1 /*
2 * Copyright (c) 2014, 2022, 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.jimage;
26
27 import java.io.IOException;
28 import java.io.InputStream;
29 import java.io.UncheckedIOException;
30 import java.nio.ByteBuffer;
31 import java.nio.ByteOrder;
32 import java.nio.IntBuffer;
33 import java.nio.file.Files;
34 import java.nio.file.attribute.BasicFileAttributes;
35 import java.nio.file.attribute.FileTime;
36 import java.nio.file.Path;
37 import java.util.ArrayList;
38 import java.util.Collections;
39 import java.util.HashMap;
40 import java.util.HashSet;
41 import java.util.List;
42 import java.util.Map;
43 import java.util.Objects;
44 import java.util.Set;
45 import java.util.function.Consumer;
46
47 /**
48 * @implNote This class needs to maintain JDK 8 source compatibility.
49 *
50 * It is used internally in the JDK to implement jimage/jrtfs access,
51 * but also compiled and delivered as part of the jrtfs.jar to support access
52 * to the jimage file provided by the shipped JDK by tools running on JDK 8.
53 */
54 public final class ImageReader implements AutoCloseable {
55 private final SharedImageReader reader;
56
57 private volatile boolean closed;
58
59 private ImageReader(SharedImageReader reader) {
60 this.reader = reader;
61 }
62
63 public static ImageReader open(Path imagePath, ByteOrder byteOrder) throws IOException {
64 Objects.requireNonNull(imagePath);
65 Objects.requireNonNull(byteOrder);
66
67 return SharedImageReader.open(imagePath, byteOrder);
68 }
69
70 public static ImageReader open(Path imagePath) throws IOException {
71 return open(imagePath, ByteOrder.nativeOrder());
72 }
73
74 @Override
75 public void close() throws IOException {
76 if (closed) {
77 throw new IOException("image file already closed");
78 }
79 reader.close(this);
80 closed = true;
81 }
82
83 private void ensureOpen() throws IOException {
84 if (closed) {
85 throw new IOException("image file closed");
86 }
87 }
88
89 private void requireOpen() {
90 if (closed) {
91 throw new IllegalStateException("image file closed");
92 }
93 }
94
95 // directory management interface
96 public Directory getRootDirectory() throws IOException {
97 ensureOpen();
98 return reader.getRootDirectory();
99 }
100
101
102 public Node findNode(String name) throws IOException {
103 ensureOpen();
104 return reader.findNode(name);
105 }
106
107 public byte[] getResource(Node node) throws IOException {
108 ensureOpen();
109 return reader.getResource(node);
110 }
111
112 public byte[] getResource(Resource rs) throws IOException {
113 ensureOpen();
114 return reader.getResource(rs);
115 }
116
117 public ImageHeader getHeader() {
118 requireOpen();
119 return reader.getHeader();
120 }
121
122 public static void releaseByteBuffer(ByteBuffer buffer) {
123 BasicImageReader.releaseByteBuffer(buffer);
124 }
125
126 public String getName() {
127 requireOpen();
128 return reader.getName();
129 }
130
131 public ByteOrder getByteOrder() {
132 requireOpen();
133 return reader.getByteOrder();
134 }
135
136 public Path getImagePath() {
137 requireOpen();
138 return reader.getImagePath();
139 }
140
141 public ImageStringsReader getStrings() {
142 requireOpen();
143 return reader.getStrings();
144 }
145
146 public ImageLocation findLocation(String mn, String rn) {
147 requireOpen();
148 return reader.findLocation(mn, rn);
149 }
150
151 public boolean verifyLocation(String mn, String rn) {
152 requireOpen();
153 return reader.verifyLocation(mn, rn);
154 }
155
156 public ImageLocation findLocation(String name) {
157 requireOpen();
158 return reader.findLocation(name);
159 }
160
161 public String[] getEntryNames() {
