/* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.apache.cassandra.cql3.statements; import org.apache.cassandra.auth.AuthenticatedUser; import org.apache.cassandra.cql3.CFName; import org.apache.cassandra.cql3.CQLStatement; import org.apache.cassandra.cql3.QueryOptions; import org.apache.cassandra.exceptions.InvalidRequestException; import org.apache.cassandra.exceptions.RequestValidationException; import org.apache.cassandra.service.ClientState; import org.apache.cassandra.service.QueryState; import org.apache.cassandra.transport.Event; import org.apache.cassandra.transport.messages.ResultMessage; /** * Abstract class for statements that alter the schema. */ public abstract class SchemaAlteringStatement extends CFStatement implements CQLStatement { private final boolean isColumnFamilyLevel; protected SchemaAlteringStatement() { super(null); this.isColumnFamilyLevel = false; } protected SchemaAlteringStatement(CFName name) { super(name); this.isColumnFamilyLevel = true; } public int getBoundTerms() { return 0; } @Override public void prepareKeyspace(ClientState state) throws InvalidRequestException { if (isColumnFamilyLevel) super.prepareKeyspace(state); } @Override public Prepared prepare() { return new Prepared(this); } /** * Schema alteration may result in a new database object (keyspace, table, role, function) being created capable of * having permissions GRANTed on it. The creator of the object (the primary role assigned to the AuthenticatedUser * performing the operation) is automatically granted ALL applicable permissions on the object. This is a hook for * subclasses to override in order to perform that grant when the statement is executed. */ protected void grantPermissionsToCreator(QueryState state) { // no-op by default } /** * Announces the migration to other nodes in the cluster. * * @return the schema change event corresponding to the execution of this statement, or {@code null} if no schema change * has occurred (when IF NOT EXISTS is used, for example) * * @throws RequestValidationException */ public abstract Event.SchemaChange announceMigration(boolean isLocalOnly) throws RequestValidationException; public ResultMessage execute(QueryState state, QueryOptions options) throws RequestValidationException { // If an IF [NOT] EXISTS clause was used, this may not result in an actual schema change. To avoid doing // extra work in the drivers to handle schema changes, we return an empty message in this case. (CASSANDRA-7600) Event.SchemaChange ce = announceMigration(false); if (ce == null) return new ResultMessage.Void(); // when a schema alteration results in a new db object being created, we grant permissions on the new // object to the user performing the request if: // * the user is not anonymous // * the configured IAuthorizer supports granting of permissions (not all do, AllowAllAuthorizer doesn't and // custom external implementations may not) AuthenticatedUser user = state.getClientState().getUser(); if (user != null && !user.isAnonymous() && ce.change == Event.SchemaChange.Change.CREATED) { try { grantPermissionsToCreator(state); } catch (UnsupportedOperationException e) { // not a problem, grant is an optional method on IAuthorizer } } return new ResultMessage.SchemaChange(ce); } public ResultMessage executeInternal(QueryState state, QueryOptions options) { Event.SchemaChange ce = announceMigration(true); return ce == null ? new ResultMessage.Void() : new ResultMessage.SchemaChange(ce); } }