rev 52979 : 8215281: Use String.isEmpty() when applicable in java.base
Reviewed-by: TBD

   1 /*
   2  * Copyright (c) 2015, 2018, 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.module;
  26 
  27 import java.io.Closeable;
  28 import java.io.File;
  29 import java.io.IOError;
  30 import java.io.IOException;
  31 import java.io.InputStream;
  32 import java.io.UncheckedIOException;
  33 import java.lang.module.ModuleDescriptor;
  34 import java.lang.module.ModuleDescriptor.Builder;
  35 import java.lang.module.ModuleReader;
  36 import java.lang.module.ModuleReference;
  37 import java.net.MalformedURLException;
  38 import java.net.URI;
  39 import java.net.URL;
  40 import java.nio.ByteBuffer;
  41 import java.nio.file.Files;
  42 import java.nio.file.Path;
  43 import java.nio.file.Paths;
  44 import java.util.ArrayList;
  45 import java.util.HashMap;
  46 import java.util.HashSet;
  47 import java.util.List;
  48 import java.util.Map;
  49 import java.util.Optional;
  50 import java.util.Set;
  51 import java.util.jar.JarEntry;
  52 import java.util.jar.JarFile;
  53 import java.util.stream.Collectors;
  54 import java.util.stream.Stream;
  55 
  56 import jdk.internal.loader.Resource;
  57 import jdk.internal.access.JavaLangModuleAccess;
  58 import jdk.internal.access.SharedSecrets;
  59 import sun.net.www.ParseUtil;
  60 
  61 
  62 /**
  63  * Provides support for patching modules, mostly the boot layer.
  64  */
  65 
  66 public final class ModulePatcher {
  67 
  68     private static final JavaLangModuleAccess JLMA
  69         = SharedSecrets.getJavaLangModuleAccess();
  70 
  71     // module name -> sequence of patches (directories or JAR files)
  72     private final Map<String, List<Path>> map;
  73 
  74     /**
  75      * Initialize the module patcher with the given map. The map key is
  76      * the module name, the value is a list of path strings.
  77      */
  78     public ModulePatcher(Map<String, List<String>> input) {
  79         if (input.isEmpty()) {
  80             this.map = Map.of();
  81         } else {
  82             Map<String, List<Path>> map = new HashMap<>();
  83             for (Map.Entry<String, List<String>> e : input.entrySet()) {
  84                 String mn = e.getKey();
  85                 List<Path> paths = e.getValue().stream()
  86                         .map(Paths::get)
  87                         .collect(Collectors.toList());
  88                 map.put(mn, paths);
  89             }
  90             this.map = map;
  91         }
  92     }
  93 
  94     /**
  95      * Returns a module reference that interposes on the given module if
  96      * needed. If there are no patches for the given module then the module
  97      * reference is simply returned. Otherwise the patches for the module
  98      * are scanned (to find any new packages) and a new module reference is
  99      * returned.
 100      *
 101      * @throws UncheckedIOException if an I/O error is detected
 102      */
 103     public ModuleReference patchIfNeeded(ModuleReference mref) {
 104         // if there are no patches for the module then nothing to do
 105         ModuleDescriptor descriptor = mref.descriptor();
 106         String mn = descriptor.name();
 107         List<Path> paths = map.get(mn);
 108         if (paths == null)
 109             return mref;
 110 
 111         // Scan the JAR file or directory tree to get the set of packages.
 112         // For automatic modules then packages that do not contain class files
 113         // must be ignored.
