software.amazon.awssdk.http.async.AbortableInputStreamSubscriber Maven / Gradle / Ivy

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/*
 * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License").
 * You may not use this file except in compliance with the License.
 * A copy of the License is located at
 *
 *  http://aws.amazon.com/apache2.0
 *
 * or in the "license" file accompanying this file. This file 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 software.amazon.awssdk.http.async;

import java.io.IOException;
import java.io.InputStream;
import java.nio.ByteBuffer;
import org.reactivestreams.Subscriber;
import org.reactivestreams.Subscription;
import software.amazon.awssdk.annotations.SdkProtectedApi;
import software.amazon.awssdk.annotations.SdkTestInternalApi;
import software.amazon.awssdk.http.Abortable;
import software.amazon.awssdk.utils.FunctionalUtils;
import software.amazon.awssdk.utils.async.InputStreamSubscriber;

/**
 * Wrapper of {@link InputStreamSubscriber} that also implements {@link Abortable}. It will invoke {@link #close()}
 * when {@link #abort()} is invoked. Upon closing, the underlying {@link InputStreamSubscriber} will be closed, and additional
 * action can be added via {@link Builder#doAfterClose(Runnable)}.
 *
 */
@SdkProtectedApi
public final class AbortableInputStreamSubscriber extends InputStream implements Subscriber, Abortable {
    private final InputStreamSubscriber delegate;

    private final Runnable doAfterClose;

    private AbortableInputStreamSubscriber(Builder builder) {
        this(builder, new InputStreamSubscriber());
    }

    @SdkTestInternalApi
    AbortableInputStreamSubscriber(Builder builder, InputStreamSubscriber delegate) {
        this.delegate = delegate;
        this.doAfterClose = builder.doAfterClose == null ? FunctionalUtils.noOpRunnable() : builder.doAfterClose;
    }

    public static Builder builder() {
        return new Builder();
    }

    @Override
    public void abort() {
        close();
    }

    @Override
    public int read() throws IOException {
        return delegate.read();
    }

    @Override
    public int read(byte[] b, int off, int len) throws IOException {
        return delegate.read(b, off, len);
    }

    @Override
    public int read(byte[] b) throws IOException {
        return delegate.read(b);
    }

    @Override
    public void onSubscribe(Subscription s) {
        delegate.onSubscribe(s);
    }

    @Override
    public void onNext(ByteBuffer byteBuffer) {
        delegate.onNext(byteBuffer);
    }

    @Override
    public void onError(Throwable t) {
        delegate.onError(t);
    }

    @Override
    public void onComplete() {
        delegate.onComplete();
    }

    @Override
    public void close() {
        delegate.close();
        FunctionalUtils.invokeSafely(() -> doAfterClose.run());
    }
    
    public static final class Builder {
        private Runnable doAfterClose;

        /**
         * Additional action to run when {@link #close()} is invoked
         */
        public Builder doAfterClose(Runnable doAfterClose) {
            this.doAfterClose = doAfterClose;
            return this;
        }

        public AbortableInputStreamSubscriber build() {
            return new AbortableInputStreamSubscriber(this);
        }
    }
}