1 /*

     2  * Copyright (c) 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.  Oracle designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Oracle in the LICENSE file that accompanied this code.

    10  *

    11  * This code is distributed in the hope that it will be useful, but WITHOUT

    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    14  * version 2 for more details (a copy is included in the LICENSE file that

    15  * accompanied this code).

    16  *

    17  * You should have received a copy of the GNU General Public License version

    18  * 2 along with this work; if not, write to the Free Software Foundation,

    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    20  *

    21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    22  * or visit www.oracle.com if you need additional information or have any

    23  * questions.

    24  */

    25 package jdk.internal.jrtfs;

    26 

    27 import java.io.IOException;

    28 import java.nio.file.DirectoryStream;

    29 import java.nio.file.FileSystem;

    30 import java.nio.file.FileSystemException;

    31 import java.nio.file.FileSystems;

    32 import java.nio.file.Files;

    33 import java.nio.file.Path;

    34 import java.nio.file.attribute.BasicFileAttributes;

    35 import java.util.ArrayList;

    36 import java.util.Collections;

    37 import java.util.HashMap;

    38 import java.util.List;

    39 import java.util.Map;

    40 

    41 import jdk.internal.jimage.ImageReader.Node;

    42 

    43 /**

    44  * A jrt file system built on $JAVA_HOME/modules directory ('exploded modules

    45  * build')

    46  *

    47  * @implNote This class needs to maintain JDK 8 source compatibility.

    48  *

    49  * It is used internally in the JDK to implement jimage/jrtfs access,

    50  * but also compiled and delivered as part of the jrtfs.jar to support access

    51  * to the jimage file provided by the shipped JDK by tools running on JDK 8.

    52  */

    53 class ExplodedImage extends SystemImage {

    54 

    55     private static final String MODULES = "/modules/";

    56     private static final String PACKAGES = "/packages/";

    57     private static final int PACKAGES_LEN = PACKAGES.length();

    58 

    59     private final FileSystem defaultFS;

    60     private final String separator;

    61     private final Map<String, PathNode> nodes = Collections.synchronizedMap(new HashMap<>());

    62     private final BasicFileAttributes modulesDirAttrs;

    63 

    64     ExplodedImage(Path modulesDir) throws IOException {

    65         defaultFS = FileSystems.getDefault();

    66         String str = defaultFS.getSeparator();

    67         separator = str.equals("/") ? null : str;

    68         modulesDirAttrs = Files.readAttributes(modulesDir, BasicFileAttributes.class);

    69         initNodes();

    70     }

    71 

    72     // A Node that is backed by actual default file system Path

    73     private final class PathNode extends Node {

    74 

    75         // Path in underlying default file system

    76         private Path path;

    77         private PathNode link;

    78         private List<Node> children;

    79 

    80         PathNode(String name, Path path, BasicFileAttributes attrs) {  // path

    81             super(name, attrs);

    82             this.path = path;

    83         }

    84 

    85         PathNode(String name, Node link) {              // link

    86             super(name, link.getFileAttributes());

    87             this.link = (PathNode)link;

    88         }

    89 

    90         PathNode(String name, List<Node> children) {    // dir

    91             super(name, modulesDirAttrs);

    92             this.children = children;

    93         }

    94 

    95         @Override

    96         public boolean isDirectory() {

    97             return children != null ||

    98                    (link == null && getFileAttributes().isDirectory());

    99         }

   100 

   101         @Override

   102         public boolean isLink() {

   103             return link != null;

   104         }

   105 

   106         @Override

   107         public PathNode resolveLink(boolean recursive) {

   108             if (link == null)

   109                 return this;

   110             return recursive && link.isLink() ? link.resolveLink(true) : link;

   111         }

   112 

   113         byte[] getContent() throws IOException {

   114             if (!getFileAttributes().isRegularFile())

   115                 throw new FileSystemException(getName() + " is not file");

   116             return Files.readAllBytes(path);

   117         }

   118 

   119         @Override

   120         public List<Node> getChildren() {

   121             if (!isDirectory())

   122                 throw new IllegalArgumentException("not a directory: " + getNameString());

   123             if (children == null) {

   124                 List<Node> list = new ArrayList<>();

   125                 try (DirectoryStream<Path> stream = Files.newDirectoryStream(path)) {

   126                     for (Path p : stream) {

   127                         p = explodedModulesDir.relativize(p);

   128                         String pName = MODULES + nativeSlashToFrontSlash(p.toString());

   129                         Node node = findNode(pName);

   130                         if (node != null) {  // findNode may choose to hide certain files!

   131                             list.add(node);

   132                         }

   133                     }

   134                 } catch (IOException x) {

   135                     return null;

   136                 }

   137                 children = list;

   138             }

   139             return children;

   140         }

   141     }

   142 

   143     @Override

   144     public void close() throws IOException {

   145         nodes.clear();

   146     }

   147 

   148     @Override

   149     public byte[] getResource(Node node) throws IOException {

   150         return ((PathNode)node).getContent();

   151     }

   152 

   153     // find Node for the given Path

   154     @Override

   155     public synchronized Node findNode(String str) {

   156         Node node = findModulesNode(str);

   157         if (node != null) {

   158             return node;

   159         }

   160         // lazily created for paths like /packages/<package>/<module>/xyz

   161         // For example /packages/java.lang/java.base/java/lang/

   162         if (str.startsWith(PACKAGES)) {

   163             // pkgEndIdx marks end of <package> part

   164             int pkgEndIdx = str.indexOf('/', PACKAGES_LEN);

   165             if (pkgEndIdx != -1) {

   166                 // modEndIdx marks end of <module> part

   167                 int modEndIdx = str.indexOf('/', pkgEndIdx + 1);

   168                 if (modEndIdx != -1) {

   169                     // make sure we have such module link!