 114         Set<String> packages = new HashSet<>();
 115         boolean isAutomatic = descriptor.isAutomatic();
 116         try {
 117             for (Path file : paths) {
 118                 if (Files.isRegularFile(file)) {
 119 
 120                     // JAR file - do not open as a multi-release JAR as this
 121                     // is not supported by the boot class loader
 122                     try (JarFile jf = new JarFile(file.toString())) {
 123                         jf.stream()
 124                           .filter(e -> !e.isDirectory()
 125                                   && (!isAutomatic || e.getName().endsWith(".class")))
 126                           .map(e -> toPackageName(file, e))
 127                           .filter(Checks::isPackageName)
 128                           .forEach(packages::add);
 129                     }
 130 
 131                 } else if (Files.isDirectory(file)) {
 132 
 133                     // exploded directory without following sym links
 134                     Path top = file;
 135                     Files.find(top, Integer.MAX_VALUE,
 136                                ((path, attrs) -> attrs.isRegularFile()))
 137                             .filter(path -> (!isAutomatic
 138                                     || path.toString().endsWith(".class"))
 139                                     && !isHidden(path))
 140                             .map(path -> toPackageName(top, path))
 141                             .filter(Checks::isPackageName)
 142                             .forEach(packages::add);
 143 
 144                 }
 145             }
 146 
 147         } catch (IOException ioe) {
 148             throw new UncheckedIOException(ioe);
 149         }
 150 
 151         // if there are new packages then we need a new ModuleDescriptor
 152         packages.removeAll(descriptor.packages());
 153         if (!packages.isEmpty()) {
 154             Builder builder = JLMA.newModuleBuilder(descriptor.name(),
 155                                                     /*strict*/ false,
 156                                                     descriptor.modifiers());
 157             if (!descriptor.isAutomatic()) {
 158                 descriptor.requires().forEach(builder::requires);
 159                 descriptor.exports().forEach(builder::exports);
 160                 descriptor.opens().forEach(builder::opens);
 161                 descriptor.uses().forEach(builder::uses);
 162             }
 163             descriptor.provides().forEach(builder::provides);
 164 
 165             descriptor.version().ifPresent(builder::version);
 166             descriptor.mainClass().ifPresent(builder::mainClass);
 167 
 168             // original + new packages
 169             builder.packages(descriptor.packages());
 170             builder.packages(packages);
 171 
 172             descriptor = builder.build();
 173         }
 174 
 175         // return a module reference to the patched module
 176         URI location = mref.location().orElse(null);
 177 
 178         ModuleTarget target = null;
 179         ModuleHashes recordedHashes = null;
 180         ModuleHashes.HashSupplier hasher = null;
 181         ModuleResolution mres = null;
 182         if (mref instanceof ModuleReferenceImpl) {
 183             ModuleReferenceImpl impl = (ModuleReferenceImpl)mref;
 184             target = impl.moduleTarget();
 185             recordedHashes = impl.recordedHashes();
 186             hasher = impl.hasher();
 187             mres = impl.moduleResolution();
 188         }
 189 
 190         return new ModuleReferenceImpl(descriptor,
 191                                        location,
 192                                        () -> new PatchedModuleReader(paths, mref),
 193                                        this,
 194                                        target,
 195                                        recordedHashes,
 196                                        hasher,
 197                                        mres);
 198 
 199     }
 200 
 201     /**
 202      * Returns true is this module patcher has patches.
 203      */
 204     public boolean hasPatches() {
 205         return !map.isEmpty();
 206     }
 207 
 208     /*
 209      * Returns the names of the patched modules.
 210      */
 211     Set<String> patchedModules() {
 212         return map.keySet();
 213     }
 214 
 215     /**
 216      * A ModuleReader that reads resources from a patched module.
 217      *
 218      * This class is public so as to expose the findResource method to the
 219      * built-in class loaders and avoid locating the resource twice during
 220      * class loading (once to locate the resource, the second to gets the
 221      * URL for the CodeSource).
 222      */
 223     public static class PatchedModuleReader implements ModuleReader {
 224         private final List<ResourceFinder> finders;
 225         private final ModuleReference mref;
 226         private final URL delegateCodeSourceURL;
 227         private volatile ModuleReader delegate;
 228 
 229         /**
 230          * Creates the ModuleReader to reads resources in a patched module.
 231          */
 232         PatchedModuleReader(List<Path> patches, ModuleReference mref) {
 233             List<ResourceFinder> finders = new ArrayList<>();
 234             boolean initialized = false;
 235             try {
 236                 for (Path file : patches) {
 237                     if (Files.isRegularFile(file)) {
 238                         finders.add(new JarResourceFinder(file));
 239                     } else {
 240                         finders.add(new ExplodedResourceFinder(file));
 241                     }
 242                 }
 243                 initialized = true;
 244             } catch (IOException ioe) {
 245                 throw new UncheckedIOException(ioe);
 246             } finally {
 247                 // close all ResourceFinder in the event of an error
 248                 if (!initialized) closeAll(finders);
 249             }
 250 
 251             this.finders = finders;
 252             this.mref = mref;
 253             this.delegateCodeSourceURL = codeSourceURL(mref);
 254         }
 255 
 256         /**
 257          * Closes all resource finders.
 258          */
 259         private static void closeAll(List<ResourceFinder> finders) {
 260             for (ResourceFinder finder : finders) {
 261                 try { finder.close(); } catch (IOException ioe) { }
 262             }
 263         }
 264 
 265         /**
 266          * Returns the code source URL for the given module.
 267          */
 268         private static URL codeSourceURL(ModuleReference mref) {
 269             try {
 270                 Optional<URI> ouri = mref.location();
 271                 if (ouri.isPresent())
 272                     return ouri.get().toURL();
 273             } catch (MalformedURLException e) { }
 274             return null;
 275         }
 276 
 277         /**
 278          * Returns the ModuleReader to delegate to when the resource is not
 279          * found in a patch location.
