1 /*
2 * Copyright (c) 1996, 2024, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2024, Alibaba Group Holding Limited. All Rights Reserved.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation. Oracle designates this
9 * particular file as subject to the "Classpath" exception as provided
10 * by Oracle in the LICENSE file that accompanied this code.
11 *
12 * This code is distributed in the hope that it will be useful, but WITHOUT
13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 * version 2 for more details (a copy is included in the LICENSE file that
16 * accompanied this code).
17 *
18 * You should have received a copy of the GNU General Public License version
19 * 2 along with this work; if not, write to the Free Software Foundation,
20 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
21 *
22 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
23 * or visit www.oracle.com if you need additional information or have any
24 * questions.
25 */
26
27 package java.io;
28
29 import java.util.ArrayList;
30 import java.util.Arrays;
31 import java.util.List;
32 import java.util.Objects;
33 import java.util.StringJoiner;
34
35 import jdk.internal.util.ByteArray;
36 import jdk.internal.access.JavaLangAccess;
37 import jdk.internal.access.SharedSecrets;
38
39 import static jdk.internal.util.ModifiedUtf.putChar;
40 import static jdk.internal.util.ModifiedUtf.utfLen;
41
42 /**
43 * An ObjectOutputStream writes primitive data types and graphs of Java objects
44 * to an OutputStream. The objects can be read (reconstituted) using an
45 * ObjectInputStream. Persistent storage of objects can be accomplished by
46 * using a file for the stream. If the stream is a network socket stream, the
47 * objects can be reconstituted on another host or in another process.
48 *
49 * <p>Only objects that support the java.io.Serializable interface can be
50 * written to streams. The class of each serializable object is encoded
51 * including the class name and signature of the class, the values of the
52 * object's fields and arrays, and the closure of any other objects referenced
53 * from the initial objects.
54 *
55 * <p>The method writeObject is used to write an object to the stream. Any
56 * object, including Strings and arrays, is written with writeObject. Multiple
57 * objects or primitives can be written to the stream. The objects must be
58 * read back from the corresponding ObjectInputstream with the same types and
59 * in the same order as they were written.
60 *
61 * <p>Primitive data types can also be written to the stream using the
62 * appropriate methods from DataOutput. Strings can also be written using the
63 * writeUTF method.
64 *
65 * <p>The default serialization mechanism for an object writes the class of the
66 * object, the class signature, and the values of all non-transient and
67 * non-static fields. References to other objects (except in transient or
68 * static fields) cause those objects to be written also. Multiple references
69 * to a single object are encoded using a reference sharing mechanism so that
70 * graphs of objects can be restored to the same shape as when the original was
71 * written.
72 *
73 * <p>For example to write an object that can be read by the example in
74 * {@link ObjectInputStream}:
75 * {@snippet lang="java":
76 * try (FileOutputStream fos = new FileOutputStream("t.tmp");
77 * ObjectOutputStream oos = new ObjectOutputStream(fos)) {
78 * oos.writeObject("Today");
79 * oos.writeObject(LocalDateTime.now());
80 * } catch (Exception ex) {
81 * // handle exception
82 * }
83 * }
84 *
85 * <p>Serializable classes that require special handling during the
86 * serialization and deserialization process should implement methods
87 * with the following signatures:
88 *
89 * {@snippet lang="java":
90 * private void readObject(java.io.ObjectInputStream stream)
91 * throws IOException, ClassNotFoundException;
92 * private void writeObject(java.io.ObjectOutputStream stream)
93 * throws IOException;
94 * private void readObjectNoData()
95 * throws ObjectStreamException;
96 * }
97 *
98 * <p>The method name, modifiers, return type, and number and type of
99 * parameters must match exactly for the method to be used by
100 * serialization or deserialization. The methods should only be
101 * declared to throw checked exceptions consistent with these
102 * signatures.
103 *
104 * <p>The writeObject method is responsible for writing the state of the object
105 * for its particular class so that the corresponding readObject method can
106 * restore it. The method does not need to concern itself with the state
107 * belonging to the object's superclasses or subclasses. State is saved by
108 * writing the individual fields to the ObjectOutputStream using the
109 * writeObject method or by using the methods for primitive data types
110 * supported by DataOutput.
111 *
112 * <p>Serialization does not write out the fields of any object that does not
113 * implement the java.io.Serializable interface. Subclasses of Objects that
114 * are not serializable can be serializable. In this case the non-serializable
115 * class must have a no-arg constructor to allow its fields to be initialized.
116 * In this case it is the responsibility of the subclass to save and restore
117 * the state of the non-serializable class. It is frequently the case that the
118 * fields of that class are accessible (public, package, or protected) or that
119 * there are get and set methods that can be used to restore the state.
120 *
121 * <p>Serialization of an object can be prevented by implementing writeObject
122 * and readObject methods that throw the NotSerializableException. The
123 * exception will be caught by the ObjectOutputStream and abort the
124 * serialization process.
125 *
126 * <p>Implementing the Externalizable interface allows the object to assume
127 * complete control over the contents and format of the object's serialized
128 * form. The methods of the Externalizable interface, writeExternal and
129 * readExternal, are called to save and restore the objects state. When
130 * implemented by a class they can write and read their own state using all of
131 * the methods of ObjectOutput and ObjectInput. It is the responsibility of
132 * the objects to handle any versioning that occurs.
133 *
134 * <p>Enum constants are serialized differently than ordinary serializable or
135 * externalizable objects. The serialized form of an enum constant consists
136 * solely of its name; field values of the constant are not transmitted. To
137 * serialize an enum constant, ObjectOutputStream writes the string returned by
138 * the constant's name method. Like other serializable or externalizable
139 * objects, enum constants can function as the targets of back references
140 * appearing subsequently in the serialization stream. The process by which
141 * enum constants are serialized cannot be customized; any class-specific
142 * writeObject and writeReplace methods defined by enum types are ignored
143 * during serialization. Similarly, any serialPersistentFields or
144 * serialVersionUID field declarations are also ignored--all enum types have a
145 * fixed serialVersionUID of 0L.
146 *
147 * <p>Primitive data, excluding serializable fields and externalizable data, is
148 * written to the ObjectOutputStream in block-data records. A block data record
149 * is composed of a header and data. The block data header consists of a marker
150 * and the number of bytes to follow the header. Consecutive primitive data
151 * writes are merged into one block-data record. The blocking factor used for
152 * a block-data record will be 1024 bytes. Each block-data record will be
153 * filled up to 1024 bytes, or be written whenever there is a termination of
154 * block-data mode. Calls to the ObjectOutputStream methods writeObject,
155 * defaultWriteObject and writeFields initially terminate any existing
156 * block-data record.
157 *
158 * <p>Records are serialized differently than ordinary serializable or externalizable
159 * objects, see <a href="ObjectInputStream.html#record-serialization">record serialization</a>.
160 *
161 * @spec serialization/index.html Java Object Serialization Specification
162 * @author Mike Warres
163 * @author Roger Riggs
164 * @see java.io.DataOutput
165 * @see java.io.ObjectInputStream
166 * @see java.io.Serializable
167 * @see java.io.Externalizable
168 * @see <a href="{@docRoot}/../specs/serialization/output.html">
169 * <cite>Java Object Serialization Specification,</cite> Section 2, "Object Output Classes"</a>
170 * @since 1.1
171 */
172 public class ObjectOutputStream
173 extends OutputStream implements ObjectOutput, ObjectStreamConstants
174 {
175 private static final JavaLangAccess JLA = SharedSecrets.getJavaLangAccess();
176
177 private static class Caches {
178 /** cache of subclass security audit results */
179 static final ClassValue<Boolean> subclassAudits =
180 new ClassValue<>() {
181 @Override
182 protected Boolean computeValue(Class<?> type) {
183 return auditSubclass(type);
184 }
185 };
186 }
187
188 /** filter stream for handling block data conversion */
189 private final BlockDataOutputStream bout;
190 /** obj -> wire handle map */
191 private final HandleTable handles;
192 /** obj -> replacement obj map */
193 private final ReplaceTable subs;
194 /** stream protocol version */
195 private int protocol = PROTOCOL_VERSION_2;
196 /** recursion depth */
197 private int depth;
198
199 /** buffer for writing primitive field values */
200 private byte[] primVals;
201
202 /** if true, invoke writeObjectOverride() instead of writeObject() */
203 private final boolean enableOverride;
204 /** if true, invoke replaceObject() */
205 private boolean enableReplace;
206
207 // values below valid only during upcalls to writeObject()/writeExternal()
208 /**
209 * Context during upcalls to class-defined writeObject methods; holds
210 * object currently being serialized and descriptor for current class.
211 * Null when not during writeObject upcall.
212 */
213 private SerialCallbackContext curContext;
214 /** current PutField object */
215 private PutFieldImpl curPut;
216
217 /** custom storage for debug trace info */
218 private final DebugTraceInfoStack debugInfoStack;
219
220 /**
221 * value of "sun.io.serialization.extendedDebugInfo" property,
222 * as true or false for extended information about exception's place
223 */
224 private static final boolean extendedDebugInfo =
225 Boolean.getBoolean("sun.io.serialization.extendedDebugInfo");
226
227 /**
228 * Creates an ObjectOutputStream that writes to the specified OutputStream.
229 * This constructor writes the serialization stream header to the
230 * underlying stream; callers may wish to flush the stream immediately to
231 * ensure that constructors for receiving ObjectInputStreams will not block
232 * when reading the header.