   170                     // ie., /packages/<package>/<module> is valid

   171                     Node linkNode = nodes.get(str.substring(0, modEndIdx));

   172                     if (linkNode == null || !linkNode.isLink()) {

   173                         return null;

   174                     }

   175                     // map to "/modules/zyz" path and return that node

   176                     // For example, "/modules/java.base/java/lang" for

   177                     // "/packages/java.lang/java.base/java/lang".

   178                     String mod = MODULES + str.substring(pkgEndIdx + 1);

   179                     return findModulesNode(mod);

   180                 }

   181             }

   182         }

   183         return null;

   184     }

   185 

   186     // find a Node for a path that starts like "/modules/..."

   187     Node findModulesNode(String str) {

   188         PathNode node = nodes.get(str);

   189         if (node != null) {

   190             return node;

   191         }

   192         // lazily created "/modules/xyz/abc/" Node

   193         // This is mapped to default file system path "<JDK_MODULES_DIR>/xyz/abc"

   194         Path p = underlyingPath(str);

   195         if (p != null) {

   196             try {

   197                 BasicFileAttributes attrs = Files.readAttributes(p, BasicFileAttributes.class);

   198                 if (attrs.isRegularFile()) {

   199                     Path f = p.getFileName();

   200                     if (f.toString().startsWith("_the."))

   201                         return null;

   202                 }

   203                 node = new PathNode(str, p, attrs);

   204                 nodes.put(str, node);

   205                 return node;

   206             } catch (IOException x) {

   207                 // does not exists or unable to determine

   208             }

   209         }

   210         return null;

   211     }

   212 

   213     Path underlyingPath(String str) {

   214         if (str.startsWith(MODULES)) {

   215             str = frontSlashToNativeSlash(str.substring("/modules".length()));

   216             return defaultFS.getPath(explodedModulesDir.toString(), str);

   217         }

   218         return null;

   219     }

   220 

   221     // convert "/" to platform path separator

   222     private String frontSlashToNativeSlash(String str) {

   223         return separator == null ? str : str.replace("/", separator);

   224     }

   225 

   226     // convert platform path separator to "/"

   227     private String nativeSlashToFrontSlash(String str) {

   228         return separator == null ? str : str.replace(separator, "/");

   229     }

   230 

   231     // convert "/"s to "."s

   232     private String slashesToDots(String str) {

   233         return str.replace(separator != null ? separator : "/", ".");

   234     }

   235 

   236     // initialize file system Nodes

   237     private void initNodes() throws IOException {

   238         // same package prefix may exist in mutliple modules. This Map

   239         // is filled by walking "jdk modules" directory recursively!

   240         Map<String, List<String>> packageToModules = new HashMap<>();

   241         try (DirectoryStream<Path> stream = Files.newDirectoryStream(explodedModulesDir)) {

   242             for (Path module : stream) {

   243                 if (Files.isDirectory(module)) {

   244                     String moduleName = module.getFileName().toString();

   245                     // make sure "/modules/<moduleName>" is created

   246                     findModulesNode(MODULES + moduleName);

   247                     Files.walk(module).filter(Files::isDirectory).forEach((p) -> {

   248                         p = module.relativize(p);

   249                         String pkgName = slashesToDots(p.toString());

   250                         // skip META-INFO and empty strings

   251                         if (!pkgName.isEmpty() && !pkgName.startsWith("META-INF")) {

   252                             List<String> moduleNames = packageToModules.get(pkgName);

   253                             if (moduleNames == null) {

   254                                 moduleNames = new ArrayList<>();

   255                                 packageToModules.put(pkgName, moduleNames);

   256                             }

   257                             moduleNames.add(moduleName);

   258                         }

   259                     });

   260                 }

   261             }

   262         }

   263         // create "/modules" directory

   264         // "nodes" map contains only /modules/<foo> nodes only so far and so add all as children of /modules

   265         PathNode modulesDir = new PathNode("/modules", new ArrayList<>(nodes.values()));

   266         nodes.put(modulesDir.getName(), modulesDir);

   267 

   268         // create children under "/packages"

   269         List<Node> packagesChildren = new ArrayList<>(packageToModules.size());

   270         for (Map.Entry<String, List<String>> entry : packageToModules.entrySet()) {

   271             String pkgName = entry.getKey();

   272             List<String> moduleNameList = entry.getValue();

   273             List<Node> moduleLinkNodes = new ArrayList<>(moduleNameList.size());

   274             for (String moduleName : moduleNameList) {

   275                 Node moduleNode = findModulesNode(MODULES + moduleName);

   276                 PathNode linkNode = new PathNode(PACKAGES + pkgName + "/" + moduleName, moduleNode);

   277                 nodes.put(linkNode.getName(), linkNode);

   278                 moduleLinkNodes.add(linkNode);

   279             }

   280             PathNode pkgDir = new PathNode(PACKAGES + pkgName, moduleLinkNodes);

   281             nodes.put(pkgDir.getName(), pkgDir);

   282             packagesChildren.add(pkgDir);

   283         }

   284         // "/packages" dir

   285         PathNode packagesDir = new PathNode("/packages", packagesChildren);

   286         nodes.put(packagesDir.getName(), packagesDir);

   287 

   288         // finally "/" dir!

   289         List<Node> rootChildren = new ArrayList<>();

   290         rootChildren.add(packagesDir);

   291         rootChildren.add(modulesDir);

   292         PathNode root = new PathNode("/", rootChildren);

   293         nodes.put(root.getName(), root);

   294     }

   295 }