| /* |
| * Copyright (c) 2005, 2011, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package build.tools.buildmetaindex; |
| |
| import java.io.*; |
| import java.util.*; |
| import java.util.jar.*; |
| |
| /** Constructs a meta-index of the specified jar files. The meta-index |
| contains prefixes of packages contained in these jars, indexed by |
| the jar file name. It is intended to be consumed by the JVM to |
| allow the boot class loader to be made lazier. For example, when |
| class data sharing is enabled, the presence of the meta-index |
| allows the JVM to skip opening rt.jar if all of the dependent |
| classes of the application are in the shared archive. A similar |
| mechanism could be useful at the application level as well, for |
| example to make the extension class loader lazier. |
| |
| <p> The contents of the meta-index file for jre/lib look something |
| like this: |
| |
| <PRE> |
| % VERSION 2 |
| # charsets.jar |
| sun/ |
| # jce.jar |
| javax/ |
| ! jsse.jar |
| sun/ |
| com/sun/net/ |
| javax/ |
| com/sun/security/ |
| # management-agent.jar |
| ! rt.jar |
| org/w3c/ |
| com/sun/image/ |
| com/sun/org/ |
| com/sun/imageio/ |
| com/sun/accessibility/ |
| javax/ |
| ... |
| </PRE> |
| |
| <p> It is a current invariant of the code in the JVM which |
| consumes the meta-index that the meta-index indexes only jars in |
| one directory. It is acceptable for jars in that directory to not |
| be mentioned in the meta-index. The meta-index is designed more to |
| be able to perform a quick rejection test of the presence of a |
| particular class in a particular jar file than to be a precise |
| index of the contents of the jar. */ |
| |
| public class BuildMetaIndex { |
| public static void main(String[] args) throws IOException { |
| /* The correct usage of this class is as following: |
| * java BuildMetaIndex -o <meta-index> <a list of jar files> |
| * So the argument length should be at least 3 and the first argument should |
| * be '-o'. |
| */ |
| if (args.length < 3 || |
| !args[0].equals("-o")) { |
| printUsage(); |
| System.exit(1); |
| } |
| |
| try { |
| PrintStream out = new PrintStream(new FileOutputStream(args[1])); |
| out.println("% VERSION 2"); |
| out.println("% WARNING: this file is auto-generated; do not edit"); |
| out.println("% UNSUPPORTED: this file and its format may change and/or"); |
| out.println("% may be removed in a future release"); |
| for (int i = 2; i < args.length; i++) { |
| String filename = args[i]; |
| JarMetaIndex jmi = new JarMetaIndex(filename); |
| HashSet<String> index = jmi.getMetaIndex(); |
| if (index == null) { |
| continue; |
| } |
| /* |
| * meta-index file plays different role in JVM and JDK side. |
| * On the JVM side, meta-index file is used to speed up locating the |
| * class files only while on the JDK side, meta-index file is used to speed |
| * up the resources file and class file. |
| * To help the JVM and JDK code to better utilize the information in meta-index |
| * file, we mark the jar file differently. Here is the current rule we use (See |
| * JarFileKind.getMarkChar() method. ) |
| * For jar file containing only class file, we put '!' before the jar file name; |
| * for jar file containing only resources file, we put '@' before the jar file name; |
| * for jar file containing both resources and class file, we put '#' before the jar name. |
| * Notice the fact that every jar file contains at least the manifest file, so when |
| * we say "jar file containing only class file", we don't include that file. |
| */ |
| |
| out.println(jmi.getJarFileKind().getMarkerChar() + " " + filename); |
| for (String entry : index) { |
| out.println(entry); |
| } |
| |
| } |
| out.flush(); |
| out.close(); |
| } catch (FileNotFoundException fnfe) { |
| System.err.println("FileNotFoundException occurred"); |
| System.exit(2); |
| } |
| } |
| |
| private static void printUsage() { |
| String usage = |
| "BuildMetaIndex is used to generate a meta index file for the jar files\n" + |