233 *
234 * @param out output stream to write to
235 * @throws IOException if an I/O error occurs while writing stream header
236 * @throws NullPointerException if {@code out} is {@code null}
237 * @since 1.4
238 * @see ObjectOutputStream#ObjectOutputStream()
239 * @see ObjectOutputStream#putFields()
240 * @see ObjectInputStream#ObjectInputStream(InputStream)
241 */
242 @SuppressWarnings("this-escape")
243 public ObjectOutputStream(OutputStream out) throws IOException {
244 bout = new BlockDataOutputStream(out);
245 handles = new HandleTable(10, (float) 3.00);
246 subs = new ReplaceTable(10, (float) 3.00);
247 enableOverride = false;
248 writeStreamHeader();
249 bout.setBlockDataMode(true);
250 if (extendedDebugInfo) {
251 debugInfoStack = new DebugTraceInfoStack();
252 } else {
253 debugInfoStack = null;
254 }
255 }
256
257 /**
258 * Provide a way for subclasses that are completely reimplementing
259 * ObjectOutputStream to not have to allocate private data just used by
260 * this implementation of ObjectOutputStream.
261 *
262 * @throws IOException if an I/O error occurs while creating this stream
263 */
264 protected ObjectOutputStream() throws IOException {
265 bout = null;
266 handles = null;
267 subs = null;
268 enableOverride = true;
269 debugInfoStack = null;
270 }
271
272 /**
273 * Specify stream protocol version to use when writing the stream.
274 *
275 * <p>This routine provides a hook to enable the current version of
276 * Serialization to write in a format that is backwards compatible to a
277 * previous version of the stream format.
278 *
279 * <p>Every effort will be made to avoid introducing additional
280 * backwards incompatibilities; however, sometimes there is no
281 * other alternative.
282 *
283 * @param version use ProtocolVersion from java.io.ObjectStreamConstants.
284 * @throws IllegalStateException if called after any objects
285 * have been serialized.
286 * @throws IllegalArgumentException if invalid version is passed in.
287 * @throws IOException if I/O errors occur
288 * @see java.io.ObjectStreamConstants#PROTOCOL_VERSION_1
289 * @see java.io.ObjectStreamConstants#PROTOCOL_VERSION_2
290 * @since 1.2
291 */
292 public void useProtocolVersion(int version) throws IOException {
293 if (handles.size() != 0) {
294 // REMIND: implement better check for pristine stream?
295 throw new IllegalStateException("stream non-empty");
296 }
297 switch (version) {
298 case PROTOCOL_VERSION_1:
299 case PROTOCOL_VERSION_2:
300 protocol = version;
301 break;
302
303 default:
304 throw new IllegalArgumentException(
305 "unknown version: " + version);
306 }
307 }
308
309 /**
310 * Write the specified object to the ObjectOutputStream. The class of the
311 * object, the signature of the class, and the values of the non-transient
312 * and non-static fields of the class and all of its supertypes are
313 * written. Default serialization for a class can be overridden using the
314 * writeObject and the readObject methods. Objects referenced by this
315 * object are written transitively so that a complete equivalent graph of
316 * objects can be reconstructed by an ObjectInputStream.
317 *
318 * <p>Exceptions are thrown for problems with the OutputStream and for
319 * classes that should not be serialized. All exceptions are fatal to the
320 * OutputStream, which is left in an indeterminate state, and it is up to
321 * the caller to ignore or recover the stream state.
322 *
323 * @throws InvalidClassException Something is wrong with a class used by
324 * serialization.
325 * @throws NotSerializableException Some object to be serialized does not
326 * implement the java.io.Serializable interface.
327 * @throws IOException Any exception thrown by the underlying
328 * OutputStream.
329 */
330 public final void writeObject(Object obj) throws IOException {
331 if (enableOverride) {
332 writeObjectOverride(obj);
333 return;
334 }
335 try {
336 writeObject0(obj, false);
337 } catch (IOException ex) {
338 if (depth == 0) {
339 writeFatalException(ex);
340 }
341 throw ex;
342 }
343 }
344
345 /**
346 * Method used by subclasses to override the default writeObject method.
347 * This method is called by trusted subclasses of ObjectOutputStream that
348 * constructed ObjectOutputStream using the protected no-arg constructor.
349 * The subclass is expected to provide an override method with the modifier
350 * "final".
351 *
352 * @param obj object to be written to the underlying stream
353 * @throws IOException if there are I/O errors while writing to the
354 * underlying stream
355 * @see #ObjectOutputStream()
356 * @see #writeObject(Object)
357 * @since 1.2
358 */
359 protected void writeObjectOverride(Object obj) throws IOException {
360 }
361
362 /**
363 * Writes an "unshared" object to the ObjectOutputStream. This method is
364 * identical to writeObject, except that it always writes the given object
365 * as a new, unique object in the stream (as opposed to a back-reference
366 * pointing to a previously serialized instance). Specifically:
367 * <ul>
368 * <li>An object written via writeUnshared is always serialized in the
369 * same manner as a newly appearing object (an object that has not
370 * been written to the stream yet), regardless of whether or not the
371 * object has been written previously.
372 *
373 * <li>If writeObject is used to write an object that has been previously
374 * written with writeUnshared, the previous writeUnshared operation
375 * is treated as if it were a write of a separate object. In other
376 * words, ObjectOutputStream will never generate back-references to
377 * object data written by calls to writeUnshared.
378 * </ul>
379 * While writing an object via writeUnshared does not in itself guarantee a
380 * unique reference to the object when it is deserialized, it allows a
381 * single object to be defined multiple times in a stream, so that multiple
382 * calls to readUnshared by the receiver will not conflict. Note that the
383 * rules described above only apply to the base-level object written with
384 * writeUnshared, and not to any transitively referenced sub-objects in the
385 * object graph to be serialized.
386 *
387 * @param obj object to write to stream
388 * @throws NotSerializableException if an object in the graph to be
389 * serialized does not implement the Serializable interface
390 * @throws InvalidClassException if a problem exists with the class of an
391 * object to be serialized
392 * @throws IOException if an I/O error occurs during serialization
393 * @since 1.4
394 */
395 public void writeUnshared(Object obj) throws IOException {
396 try {
397 writeObject0(obj, true);
398 } catch (IOException ex) {
399 if (depth == 0) {
400 writeFatalException(ex);
401 }
402 throw ex;
403 }
404 }
405
406 /**
407 * Write the non-static and non-transient fields of the current class to
408 * this stream. This may only be called from the writeObject method of the
409 * class being serialized. It will throw the NotActiveException if it is
410 * called otherwise.
411 *
412 * @throws IOException if I/O errors occur while writing to the underlying
413 * {@code OutputStream}
414 */
415 public void defaultWriteObject() throws IOException {
416 SerialCallbackContext ctx = curContext;
417 if (ctx == null) {
418 throw new NotActiveException("not in call to writeObject");
419 }
420 Object curObj = ctx.getObj();
421 ObjectStreamClass curDesc = ctx.getDesc();
422 bout.setBlockDataMode(false);
423 defaultWriteFields(curObj, curDesc);
424 bout.setBlockDataMode(true);
425 }
426
427 /**
428 * Retrieve the object used to buffer persistent fields to be written to
429 * the stream. The fields will be written to the stream when writeFields
430 * method is called.
431 *
432 * @return an instance of the class Putfield that holds the serializable
433 * fields
434 * @throws IOException if I/O errors occur
435 * @since 1.2
436 */
437 public ObjectOutputStream.PutField putFields() throws IOException {
438 if (curPut == null) {
439 SerialCallbackContext ctx = curContext;
440 if (ctx == null) {
441 throw new NotActiveException("not in call to writeObject");
442 }
443 ctx.checkAndSetUsed();
444 ObjectStreamClass curDesc = ctx.getDesc();
445 curPut = new PutFieldImpl(curDesc);
446 }
447 return curPut;
448 }
449
450 /**
451 * Write the buffered fields to the stream.
452 *
453 * @throws IOException if I/O errors occur while writing to the underlying
454 * stream
455 * @throws NotActiveException Called when a classes writeObject method was
456 * not called to write the state of the object.
457 * @since 1.2
458 */
459 public void writeFields() throws IOException {
460 if (curPut == null) {
461 throw new NotActiveException("no current PutField object");
462 }
463 bout.setBlockDataMode(false);
464 curPut.writeFields();
465 bout.setBlockDataMode(true);
466 }
467
468 /**
469 * Reset will disregard the state of any objects already written to the
470 * stream. The state is reset to be the same as a new ObjectOutputStream.
471 * The current point in the stream is marked as reset so the corresponding
472 * ObjectInputStream will be reset at the same point. Objects previously
473 * written to the stream will not be referred to as already being in the
474 * stream. They will be written to the stream again.
475 *
476 * @throws IOException if reset() is invoked while serializing an object.
477 */
478 public void reset() throws IOException {
479 if (depth != 0) {
480 throw new IOException("stream active");
481 }
482 bout.setBlockDataMode(false);
483 bout.writeByte(TC_RESET);
484 clear();
485 bout.setBlockDataMode(true);
486 }
487
488 /**
489 * Subclasses may implement this method to allow class data to be stored in
490 * the stream. By default this method does nothing. The corresponding
491 * method in ObjectInputStream is resolveClass. This method is called
492 * exactly once for each unique class in the stream. The class name and
493 * signature will have already been written to the stream. This method may
494 * make free use of the ObjectOutputStream to save any representation of
495 * the class it deems suitable (for example, the bytes of the class file).
496 * The resolveClass method in the corresponding subclass of
497 * ObjectInputStream must read and use any data or objects written by
498 * annotateClass.
499 *
500 * @param cl the class to annotate custom data for
501 * @throws IOException Any exception thrown by the underlying
502 * OutputStream.
503 */
504 protected void annotateClass(Class<?> cl) throws IOException {
505 }
506
507 /**
508 * Subclasses may implement this method to store custom data in the stream
509 * along with descriptors for dynamic proxy classes.