162 requireOpen();
163 return reader.getEntryNames();
164 }
165
166 public String[] getModuleNames() {
167 requireOpen();
168 int off = "/modules/".length();
169 return reader.findNode("/modules")
170 .getChildren()
171 .stream()
172 .map(Node::getNameString)
173 .map(s -> s.substring(off, s.length()))
174 .toArray(String[]::new);
175 }
176
177 public long[] getAttributes(int offset) {
178 requireOpen();
179 return reader.getAttributes(offset);
180 }
181
182 public String getString(int offset) {
183 requireOpen();
184 return reader.getString(offset);
185 }
186
187 public byte[] getResource(String name) {
188 requireOpen();
189 return reader.getResource(name);
190 }
191
192 public byte[] getResource(ImageLocation loc) {
193 requireOpen();
194 return reader.getResource(loc);
195 }
196
197 public ByteBuffer getResourceBuffer(ImageLocation loc) {
198 requireOpen();
199 return reader.getResourceBuffer(loc);
200 }
201
202 public InputStream getResourceStream(ImageLocation loc) {
203 requireOpen();
204 return reader.getResourceStream(loc);
205 }
206
207 private static final class SharedImageReader extends BasicImageReader {
208 static final int SIZE_OF_OFFSET = Integer.BYTES;
209
210 static final Map<Path, SharedImageReader> OPEN_FILES = new HashMap<>();
211
212 // List of openers for this shared image.
213 final Set<ImageReader> openers;
214
215 // attributes of the .jimage file. jimage file does not contain
216 // attributes for the individual resources (yet). We use attributes
217 // of the jimage file itself (creation, modification, access times).
218 // Iniitalized lazily, see {@link #imageFileAttributes()}.
219 BasicFileAttributes imageFileAttributes;
220
221 // directory management implementation
222 final HashMap<String, Node> nodes;
223 volatile Directory rootDir;
224
225 Directory packagesDir;
226 Directory modulesDir;
227
228 private SharedImageReader(Path imagePath, ByteOrder byteOrder) throws IOException {
229 super(imagePath, byteOrder);
230 this.openers = new HashSet<>();
231 this.nodes = new HashMap<>();
232 }
233
234 public static ImageReader open(Path imagePath, ByteOrder byteOrder) throws IOException {
235 Objects.requireNonNull(imagePath);
236 Objects.requireNonNull(byteOrder);
237
238 synchronized (OPEN_FILES) {
239 SharedImageReader reader = OPEN_FILES.get(imagePath);
240
241 if (reader == null) {
242 // Will fail with an IOException if wrong byteOrder.
243 reader = new SharedImageReader(imagePath, byteOrder);
244 OPEN_FILES.put(imagePath, reader);
245 } else if (reader.getByteOrder() != byteOrder) {
246 throw new IOException("\"" + reader.getName() + "\" is not an image file");
247 }
248
249 ImageReader image = new ImageReader(reader);
250 reader.openers.add(image);
251
252 return image;
253 }
254 }
255
256 public void close(ImageReader image) throws IOException {
257 Objects.requireNonNull(image);
258
259 synchronized (OPEN_FILES) {
260 if (!openers.remove(image)) {
261 throw new IOException("image file already closed");
262 }
263
264 if (openers.isEmpty()) {
265 close();
266 nodes.clear();
267 rootDir = null;
268
269 if (!OPEN_FILES.remove(this.getImagePath(), this)) {
270 throw new IOException("image file not found in open list");
271 }
272 }
273 }
274 }
275
276 void addOpener(ImageReader reader) {
277 synchronized (OPEN_FILES) {
278 openers.add(reader);
279 }
280 }
281
282 boolean removeOpener(ImageReader reader) {
283 synchronized (OPEN_FILES) {
284 return openers.remove(reader);
285 }
286 }
287
288 // directory management interface
289 Directory getRootDirectory() {
290 return buildRootDirectory();
291 }
292
293 /**
294 * Lazily build a node from a name.
