/*
* Copyright 2014 Google 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.google.gwt.dev.util;
import com.google.gwt.core.ext.TreeLogger;
import com.google.gwt.thirdparty.guava.common.base.Joiner;
import com.google.gwt.util.tools.shared.Md5Utils;
import com.google.gwt.util.tools.shared.StringUtils;
import java.io.File;
import java.util.List;
/**
* General utility functions for disk caching.
*/
public class DiskCachingUtil {
/**
* Computes and returns a consistent preferred cache dir based on the given set of module names
* and the current working directory.
* <p>
* Using a consistent cache dir has performance advantages since caches can be reused between JVM
* process launches.
*/
public static synchronized File computePreferredCacheDir(List<String> moduleNames,
TreeLogger logger) {
String tempDir = System.getProperty("java.io.tmpdir");
String currentWorkingDirectory = System.getProperty("user.dir");
String preferredCacheDirName = "gwt-cache-" + StringUtils.toHexString(
Md5Utils.getMd5Digest(currentWorkingDirectory + Joiner.on(", ").join(moduleNames)));
File preferredCacheDir = new File(tempDir, preferredCacheDirName);
if (!preferredCacheDir.exists() && !preferredCacheDir.mkdir()) {
logger.log(TreeLogger.WARN, "Can't create cache directory: " + preferredCacheDir);
return null;
}
return preferredCacheDir;
}
}