510 *
511 * <p>This method is called exactly once for each unique proxy class
512 * descriptor in the stream. The default implementation of this method in
513 * {@code ObjectOutputStream} does nothing.
514 *
515 * <p>The corresponding method in {@code ObjectInputStream} is
516 * {@code resolveProxyClass}. For a given subclass of
517 * {@code ObjectOutputStream} that overrides this method, the
518 * {@code resolveProxyClass} method in the corresponding subclass of
519 * {@code ObjectInputStream} must read any data or objects written by
520 * {@code annotateProxyClass}.
521 *
522 * @param cl the proxy class to annotate custom data for
523 * @throws IOException any exception thrown by the underlying
524 * {@code OutputStream}
525 * @see ObjectInputStream#resolveProxyClass(String[])
526 * @since 1.3
527 */
528 protected void annotateProxyClass(Class<?> cl) throws IOException {
529 }
530
531 /**
532 * This method will allow trusted subclasses of ObjectOutputStream to
533 * substitute one object for another during serialization. Replacing
534 * objects is disabled until enableReplaceObject is called. The
535 * enableReplaceObject method checks that the stream requesting to do
536 * replacement can be trusted. The first occurrence of each object written
537 * into the serialization stream is passed to replaceObject. Subsequent
538 * references to the object are replaced by the object returned by the
539 * original call to replaceObject. To ensure that the private state of
540 * objects is not unintentionally exposed, only trusted streams may use
541 * replaceObject.
542 *
543 * <p>The ObjectOutputStream.writeObject method takes a parameter of type
544 * Object (as opposed to type Serializable) to allow for cases where
545 * non-serializable objects are replaced by serializable ones.
546 *
547 * <p>When a subclass is replacing objects it must ensure that either a
548 * complementary substitution must be made during deserialization or that
549 * the substituted object is compatible with every field where the
550 * reference will be stored. Objects whose type is not a subclass of the
551 * type of the field or array element abort the serialization by raising an
552 * exception and the object is not be stored.
553 *
554 * <p>This method is called only once when each object is first
555 * encountered. All subsequent references to the object will be redirected
556 * to the new object. This method should return the object to be
557 * substituted or the original object.
558 *
559 * <p>Null can be returned as the object to be substituted, but may cause
560 * {@link NullPointerException} in classes that contain references to the
561 * original object since they may be expecting an object instead of
562 * null.
563 *
564 * @param obj the object to be replaced
565 * @return the alternate object that replaced the specified one
566 * @throws IOException Any exception thrown by the underlying
567 * OutputStream.
568 */
569 protected Object replaceObject(Object obj) throws IOException {
570 return obj;
571 }
572
573 /**
574 * Enables the stream to do replacement of objects written to the stream. When
575 * enabled, the {@link #replaceObject} method is called for every object being
576 * serialized.
577 *
578 * @param enable true for enabling use of {@code replaceObject} for
579 * every object being serialized
580 * @return the previous setting before this method was invoked
581 */
582 protected boolean enableReplaceObject(boolean enable) {
583 if (enable == enableReplace) {
584 return enable;
585 }
586 enableReplace = enable;
587 return !enableReplace;
588 }
589
590 /**
591 * The writeStreamHeader method is provided so subclasses can append or
592 * prepend their own header to the stream. It writes the magic number and
593 * version to the stream.
594 *
595 * @throws IOException if I/O errors occur while writing to the underlying
596 * stream
597 */
598 protected void writeStreamHeader() throws IOException {
599 bout.writeShort(STREAM_MAGIC);
600 bout.writeShort(STREAM_VERSION);
601 }
602
603 /**
604 * Write the specified class descriptor to the ObjectOutputStream. Class
605 * descriptors are used to identify the classes of objects written to the
606 * stream. Subclasses of ObjectOutputStream may override this method to
607 * customize the way in which class descriptors are written to the
608 * serialization stream. The corresponding method in ObjectInputStream,
609 * {@link ObjectInputStream#readClassDescriptor readClassDescriptor}, should then be
610 * overridden to reconstitute the class descriptor from its custom stream representation.
611 * By default, this method writes class descriptors according to the format
612 * defined in the <a href="{@docRoot}/../specs/serialization/index.html">
613 * <cite>Java Object Serialization Specification</cite></a>.
614 *
615 * <p>Note that this method will only be called if the ObjectOutputStream
616 * is not using the old serialization stream format (set by calling
617 * ObjectOutputStream's {@code useProtocolVersion} method). If this
618 * serialization stream is using the old format
619 * ({@code PROTOCOL_VERSION_1}), the class descriptor will be written
620 * internally in a manner that cannot be overridden or customized.
621 *
622 * @param desc class descriptor to write to the stream
623 * @throws IOException If an I/O error has occurred.
624 * @spec serialization/index.html Java Object Serialization Specification
625 * @see java.io.ObjectInputStream#readClassDescriptor()
626 * @see #useProtocolVersion(int)
627 * @see java.io.ObjectStreamConstants#PROTOCOL_VERSION_1
628 * @since 1.3
629 */
630 protected void writeClassDescriptor(ObjectStreamClass desc)
631 throws IOException
632 {
633 desc.writeNonProxy(this);
634 }
635
636 /**
637 * Writes a byte. This method will block until the byte is actually
638 * written.
639 *
640 * @param val the byte to be written to the stream
641 * @throws IOException If an I/O error has occurred.
642 */
643 @Override
644 public void write(int val) throws IOException {
645 bout.write(val);
646 }
647
648 /**
649 * Writes an array of bytes. This method will block until the bytes are
650 * actually written.
651 *
652 * @param buf the data to be written
653 * @throws IOException If an I/O error has occurred.
654 */
655 @Override
656 public void write(byte[] buf) throws IOException {
657 bout.write(buf, 0, buf.length, false);
658 }
659
660 /**
661 * Writes a sub array of bytes.
662 *
663 * @param buf the data to be written
664 * @param off the start offset in the data
665 * @param len the number of bytes that are written
666 * @throws IOException {@inheritDoc}
667 * @throws IndexOutOfBoundsException {@inheritDoc}
668 */
669 @Override
670 public void write(byte[] buf, int off, int len) throws IOException {
671 if (buf == null) {
672 throw new NullPointerException();
673 }
674 Objects.checkFromIndexSize(off, len, buf.length);
675 bout.write(buf, off, len, false);
676 }
677
678 /**
679 * Flushes the stream. This will write any buffered output bytes and flush
680 * through to the underlying stream.
681 *
682 * @throws IOException {@inheritDoc}
683 */
684 @Override
685 public void flush() throws IOException {
686 bout.flush();
687 }
688
689 /**
690 * Drain any buffered data in ObjectOutputStream. Similar to flush but
691 * does not propagate the flush to the underlying stream.
692 *
693 * @throws IOException if I/O errors occur while writing to the underlying
694 * stream
695 */
696 protected void drain() throws IOException {
697 bout.drain();
698 }
699
700 /**
701 * Closes the stream. This method must be called to release any resources
702 * associated with the stream.
703 *
704 * @throws IOException If an I/O error has occurred.
705 */
706 @Override
707 public void close() throws IOException {
708 flush();
709 clear();
710 bout.close();
711 }
712
713 /**
714 * Writes a boolean.
715 *
716 * @param val the boolean to be written
717 * @throws IOException if I/O errors occur while writing to the underlying
718 * stream
719 */
720 public void writeBoolean(boolean val) throws IOException {
721 bout.writeBoolean(val);
722 }
723
724 /**
725 * Writes an 8-bit byte.
726 *
727 * @param val the byte value to be written
728 * @throws IOException if I/O errors occur while writing to the underlying
729 * stream
730 */
731 public void writeByte(int val) throws IOException {
732 bout.writeByte(val);
733 }
734
735 /**
736 * Writes a 16-bit short.
737 *
738 * @param val the short value to be written
739 * @throws IOException if I/O errors occur while writing to the underlying
740 * stream
741 */
742 public void writeShort(int val) throws IOException {
743 bout.writeShort(val);
744 }
745
746 /**
747 * Writes a 16-bit char.
748 *
749 * @param val the char value to be written
750 * @throws IOException if I/O errors occur while writing to the underlying
751 * stream
752 */
753 public void writeChar(int val) throws IOException {
754 bout.writeChar(val);
755 }
756
757 /**
758 * Writes a 32-bit int.
759 *
760 * @param val the integer value to be written
761 * @throws IOException if I/O errors occur while writing to the underlying
762 * stream
763 */
764 public void writeInt(int val) throws IOException {
765 bout.writeInt(val);
766 }
767
768 /**
769 * Writes a 64-bit long.
770 *
771 * @param val the long value to be written
772 * @throws IOException if I/O errors occur while writing to the underlying
773 * stream
774 */
775 public void writeLong(long val) throws IOException {
776 bout.writeLong(val);
777 }
778
779 /**
780 * Writes a 32-bit float.
781 *
782 * @param val the float value to be written
783 * @throws IOException if I/O errors occur while writing to the underlying
784 * stream
785 */
786 public void writeFloat(float val) throws IOException {
787 bout.writeFloat(val);
788 }
789
790 /**
791 * Writes a 64-bit double.
792 *
793 * @param val the double value to be written
794 * @throws IOException if I/O errors occur while writing to the underlying
795 * stream
796 */
797 public void writeDouble(double val) throws IOException {
798 bout.writeDouble(val);
799 }
800
801 /**
802 * Writes a String as a sequence of bytes.
803 *
804 * @param str the String of bytes to be written
805 * @throws IOException if I/O errors occur while writing to the underlying
806 * stream
807 */
808 public void writeBytes(String str) throws IOException {
809 bout.writeBytes(str);
810 }
811
812 /**
813 * Writes a String as a sequence of chars.