295 */
296 synchronized Node buildNode(String name) {
297 Node n;
298 boolean isPackages = name.startsWith("/packages");
299 boolean isModules = !isPackages && name.startsWith("/modules");
300
301 if (!(isModules || isPackages)) {
302 return null;
303 }
304
305 ImageLocation loc = findLocation(name);
306
307 if (loc != null) { // A sub tree node
308 if (isPackages) {
309 n = handlePackages(name, loc);
310 } else { // modules sub tree
311 n = handleModulesSubTree(name, loc);
312 }
313 } else { // Asking for a resource? /modules/java.base/java/lang/Object.class
314 if (isModules) {
315 n = handleResource(name);
316 } else {
317 // Possibly ask for /packages/java.lang/java.base
318 // although /packages/java.base not created
319 n = handleModuleLink(name);
320 }
321 }
322 return n;
323 }
324
325 synchronized Directory buildRootDirectory() {
326 Directory root = rootDir; // volatile read
327 if (root != null) {
328 return root;
329 }
330
331 root = newDirectory(null, "/");
332 root.setIsRootDir();
333
334 // /packages dir
335 packagesDir = newDirectory(root, "/packages");
336 packagesDir.setIsPackagesDir();
337
338 // /modules dir
339 modulesDir = newDirectory(root, "/modules");
340 modulesDir.setIsModulesDir();
341
342 root.setCompleted(true);
343 return rootDir = root;
344 }
345
346 /**
347 * To visit sub tree resources.
348 */
349 interface LocationVisitor {
350 void visit(ImageLocation loc);
351 }
352
353 void visitLocation(ImageLocation loc, LocationVisitor visitor) {
354 byte[] offsets = getResource(loc);
355 ByteBuffer buffer = ByteBuffer.wrap(offsets);
356 buffer.order(getByteOrder());
357 IntBuffer intBuffer = buffer.asIntBuffer();
358 for (int i = 0; i < offsets.length / SIZE_OF_OFFSET; i++) {
359 int offset = intBuffer.get(i);
360 ImageLocation pkgLoc = getLocation(offset);
361 visitor.visit(pkgLoc);
362 }
363 }
364
365 void visitPackageLocation(ImageLocation loc) {
366 // Retrieve package name
367 String pkgName = getBaseExt(loc);
368 // Content is array of offsets in Strings table
369 byte[] stringsOffsets = getResource(loc);
370 ByteBuffer buffer = ByteBuffer.wrap(stringsOffsets);
371 buffer.order(getByteOrder());
372 IntBuffer intBuffer = buffer.asIntBuffer();
373 // For each module, create a link node.
374 for (int i = 0; i < stringsOffsets.length / SIZE_OF_OFFSET; i++) {
375 // skip empty state, useless.
376 intBuffer.get(i);
377 i++;
378 int offset = intBuffer.get(i);
379 String moduleName = getString(offset);
380 Node targetNode = findNode("/modules/" + moduleName);
381 if (targetNode != null) {
382 String pkgDirName = packagesDir.getName() + "/" + pkgName;
383 Directory pkgDir = (Directory) nodes.get(pkgDirName);
384 newLinkNode(pkgDir, pkgDir.getName() + "/" + moduleName, targetNode);
385 }
386 }
387 }
388
389 Node handlePackages(String name, ImageLocation loc) {
390 long size = loc.getUncompressedSize();
391 Node n = null;
392 // Only possibilities are /packages, /packages/package/module
393 if (name.equals("/packages")) {
394 visitLocation(loc, (childloc) -> {
395 findNode(childloc.getFullName());
396 });
397 packagesDir.setCompleted(true);
398 n = packagesDir;
399 } else {
400 if (size != 0) { // children are offsets to module in StringsTable
401 String pkgName = getBaseExt(loc);
402 Directory pkgDir = newDirectory(packagesDir, packagesDir.getName() + "/" + pkgName);
403 visitPackageLocation(loc);
404 pkgDir.setCompleted(true);
405 n = pkgDir;
406 } else { // Link to module
407 String pkgName = loc.getParent();
408 String modName = getBaseExt(loc);
409 Node targetNode = findNode("/modules/" + modName);
410 if (targetNode != null) {
411 String pkgDirName = packagesDir.getName() + "/" + pkgName;
412 Directory pkgDir = (Directory) nodes.get(pkgDirName);
413 Node linkNode = newLinkNode(pkgDir, pkgDir.getName() + "/" + modName, targetNode);
414 n = linkNode;
415 }
416 }
417 }
418 return n;
419 }
420
421 // Asking for /packages/package/module although
422 // /packages/<pkg>/ not yet created, need to create it
423 // prior to return the link to module node.