| "you specified. The following is its usage:\n" + |
| " java BuildMetaIndex -o <the output meta index file> <a list of jar files> \n" + |
| " You can specify *.jar to refer to all the jar files in the current directory"; |
| |
| System.err.println(usage); |
| } |
| } |
| |
| enum JarFileKind { |
| |
| CLASSONLY ('!'), |
| RESOURCEONLY ('@'), |
| MIXED ('#'); |
| |
| private char markerChar; |
| |
| JarFileKind(char markerChar) { |
| this.markerChar = markerChar; |
| } |
| |
| public char getMarkerChar() { |
| return markerChar; |
| } |
| } |
| |
| /* |
| * JarMetaIndex associates the jar file with a set of what so called |
| * "meta-index" of the jar file. Essentially, the meta-index is a list |
| * of class prefixes and the plain files contained in META-INF directory ( |
| * not include the manifest file itself). This will help sun.misc.URLClassPath |
| * to quickly locate the resource file and hotspot VM to locate the class file. |
| * |
| */ |
| class JarMetaIndex { |
| private JarFile jar; |
| private volatile HashSet<String> indexSet; |
| |
| /* |
| * A hashmap contains a mapping from the prefix string to |
| * a hashset which contains a set of the second level of prefix string. |
| */ |
| private HashMap<String, HashSet<String>> knownPrefixMap = new HashMap<>(); |
| |
| /** |
| * Special value for the HashSet to indicate that there are classes in |
| * the top-level package. |
| */ |
| private static final String TOP_LEVEL = "TOP"; |
| |
| /* |
| * A class for mapping package prefixes to the number of |
| * levels of package elements to include. |
| */ |
| static class ExtraLevel { |
| public ExtraLevel(String prefix, int levels) { |
| this.prefix = prefix; |
| this.levels = levels; |
| } |
| String prefix; |
| int levels; |
| } |
| |
| /* |
| * A list of the special-cased package names. |
| */ |
| private static ArrayList<ExtraLevel> extraLevels = new ArrayList<>(); |
| |
| static { |
| // The order of these statements is significant, |
| // since we stop looking after the first match. |
| |
| // Need more precise information to disambiguate |
| // (illegal) references from applications to |
| // obsolete backported collections classes in |
| // com/sun/java/util |
| extraLevels.add(new ExtraLevel("com/sun/java/util/", Integer.MAX_VALUE)); |
| extraLevels.add(new ExtraLevel("com/sun/java/", 4)); |
| // Need more information than just first two package |
| // name elements to determine that classes in |
| // deploy.jar are not in rt.jar |
| extraLevels.add(new ExtraLevel("com/sun/", 3)); |
| // Need to make sure things in jfr.jar aren't |
| // confused with other com/oracle/** packages |
| extraLevels.add(new ExtraLevel("com/oracle/jrockit", 3)); |
| } |
| |
| |
| /* |
| * We add maximum 5 second level entries to "sun", "jdk", "java" and |
| * "javax" entries. Tune this parameter to get a balance on the |
| * cold start and footprint. |
| */ |
| private static final int MAX_PKGS_WITH_KNOWN_PREFIX = 5; |
| |
| private JarFileKind jarFileKind; |
| |
| JarMetaIndex(String fileName) throws IOException { |
| jar = new JarFile(fileName); |
| knownPrefixMap.put("sun", new HashSet<String>()); |
| knownPrefixMap.put("jdk", new HashSet<String>()); |
| knownPrefixMap.put("java", new HashSet<String>()); |
| knownPrefixMap.put("javax", new HashSet<String>()); |
| } |
| |
| /* Returns a HashSet contains the meta index string. */ |
| HashSet<String> getMetaIndex() { |
| if (indexSet == null) { |
| synchronized(this) { |
| if (indexSet == null) { |
| indexSet = new HashSet<>(); |
| Enumeration<JarEntry> entries = jar.entries(); |
| boolean containsOnlyClass = true; |
| boolean containsOnlyResource = true; |
| while (entries.hasMoreElements()) { |
| JarEntry entry = entries.nextElement(); |
| String name = entry.getName(); |
| /* We only look at the non-directory entry. |
| MANIFEST file is also skipped. */ |
| if (entry.isDirectory() |
| || name.equals("META-INF/MANIFEST.MF")) { |
| continue; |
| } |
| |
| /* Once containsOnlyResource or containsOnlyClass |
