| /* |
| * 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.dev.jjs.ast.JNode; |
| import com.google.gwt.thirdparty.guava.common.hash.Hashing; |
| import com.google.gwt.thirdparty.guava.common.io.Files; |
| import com.google.gwt.util.tools.shared.Md5Utils; |
| import com.google.gwt.util.tools.shared.StringUtils; |
| |
| import java.io.File; |
| import java.io.IOException; |
| import java.net.JarURLConnection; |
| import java.net.URLConnection; |
| |
| /** |
| * Utility for uniquely identifying the current compiler version. |
| */ |
| public class CompilerVersion { |
| |
| private static String versionHash; |
| |
| /** |
| * Calculates and returns a hash to uniquely identify the current compiler version if possible. |
| * <p> |
| * If the compiler jar can not be found then a random hash is returned. |
| */ |
| public static synchronized String getHash() { |
| if (versionHash == null) { |
| versionHash = "unknown-version-" + StringUtils.toHexString( |
| Md5Utils.getMd5Digest(Long.toString((long) (Long.MAX_VALUE * Math.random())))); |
| |
| try { |
| URLConnection urlConnection = JNode.class.getResource("JNode.class").openConnection(); |
| if (urlConnection instanceof JarURLConnection) { |
| String gwtdevJar = ((JarURLConnection) urlConnection).getJarFile().getName(); |
| versionHash = Files.hash(new File(gwtdevJar), Hashing.sha1()).toString(); |
| } else { |
| System.err.println("Could not find the GWT compiler jarfile. " |
| + "Serialization errors might occur when accessing the persistent unit cache."); |
| } |
| } catch (IOException e) { |
| System.err.println("Could not compute the hash for the GWT compiler jarfile." |
| + "Serialization errors might occur when accessing the persistent unit cache."); |
| } |
| } |
| return versionHash; |
| } |
| } |