korlov42 commented on a change in pull request #8472: URL: https://github.com/apache/ignite/pull/8472#discussion_r527631132
########## File path: modules/calcite/src/main/java/org/apache/ignite/internal/processors/query/calcite/exec/rel/TableSpoolNode.java ########## @@ -0,0 +1,146 @@ +/* + * 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.ignite.internal.processors.query.calcite.exec.rel; + +import java.util.ArrayList; +import java.util.List; +import org.apache.calcite.rel.type.RelDataType; +import org.apache.ignite.internal.processors.query.calcite.exec.ExecutionContext; +import org.apache.ignite.internal.util.typedef.F; + +/** + * Spool node. + */ +public class TableSpoolNode<Row> extends AbstractNode<Row> implements SingleNode<Row>, Downstream<Row> { + /** How many rows are requested by downstream. */ + private int requested; + + /** How many rows are we waiting for from the upstream. {@code -1} means end of source stream. */ + private int waiting; + + /** Index of the current row to push. */ + private int rowIdx; + + /** Rows buffer. */ + private final List<Row> rows; + + /** + * @param ctx Execution context. + */ + public TableSpoolNode(ExecutionContext<Row> ctx, RelDataType rowType) { + super(ctx, rowType); + + rows = new ArrayList<>(); + } + + /** {@inheritDoc} */ + @Override protected void rewindInternal() { + requested = 0; + rowIdx = 0; + } + + /** {@inheritDoc} */ + @Override public void rewind() { + rewindInternal(); + } + + /** {@inheritDoc} */ + @Override protected Downstream<Row> requestDownstream(int idx) { + if (idx != 0) + throw new IndexOutOfBoundsException(); + + return this; + } + + /** {@inheritDoc} */ + @Override public void request(int rowsCnt) { + assert !F.isEmpty(sources()) && sources().size() == 1; + assert rowsCnt > 0; + + try { + checkState(); + + requested += rowsCnt; + + if (waiting == -1) + context().execute(this::doPush); + else if (waiting == 0) + source().request(waiting = IN_BUFFER_SIZE); + } + catch (Exception e) { + onError(e); + } + } + + /** */ + private void doPush() { + while (requested > 0 && rowIdx < rows.size()) + pushToDownstream(); + } + + /** */ + private void pushToDownstream() { + downstream().push(rows.get(rowIdx)); + + rowIdx++; + requested--; + + if (rowIdx >= rows.size() && waiting == -1 && requested > 0) + downstream().end(); + } + + /** {@inheritDoc} */ + @Override public void push(Row row) { + assert downstream() != null; + assert waiting > 0; + + try { + checkState(); + + waiting--; + + rows.add(row); + + if (waiting == 0) + source().request(waiting = IN_BUFFER_SIZE); + + if (requested > 0 && rowIdx < rows.size()) + pushToDownstream(); + } + catch (Exception e) { + onError(e); + } + } + + /** {@inheritDoc} */ + @Override public void end() { + assert downstream() != null; + assert waiting > 0; + + try { + checkState(); + + waiting = -1; + + if (rowIdx >= rows.size() && waiting == -1) Review comment: ```suggestion if (rowIdx >= rows.size() && requested > 0) ``` ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected]