814 *
815 * @param str the String of chars to be written
816 * @throws IOException if I/O errors occur while writing to the underlying
817 * stream
818 */
819 public void writeChars(String str) throws IOException {
820 bout.writeChars(str);
821 }
822
823 /**
824 * Primitive data write of this String in
825 * <a href="DataInput.html#modified-utf-8">modified UTF-8</a>
826 * format. Note that there is a
827 * significant difference between writing a String into the stream as
828 * primitive data or as an Object. A String instance written by writeObject
829 * is written into the stream as a String initially. Future writeObject()
830 * calls write references to the string into the stream.
831 *
832 * @param str the String to be written
833 * @throws IOException if I/O errors occur while writing to the underlying
834 * stream
835 */
836 public void writeUTF(String str) throws IOException {
837 bout.writeUTFInternal(str, false);
838 }
839
840 /**
841 * Provide programmatic access to the persistent fields to be written
842 * to ObjectOutput.
843 *
844 * @since 1.2
845 */
846 public abstract static class PutField {
847 /**
848 * Constructor for subclasses to call.
849 */
850 public PutField() {}
851
852 /**
853 * Put the value of the named boolean field into the persistent field.
854 *
855 * @param name the name of the serializable field
856 * @param val the value to assign to the field
857 * @throws IllegalArgumentException if {@code name} does not
858 * match the name of a serializable field for the class whose fields
859 * are being written, or if the type of the named field is not
860 * {@code boolean}
861 */
862 public abstract void put(String name, boolean val);
863
864 /**
865 * Put the value of the named byte field into the persistent field.
866 *
867 * @param name the name of the serializable field
868 * @param val the value to assign to the field
869 * @throws IllegalArgumentException if {@code name} does not
870 * match the name of a serializable field for the class whose fields
871 * are being written, or if the type of the named field is not
872 * {@code byte}
873 */
874 public abstract void put(String name, byte val);
875
876 /**
877 * Put the value of the named char field into the persistent field.
878 *
879 * @param name the name of the serializable field
880 * @param val the value to assign to the field
881 * @throws IllegalArgumentException if {@code name} does not
882 * match the name of a serializable field for the class whose fields
883 * are being written, or if the type of the named field is not
884 * {@code char}
885 */
886 public abstract void put(String name, char val);
887
888 /**
889 * Put the value of the named short field into the persistent field.
890 *
891 * @param name the name of the serializable field
892 * @param val the value to assign to the field
893 * @throws IllegalArgumentException if {@code name} does not
894 * match the name of a serializable field for the class whose fields
895 * are being written, or if the type of the named field is not
896 * {@code short}
897 */
898 public abstract void put(String name, short val);
899
900 /**
901 * Put the value of the named int field into the persistent field.
902 *
903 * @param name the name of the serializable field
904 * @param val the value to assign to the field
905 * @throws IllegalArgumentException if {@code name} does not
906 * match the name of a serializable field for the class whose fields
907 * are being written, or if the type of the named field is not
908 * {@code int}
909 */
910 public abstract void put(String name, int val);
911
912 /**
913 * Put the value of the named long field into the persistent field.
914 *
915 * @param name the name of the serializable field
916 * @param val the value to assign to the field
917 * @throws IllegalArgumentException if {@code name} does not
918 * match the name of a serializable field for the class whose fields
919 * are being written, or if the type of the named field is not
920 * {@code long}
921 */
922 public abstract void put(String name, long val);
923
924 /**
925 * Put the value of the named float field into the persistent field.
926 *
927 * @param name the name of the serializable field
928 * @param val the value to assign to the field
929 * @throws IllegalArgumentException if {@code name} does not
930 * match the name of a serializable field for the class whose fields
931 * are being written, or if the type of the named field is not
932 * {@code float}
933 */
934 public abstract void put(String name, float val);
935
936 /**
937 * Put the value of the named double field into the persistent field.
938 *
939 * @param name the name of the serializable field
940 * @param val the value to assign to the field
941 * @throws IllegalArgumentException if {@code name} does not
942 * match the name of a serializable field for the class whose fields
943 * are being written, or if the type of the named field is not
944 * {@code double}
945 */
946 public abstract void put(String name, double val);
947
948 /**
949 * Put the value of the named Object field into the persistent field.
950 *
951 * @param name the name of the serializable field
952 * @param val the value to assign to the field
953 * (which may be {@code null})
954 * @throws IllegalArgumentException if {@code name} does not
955 * match the name of a serializable field for the class whose fields
956 * are being written, or if the type of the named field is not a
957 * reference type
958 */
959 public abstract void put(String name, Object val);
960
961 /**
962 * Write the data and fields to the specified ObjectOutput stream,
963 * which must be the same stream that produced this
964 * {@code PutField} object.
965 *
966 * @param out the stream to write the data and fields to
967 * @throws IOException if I/O errors occur while writing to the
968 * underlying stream
969 * @throws IllegalArgumentException if the specified stream is not
970 * the same stream that produced this {@code PutField}
971 * object
972 * @deprecated This method does not write the values contained by this
973 * {@code PutField} object in a proper format, and may
974 * result in corruption of the serialization stream. The
975 * correct way to write {@code PutField} data is by
976 * calling the {@link java.io.ObjectOutputStream#writeFields()}
977 * method.
978 */
979 @Deprecated(forRemoval = true, since = "1.4")
980 public abstract void write(ObjectOutput out) throws IOException;
981 }
982
983
984 /**
985 * Returns protocol version in use.
986 */
987 int getProtocolVersion() {
988 return protocol;
989 }
990
991 /**
992 * Writes string without allowing it to be replaced in stream. Used by
993 * ObjectStreamClass to write class descriptor type strings.
994 */
995 void writeTypeString(String str) throws IOException {
996 int handle;
997 if (str == null) {
998 writeNull();
999 } else if ((handle = handles.lookup(str)) != -1) {
1000 writeHandle(handle);
1001 } else {
1002 writeString(str, false);
1003 }
1004 }
1005
1006 /**
1007 * Performs reflective checks on given subclass to verify that it doesn't
1008 * override security-sensitive non-final methods. Returns TRUE if subclass
1009 * is "safe", FALSE otherwise.
1010 */
1011 private static Boolean auditSubclass(Class<?> subcl) {
1012 for (Class<?> cl = subcl;
1013 cl != ObjectOutputStream.class;
1014 cl = cl.getSuperclass())
1015 {
1016 try {
1017 cl.getDeclaredMethod(
1018 "writeUnshared", new Class<?>[] { Object.class });
1019 return Boolean.FALSE;
1020 } catch (NoSuchMethodException ex) {
1021 }
1022 try {
1023 cl.getDeclaredMethod("putFields", (Class<?>[]) null);
1024 return Boolean.FALSE;
1025 } catch (NoSuchMethodException ex) {
1026 }
1027 }
1028 return Boolean.TRUE;
1029 }
1030
1031 /**
1032 * Clears internal data structures.
1033 */
1034 private void clear() {
1035 subs.clear();
1036 handles.clear();
1037 }
1038
1039 /**
1040 * Underlying writeObject/writeUnshared implementation.
1041 */
1042 private void writeObject0(Object obj, boolean unshared)
1043 throws IOException
1044 {
1045 boolean oldMode = bout.setBlockDataMode(false);
1046 depth++;
1047 try {
1048 // handle previously written and non-replaceable objects
1049 int h;
1050 if ((obj = subs.lookup(obj)) == null) {
1051 writeNull();
1052 return;
1053 } else if (!unshared && (h = handles.lookup(obj)) != -1) {
1054 writeHandle(h);
1055 return;
1056 } else if (obj instanceof Class) {
1057 writeClass((Class) obj, unshared);
1058 return;
1059 } else if (obj instanceof ObjectStreamClass) {
1060 writeClassDesc((ObjectStreamClass) obj, unshared);
1061 return;
1062 }
1063
1064 // check for replacement object
1065 Object orig = obj;
1066 Class<?> cl = obj.getClass();
1067 ObjectStreamClass desc;
1068 for (;;) {
1069 // REMIND: skip this check for strings/arrays?
1070 Class<?> repCl;
1071 desc = ObjectStreamClass.lookup(cl, true);
1072 if (!desc.hasWriteReplaceMethod() ||
1073 (obj = desc.invokeWriteReplace(obj)) == null ||
1074 (repCl = obj.getClass()) == cl)
1075 {
1076 break;
1077 }
1078 cl = repCl;
1079 }
1080 if (enableReplace) {
1081 Object rep = replaceObject(obj);
1082 if (rep != obj && rep != null) {
1083 cl = rep.getClass();
1084 desc = ObjectStreamClass.lookup(cl, true);
1085 }
1086 obj = rep;
1087 }
1088
1089 // if object replaced, run through original checks a second time
1090 if (obj != orig) {
1091 subs.assign(orig, obj);
1092 if (obj == null) {
1093 writeNull();
1094 return;
1095 } else if (!unshared && (h = handles.lookup(obj)) != -1) {
1096 writeHandle(h);
1097 return;
1098 } else if (obj instanceof Class) {
1099 writeClass((Class) obj, unshared);
1100 return;
1101 } else if (obj instanceof ObjectStreamClass) {
1102 writeClassDesc((ObjectStreamClass) obj, unshared);
1103 return;
1104 }
1105 }
1106
1107 // remaining cases
1108 if (obj instanceof String) {
1109 writeString((String) obj, unshared);
1110 } else if (cl.isArray()) {
1111 writeArray(obj, desc, unshared);
1112 } else if (obj instanceof Enum) {
1113 writeEnum((Enum<?>) obj, desc, unshared);
1114 } else if (obj instanceof Serializable) {
1115 writeOrdinaryObject(obj, desc, unshared);
1116 } else {
1117 if (extendedDebugInfo) {
1118 throw new NotSerializableException(
1119 cl.getName() + "\n" + debugInfoStack.toString());
1120 } else {
1121 throw new NotSerializableException(cl.getName());
1122 }
1123 }
1124 } finally {
1125 depth--;
1126 bout.setBlockDataMode(oldMode);
1127 }
1128 }
1129
1130 /**
1131 * Writes null code to stream.
