Java tutorial
/* * Licensed 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 io.prestosql.split; import com.google.common.collect.ImmutableList; import com.google.common.util.concurrent.Futures; import com.google.common.util.concurrent.ListenableFuture; import io.prestosql.connector.ConnectorId; import io.prestosql.execution.Lifespan; import io.prestosql.metadata.Split; import io.prestosql.spi.connector.ConnectorPartitionHandle; import io.prestosql.spi.connector.ConnectorSplit; import io.prestosql.spi.connector.ConnectorSplitSource; import io.prestosql.spi.connector.ConnectorSplitSource.ConnectorSplitBatch; import io.prestosql.spi.connector.ConnectorTransactionHandle; import static com.google.common.util.concurrent.MoreExecutors.directExecutor; import static io.airlift.concurrent.MoreFutures.toListenableFuture; import static java.util.Objects.requireNonNull; public class ConnectorAwareSplitSource implements SplitSource { private final ConnectorId connectorId; private final ConnectorTransactionHandle transactionHandle; private final ConnectorSplitSource source; public ConnectorAwareSplitSource(ConnectorId connectorId, ConnectorTransactionHandle transactionHandle, ConnectorSplitSource source) { this.connectorId = requireNonNull(connectorId, "connectorId is null"); this.transactionHandle = requireNonNull(transactionHandle, "transactionHandle is null"); this.source = requireNonNull(source, "source is null"); } @Override public ConnectorId getConnectorId() { return connectorId; } @Override public ConnectorTransactionHandle getTransactionHandle() { return transactionHandle; } @Override public ListenableFuture<SplitBatch> getNextBatch(ConnectorPartitionHandle partitionHandle, Lifespan lifespan, int maxSize) { ListenableFuture<ConnectorSplitBatch> nextBatch = toListenableFuture( source.getNextBatch(partitionHandle, maxSize)); return Futures.transform(nextBatch, splitBatch -> { ImmutableList.Builder<Split> result = ImmutableList.builder(); for (ConnectorSplit connectorSplit : splitBatch.getSplits()) { result.add(new Split(connectorId, transactionHandle, connectorSplit, lifespan)); } return new SplitBatch(result.build(), splitBatch.isNoMoreSplits()); }, directExecutor()); } @Override public void close() { source.close(); } @Override public boolean isFinished() { return source.isFinished(); } @Override public String toString() { return connectorId + ":" + source; } }