com.amazonaws.services.s3.internal.MultiFileOutputStream Maven / Gradle / Ivy
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/*
* Copyright 2014-2018 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 com.amazonaws.services.s3.internal;
import com.amazonaws.AbortedException;
import com.amazonaws.services.s3.OnFileDelete;
import com.amazonaws.services.s3.UploadObjectObserver;
import org.apache.commons.logging.LogFactory;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.UUID;
import java.util.concurrent.Semaphore;
/**
* Used to split an output stream into multiple files for purposes such as
* parallel uploads.
*/
public class MultiFileOutputStream extends OutputStream implements OnFileDelete {
private static final int SHIFT_VALUE = 20;
private static final int PART_BYTE = 5;
private static final int DEFAULT_PART_SIZE = PART_BYTE << SHIFT_VALUE; // 5MB
private final File root;
private final String namePrefix;
private int filesCreated;
private long partSize = DEFAULT_PART_SIZE;
private long diskLimit = Long.MAX_VALUE;
private UploadObjectObserver observer;
/**
* Number of bytes that have been written to the current file.
*/
private int currFileBytesWritten;
/**
* Total number of bytes written to all files so far.
*/
private long totalBytesWritten;
private FileOutputStream os;
private boolean closed;
/** null means no blocking necessary. */
private Semaphore diskPermits;
/**
* Construct an instance to use the default temporary directory and temp
* file naming convention. The
* {@link #init(UploadObjectObserver, long, long)} must be called before
* this stream is considered fully initialized.
*/
public MultiFileOutputStream() {
root = new File(System.getProperty("java.io.tmpdir"));
namePrefix = yyMMdd_hhmmss() + "." + UUID.randomUUID();
}
/**
* Construct an instance to use the specified directory for temp file
* creations, and the specified prefix for temp file naming. The
* {@link #init(UploadObjectObserver, long, long)} must be called before
* this stream is considered fully initialized.
* @param namePrefix the prefix for file naming.
* @param root the file foot.
*/
public MultiFileOutputStream(File root, String namePrefix) {
if (root == null || !root.isDirectory() || !root.canWrite()) {
throw new IllegalArgumentException(root
+ " must be a writable directory");
}
if (namePrefix == null || namePrefix.trim().length() == 0) {
throw new IllegalArgumentException(
"Please specify a non-empty name prefix");
}
this.root = root;
this.namePrefix = namePrefix;
}
/**
* Used to initialized this stream. This method is an SPI (service provider
* interface) that is called from AmazonS3EncryptionClient.
*
* Implementation of this method should never block.
*
* @param observer
* the upload object observer
* @param partSize
* part size for multi-part upload
* @param diskLimit
* the maximum disk space to be used for this multi-part upload
*
* @return this object
*/
@SuppressWarnings("checkstyle:hiddenfield")
public MultiFileOutputStream init(UploadObjectObserver observer,
long partSize, long diskLimit) {
if (observer == null) {
throw new IllegalArgumentException("Observer must be specified");
}
this.observer = observer;
if (diskLimit < partSize << 1) {
throw new IllegalArgumentException(
"Maximum temporary disk space must be at least twice as large as the part size: partSize="
+ partSize + ", diskSize=" + diskLimit);
}
this.partSize = partSize;
this.diskLimit = diskLimit;
final int max = (int) (diskLimit / partSize);
this.diskPermits = max < 0 ? null : new Semaphore(max);
return this;
}
/**
* {@inheritDoc}
*
* This method would block as necessary if running out of disk space.
*/
@Override
public void write(int b) throws IOException {
fos().write(b);
currFileBytesWritten++;
totalBytesWritten++;
}
/**
* {@inheritDoc}
*
* This method would block as necessary if running out of disk space.
*/
@Override
public void write(byte[] b) throws IOException {
if (b.length == 0) {
return;
}
fos().write(b);
currFileBytesWritten += b.length;
totalBytesWritten += b.length;
}
/**
* {@inheritDoc}
*
* This method would block as necessary if running out of disk space.
*/
@Override
public void write(byte[] b, int off, int len) throws IOException {
if (b.length == 0) {
return;
}
fos().write(b, off, len);
currFileBytesWritten += len;
totalBytesWritten += len;
}
/**
* Returns the file output stream to be used for writing, blocking if
* necessary if running out of disk space.
*
* @throws InterruptedException if the running thread was interrupted
*/
private FileOutputStream fos() throws IOException {
if (closed) {
throw new IOException("Output stream is already closed");
}
if (os == null || currFileBytesWritten >= partSize) {
if (os != null) {
os.close();
// notify about the new file ready for processing
observer.onPartCreate(new PartCreationEvent(
getFile(filesCreated), filesCreated, false, this));
}
currFileBytesWritten = 0;
filesCreated++;
blockIfNecessary();
final File file = getFile(filesCreated);
file.deleteOnExit();
os = new FileOutputStream(file);
}
return os;
}
@Override
public void onFileDelete(FileDeletionEvent event) {
if (diskPermits != null) {
diskPermits.release();
}
}
/**
* Blocks the running thread if running out of disk space.
*
* @throws AbortedException
* if the running thread is interrupted while acquiring a
* semaphore
*/
private void blockIfNecessary() {
if (diskPermits == null || diskLimit == Long.MAX_VALUE) {
return;
}
try {
diskPermits.acquire();
} catch (final InterruptedException e) {
// don't want to re-interrupt so it won't cause SDK stream to be
// closed in case the thread is reused for a different request
throw new AbortedException(e);
}
}
@Override
public void flush() throws IOException {
if (os != null) {
os.flush();
}
}
@Override
public void close() throws IOException {
if (closed) {
return;
}
closed = true;
if (os != null) {
os.close();
final File lastPart = getFile(filesCreated);
if (lastPart.length() == 0) {
if (!lastPart.delete()) {
LogFactory.getLog(getClass()).debug(
"Ignoring failure to delete empty file " + lastPart);
}
} else {
// notify about the new file ready for processing
observer.onPartCreate(new PartCreationEvent(
getFile(filesCreated), filesCreated, true, this));
}
}
}
/**
* Deletes files.
*/
public void cleanup() {
for (int i = 0; i < getNumFilesWritten(); i++) {
final File f = getFile(i);
if (f.exists()) {
if (!f.delete()) {
LogFactory.getLog(getClass()).debug(
"Ignoring failure to delete file " + f);
}
}
}
}
/**
* @return the number of files written with the specified prefix with the
* part number as the file extension.
*/
public int getNumFilesWritten() {
return filesCreated;
}
/**
* Retrieves the file with the specified part number as the file extension.
* @param partNumber the file extension.
* @return File.
*/
public File getFile(int partNumber) {
return new File(root, namePrefix + "." + partNumber);
}
public long getPartSize() {
return partSize;
}
public File getRoot() {
return root;
}
public String getNamePrefix() {
return namePrefix;
}
public long getTotalBytesWritten() {
return totalBytesWritten;
}
@SuppressWarnings("checkstyle:methodname")
static String yyMMdd_hhmmss() {
return new SimpleDateFormat("yyMMdd-hhmmss").format(new Date());
}
public boolean isClosed() {
return closed;
}
public long getDiskLimit() {
return diskLimit;
}
}