1132 */
1133 private void writeNull() throws IOException {
1134 bout.writeByte(TC_NULL);
1135 }
1136
1137 /**
1138 * Writes given object handle to stream.
1139 */
1140 private void writeHandle(int handle) throws IOException {
1141 bout.writeByte(TC_REFERENCE);
1142 bout.writeInt(baseWireHandle + handle);
1143 }
1144
1145 /**
1146 * Writes representation of given class to stream.
1147 */
1148 private void writeClass(Class<?> cl, boolean unshared) throws IOException {
1149 bout.writeByte(TC_CLASS);
1150 writeClassDesc(ObjectStreamClass.lookup(cl, true), false);
1151 handles.assign(unshared ? null : cl);
1152 }
1153
1154 /**
1155 * Writes representation of given class descriptor to stream.
1156 */
1157 private void writeClassDesc(ObjectStreamClass desc, boolean unshared)
1158 throws IOException
1159 {
1160 int handle;
1161 if (desc == null) {
1162 writeNull();
1163 } else if (!unshared && (handle = handles.lookup(desc)) != -1) {
1164 writeHandle(handle);
1165 } else if (desc.isProxy()) {
1166 writeProxyDesc(desc, unshared);
1167 } else {
1168 writeNonProxyDesc(desc, unshared);
1169 }
1170 }
1171
1172 /**
1173 * Writes class descriptor representing a dynamic proxy class to stream.
1174 */
1175 private void writeProxyDesc(ObjectStreamClass desc, boolean unshared)
1176 throws IOException
1177 {
1178 bout.writeByte(TC_PROXYCLASSDESC);
1179 handles.assign(unshared ? null : desc);
1180
1181 Class<?> cl = desc.forClass();
1182 Class<?>[] ifaces = cl.getInterfaces();
1183 bout.writeInt(ifaces.length);
1184 for (int i = 0; i < ifaces.length; i++) {
1185 bout.writeUTF(ifaces[i].getName());
1186 }
1187
1188 bout.setBlockDataMode(true);
1189 annotateProxyClass(cl);
1190 bout.setBlockDataMode(false);
1191 bout.writeByte(TC_ENDBLOCKDATA);
1192
1193 writeClassDesc(desc.getSuperDesc(), false);
1194 }
1195
1196 /**
1197 * Writes class descriptor representing a standard (i.e., not a dynamic
1198 * proxy) class to stream.
1199 */
1200 private void writeNonProxyDesc(ObjectStreamClass desc, boolean unshared)
1201 throws IOException
1202 {
1203 bout.writeByte(TC_CLASSDESC);
1204 handles.assign(unshared ? null : desc);
1205
1206 if (protocol == PROTOCOL_VERSION_1) {
1207 // do not invoke class descriptor write hook with old protocol
1208 desc.writeNonProxy(this);
1209 } else {
1210 writeClassDescriptor(desc);
1211 }
1212
1213 Class<?> cl = desc.forClass();
1214 bout.setBlockDataMode(true);
1215 annotateClass(cl);
1216 bout.setBlockDataMode(false);
1217 bout.writeByte(TC_ENDBLOCKDATA);
1218
1219 writeClassDesc(desc.getSuperDesc(), false);
1220 }
1221
1222 /**
1223 * Writes given string to stream, using standard or long UTF format
1224 * depending on string length.
1225 */
1226 private void writeString(String str, boolean unshared) throws IOException {
1227 handles.assign(unshared ? null : str);
1228 bout.writeUTFInternal(str, true);
1229 }
1230
1231 /**
1232 * Writes given array object to stream.
1233 */
1234 private void writeArray(Object array,
1235 ObjectStreamClass desc,
1236 boolean unshared)
1237 throws IOException
1238 {
1239 bout.writeByte(TC_ARRAY);
1240 writeClassDesc(desc, false);
1241 handles.assign(unshared ? null : array);
1242
1243 Class<?> ccl = desc.forClass().getComponentType();
1244 if (ccl.isPrimitive()) {
1245 if (ccl == Integer.TYPE) {
1246 int[] ia = (int[]) array;
1247 bout.writeInt(ia.length);
1248 bout.writeInts(ia, 0, ia.length);
1249 } else if (ccl == Byte.TYPE) {
1250 byte[] ba = (byte[]) array;
1251 bout.writeInt(ba.length);
1252 bout.write(ba, 0, ba.length, true);
1253 } else if (ccl == Long.TYPE) {
1254 long[] ja = (long[]) array;
1255 bout.writeInt(ja.length);
1256 bout.writeLongs(ja, 0, ja.length);
1257 } else if (ccl == Float.TYPE) {
1258 float[] fa = (float[]) array;
1259 bout.writeInt(fa.length);
1260 bout.writeFloats(fa, 0, fa.length);
1261 } else if (ccl == Double.TYPE) {
1262 double[] da = (double[]) array;
1263 bout.writeInt(da.length);
1264 bout.writeDoubles(da, 0, da.length);
1265 } else if (ccl == Short.TYPE) {
1266 short[] sa = (short[]) array;
1267 bout.writeInt(sa.length);
1268 bout.writeShorts(sa, 0, sa.length);
1269 } else if (ccl == Character.TYPE) {
1270 char[] ca = (char[]) array;
1271 bout.writeInt(ca.length);
1272 bout.writeChars(ca, 0, ca.length);
1273 } else if (ccl == Boolean.TYPE) {
1274 boolean[] za = (boolean[]) array;
1275 bout.writeInt(za.length);
1276 bout.writeBooleans(za, 0, za.length);
1277 } else {
1278 throw new InternalError();
1279 }
1280 } else {
1281 Object[] objs = (Object[]) array;
1282 int len = objs.length;
1283 bout.writeInt(len);
1284 if (extendedDebugInfo) {
1285 debugInfoStack.push(
1286 "array (class \"" + array.getClass().getName() +
1287 "\", size: " + len + ")");
1288 }
1289 try {
1290 for (int i = 0; i < len; i++) {
1291 if (extendedDebugInfo) {
1292 debugInfoStack.push(
1293 "element of array (index: " + i + ")");
1294 }
1295 try {
1296 writeObject0(objs[i], false);
1297 } finally {
1298 if (extendedDebugInfo) {
1299 debugInfoStack.pop();
1300 }
1301 }
1302 }
1303 } finally {
1304 if (extendedDebugInfo) {
1305 debugInfoStack.pop();
1306 }
1307 }
1308 }
1309 }
1310
1311 /**
1312 * Writes given enum constant to stream.
1313 */
1314 private void writeEnum(Enum<?> en,
1315 ObjectStreamClass desc,
1316 boolean unshared)
1317 throws IOException
1318 {
1319 bout.writeByte(TC_ENUM);
1320 ObjectStreamClass sdesc = desc.getSuperDesc();
1321 writeClassDesc((sdesc.forClass() == Enum.class) ? desc : sdesc, false);
1322 handles.assign(unshared ? null : en);
1323 writeString(en.name(), false);
1324 }
1325
1326 /**
1327 * Writes representation of an "ordinary" (i.e., not a String, Class,
1328 * ObjectStreamClass, array, or enum constant) serializable object to the
1329 * stream.
1330 */
1331 private void writeOrdinaryObject(Object obj,
1332 ObjectStreamClass desc,
1333 boolean unshared)
1334 throws IOException
1335 {
1336 if (extendedDebugInfo) {
1337 debugInfoStack.push(
1338 (depth == 1 ? "root " : "") + "object (class \"" +
1339 obj.getClass().getName() + "\", " + obj.toString() + ")");
1340 }
1341 try {
1342 desc.checkSerialize();
1343
1344 bout.writeByte(TC_OBJECT);
1345 writeClassDesc(desc, false);
1346 handles.assign(unshared ? null : obj);
1347
1348 if (desc.isRecord()) {
1349 writeRecordData(obj, desc);
1350 } else if (desc.isExternalizable() && !desc.isProxy()) {
1351 writeExternalData((Externalizable) obj);
1352 } else {
1353 writeSerialData(obj, desc);
1354 }
1355 } finally {
1356 if (extendedDebugInfo) {
1357 debugInfoStack.pop();
1358 }
1359 }
1360 }
1361
1362 /**
1363 * Writes externalizable data of given object by invoking its
1364 * writeExternal() method.
1365 */
1366 private void writeExternalData(Externalizable obj) throws IOException {
1367 PutFieldImpl oldPut = curPut;
1368 curPut = null;
1369
1370 if (extendedDebugInfo) {
1371 debugInfoStack.push("writeExternal data");
1372 }
1373 SerialCallbackContext oldContext = curContext;
1374 try {
1375 curContext = null;
1376 if (protocol == PROTOCOL_VERSION_1) {
1377 obj.writeExternal(this);
1378 } else {
1379 bout.setBlockDataMode(true);
1380 obj.writeExternal(this);
1381 bout.setBlockDataMode(false);
1382 bout.writeByte(TC_ENDBLOCKDATA);
1383 }
1384 } finally {
1385 curContext = oldContext;
1386 if (extendedDebugInfo) {
1387 debugInfoStack.pop();
1388 }
1389 }
1390
1391 curPut = oldPut;
1392 }
1393
1394 /** Writes the record component values for the given record object. */
1395 private void writeRecordData(Object obj, ObjectStreamClass desc)
1396 throws IOException
1397 {
1398 assert obj.getClass().isRecord();
1399 ObjectStreamClass.ClassDataSlot[] slots = desc.getClassDataLayout();
1400 if (slots.length != 1) {
1401 throw new InvalidClassException(
1402 "expected a single record slot length, but found: " + slots.length);
1403 }
1404
1405 defaultWriteFields(obj, desc); // #### seems unnecessary to use the accessors
1406 }
1407
1408 /**
1409 * Writes instance data for each serializable class of given object, from
1410 * superclass to subclass.