| turns to false, no need to check the entry type. |
| */ |
| if (containsOnlyResource || containsOnlyClass) { |
| if (name.endsWith(".class")) { |
| containsOnlyResource = false; |
| } else { |
| containsOnlyClass = false; |
| } |
| } |
| |
| /* Add the full-qualified name of plain files under |
| META-INF directory to the indexSet. |
| */ |
| if (name.startsWith("META-INF")) { |
| indexSet.add(name); |
| continue; |
| } |
| |
| /* Add the prefix name to the knownPrefixMap if the |
| name starts with any string in the knownPrefix list. |
| */ |
| if (isPrefixKnown(name)) { |
| continue; |
| } |
| |
| String[] pkgElements = name.split("/"); |
| // Last one is the class name; definitely ignoring that |
| if (pkgElements.length > 2) { |
| String meta = ""; |
| |
| // Default is 2 levels of package elements |
| int levels = 2; |
| |
| // But for some packages we add more elements |
| for(ExtraLevel el : extraLevels) { |
| if (name.startsWith(el.prefix)) { |
| levels = el.levels; |
| break; |
| } |
| } |
| for (int i = 0; i < levels && i < pkgElements.length - 1; i++) { |
| meta += pkgElements[i] + "/"; |
| } |
| |
| if (!meta.equals("")) { |
| indexSet.add(meta); |
| } |
| } |
| |
| } // end of "while" loop; |
| |
| // Add the second level package names to the indexSet for |
| // the predefined names such as "sun", "java" and "javax". |
| addKnownPrefix(); |
| |
| /* Set "jarFileKind" attribute. */ |
| if (containsOnlyClass) { |
| jarFileKind = JarFileKind.CLASSONLY; |
| } else if (containsOnlyResource) { |
| jarFileKind = JarFileKind.RESOURCEONLY; |
| } else { |
| jarFileKind = JarFileKind.MIXED; |
| } |
| } |
| } |
| } |
| return indexSet; |
| } |
| |
| /* |
| * Checks to see whether the name starts with a string which is in the predefined |
| * list. If it is among one of the predefined prefixes, add it to the knowPrefixMap |
| * and returns true, otherwise, returns false. |
| * Returns true if the name is in a predefined prefix list. Otherwise, returns false. |
| */ |
| boolean isPrefixKnown(String name) { |
| int firstSlashIndex = name.indexOf("/"); |
| if (firstSlashIndex == -1) { |
| return false; |
| } |
| |
| String firstPkgElement = name.substring(0, firstSlashIndex); |
| HashSet<String> pkgSet = knownPrefixMap.get(firstPkgElement); |
| |
| /* The name does not starts with "sun", "java" or "javax". */ |
| if (pkgSet == null) { |
| return false; |
| } |
| |
| /* Add the second level package name to the corresponding hashset. */ |
| int secondSlashIndex = name.indexOf("/", firstSlashIndex+1); |
| if (secondSlashIndex == -1) { |
| pkgSet.add(TOP_LEVEL); |
| } else { |
| String secondPkgElement = name.substring(firstSlashIndex+1, secondSlashIndex); |
| pkgSet.add(secondPkgElement); |
| } |
| |
| return true; |
| } |
| |
| /* |
| * Adds all the second level package elements for "sun", "java" and "javax" |
| * if the corresponding jar file does not contain more than |
| * MAX_PKGS_WITH_KNOWN_PREFIX such entries. |
| */ |
| void addKnownPrefix() { |
| if (indexSet == null) { |
| return; |
| } |
| |
| /* Iterate through the hash map, add the second level package names |
| * to the indexSet if has any. |
| */ |
| for (String key : knownPrefixMap.keySet()) { |
| HashSet<String> pkgSetStartsWithKey = knownPrefixMap.get(key); |
| int setSize = pkgSetStartsWithKey.size(); |
| |
| if (setSize == 0) { |
| continue; |
| } |
| if (setSize > JarMetaIndex.MAX_PKGS_WITH_KNOWN_PREFIX || |
| pkgSetStartsWithKey.contains(TOP_LEVEL)) { |
| indexSet.add(key + "/"); |
| } else { |
| /* If the set contains less than MAX_PKGS_WITH_KNOWN_PREFIX, add |
| * them to the indexSet of the MetaIndex object. |
| */ |
| for (String secondPkgElement : pkgSetStartsWithKey) { |
| indexSet.add(key + "/" + secondPkgElement); |
| } |
| } |
| } // end the outer "for" |
| } |
| |
| JarFileKind getJarFileKind() { |
| // Build meta index if it hasn't. |
| if (indexSet == null) { |
| indexSet = getMetaIndex(); |
| } |
| return jarFileKind; |
| } |
| } |