remove temp relations at backend exit. + */ +static void +RemoveTempRelationsCallback(int code, Datum arg) +{ + if (OidIsValid(myTempNamespace)) /* should always be true */ + { + /* Need to ensure we have a usable transaction. */ + AbortOutOfAnyTransaction(); + StartTransactionCommand(); + + RemoveTempRelations(myTempNamespace); + + CommitTransactionCommand(); + } +} + +/* + * Remove all temp tables from the temporary namespace. + */ +void +ResetTempTableNamespace(void) +{ + if (OidIsValid(myTempNamespace)) + RemoveTempRelations(myTempNamespace); +} + + +/* + * Routines for handling the GUC variable 'search_path'. + */ + +/* check_hook: validate new search_path value */ +bool +check_search_path(char **newval, void **extra, GucSource source) +{ + char *rawname; + List *namelist; + + /* Need a modifiable copy of string */ + rawname = pstrdup(*newval); + + /* Parse string into list of identifiers */ + if (!SplitIdentifierString(rawname, ',', &namelist)) + { + /* syntax error in name list */ + GUC_check_errdetail("List syntax is invalid."); + pfree(rawname); + list_free(namelist); + return false; + } + + /* + * We used to try to check that the named schemas exist, but there are + * many valid use-cases for having search_path settings that include + * schemas that don't exist; and often, we are not inside a transaction + * here and so can't consult the system catalogs anyway. So now, the only + * requirement is syntactic validity of the identifier list. + */ + + pfree(rawname); + list_free(namelist); + + return true; +} + +/* assign_hook: do extra actions as needed */ +void +assign_search_path(const char *newval, void *extra) +{ + /* + * We mark the path as needing recomputation, but don't do anything until + * it's needed. This avoids trying to do database access during GUC + * initialization, or outside a transaction. + */ + baseSearchPathValid = false; +} + +/* + * InitializeSearchPath: initialize module during InitPostgres. + * + * This is called after we are up enough to be able to do catalog lookups. + */ +void +InitializeSearchPath(void) +{ + if (IsBootstrapProcessingMode()) + { + /* + * In bootstrap mode, the search path must be 'pg_catalog' so that + * tables are created in the proper namespace; ignore the GUC setting. + */ + MemoryContext oldcxt; + + oldcxt = MemoryContextSwitchTo(TopMemoryContext); + baseSearchPath = list_make1_oid(PG_CATALOG_NAMESPACE); + MemoryContextSwitchTo(oldcxt); + baseCreationNamespace = PG_CATALOG_NAMESPACE; + baseTempCreationPending = false; + baseSearchPathValid = true; + namespaceUser = GetUserId(); + activeSearchPath = baseSearchPath; + activeCreationNamespace = baseCreationNamespace; + activeTempCreationPending = baseTempCreationPending; + activePathGeneration++; /* pro forma */ + } + else + { + /* + * In normal mode, arrange for a callback on any syscache invalidation + * of pg_namespace rows. + */ + CacheRegisterSyscacheCallback(NAMESPACEOID, + NamespaceCallback, + (Datum) 0); + /* Force search path to be recomputed on next use */ + baseSearchPathValid = false; + } +} + +/* + * NamespaceCallback + * Syscache inval callback function + */ +static void +NamespaceCallback(Datum arg, int cacheid, uint32 hashvalue) +{ + /* Force search path to be recomputed on next use */ + baseSearchPathValid = false; +} + +/* + * Fetch the active search path. The return value is a palloc'ed list + * of OIDs; the caller is responsible for freeing this storage as + * appropriate. + * + * The returned list includes the implicitly-prepended namespaces only if + * includeImplicit is true. + * + * Note: calling this may result in a CommandCounterIncrement operation, + * if we have to create or clean out the temp namespace. + */ +List * +fetch_search_path(bool includeImplicit) +{ + List *result; + + recomputeNamespacePath(); + + /* + * If the temp namespace should be first, force it to exist. This is so + * that callers can trust the result to reflect the actual default + * creation namespace. It's a bit bogus to do this here, since + * current_schema() is supposedly a stable function without side-effects, + * but the alternatives seem worse. + */ + if (activeTempCreationPending) + { + AccessTempTableNamespace(true); + recomputeNamespacePath(); + } + + result = list_copy(activeSearchPath); + if (!includeImplicit) + { + while (result && linitial_oid(result) != activeCreationNamespace) + result = list_delete_first(result); + } + + return result; +} + +/* + * Fetch the active search path into a caller-allocated array of OIDs. + * Returns the