1411 */
1412 private void writeSerialData(Object obj, ObjectStreamClass desc)
1413 throws IOException
1414 {
1415 ObjectStreamClass.ClassDataSlot[] slots = desc.getClassDataLayout();
1416 for (int i = 0; i < slots.length; i++) {
1417 ObjectStreamClass slotDesc = slots[i].desc;
1418 if (slotDesc.hasWriteObjectMethod()) {
1419 PutFieldImpl oldPut = curPut;
1420 curPut = null;
1421 SerialCallbackContext oldContext = curContext;
1422
1423 if (extendedDebugInfo) {
1424 debugInfoStack.push(
1425 "custom writeObject data (class \"" +
1426 slotDesc.getName() + "\")");
1427 }
1428 try {
1429 curContext = new SerialCallbackContext(obj, slotDesc);
1430 bout.setBlockDataMode(true);
1431 slotDesc.invokeWriteObject(obj, this);
1432 bout.setBlockDataMode(false);
1433 bout.writeByte(TC_ENDBLOCKDATA);
1434 } finally {
1435 curContext.setUsed();
1436 curContext = oldContext;
1437 if (extendedDebugInfo) {
1438 debugInfoStack.pop();
1439 }
1440 }
1441
1442 curPut = oldPut;
1443 } else {
1444 defaultWriteFields(obj, slotDesc);
1445 }
1446 }
1447 }
1448
1449 /**
1450 * Fetches and writes values of serializable fields of given object to
1451 * stream. The given class descriptor specifies which field values to
1452 * write, and in which order they should be written.
1453 */
1454 private void defaultWriteFields(Object obj, ObjectStreamClass desc)
1455 throws IOException
1456 {
1457 Class<?> cl = desc.forClass();
1458 if (cl != null && obj != null && !cl.isInstance(obj)) {
1459 throw new ClassCastException();
1460 }
1461
1462 desc.checkDefaultSerialize();
1463
1464 int primDataSize = desc.getPrimDataSize();
1465 if (primDataSize > 0) {
1466 if (primVals == null || primVals.length < primDataSize) {
1467 primVals = new byte[primDataSize];
1468 }
1469 desc.getPrimFieldValues(obj, primVals);
1470 bout.write(primVals, 0, primDataSize, false);
1471 }
1472
1473 int numObjFields = desc.getNumObjFields();
1474 if (numObjFields > 0) {
1475 ObjectStreamField[] fields = desc.getFields(false);
1476 Object[] objVals = new Object[numObjFields];
1477 int numPrimFields = fields.length - objVals.length;
1478 desc.getObjFieldValues(obj, objVals);
1479 for (int i = 0; i < objVals.length; i++) {
1480 if (extendedDebugInfo) {
1481 debugInfoStack.push(
1482 "field (class \"" + desc.getName() + "\", name: \"" +
1483 fields[numPrimFields + i].getName() + "\", type: \"" +
1484 fields[numPrimFields + i].getType() + "\")");
1485 }
1486 try {
1487 writeObject0(objVals[i],
1488 fields[numPrimFields + i].isUnshared());
1489 } finally {
1490 if (extendedDebugInfo) {
1491 debugInfoStack.pop();
1492 }
1493 }
1494 }
1495 }
1496 }
1497
1498 /**
1499 * Attempts to write to stream fatal IOException that has caused
1500 * serialization to abort.
1501 */
1502 private void writeFatalException(IOException ex) throws IOException {
1503 /*
1504 * Note: the serialization specification states that if a second
1505 * IOException occurs while attempting to serialize the original fatal
1506 * exception to the stream, then a StreamCorruptedException should be
1507 * thrown (section 2.1). However, due to a bug in previous
1508 * implementations of serialization, StreamCorruptedExceptions were
1509 * rarely (if ever) actually thrown--the "root" exceptions from
1510 * underlying streams were thrown instead. This historical behavior is
1511 * followed here for consistency.
1512 */
1513 clear();
1514 boolean oldMode = bout.setBlockDataMode(false);
1515 try {
1516 bout.writeByte(TC_EXCEPTION);
1517 writeObject0(ex, false);
1518 clear();
1519 } finally {
1520 bout.setBlockDataMode(oldMode);
1521 }
1522 }
1523
1524 /**
1525 * Default PutField implementation.
1526 */
1527 private class PutFieldImpl extends PutField {
1528
1529 /** class descriptor describing serializable fields */
1530 private final ObjectStreamClass desc;
1531 /** primitive field values */
1532 private final byte[] primVals;
1533 /** object field values */
1534 private final Object[] objVals;
1535
1536 /**
1537 * Creates PutFieldImpl object for writing fields defined in given
1538 * class descriptor.
1539 */
1540 PutFieldImpl(ObjectStreamClass desc) {
1541 this.desc = desc;
1542 primVals = new byte[desc.getPrimDataSize()];
1543 objVals = new Object[desc.getNumObjFields()];
1544 }
1545
1546 public void put(String name, boolean val) {
1547 ByteArray.setBoolean(primVals, getFieldOffset(name, Boolean.TYPE), val);
1548 }
1549
1550 public void put(String name, byte val) {
1551 primVals[getFieldOffset(name, Byte.TYPE)] = val;
1552 }
1553
1554 public void put(String name, char val) {
1555 ByteArray.setChar(primVals, getFieldOffset(name, Character.TYPE), val);
1556 }
1557
1558 public void put(String name, short val) {
1559 ByteArray.setShort(primVals, getFieldOffset(name, Short.TYPE), val);
1560 }
1561
1562 public void put(String name, int val) {
1563 ByteArray.setInt(primVals, getFieldOffset(name, Integer.TYPE), val);
1564 }
1565
1566 public void put(String name, float val) {
1567 ByteArray.setFloat(primVals, getFieldOffset(name, Float.TYPE), val);
1568 }
1569
1570 public void put(String name, long val) {
1571 ByteArray.setLong(primVals, getFieldOffset(name, Long.TYPE), val);
1572 }
1573
1574 public void put(String name, double val) {
1575 ByteArray.setDouble(primVals, getFieldOffset(name, Double.TYPE), val);
1576 }
1577
1578 public void put(String name, Object val) {
1579 objVals[getFieldOffset(name, Object.class)] = val;
1580 }
1581
1582 // deprecated in ObjectOutputStream.PutField
1583 public void write(ObjectOutput out) throws IOException {
1584 /*
1585 * Applications should *not* use this method to write PutField
1586 * data, as it will lead to stream corruption if the PutField
1587 * object writes any primitive data (since block data mode is not
1588 * unset/set properly, as is done in OOS.writeFields()). This
1589 * broken implementation is being retained solely for behavioral
1590 * compatibility, in order to support applications which use
1591 * OOS.PutField.write() for writing only non-primitive data.
1592 *
1593 * Serialization of unshared objects is not implemented here since
1594 * it is not necessary for backwards compatibility; also, unshared
1595 * semantics may not be supported by the given ObjectOutput
1596 * instance. Applications which write unshared objects using the
1597 * PutField API must use OOS.writeFields().
1598 */
1599 if (ObjectOutputStream.this != out) {
1600 throw new IllegalArgumentException("wrong stream");
1601 }
1602 out.write(primVals, 0, primVals.length);
1603
1604 ObjectStreamField[] fields = desc.getFields(false);
1605 int numPrimFields = fields.length - objVals.length;
1606 // REMIND: warn if numPrimFields > 0?
1607 for (int i = 0; i < objVals.length; i++) {
1608 if (fields[numPrimFields + i].isUnshared()) {
1609 throw new IOException("cannot write unshared object");
1610 }
1611 out.writeObject(objVals[i]);
1612 }
1613 }
1614
1615 /**
1616 * Writes buffered primitive data and object fields to stream.
1617 */
1618 void writeFields() throws IOException {
1619 bout.write(primVals, 0, primVals.length, false);
1620
1621 ObjectStreamField[] fields = desc.getFields(false);
1622 int numPrimFields = fields.length - objVals.length;
1623 for (int i = 0; i < objVals.length; i++) {
1624 if (extendedDebugInfo) {
1625 debugInfoStack.push(
1626 "field (class \"" + desc.getName() + "\", name: \"" +
1627 fields[numPrimFields + i].getName() + "\", type: \"" +
1628 fields[numPrimFields + i].getType() + "\")");
1629 }
1630 try {
1631 writeObject0(objVals[i],
1632 fields[numPrimFields + i].isUnshared());
1633 } finally {
1634 if (extendedDebugInfo) {
1635 debugInfoStack.pop();
1636 }
1637 }
1638 }
1639 }
1640
1641 /**
1642 * Returns offset of field with given name and type. A specified type
1643 * of null matches all types, Object.class matches all non-primitive
1644 * types, and any other non-null type matches assignable types only.
1645 * Throws IllegalArgumentException if no matching field found.