 280          */
 281         private ModuleReader delegate() throws IOException {
 282             ModuleReader r = delegate;
 283             if (r == null) {
 284                 synchronized (this) {
 285                     r = delegate;
 286                     if (r == null) {
 287                         delegate = r = mref.open();
 288                     }
 289                 }
 290             }
 291             return r;
 292         }
 293 
 294         /**
 295          * Finds a resources in the patch locations. Returns null if not found
 296          * or the name is "module-info.class" as that cannot be overridden.
 297          */
 298         private Resource findResourceInPatch(String name) throws IOException {
 299             if (!name.equals("module-info.class")) {
 300                 for (ResourceFinder finder : finders) {
 301                     Resource r = finder.find(name);
 302                     if (r != null)
 303                         return r;
 304                 }
 305             }
 306             return null;
 307         }
 308 
 309         /**
 310          * Finds a resource of the given name in the patched module.
 311          */
 312         public Resource findResource(String name) throws IOException {
 313 
 314             // patch locations
 315             Resource r = findResourceInPatch(name);
 316             if (r != null)
 317                 return r;
 318 
 319             // original module
 320             ByteBuffer bb = delegate().read(name).orElse(null);
 321             if (bb == null)
 322                 return null;
 323 
 324             return new Resource() {
 325                 private <T> T shouldNotGetHere(Class<T> type) {
 326                     throw new InternalError("should not get here");
 327                 }
 328                 @Override
 329                 public String getName() {
 330                     return shouldNotGetHere(String.class);
 331                 }
 332                 @Override
 333                 public URL getURL() {
 334                     return shouldNotGetHere(URL.class);
 335                 }
 336                 @Override
 337                 public URL getCodeSourceURL() {
 338                     return delegateCodeSourceURL;
 339                 }
 340                 @Override
 341                 public ByteBuffer getByteBuffer() throws IOException {
 342                     return bb;
 343                 }
 344                 @Override
 345                 public InputStream getInputStream() throws IOException {
 346                     return shouldNotGetHere(InputStream.class);
 347                 }
 348                 @Override
 349                 public int getContentLength() throws IOException {
 350                     return shouldNotGetHere(int.class);
 351                 }
 352             };
 353         }
 354 
 355         @Override
 356         public Optional<URI> find(String name) throws IOException {
 357             Resource r = findResourceInPatch(name);
 358             if (r != null) {
 359                 URI uri = URI.create(r.getURL().toString());
 360                 return Optional.of(uri);
 361             } else {
 362                 return delegate().find(name);
 363             }
 364         }
 365 
 366         @Override
 367         public Optional<InputStream> open(String name) throws IOException {
 368             Resource r = findResourceInPatch(name);
 369             if (r != null) {
 370                 return Optional.of(r.getInputStream());
 371             } else {
 372                 return delegate().open(name);
 373             }
 374         }
 375 
 376         @Override
 377         public Optional<ByteBuffer> read(String name) throws IOException {
 378             Resource r = findResourceInPatch(name);
 379             if (r != null) {
 380                 ByteBuffer bb = r.getByteBuffer();
 381                 assert !bb.isDirect();
 382                 return Optional.of(bb);
 383             } else {
 384                 return delegate().read(name);
 385             }
 386         }
 387 
 388         @Override
 389         public void release(ByteBuffer bb) {
 390             if (bb.isDirect()) {
 391                 try {
 392                     delegate().release(bb);
 393                 } catch (IOException ioe) {
 394                     throw new InternalError(ioe);
 395                 }
 396             }
 397         }
 398 
 399         @Override
 400         public Stream<String> list() throws IOException {
 401             Stream<String> s = delegate().list();
 402             for (ResourceFinder finder : finders) {
 403                 s = Stream.concat(s, finder.list());
 404             }
 405             return s.distinct();
 406         }
 407 
 408         @Override
 409         public void close() throws IOException {
 410             closeAll(finders);
 411             delegate().close();
 412         }
 413     }
 414 
 415 
 416     /**
 417      * A resource finder that find resources in a patch location.
 418      */
 419     private static interface ResourceFinder extends Closeable {
 420         Resource find(String name) throws IOException;
 421         Stream<String> list() throws IOException;
 422     }
 423 
 424 
 425     /**
 426      * A ResourceFinder that finds resources in a JAR file.
