pg_type.c

来自「PostgreSQL7.4.6 for Linux」· C语言 代码 · 共 542 行 · 第 1/2 页

	 */
	pg_type_desc = heap_openr(TypeRelationName, RowExclusiveLock);

	tup = SearchSysCacheCopy(TYPENAMENSP,
							 CStringGetDatum(typeName),
							 ObjectIdGetDatum(typeNamespace),
							 0, 0);
	if (HeapTupleIsValid(tup))
	{
		/*
		 * check that the type is not already defined.	It may exist as a
		 * shell type, however (but only if assignedTypeOid is not given).
		 */
		if (((Form_pg_type) GETSTRUCT(tup))->typisdefined ||
			assignedTypeOid != InvalidOid)
			ereport(ERROR,
					(errcode(ERRCODE_DUPLICATE_OBJECT),
					 errmsg("type \"%s\" already exists", typeName)));

		/*
		 * Okay to update existing "shell" type tuple
		 */
		tup = heap_modifytuple(tup,
							   pg_type_desc,
							   values,
							   nulls,
							   replaces);

		simple_heap_update(pg_type_desc, &tup->t_self, tup);

		typeObjectId = HeapTupleGetOid(tup);

		rebuildDeps = true;		/* get rid of shell type's dependencies */
	}
	else
	{
		tupDesc = pg_type_desc->rd_att;

		tup = heap_formtuple(tupDesc,
							 values,
							 nulls);

		/* preassign tuple Oid, if one was given */
		HeapTupleSetOid(tup, assignedTypeOid);

		typeObjectId = simple_heap_insert(pg_type_desc, tup);
	}

	/* Update indexes */
	CatalogUpdateIndexes(pg_type_desc, tup);

	/*
	 * Create dependencies.  We can/must skip this in bootstrap mode.
	 */
	if (!IsBootstrapProcessingMode())
		GenerateTypeDependencies(typeNamespace,
								 typeObjectId,
								 relationOid,
								 relationKind,
								 inputProcedure,
								 outputProcedure,
								 receiveProcedure,
								 sendProcedure,
								 elementType,
								 baseType,
								 (defaultTypeBin ?
								  stringToNode(defaultTypeBin) :
								  (void *) NULL),
								 rebuildDeps);

	/*
	 * finish up
	 */
	heap_close(pg_type_desc, RowExclusiveLock);

	return typeObjectId;
}

/*
 * GenerateTypeDependencies: build the dependencies needed for a type
 *
 * If rebuild is true, we remove existing dependencies and rebuild them
 * from scratch.  This is needed for ALTER TYPE, and also when replacing
 * a shell type.
 *
 * NOTE: a shell type will have a dependency to its namespace, and no others.
 */
void
GenerateTypeDependencies(Oid typeNamespace,
						 Oid typeObjectId,
						 Oid relationOid,		/* only for 'c'atalog
												 * types */
						 char relationKind,		/* ditto */
						 Oid inputProcedure,
						 Oid outputProcedure,
						 Oid receiveProcedure,
						 Oid sendProcedure,
						 Oid elementType,
						 Oid baseType,
						 Node *defaultExpr,
						 bool rebuild)
{
	ObjectAddress myself,
				referenced;

	if (rebuild)
		deleteDependencyRecordsFor(RelOid_pg_type,
								   typeObjectId);

	myself.classId = RelOid_pg_type;
	myself.objectId = typeObjectId;
	myself.objectSubId = 0;

	/* dependency on namespace */
	/* skip for relation rowtype, since we have indirect dependency */
	if (!OidIsValid(relationOid))
	{
		referenced.classId = get_system_catalog_relid(NamespaceRelationName);
		referenced.objectId = typeNamespace;
		referenced.objectSubId = 0;
		recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
	}

	/* Normal dependencies on the I/O functions */
	if (OidIsValid(inputProcedure))
	{
		referenced.classId = RelOid_pg_proc;
		referenced.objectId = inputProcedure;
		referenced.objectSubId = 0;
		recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
	}

	if (OidIsValid(outputProcedure))
	{
		referenced.classId = RelOid_pg_proc;
		referenced.objectId = outputProcedure;
		referenced.objectSubId = 0;
		recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
	}

	if (OidIsValid(receiveProcedure))
	{
		referenced.classId = RelOid_pg_proc;
		referenced.objectId = receiveProcedure;
		referenced.objectSubId = 0;
		recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
	}

	if (OidIsValid(sendProcedure))
	{
		referenced.classId = RelOid_pg_proc;
		referenced.objectId = sendProcedure;
		referenced.objectSubId = 0;
		recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
	}