1646 */
1647 private int getFieldOffset(String name, Class<?> type) {
1648 ObjectStreamField field = desc.getField(name, type);
1649 if (field == null) {
1650 throw new IllegalArgumentException("no such field " + name +
1651 " with type " + type);
1652 }
1653 return field.getOffset();
1654 }
1655 }
1656
1657 /**
1658 * Buffered output stream with two modes: in default mode, outputs data in
1659 * same format as DataOutputStream; in "block data" mode, outputs data
1660 * bracketed by block data markers (see object serialization specification
1661 * for details).
1662 */
1663 private static final class BlockDataOutputStream
1664 extends OutputStream implements DataOutput
1665 {
1666 /** maximum data block length */
1667 private static final int MAX_BLOCK_SIZE = 1024;
1668 /** maximum data block header length */
1669 private static final int MAX_HEADER_SIZE = 5;
1670 /** (tunable) length of char buffer (for writing strings) */
1671 private static final int CHAR_BUF_SIZE = 256;
1672
1673 /** buffer for writing general/block data */
1674 private final byte[] buf = new byte[MAX_BLOCK_SIZE];
1675 /** buffer for writing block data headers */
1676 private final byte[] hbuf = new byte[MAX_HEADER_SIZE];
1677 /** char buffer for fast string writes */
1678 private final char[] cbuf = new char[CHAR_BUF_SIZE];
1679
1680 /** block data mode */
1681 private boolean blkmode = false;
1682 /** current offset into buf */
1683 private int pos = 0;
1684
1685 /** underlying output stream */
1686 private final OutputStream out;
1687 /** loopback stream (for data writes that span data blocks) */
1688 private final DataOutputStream dout;
1689
1690 /**
1691 * Creates new BlockDataOutputStream on top of given underlying stream.
1692 * Block data mode is turned off by default.
1693 */
1694 BlockDataOutputStream(OutputStream out) {
1695 this.out = out;
1696 dout = new DataOutputStream(this);
1697 }
1698
1699 /**
1700 * Sets block data mode to the given mode (true == on, false == off)
1701 * and returns the previous mode value. If the new mode is the same as
1702 * the old mode, no action is taken. If the new mode differs from the
1703 * old mode, any buffered data is flushed before switching to the new
1704 * mode.
1705 */
1706 boolean setBlockDataMode(boolean mode) throws IOException {
1707 if (blkmode == mode) {
1708 return blkmode;
1709 }
1710 drain();
1711 blkmode = mode;
1712 return !blkmode;
1713 }
1714
1715 /**
1716 * Returns true if the stream is currently in block data mode, false
1717 * otherwise.
1718 */
1719 boolean getBlockDataMode() {
1720 return blkmode;
1721 }
1722
1723 /* ----------------- generic output stream methods ----------------- */
1724 /*
1725 * The following methods are equivalent to their counterparts in
1726 * OutputStream, except that they partition written data into data
1727 * blocks when in block data mode.
1728 */
1729
1730 public void write(int b) throws IOException {
1731 if (pos >= MAX_BLOCK_SIZE) {
1732 drain();
1733 }
1734 buf[pos++] = (byte) b;
1735 }
1736
1737 public void write(byte[] b) throws IOException {
1738 write(b, 0, b.length, false);
1739 }
1740
1741 public void write(byte[] b, int off, int len) throws IOException {
1742 write(b, off, len, false);
1743 }
1744
1745 public void flush() throws IOException {
1746 drain();
1747 out.flush();
1748 }
1749
1750 public void close() throws IOException {
1751 flush();
1752 out.close();
1753 }
1754
1755 /**
1756 * Writes specified span of byte values from given array. If copy is
1757 * true, copies the values to an intermediate buffer before writing
1758 * them to underlying stream (to avoid exposing a reference to the
1759 * original byte array).
1760 */
1761 void write(byte[] b, int off, int len, boolean copy)
1762 throws IOException
1763 {
1764 if (!(copy || blkmode)) { // write directly
1765 drain();
1766 out.write(b, off, len);
1767 return;
1768 }
1769
1770 while (len > 0) {
1771 if (pos >= MAX_BLOCK_SIZE) {
1772 drain();
1773 }
1774 if (len >= MAX_BLOCK_SIZE && !copy && pos == 0) {
1775 // avoid unnecessary copy
1776 writeBlockHeader(MAX_BLOCK_SIZE);
1777 out.write(b, off, MAX_BLOCK_SIZE);
1778 off += MAX_BLOCK_SIZE;
1779 len -= MAX_BLOCK_SIZE;
1780 } else {
1781 int wlen = Math.min(len, MAX_BLOCK_SIZE - pos);
1782 System.arraycopy(b, off, buf, pos, wlen);
1783 pos += wlen;
1784 off += wlen;
1785 len -= wlen;
1786 }
1787 }
1788 }
1789
1790 /**
1791 * Writes all buffered data from this stream to the underlying stream,
1792 * but does not flush underlying stream.
1793 */
1794 void drain() throws IOException {
1795 if (pos == 0) {
1796 return;
1797 }
1798 if (blkmode) {
1799 writeBlockHeader(pos);
1800 }
1801 out.write(buf, 0, pos);
1802 pos = 0;
1803 }
1804
1805 /**
1806 * Writes block data header. Data blocks shorter than 256 bytes are
1807 * prefixed with a 2-byte header; all others start with a 5-byte
1808 * header.
1809 */
1810 private void writeBlockHeader(int len) throws IOException {
1811 if (len <= 0xFF) {
1812 hbuf[0] = TC_BLOCKDATA;
1813 hbuf[1] = (byte) len;
1814 out.write(hbuf, 0, 2);
1815 } else {
1816 hbuf[0] = TC_BLOCKDATALONG;
1817 ByteArray.setInt(hbuf, 1, len);
1818 out.write(hbuf, 0, 5);
1819 }
1820 }
1821
1822
1823 /* ----------------- primitive data output methods ----------------- */
1824 /*
1825 * The following methods are equivalent to their counterparts in
1826 * DataOutputStream, except that they partition written data into data
1827 * blocks when in block data mode.
1828 */
1829
1830 public void writeBoolean(boolean v) throws IOException {
1831 if (pos >= MAX_BLOCK_SIZE) {
1832 drain();
1833 }
1834 ByteArray.setBoolean(buf, pos++, v);
1835 }
1836
1837 public void writeByte(int v) throws IOException {
1838 if (pos >= MAX_BLOCK_SIZE) {
1839 drain();
1840 }
1841 buf[pos++] = (byte) v;
1842 }
1843
1844 public void writeChar(int v) throws IOException {
1845 if (pos + 2 <= MAX_BLOCK_SIZE) {
1846 ByteArray.setChar(buf, pos, (char) v);
1847 pos += 2;
1848 } else {
1849 dout.writeChar(v);
1850 }
1851 }
1852
1853 public void writeShort(int v) throws IOException {
1854 if (pos + 2 <= MAX_BLOCK_SIZE) {
1855 ByteArray.setShort(buf, pos, (short) v);
1856 pos += 2;
1857 } else {
1858 dout.writeShort(v);
1859 }
1860 }
1861
1862 public void writeInt(int v) throws IOException {
1863 if (pos + 4 <= MAX_BLOCK_SIZE) {
1864 ByteArray.setInt(buf, pos, v);
1865 pos += 4;
1866 } else {
1867 dout.writeInt(v);
1868 }
1869 }
1870
1871 public void writeFloat(float v) throws IOException {
1872 if (pos + 4 <= MAX_BLOCK_SIZE) {
1873 ByteArray.setFloat(buf, pos, v);
1874 pos += 4;
1875 } else {
1876 dout.writeFloat(v);
1877 }
1878 }
1879
1880 public void writeLong(long v) throws IOException {
1881 if (pos + 8 <= MAX_BLOCK_SIZE) {
1882 ByteArray.setLong(buf, pos, v);
1883 pos += 8;
1884 } else {
1885 dout.writeLong(v);
1886 }
1887 }
1888
1889 public void writeDouble(double v) throws IOException {
1890 if (pos + 8 <= MAX_BLOCK_SIZE) {
1891 ByteArray.setDouble(buf, pos, v);
1892 pos += 8;
1893 } else {
1894 dout.writeDouble(v);
1895 }
1896 }
1897
1898 @SuppressWarnings("deprecation")
1899 void writeBytes(String s, int len) throws IOException {
1900 int pos = this.pos;
1901 for (int strpos = 0; strpos < len;) {
1902 int rem = MAX_BLOCK_SIZE - pos;
1903 int csize = Math.min(len - strpos, rem);
1904 s.getBytes(strpos, strpos + csize, buf, pos);
1905 pos += csize;
1906 strpos += csize;
1907
1908 if (pos == MAX_BLOCK_SIZE) {
1909 this.pos = pos;
1910 drain();
1911 pos = 0;
1912 }
1913 }
1914 this.pos = pos;
1915 }
1916
1917 public void writeBytes(String s) throws IOException {
1918 writeBytes(s, s.length());
1919 }
1920
1921 public void writeChars(String s) throws IOException {
1922 int endoff = s.length();
1923 for (int off = 0; off < endoff; ) {
1924 int csize = Math.min(endoff - off, CHAR_BUF_SIZE);
1925 s.getChars(off, off + csize, cbuf, 0);
1926 writeChars(cbuf, 0, csize);
1927 off += csize;
1928 }
1929 }
1930
1931 public void writeUTF(String str) throws IOException {
1932 writeUTFInternal(str, false);
1933 }
1934
1935 private void writeUTFInternal(String str, boolean writeHeader) throws IOException {
1936 int strlen = str.length();
1937 int countNonZeroAscii = JLA.countNonZeroAscii(str);
1938 int utflen = utfLen(str, countNonZeroAscii);
1939 if (utflen <= 0xFFFF) {
1940 if(writeHeader) {
1941 writeByte(TC_STRING);
1942 }
1943 writeShort(utflen);
1944 } else {
1945 if(writeHeader) {
1946 writeByte(TC_LONGSTRING);
1947 }
1948 writeLong(utflen);
1949 }
1950
1951 if (countNonZeroAscii != 0) {
1952 writeBytes(str, countNonZeroAscii);
1953 }
1954 if (countNonZeroAscii != strlen) {
1955 writeMoreUTF(str, countNonZeroAscii);
1956 }
1957 }
1958
1959 private void writeMoreUTF(String str, int stroff) throws IOException {
1960 int pos = this.pos;
1961 for (int strlen = str.length(); stroff < strlen;) {
1962 char c = str.charAt(stroff++);
1963 int csize = c != 0 && c < 0x80 ? 1 : c >= 0x800 ? 3 : 2;
1964 if (pos + csize >= MAX_BLOCK_SIZE) {
1965 this.pos = pos;
1966 drain();
1967 pos = 0;
1968 }
1969 pos = putChar(buf, pos, c);
1970 }
1971 this.pos = pos;
1972 }
1973
1974
1975 /* -------------- primitive data array output methods -------------- */
1976 /*
1977 * The following methods write out spans of primitive data values.