424 Node handleModuleLink(String name) {
425 // eg: unresolved /packages/package/module
426 // Build /packages/package node
427 Node ret = null;
428 String radical = "/packages/";
429 String path = name;
430 if (path.startsWith(radical)) {
431 int start = radical.length();
432 int pkgEnd = path.indexOf('/', start);
433 if (pkgEnd != -1) {
434 String pkg = path.substring(start, pkgEnd);
435 String pkgPath = radical + pkg;
436 Node n = findNode(pkgPath);
437 // If not found means that this is a symbolic link such as:
438 // /packages/java.util/java.base/java/util/Vector.class
439 // and will be done by a retry of the filesystem
440 for (Node child : n.getChildren()) {
441 if (child.name.equals(name)) {
442 ret = child;
443 break;
444 }
445 }
446 }
447 }
448 return ret;
449 }
450
451 Node handleModulesSubTree(String name, ImageLocation loc) {
452 Node n;
453 assert (name.equals(loc.getFullName()));
454 Directory dir = makeDirectories(name);
455 visitLocation(loc, (childloc) -> {
456 String path = childloc.getFullName();
457 if (path.startsWith("/modules")) { // a package
458 makeDirectories(path);
459 } else { // a resource
460 makeDirectories(childloc.buildName(true, true, false));
461 // if we have already created a resource for this name previously, then don't
462 // recreate it
463 if (!nodes.containsKey(childloc.getFullName(true))) {
464 newResource(dir, childloc);
465 }
466 }
467 });
468 dir.setCompleted(true);
469 n = dir;
470 return n;
471 }
472
473 Node handleResource(String name) {
474 Node n = null;
475 if (!name.startsWith("/modules/")) {
476 return null;
477 }
478 // Make sure that the thing that follows "/modules/" is a module name.
479 int moduleEndIndex = name.indexOf('/', "/modules/".length());
480 if (moduleEndIndex == -1) {
481 return null;
482 }
483 ImageLocation moduleLoc = findLocation(name.substring(0, moduleEndIndex));
484 if (moduleLoc == null || moduleLoc.getModuleOffset() == 0) {
485 return null;
486 }
487
488 String locationPath = name.substring("/modules".length());
489 ImageLocation resourceLoc = findLocation(locationPath);
490 if (resourceLoc != null) {
491 Directory dir = makeDirectories(resourceLoc.buildName(true, true, false));
492 Resource res = newResource(dir, resourceLoc);
493 n = res;
494 }
495 return n;
496 }
497
498 String getBaseExt(ImageLocation loc) {
499 String base = loc.getBase();
500 String ext = loc.getExtension();
501 if (ext != null && !ext.isEmpty()) {
502 base = base + "." + ext;
503 }
504 return base;
505 }
506
507 synchronized Node findNode(String name) {
508 buildRootDirectory();
509 Node n = nodes.get(name);
510 if (n == null || !n.isCompleted()) {
511 n = buildNode(name);
512 }
513 return n;
514 }
515
516 /**
517 * Returns the file attributes of the image file.
