@@ -0,0 +1,1732 @@
+/*%0A * Licensed to the Apache Software Foundation (ASF) under one%0A * or more contributor license agreements.  See the NOTICE file%0A * distributed with this work for additional information%0A * regarding copyright ownership.  The ASF licenses this file%0A * to you under the Apache License, Version 2.0 (the%0A * %22License%22); you may not use this file except in compliance%0A * with the License.  You may obtain a copy of the License at%0A *%0A *     http://www.apache.org/licenses/LICENSE-2.0%0A *%0A * Unless required by applicable law or agreed to in writing, software%0A * distributed under the License is distributed on an %22AS IS%22 BASIS,%0A * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.%0A * See the License for the specific language governing permissions and%0A * limitations under the License.%0A */%0A%0Apackage org.apache.flink.table.sources;%0A%0Aimport org.apache.flink.annotation.Experimental;%0A%0A/**%0A * Adds support for limiting push-down to a %7B@link TableSource%7D.%0A * A %7B@link TableSource%7D extending this interface is able to limit the number of records.%0A *%0A * %3Cp%3EAfter pushing down, source only needs to try its best to limit the number of output records,%0A * but does not need to guarantee that the number must be less than or equal to the limit.%0A */%0A@Experimental%0Apublic interface LimitableTableSource%3CT%3E %7B%0A%0A%09/**%0A%09 * Return the flag to indicate whether limit push down has been tried. Must return true on%0A%09 * the returned instance of %7B@link #applyLimit(long)%7D.%0A%09 */%0A%09boolean isLimitPushedDown();%0A%0A%09/**%0A%09 * Check and push down the limit to the table source.%0A%09 *%0A%09 * @param limit the value which limit the number of records.%0A%09 * @return A new cloned instance of %7B@link TableSource%7D.%0A%09 */%0A%09TableSource%3CT%3E applyLimit(long limit);%0A%7D%0A

Introduce LimitableTableSource for optimizing limit