| /* |
| * ==================================================================== |
| * 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. |
| * ==================================================================== |
| * |
| * This software consists of voluntary contributions made by many |
| * individuals on behalf of the Apache Software Foundation. For more |
| * information on the Apache Software Foundation, please see |
| * <http://www.apache.org/>. |
| * |
| */ |
| |
| package org.apache.hc.core5.testing.reactive; |
| |
| import java.nio.ByteBuffer; |
| import java.nio.charset.StandardCharsets; |
| import java.security.MessageDigest; |
| import java.security.NoSuchAlgorithmException; |
| import java.util.Random; |
| import java.util.concurrent.atomic.AtomicReference; |
| |
| import org.apache.hc.core5.util.TextUtils; |
| import org.reactivestreams.Publisher; |
| |
| import io.reactivex.Emitter; |
| import io.reactivex.Flowable; |
| import io.reactivex.Single; |
| import io.reactivex.functions.Consumer; |
| |
| public class ReactiveTestUtils { |
| /** The range from which to generate random data. */ |
| private final static byte[] RANGE = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789" |
| .getBytes(StandardCharsets.US_ASCII); |
| |
| /** |
| * Produces a deterministic stream of bytes, in randomly sized chunks of up to 128kB. |
| * |
| * @param length the number of bytes in the stream |
| * @return a reactive stream of bytes |
| */ |
| public static Flowable<ByteBuffer> produceStream(final long length) { |
| return produceStream(length, null); |
| } |
| |
| /** |
| * Produces a deterministic stream of bytes, in randomly sized chunks of up to 128kB, while computing the hash of |
| * the random data. |
| * |
| * @param length the number of bytes in the stream |
| * @param hash an output argument for the hash, set when the end of the stream is reached; if {@code null}, the |
| * hash will not be computed |
| * @return a reactive stream of bytes |
| */ |
| public static Flowable<ByteBuffer> produceStream(final long length, final AtomicReference<String> hash) { |
| return produceStream(length, 128 * 1024, hash); |
| } |
| |
| /** |
| * Produces a deterministic stream of bytes, in randomly sized chunks, while computing the hash of the random data. |
| * |
| * @param length the number of bytes in the stream |
| * @param maximumBlockSize the maximum size of any {@code ByteBuffer in the stream} |
| * @param hash an output argument for the hash, set when the end of the stream is reached; if {@code null}, the |
| * hash will not be computed |
| * @return a reactive stream of bytes |
| */ |
| public static Flowable<ByteBuffer> produceStream( |
| final long length, |
| final int maximumBlockSize, |
| final AtomicReference<String> hash |
| ) { |
| return Flowable.generate(new Consumer<Emitter<ByteBuffer>>() { |
| final Random random = new Random(length); // Use the length as the random seed for easy reproducibility |
| long bytesEmitted; |
| final MessageDigest md = newMessageDigest(); |
| |
| @Override |
| public void accept(final Emitter<ByteBuffer> emitter) { |
| final long remainingLength = length - bytesEmitted; |
| if (remainingLength == 0) { |
| emitter.onComplete(); |
| if (hash != null) { |
| hash.set(TextUtils.toHexString(md.digest())); |
| } |
| } else { |
| final int bufferLength = (int) Math.min(remainingLength, 1 + random.nextInt(maximumBlockSize)); |
| final byte[] bs = new byte[bufferLength]; |
| for (int i = 0; i < bufferLength; i++) { |
| final byte b = RANGE[(int) (random.nextDouble() * RANGE.length)]; |
| bs[i] = b; |
| } |
| if (hash != null) { |
| md.update(bs); |
| } |
| emitter.onNext(ByteBuffer.wrap(bs)); |
| bytesEmitted += bufferLength; |
| } |
| } |
| }); |
| } |
| |
| /** |
| * Computes the hash of the deterministic stream (as produced by {@link #produceStream(long)}). |
| */ |
| public static String getStreamHash(final long length) { |
| return TextUtils.toHexString(consumeStream(produceStream(length)).blockingGet().md.digest()); |
| } |
| |
| /** |
| * Consumes the given stream and returns a data structure containing its length and digest. |
| */ |
| public static Single<StreamDescription> consumeStream(final Publisher<ByteBuffer> publisher) { |
| final StreamDescription seed = new StreamDescription(0, newMessageDigest()); |
| return Flowable.fromPublisher(publisher) |
| .reduce(seed, (desc, byteBuffer) -> { |
| final long length = desc.length + byteBuffer.remaining(); |
| desc.md.update(byteBuffer); |
| return new StreamDescription(length, desc.md); |
| }); |
| } |
| |
| private static MessageDigest newMessageDigest() { |
| try { |
| return MessageDigest.getInstance("MD5"); |
| } catch (final NoSuchAlgorithmException ex) { |
| throw new AssertionError(ex); |
| } |
| } |
| |
| public static class StreamDescription { |
| public final long length; |
| public final MessageDigest md; |
| |
| public StreamDescription(final long length, final MessageDigest md) { |
| this.length = length; |
| this.md = md; |
| } |
| } |
| } |