 427      */
 428     private static class JarResourceFinder implements ResourceFinder {
 429         private final JarFile jf;
 430         private final URL csURL;
 431 
 432         JarResourceFinder(Path path) throws IOException {
 433             this.jf = new JarFile(path.toString());
 434             this.csURL = path.toUri().toURL();
 435         }
 436 
 437         @Override
 438         public void close() throws IOException {
 439             jf.close();
 440         }
 441 
 442         @Override
 443         public Resource find(String name) throws IOException {
 444             JarEntry entry = jf.getJarEntry(name);
 445             if (entry == null)
 446                 return null;
 447 
 448             return new Resource() {
 449                 @Override
 450                 public String getName() {
 451                     return name;
 452                 }
 453                 @Override
 454                 public URL getURL() {
 455                     String encodedPath = ParseUtil.encodePath(name, false);
 456                     try {
 457                         return new URL("jar:" + csURL + "!/" + encodedPath);
 458                     } catch (MalformedURLException e) {
 459                         return null;
 460                     }
 461                 }
 462                 @Override
 463                 public URL getCodeSourceURL() {
 464                     return csURL;
 465                 }
 466                 @Override
 467                 public ByteBuffer getByteBuffer() throws IOException {
 468                     byte[] bytes = getInputStream().readAllBytes();
 469                     return ByteBuffer.wrap(bytes);
 470                 }
 471                 @Override
 472                 public InputStream getInputStream() throws IOException {
 473                     return jf.getInputStream(entry);
 474                 }
 475                 @Override
 476                 public int getContentLength() throws IOException {
 477                     long size = entry.getSize();
 478                     return (size > Integer.MAX_VALUE) ? -1 : (int) size;
 479                 }
 480             };
 481         }
 482 
 483         @Override
 484         public Stream<String> list() throws IOException {
 485             return jf.stream().map(JarEntry::getName);
 486         }
 487     }
 488 
 489 
 490     /**
 491      * A ResourceFinder that finds resources on the file system.
 492      */
 493     private static class ExplodedResourceFinder implements ResourceFinder {
 494         private final Path dir;
 495 
 496         ExplodedResourceFinder(Path dir) {
 497             this.dir = dir;
 498         }
 499 
 500         @Override
 501         public void close() { }
 502 
 503         @Override
 504         public Resource find(String name) throws IOException {
 505             Path file = Resources.toFilePath(dir, name);
 506             if (file != null) {
 507                 return newResource(name, dir, file);
 508             } else {
 509                 return null;
 510             }
 511         }
 512 
 513         private Resource newResource(String name, Path top, Path file) {
 514             return new Resource() {
 515                 @Override
 516                 public String getName() {
 517                     return name;
 518                 }
 519                 @Override
 520                 public URL getURL() {
 521                     try {
 522                         return file.toUri().toURL();
 523                     } catch (IOException | IOError e) {
 524                         return null;
 525                     }
 526                 }
 527                 @Override
 528                 public URL getCodeSourceURL() {
 529                     try {
 530                         return top.toUri().toURL();
 531                     } catch (IOException | IOError e) {
 532                         return null;
 533                     }
 534                 }
 535                 @Override
 536                 public ByteBuffer getByteBuffer() throws IOException {
 537                     return ByteBuffer.wrap(Files.readAllBytes(file));
 538                 }
 539                 @Override
 540                 public InputStream getInputStream() throws IOException {
 541                     return Files.newInputStream(file);
 542                 }
 543                 @Override
 544                 public int getContentLength() throws IOException {
 545                     long size = Files.size(file);
 546                     return (size > Integer.MAX_VALUE) ? -1 : (int)size;
 547                 }
 548             };
 549         }
 550 
 551         @Override
 552         public Stream<String> list() throws IOException {
 553             return Files.walk(dir, Integer.MAX_VALUE)
 554                         .map(f -> Resources.toResourceName(dir, f))
 555                         .filter(s -> !s.isEmpty());
 556         }
 557     }
 558 
 559 
 560     /**
 561      * Derives a package name from the file path of an entry in an exploded patch
 562      */
 563     private static String toPackageName(Path top, Path file) {
 564         Path entry = top.relativize(file);
 565         Path parent = entry.getParent();
 566         if (parent == null) {
 567             return warnIfModuleInfo(top, entry.toString());
 568         } else {
 569             return parent.toString().replace(File.separatorChar, '.');
 570         }
 571     }
 572 
 573     /**
 574      * Returns true if the given file exists and is a hidden file
 575      */
 576     private boolean isHidden(Path file) {
 577         try {
 578             return Files.isHidden(file);
 579         } catch (IOException ioe) {
 580             return false;
 581         }
 582     }
 583 
 584     /**
 585      * Derives a package name from the name of an entry in a JAR file.
 586      */
 587     private static String toPackageName(Path file, JarEntry entry) {
 588         String name = entry.getName();
 589         int index = name.lastIndexOf("/");
 590         if (index == -1) {
 591             return warnIfModuleInfo(file, name);
 592         } else {
 593             return name.substring(0, index).replace('/', '.');
 594         }
 595     }
 596 
 597     private static String warnIfModuleInfo(Path file, String e) {
 598         if (e.equals("module-info.class"))
 599             System.err.println("WARNING: " + e + " ignored in patch: " + file);
 600         return "";
 601     }
 602 }
--- EOF ---