number of path entries. (If this is more than sarray_len, + * then the data didn't fit and is not all stored.) + * + * The returned list always includes the implicitly-prepended namespaces, + * but never includes the temp namespace. (This is suitable for existing + * users, which would want to ignore the temp namespace anyway.) This + * definition allows us to not worry about initializing the temp namespace. + */ +int +fetch_search_path_array(Oid *sarray, int sarray_len) +{ + int count = 0; + ListCell *l; + + recomputeNamespacePath(); + + foreach(l, activeSearchPath) + { + Oid namespaceId = lfirst_oid(l); + + if (namespaceId == myTempNamespace) + continue; /* do not include temp namespace */ + + if (count < sarray_len) + sarray[count] = namespaceId; + count++; + } + + return count; +} + + +/* + * Export the FooIsVisible functions as SQL-callable functions. + * + * Note: as of Postgres 8.4, these will silently return NULL if called on + * a nonexistent object OID, rather than failing. This is to avoid race + * condition errors when a query that's scanning a catalog using an MVCC + * snapshot uses one of these functions. The underlying IsVisible functions + * always use an up-to-date snapshot and so might see the object as already + * gone when it's still visible to the transaction snapshot. (There is no race + * condition in the current coding because we don't accept sinval messages + * between the SearchSysCacheExists test and the subsequent lookup.) + */ + +Datum +pg_table_is_visible(PG_FUNCTION_ARGS) +{ + Oid oid = PG_GETARG_OID(0); + + if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(oid))) + PG_RETURN_NULL(); + + PG_RETURN_BOOL(RelationIsVisible(oid)); +} + +Datum +pg_type_is_visible(PG_FUNCTION_ARGS) +{ + Oid oid = PG_GETARG_OID(0); + + if (!SearchSysCacheExists1(TYPEOID, ObjectIdGetDatum(oid))) + PG_RETURN_NULL(); + + PG_RETURN_BOOL(TypeIsVisible(oid)); +} + +Datum +pg_function_is_visible(PG_FUNCTION_ARGS) +{ + Oid oid = PG_GETARG_OID(0); + + if (!SearchSysCacheExists1(PROCOID, ObjectIdGetDatum(oid))) + PG_RETURN_NULL(); + + PG_RETURN_BOOL(FunctionIsVisible(oid)); +} + +Datum +pg_operator_is_visible(PG_FUNCTION_ARGS) +{ + Oid oid = PG_GETARG_OID(0); + + if (!SearchSysCacheExists1(OPEROID, ObjectIdGetDatum(oid))) + PG_RETURN_NULL(); + + PG_RETURN_BOOL(OperatorIsVisible(oid)); +} + +Datum +pg_opclass_is_visible(PG_FUNCTION_ARGS) +{ + Oid oid = PG_GETARG_OID(0); + + if (!SearchSysCacheExists1(CLAOID, ObjectIdGetDatum(oid))) + PG_RETURN_NULL(); + + PG_RETURN_BOOL(OpclassIsVisible(oid)); +} + +Datum +pg_opfamily_is_visible(PG_FUNCTION_ARGS) +{ + Oid oid = PG_GETARG_OID(0); + + if (!SearchSysCacheExists1(OPFAMILYOID, ObjectIdGetDatum(oid))) + PG_RETURN_NULL(); + + PG_RETURN_BOOL(OpfamilyIsVisible(oid)); +} + +Datum +pg_collation_is_visible(PG_FUNCTION_ARGS) +{ + Oid oid = PG_GETARG_OID(0); + + if (!SearchSysCacheExists1(COLLOID, ObjectIdGetDatum(oid))) + PG_RETURN_NULL(); + + PG_RETURN_BOOL(CollationIsVisible(oid)); +} + +Datum +pg_conversion_is_visible(PG_FUNCTION_ARGS) +{ + Oid oid = PG_GETARG_OID(0); + + if (!SearchSysCacheExists1(CONVOID, ObjectIdGetDatum(oid))) + PG_RETURN_NULL(); + + PG_RETURN_BOOL(ConversionIsVisible(oid)); +} + +Datum +pg_statistics_obj_is_visible(PG_FUNCTION_ARGS) +{ + Oid oid = PG_GETARG_OID(0); + + if (!SearchSysCacheExists1(STATEXTOID, ObjectIdGetDatum(oid))) + PG_RETURN_NULL(); + + PG_RETURN_BOOL(StatisticsObjIsVisible(oid)); +} + +Datum +pg_ts_parser_is_visible(PG_FUNCTION_ARGS) +{ + Oid oid = PG_GETARG_OID(0); + + if (!SearchSysCacheExists1(TSPARSEROID, ObjectIdGetDatum(oid))) + PG_RETURN_NULL(); + + PG_RETURN_BOOL(TSParserIsVisible(oid)); +} + +Datum +pg_ts_dict_is_visible(PG_FUNCTION_ARGS) +{ + Oid oid = PG_GETARG_OID(0); + + if (!SearchSysCacheExists1(TSDICTOID, ObjectIdGetDatum(oid))) + PG_RETURN_NULL(); + + PG_RETURN_BOOL(TSDictionaryIsVisible(oid)); +} + +Datum +pg_ts_template_is_visible(PG_FUNCTION_ARGS) +{ + Oid oid = PG_GETARG_OID(0); + + if (!SearchSysCacheExists1(TSTEMPLATEOID, ObjectIdGetDatum(oid))) + PG_RETURN_NULL(); + + PG_RETURN_BOOL(TSTemplateIsVisible(oid)); +} + +Datum +pg_ts_config_is_visible(PG_FUNCTION_ARGS) +{ + Oid oid = PG_GETARG_OID(0); + + if (!SearchSysCacheExists1(TSCONFIGOID, ObjectIdGetDatum(oid))) + PG_RETURN_NULL(); + + PG_RETURN_BOOL(TSConfigIsVisible(oid)); +} + +Datum +pg_my_temp_schema(PG_FUNCTION_ARGS) +{ + PG_RETURN_OID(myTempNamespace); +} + +Datum +pg_is_other_temp_schema(PG_FUNCTION_ARGS) +{ + Oid oid = PG_GETARG_OID(0); + + PG_RETURN_BOOL(isOtherTempNamespace(oid)); +} |