| /* |
| * 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.druid.frame.file; |
| |
| import com.google.common.util.concurrent.Futures; |
| import com.google.common.util.concurrent.ListenableFuture; |
| import org.apache.druid.java.util.common.ISE; |
| |
| import javax.annotation.Nullable; |
| |
| /** |
| * Response object for {@link FrameFileHttpResponseHandler}. |
| * |
| * The handler mutates this object on each chunk of a chunked response. When the response is done, this object |
| * is returned to the caller. |
| */ |
| public class FrameFilePartialFetch |
| { |
| private final boolean lastFetchHeaderSet; |
| private long bytesRead; |
| |
| @Nullable |
| private Throwable exceptionCaught; |
| |
| @Nullable |
| private ListenableFuture<?> backpressureFuture; |
| |
| FrameFilePartialFetch(boolean lastFetchHeaderSet) |
| { |
| this.lastFetchHeaderSet = lastFetchHeaderSet; |
| } |
| |
| public boolean isLastFetch() |
| { |
| return exceptionCaught == null && lastFetchHeaderSet && bytesRead == 0L; |
| } |
| |
| /** |
| * The exception that was encountered, if {@link #isExceptionCaught()} is true. |
| * |
| * @throws IllegalStateException if no exception was caught |
| */ |
| public Throwable getExceptionCaught() |
| { |
| if (!isExceptionCaught()) { |
| throw new ISE("No exception caught"); |
| } |
| |
| return exceptionCaught; |
| } |
| |
| /** |
| * Whether an exception was encountered during response processing. |
| */ |
| public boolean isExceptionCaught() |
| { |
| return exceptionCaught != null; |
| } |
| |
| /** |
| * Future that resolves when it is a good time to request the next chunk of the frame file. |
| * |
| * Must only be called once, because the future is cleared once it is returned. |
| */ |
| public ListenableFuture<?> backpressureFuture() |
| { |
| final ListenableFuture<?> future = backpressureFuture; |
| backpressureFuture = null; |
| |
| if (future != null) { |
| return future; |
| } else { |
| return Futures.immediateFuture(null); |
| } |
| } |
| |
| void setBackpressureFuture(final ListenableFuture<?> future) |
| { |
| if (backpressureFuture == null) { |
| backpressureFuture = future; |
| } |
| } |
| |
| void exceptionCaught(final Throwable t) |
| { |
| if (exceptionCaught == null) { |
| exceptionCaught = t; |
| } |
| } |
| |
| void addBytesRead(final long n) |
| { |
| bytesRead += n; |
| } |
| } |