	/*
	 * If the type is a rowtype for a relation, mark it as internally
	 * dependent on the relation, *unless* it is a stand-alone composite
	 * type relation. For the latter case, we have to reverse the
	 * dependency.
	 *
	 * In the former case, this allows the type to be auto-dropped when the
	 * relation is, and not otherwise. And in the latter, of course we get
	 * the opposite effect.
	 */
	if (OidIsValid(relationOid))
	{
		referenced.classId = RelOid_pg_class;
		referenced.objectId = relationOid;
		referenced.objectSubId = 0;

		if (relationKind != RELKIND_COMPOSITE_TYPE)
			recordDependencyOn(&myself, &referenced, DEPENDENCY_INTERNAL);
		else
			recordDependencyOn(&referenced, &myself, DEPENDENCY_INTERNAL);
	}

	/*
	 * If the type is an array type, mark it auto-dependent on the base
	 * type.  (This is a compromise between the typical case where the
	 * array type is automatically generated and the case where it is
	 * manually created: we'd prefer INTERNAL for the former case and
	 * NORMAL for the latter.)
	 */
	if (OidIsValid(elementType))
	{
		referenced.classId = RelOid_pg_type;
		referenced.objectId = elementType;
		referenced.objectSubId = 0;
		recordDependencyOn(&myself, &referenced, DEPENDENCY_AUTO);
	}

	/* Normal dependency from a domain to its base type. */
	if (OidIsValid(baseType))
	{
		referenced.classId = RelOid_pg_type;
		referenced.objectId = baseType;
		referenced.objectSubId = 0;
		recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
	}

	/* Normal dependency on the default expression. */
	if (defaultExpr)
		recordDependencyOnExpr(&myself, defaultExpr, NIL, DEPENDENCY_NORMAL);
}

/*
 * TypeRename
 *		This renames a type
 *
 * Note: any associated array type is *not* renamed; caller must make
 * another call to handle that case.  Currently this is only used for
 * renaming types associated with tables, for which there are no arrays.
 */
void
TypeRename(const char *oldTypeName, Oid typeNamespace,
		   const char *newTypeName)
{
	Relation	pg_type_desc;
	HeapTuple	tuple;

	pg_type_desc = heap_openr(TypeRelationName, RowExclusiveLock);

	tuple = SearchSysCacheCopy(TYPENAMENSP,
							   CStringGetDatum(oldTypeName),
							   ObjectIdGetDatum(typeNamespace),
							   0, 0);
	if (!HeapTupleIsValid(tuple))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_OBJECT),
				 errmsg("type \"%s\" does not exist", oldTypeName)));

	if (SearchSysCacheExists(TYPENAMENSP,
							 CStringGetDatum(newTypeName),
							 ObjectIdGetDatum(typeNamespace),
							 0, 0))
		ereport(ERROR,
				(errcode(ERRCODE_DUPLICATE_OBJECT),
				 errmsg("type \"%s\" already exists", newTypeName)));

	namestrcpy(&(((Form_pg_type) GETSTRUCT(tuple))->typname), newTypeName);

	simple_heap_update(pg_type_desc, &tuple->t_self, tuple);

	/* update the system catalog indexes */
	CatalogUpdateIndexes(pg_type_desc, tuple);

	heap_freetuple(tuple);
	heap_close(pg_type_desc, RowExclusiveLock);
}

/*
 * makeArrayTypeName(typeName);
 *	  - given a base type name, make an array of type name out of it
 *
 * the caller is responsible for pfreeing the result
 */
char *
makeArrayTypeName(const char *typeName)
{
	char	   *arr;

	if (!typeName)
		return NULL;
	arr = palloc(NAMEDATALEN);
	snprintf(arr, NAMEDATALEN,
			 "_%.*s", NAMEDATALEN - 2, typeName);
	return arr;
}