518 */
519 BasicFileAttributes imageFileAttributes() {
520 BasicFileAttributes attrs = imageFileAttributes;
521 if (attrs == null) {
522 try {
523 Path file = getImagePath();
524 attrs = Files.readAttributes(file, BasicFileAttributes.class);
525 } catch (IOException ioe) {
526 throw new UncheckedIOException(ioe);
527 }
528 imageFileAttributes = attrs;
529 }
530 return attrs;
531 }
532
533 Directory newDirectory(Directory parent, String name) {
534 Directory dir = Directory.create(parent, name, imageFileAttributes());
535 nodes.put(dir.getName(), dir);
536 return dir;
537 }
538
539 Resource newResource(Directory parent, ImageLocation loc) {
540 Resource res = Resource.create(parent, loc, imageFileAttributes());
541 nodes.put(res.getName(), res);
542 return res;
543 }
544
545 LinkNode newLinkNode(Directory dir, String name, Node link) {
546 LinkNode linkNode = LinkNode.create(dir, name, link);
547 nodes.put(linkNode.getName(), linkNode);
548 return linkNode;
549 }
550
551 Directory makeDirectories(String parent) {
552 Directory last = rootDir;
553 for (int offset = parent.indexOf('/', 1);
554 offset != -1;
555 offset = parent.indexOf('/', offset + 1)) {
556 String dir = parent.substring(0, offset);
557 last = makeDirectory(dir, last);
558 }
559 return makeDirectory(parent, last);
560
561 }
562
563 Directory makeDirectory(String dir, Directory last) {
564 Directory nextDir = (Directory) nodes.get(dir);
565 if (nextDir == null) {
566 nextDir = newDirectory(last, dir);
567 }
568 return nextDir;
569 }
570
571 byte[] getResource(Node node) throws IOException {
572 if (node.isResource()) {
573 return super.getResource(node.getLocation());
574 }
575 throw new IOException("Not a resource: " + node);
576 }
577
578 byte[] getResource(Resource rs) throws IOException {
579 return super.getResource(rs.getLocation());
580 }
581 }
582
583 // jimage file does not store directory structure. We build nodes
584 // using the "path" strings found in the jimage file.
585 // Node can be a directory or a resource
586 public abstract static class Node {
587 private static final int ROOT_DIR = 0b0000_0000_0000_0001;
588 private static final int PACKAGES_DIR = 0b0000_0000_0000_0010;
589 private static final int MODULES_DIR = 0b0000_0000_0000_0100;
590
591 private int flags;
592 private final String name;
593 private final BasicFileAttributes fileAttrs;
594 private boolean completed;
595
596 protected Node(String name, BasicFileAttributes fileAttrs) {
597 this.name = Objects.requireNonNull(name);
598 this.fileAttrs = Objects.requireNonNull(fileAttrs);
599 }
600
601 /**
602 * A node is completed when all its direct children have been built.
603 *
604 * @return
605 */
606 public boolean isCompleted() {
607 return completed;
608 }
609
610 public void setCompleted(boolean completed) {
611 this.completed = completed;
612 }
613
614 public final void setIsRootDir() {
615 flags |= ROOT_DIR;
616 }
617
618 public final boolean isRootDir() {
619 return (flags & ROOT_DIR) != 0;
620 }
621
622 public final void setIsPackagesDir() {
623 flags |= PACKAGES_DIR;
624 }
625
626 public final boolean isPackagesDir() {
627 return (flags & PACKAGES_DIR) != 0;
628 }
629
630 public final void setIsModulesDir() {
631 flags |= MODULES_DIR;
632 }
633
634 public final boolean isModulesDir() {
635 return (flags & MODULES_DIR) != 0;
636 }
637
638 public final String getName() {
639 return name;
640 }
641
642 public final BasicFileAttributes getFileAttributes() {
643 return fileAttrs;
644 }
645
646 // resolve this Node (if this is a soft link, get underlying Node)
647 public final Node resolveLink() {
648 return resolveLink(false);
649 }
650
651 public Node resolveLink(boolean recursive) {
652 return this;
653 }
654
655 // is this a soft link Node?
