/*
* Copyright 2012-present Facebook, Inc.
*
* Licensed 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 com.facebook.buck.step.fs;
import com.facebook.buck.io.ProjectFilesystem;
import com.facebook.buck.log.Logger;
import com.facebook.buck.step.ExecutionContext;
import com.facebook.buck.step.Step;
import com.facebook.buck.step.StepExecutionResult;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Joiner;
import com.google.common.base.Preconditions;
import com.google.common.io.ByteStreams;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.nio.file.Path;
import java.nio.file.Paths;
import org.tukaani.xz.LZMA2Options;
import org.tukaani.xz.XZ;
import org.tukaani.xz.XZOutputStream;
/**
* A {@link Step} to compress a file with XZ / LZMA2.
*
* @see <a href="http://tukaani.org/xz/">XZ</a>
* @see <a href="http://tukaani.org/xz/java.html">XZ for Java</a>
* @see <a href="http://tukaani.org/xz/embedded.html">XZ Embedded</a>
*/
public class XzStep implements Step {
public static final int DEFAULT_COMPRESSION_LEVEL = 4;
private static final Logger LOG = Logger.get(XzStep.class);
private final ProjectFilesystem filesystem;
private final Path sourceFile;
private final Path destinationFile;
private final int compressionLevel;
private final boolean keep;
private final int check;
/**
* Create an {@link XzStep} to compress a file using XZ.
*
* @param sourceFile file to compress
* @param destinationFile where to store compressed data
* @param compressionLevel a value between 0-9, it impacts memory requirements for decompression
* @param keep by default, {@code xz} deletes the source file when compressing. This argument
* forces {@code xz} to keep it.
* @param check integrity check to use. Must be one of {@link XZ#CHECK_CRC32}, {@link
* XZ#CHECK_CRC64}, {@link XZ#CHECK_SHA256}, {@link XZ#CHECK_NONE} (Note: XZ Embedded can only
* verify CRC32).
*/
@VisibleForTesting
XzStep(
ProjectFilesystem filesystem,
Path sourceFile,
Path destinationFile,
int compressionLevel,
boolean keep,
int check) {
this.filesystem = filesystem;
this.sourceFile = sourceFile;
this.destinationFile = destinationFile;
Preconditions.checkArgument(
compressionLevel >= LZMA2Options.PRESET_MIN && compressionLevel <= LZMA2Options.PRESET_MAX,
"compressionLevel out of bounds.");
this.compressionLevel = compressionLevel;
this.keep = keep;
this.check = check;
}
/**
* Creates an XzStep to compress a file with XZ compression level 4.
*
* <p>The destination file will be {@code sourceFile} with the added {@code .xz} extension.
*
* <p>Decompression will require 5MiB of RAM.
*
* @param sourceFile file to compress
*/
public XzStep(ProjectFilesystem filesystem, Path sourceFile) {
this(filesystem, sourceFile, DEFAULT_COMPRESSION_LEVEL);
}
/**
* Creates an XzStep to compress a file with XZ compression level 4.
*
* <p>Decompression will require 5MiB of RAM.
*
* @param sourceFile file to compress
* @param outputPath desired output path
*/
public XzStep(ProjectFilesystem filesystem, Path sourceFile, Path outputPath) {
this(filesystem, sourceFile, outputPath, DEFAULT_COMPRESSION_LEVEL);
}
/**
* Creates an XzStep to compress a file with the given XZ compression level and output path.
*
* <p>Decompression will require up to 64MiB of RAM.
*
* @param sourceFile file to compress
* @param outputPath the desired output path.
* @param compressionLevel level of compression (from 0-9)
*/
public XzStep(
ProjectFilesystem filesystem, Path sourceFile, Path outputPath, int compressionLevel) {
this(filesystem, sourceFile, outputPath, compressionLevel, /* keep */ false, XZ.CHECK_CRC32);
}
/**
* Creates an XzStep to compress a file with XZ at a user supplied compression level .
*
* <p>The destination file will be {@code sourceFile} with the added {@code .xz} extension.
*
* <p>Decompression will require up to 64MiB of RAM.
*
* @param sourceFile file to compress
* @param compressionLevel value from 0 to 9. Higher values result in better compression, but also
* need more time to compress and will need more RAM to decompress.
*/
public XzStep(ProjectFilesystem filesystem, Path sourceFile, int compressionLevel) {
this(
filesystem,
sourceFile,
Paths.get(sourceFile + ".xz"),
compressionLevel,
/* keep */ false,
XZ.CHECK_CRC32);
}
@Override
public StepExecutionResult execute(ExecutionContext context) {
try (InputStream in = filesystem.newFileInputStream(sourceFile);
OutputStream out = filesystem.newFileOutputStream(destinationFile);
XZOutputStream xzOut = new XZOutputStream(out, new LZMA2Options(compressionLevel), check)) {
XzMemorySemaphore.acquireMemory(compressionLevel);
ByteStreams.copy(in, xzOut);
xzOut.finish();
if (!keep) {
filesystem.deleteFileAtPath(sourceFile);
}
} catch (IOException e) {
LOG.error(e);
return StepExecutionResult.ERROR;
} finally {
XzMemorySemaphore.releaseMemory(compressionLevel);
}
return StepExecutionResult.SUCCESS;
}
public Path getDestinationFile() {
return destinationFile;
}
@Override
public String getDescription(ExecutionContext context) {
return Joiner.on(" ")
.skipNulls()
.join(
"xz",
"-z",
"-" + compressionLevel,
(keep ? "--keep" : null),
"--check=crc32",
sourceFile);
}
@Override
public String getShortName() {
return "xz";
}
}