Java 类com.google.common.io.FileBackedOutputStream 实例源码

public IndexJsonSink(Index index, EventHandler eventHandler) {
    this.index = index;
    this.eventHandler = eventHandler;
    this.out = new FileBackedOutputStream(1024 * 1024);
    this.npw = new OutputStreamJsonSink(out);
}

/**
 * To get around the size limit, you could use FileBackedOutputStream to store
 * some in memory and some on disk.
 * <p>
 * On T3500 Machine, 22.808 seconds for 1gb payload, no caching, fbos(1Mb)
 * </p>
 * <p>
 * Sends output to nullOutputStream to avoid crashing eclipse.
 * </p>
 * <p>
 * Note: This is also generating the payload from scratch (twice,
 * duplicateInput), but this operation is better than having the payload in
 * your repo and needing to download on checkout.
 * </p>
 * <p>
 * Also has potential for crashing due to disk space.
 * </p>
 */
@Test
public void storingOnDiskIsSlowAndCanCrash() throws IOException {
  FileBackedOutputStream outputToInput = new FileBackedOutputStream(mb1);
  duplicateInput(Res.randomBytesOfLength(gb1), outputToInput);
  Processor.run(outputToInput.asByteSource(), ByteStreams.nullOutputStream());
}

/**
 * This one caches the payload to disk before duplicating to show that
 * regenerating the payload is faster than reading directly from disk.
 * <p>
 * On T3500 Machine, 31.692 seconds for 1gb payload, with caching, fbos(1Mb)
 * <p>
 * <p>
 * Caching: The randomly generated input is cached to disk so that when the
 * duplicateInput() method is called, the random generation doesnt have to run
 * again.
 * </p>
 * <p>
 * Sends output to nullOutputStream to avoid crashing eclipse.
 * </p>
 * <p>
 * Note: This is also generating the payload from scratch (twice), but this
 * operation is better than having the payload in your repo and needing to
 * download on checkout.
 * </p>
 */
@Test
public void cachedStoringOnDiskIsSlow() throws IOException {
  FileBackedOutputStream outputToInput = new FileBackedOutputStream(mb1);
  duplicateInput(Res.randomCachedBytesOfLength(gb1), outputToInput);
  Processor.run(outputToInput.asByteSource(), ByteStreams.nullOutputStream());
}