656 public boolean isLink() {
657 return false;
658 }
659
660 public boolean isDirectory() {
661 return false;
662 }
663
664 public List<Node> getChildren() {
665 throw new IllegalArgumentException("not a directory: " + getNameString());
666 }
667
668 public boolean isResource() {
669 return false;
670 }
671
672 public ImageLocation getLocation() {
673 throw new IllegalArgumentException("not a resource: " + getNameString());
674 }
675
676 public long size() {
677 return 0L;
678 }
679
680 public long compressedSize() {
681 return 0L;
682 }
683
684 public String extension() {
685 return null;
686 }
687
688 public long contentOffset() {
689 return 0L;
690 }
691
692 public final FileTime creationTime() {
693 return fileAttrs.creationTime();
694 }
695
696 public final FileTime lastAccessTime() {
697 return fileAttrs.lastAccessTime();
698 }
699
700 public final FileTime lastModifiedTime() {
701 return fileAttrs.lastModifiedTime();
702 }
703
704 public final String getNameString() {
705 return name;
706 }
707
708 @Override
709 public final String toString() {
710 return getNameString();
711 }
712
713 @Override
714 public final int hashCode() {
715 return name.hashCode();
716 }
717
718 @Override
719 public final boolean equals(Object other) {
720 if (this == other) {
721 return true;
722 }
723
724 if (other instanceof Node) {
725 return name.equals(((Node) other).name);
726 }
727
728 return false;
729 }
730 }
731
732 // directory node - directory has full path name without '/' at end.
733 static final class Directory extends Node {
734 private final List<Node> children;
735
736 private Directory(String name, BasicFileAttributes fileAttrs) {
737 super(name, fileAttrs);
738 children = new ArrayList<>();
739 }
740
741 static Directory create(Directory parent, String name, BasicFileAttributes fileAttrs) {
742 Directory d = new Directory(name, fileAttrs);
743 if (parent != null) {
744 parent.addChild(d);
745 }
746 return d;
747 }
748
749 @Override
750 public boolean isDirectory() {
751 return true;
752 }
753
754 @Override
755 public List<Node> getChildren() {
756 return Collections.unmodifiableList(children);
757 }
758
759 void addChild(Node node) {
760 assert !children.contains(node) : "Child " + node + " already added";
761 children.add(node);
762 }
763
764 public void walk(Consumer<? super Node> consumer) {
765 consumer.accept(this);
766 for (Node child : children) {
767 if (child.isDirectory()) {
768 ((Directory)child).walk(consumer);
769 } else {
770 consumer.accept(child);
771 }
772 }
773 }
774 }
775
776 // "resource" is .class or any other resource (compressed/uncompressed) in a jimage.
777 // full path of the resource is the "name" of the resource.
778 static class Resource extends Node {
779 private final ImageLocation loc;
780
781 private Resource(ImageLocation loc, BasicFileAttributes fileAttrs) {
782 super(loc.getFullName(true), fileAttrs);
783 this.loc = loc;
784 }
785
786 static Resource create(Directory parent, ImageLocation loc, BasicFileAttributes fileAttrs) {
787 Resource rs = new Resource(loc, fileAttrs);
788 parent.addChild(rs);
789 return rs;
790 }
791
792 @Override
793 public boolean isCompleted() {
794 return true;
795 }
796
797 @Override
798 public boolean isResource() {
799 return true;
800 }
801
802 @Override
803 public ImageLocation getLocation() {
804 return loc;
805 }
806
807 @Override
808 public long size() {
809 return loc.getUncompressedSize();
810 }
811
812 @Override
813 public long compressedSize() {
814 return loc.getCompressedSize();
815 }
816
817 @Override
818 public String extension() {
819 return loc.getExtension();
820 }
821
822 @Override
823 public long contentOffset() {
824 return loc.getContentOffset();
825 }
826 }
827
828 // represents a soft link to another Node
829 static class LinkNode extends Node {
830 private final Node link;
831
832 private LinkNode(String name, Node link) {
833 super(name, link.getFileAttributes());
834 this.link = link;
835 }
836
837 static LinkNode create(Directory parent, String name, Node link) {
838 LinkNode ln = new LinkNode(name, link);
839 parent.addChild(ln);
840 return ln;
841 }
842
843 @Override
844 public boolean isCompleted() {
845 return true;
846 }
847
848 @Override
849 public Node resolveLink(boolean recursive) {
850 return (recursive && link instanceof LinkNode) ? ((LinkNode)link).resolveLink(true) : link;
851 }
852
853 @Override
854 public boolean isLink() {
855 return true;
856 }
857 }
858 }