1 /*
   2  * Copyright (c) 2014, 2015, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 package jdk.vm.ci.options;
  24 
  25 import java.io.*;
  26 import java.util.*;
  27 import java.util.jar.*;
  28 import java.util.zip.*;
  29 
  30 import jdk.vm.ci.options.OptionsParser.*;
  31 
  32 /**
  33  * Access to the {@link OptionDescriptors} declared by
  34  * {@code META-INF/services/jdk.vm.ci.options.OptionDescriptors} files in {@code
  35  * <jre>/lib/jvmci/*.jar}.
  36  */
  37 class JVMCIJarsOptionDescriptorsProvider implements OptionDescriptorsProvider {
  38 
  39     static final String OptionDescriptorsServiceFile = "META-INF/services/" + OptionDescriptors.class.getName();
  40 
  41     private final Iterator<File> jars;
  42     private final List<OptionDescriptors> optionsDescriptorsList;
  43 
  44     JVMCIJarsOptionDescriptorsProvider() {
  45         List<File> jarsList = findJVMCIJars();
  46         this.jars = jarsList.iterator();
  47         this.optionsDescriptorsList = new ArrayList<>(jarsList.size() * 3);
  48     }
  49 
  50     /**
  51      * Finds the list of JVMCI jars.
  52      */
  53     private static List<File> findJVMCIJars() {
  54         File javaHome = new File(System.getProperty("java.home"));
  55         File lib = new File(javaHome, "lib");
  56         File jvmci = new File(lib, "jvmci");
  57 
  58         List<File> jarFiles = new ArrayList<>();
  59         if (jvmci.exists()) {
  60             for (String fileName : jvmci.list()) {
  61                 if (fileName.endsWith(".jar")) {
  62                     File file = new File(jvmci, fileName);
  63                     if (file.isDirectory()) {
  64                         continue;
  65                     }
  66                     jarFiles.add(file);
  67                 }
  68             }
  69         }
  70         return jarFiles;
  71     }
  72 
  73     public OptionDescriptor get(String name) {
  74         // Look up loaded option descriptors first
  75         for (OptionDescriptors optionDescriptors : optionsDescriptorsList) {
  76             OptionDescriptor desc = optionDescriptors.get(name);
  77             if (desc != null) {
  78                 return desc;
  79             }
  80         }
  81         while (jars.hasNext()) {
  82             File path = jars.next();
  83             try (JarFile jar = new JarFile(path)) {
  84                 ZipEntry entry = jar.getEntry(OptionDescriptorsServiceFile);
  85                 if (entry != null) {
  86                     BufferedReader br = new BufferedReader(new InputStreamReader(jar.getInputStream(entry)));
  87                     String line = null;
  88                     OptionDescriptor desc = null;
  89                     while ((line = br.readLine()) != null) {
  90                         OptionDescriptors options;
  91                         try {
  92                             options = (OptionDescriptors) Class.forName(line).newInstance();
  93                             optionsDescriptorsList.add(options);
  94                             if (desc == null) {
  95                                 desc = options.get(name);
  96                             }
  97                         } catch (Exception e) {
  98                             throw new InternalError("Error instantiating class " + line + " read from " + path, e);
  99                         }
 100                     }
 101                     if (desc != null) {
 102                         return desc;
 103                     }
 104                 }
 105             } catch (IOException e) {
 106                 throw new InternalError("Error reading " + path, e);
 107             }
 108         }
 109         return null;
 110     }
 111 }