1978 * Though equivalent to calling the corresponding primitive write
1979 * methods repeatedly, these methods are optimized for writing groups
1980 * of primitive data values more efficiently.
1981 */
1982
1983 void writeBooleans(boolean[] v, int off, int len) throws IOException {
1984 int endoff = off + len;
1985 while (off < endoff) {
1986 if (pos >= MAX_BLOCK_SIZE) {
1987 drain();
1988 }
1989 int stop = Math.min(endoff, off + (MAX_BLOCK_SIZE - pos));
1990 while (off < stop) {
1991 ByteArray.setBoolean(buf, pos++, v[off++]);
1992 }
1993 }
1994 }
1995
1996 void writeChars(char[] v, int off, int len) throws IOException {
1997 int limit = MAX_BLOCK_SIZE - 2;
1998 int endoff = off + len;
1999 while (off < endoff) {
2000 if (pos <= limit) {
2001 int avail = (MAX_BLOCK_SIZE - pos) >> 1;
2002 int stop = Math.min(endoff, off + avail);
2003 while (off < stop) {
2004 ByteArray.setChar(buf, pos, v[off++]);
2005 pos += 2;
2006 }
2007 } else {
2008 dout.writeChar(v[off++]);
2009 }
2010 }
2011 }
2012
2013 void writeShorts(short[] v, int off, int len) throws IOException {
2014 int limit = MAX_BLOCK_SIZE - 2;
2015 int endoff = off + len;
2016 while (off < endoff) {
2017 if (pos <= limit) {
2018 int avail = (MAX_BLOCK_SIZE - pos) >> 1;
2019 int stop = Math.min(endoff, off + avail);
2020 while (off < stop) {
2021 ByteArray.setShort(buf, pos, v[off++]);
2022 pos += 2;
2023 }
2024 } else {
2025 dout.writeShort(v[off++]);
2026 }
2027 }
2028 }
2029
2030 void writeInts(int[] v, int off, int len) throws IOException {
2031 int limit = MAX_BLOCK_SIZE - 4;
2032 int endoff = off + len;
2033 while (off < endoff) {
2034 if (pos <= limit) {
2035 int avail = (MAX_BLOCK_SIZE - pos) >> 2;
2036 int stop = Math.min(endoff, off + avail);
2037 while (off < stop) {
2038 ByteArray.setInt(buf, pos, v[off++]);
2039 pos += 4;
2040 }
2041 } else {
2042 dout.writeInt(v[off++]);
2043 }
2044 }
2045 }
2046
2047 void writeFloats(float[] v, int off, int len) throws IOException {
2048 int limit = MAX_BLOCK_SIZE - 4;
2049 int endoff = off + len;
2050 while (off < endoff) {
2051 if (pos <= limit) {
2052 int avail = (MAX_BLOCK_SIZE - pos) >> 2;
2053 int stop = Math.min(endoff, off + avail);
2054 while (off < stop) {
2055 ByteArray.setFloat(buf, pos, v[off++]);
2056 pos += 4;
2057 }
2058 } else {
2059 dout.writeFloat(v[off++]);
2060 }
2061 }
2062 }
2063
2064 void writeLongs(long[] v, int off, int len) throws IOException {
2065 int limit = MAX_BLOCK_SIZE - 8;
2066 int endoff = off + len;
2067 while (off < endoff) {
2068 if (pos <= limit) {
2069 int avail = (MAX_BLOCK_SIZE - pos) >> 3;
2070 int stop = Math.min(endoff, off + avail);
2071 while (off < stop) {
2072 ByteArray.setLong(buf, pos, v[off++]);
2073 pos += 8;
2074 }
2075 } else {
2076 dout.writeLong(v[off++]);
2077 }
2078 }
2079 }
2080
2081 void writeDoubles(double[] v, int off, int len) throws IOException {
2082 int limit = MAX_BLOCK_SIZE - 8;
2083 int endoff = off + len;
2084 while (off < endoff) {
2085 if (pos <= limit) {
2086 int avail = (MAX_BLOCK_SIZE - pos) >> 3;
2087 int stop = Math.min(endoff, off + avail);
2088 while (off < stop) {
2089 ByteArray.setDouble(buf, pos, v[off++]);
2090 pos += 8;
2091 }
2092 } else {
2093 dout.writeDouble(v[off++]);
2094 }
2095 }
2096 }
2097 }
2098
2099 /**
2100 * Lightweight identity hash table which maps objects to integer handles,
2101 * assigned in ascending order.
2102 */
2103 private static final class HandleTable {
2104
2105 /* number of mappings in table/next available handle */
2106 private int size;
2107 /* size threshold determining when to expand hash spine */
2108 private int threshold;
2109 /* factor for computing size threshold */
2110 private final float loadFactor;
2111 /* maps hash value -> candidate handle value */
2112 private int[] spine;
2113 /* maps handle value -> next candidate handle value */
2114 private int[] next;
2115 /* maps handle value -> associated object */
2116 private Object[] objs;
2117
2118 /**
2119 * Creates new HandleTable with given capacity and load factor.
2120 */
2121 HandleTable(int initialCapacity, float loadFactor) {
2122 this.loadFactor = loadFactor;
2123 spine = new int[initialCapacity];
2124 next = new int[initialCapacity];
2125 objs = new Object[initialCapacity];
2126 threshold = (int) (initialCapacity * loadFactor);
2127 clear();
2128 }
2129
2130 /**
2131 * Assigns next available handle to given object, and returns handle
2132 * value. Handles are assigned in ascending order starting at 0.
2133 */
2134 int assign(Object obj) {
2135 if (size >= next.length) {
2136 growEntries();
2137 }
2138 if (size >= threshold) {
2139 growSpine();
2140 }
2141 insert(obj, size);
2142 return size++;
2143 }
2144
2145 /**
2146 * Looks up and returns handle associated with given object, or -1 if
2147 * no mapping found.
2148 */
2149 int lookup(Object obj) {
2150 if (size == 0) {
2151 return -1;
2152 }
2153 int index = hash(obj) % spine.length;
2154 for (int i = spine[index]; i >= 0; i = next[i]) {
2155 if (objs[i] == obj) {
2156 return i;
2157 }
2158 }
2159 return -1;
2160 }
2161
2162 /**
2163 * Resets table to its initial (empty) state.
2164 */
2165 void clear() {
2166 Arrays.fill(spine, -1);
2167 Arrays.fill(objs, 0, size, null);
2168 size = 0;
2169 }
2170
2171 /**
2172 * Returns the number of mappings currently in table.
2173 */
2174 int size() {
2175 return size;
2176 }
2177
2178 /**
2179 * Inserts mapping object -> handle mapping into table. Assumes table
2180 * is large enough to accommodate new mapping.
2181 */
2182 private void insert(Object obj, int handle) {
2183 int index = hash(obj) % spine.length;
2184 objs[handle] = obj;
2185 next[handle] = spine[index];
2186 spine[index] = handle;
2187 }
2188
2189 /**
2190 * Expands the hash "spine" -- equivalent to increasing the number of
2191 * buckets in a conventional hash table.
2192 */
2193 private void growSpine() {
2194 spine = new int[(spine.length << 1) + 1];
2195 threshold = (int) (spine.length * loadFactor);
2196 Arrays.fill(spine, -1);
2197 for (int i = 0; i < size; i++) {
2198 insert(objs[i], i);
2199 }
2200 }
2201
2202 /**
2203 * Increases hash table capacity by lengthening entry arrays.
2204 */
2205 private void growEntries() {
2206 int newLength = (next.length << 1) + 1;
2207 int[] newNext = new int[newLength];
2208 System.arraycopy(next, 0, newNext, 0, size);
2209 next = newNext;
2210
2211 Object[] newObjs = new Object[newLength];
2212 System.arraycopy(objs, 0, newObjs, 0, size);
2213 objs = newObjs;
2214 }
2215
2216 /**
2217 * Returns hash value for given object.
2218 */
2219 private int hash(Object obj) {
2220 return System.identityHashCode(obj) & 0x7FFFFFFF;
2221 }
2222 }
2223
2224 /**
2225 * Lightweight identity hash table which maps objects to replacement
2226 * objects.
2227 */
2228 private static final class ReplaceTable {
2229
2230 /* maps object -> index */
2231 private final HandleTable htab;
2232 /* maps index -> replacement object */
2233 private Object[] reps;
2234
2235 /**
2236 * Creates new ReplaceTable with given capacity and load factor.
2237 */
2238 ReplaceTable(int initialCapacity, float loadFactor) {
2239 htab = new HandleTable(initialCapacity, loadFactor);
2240 reps = new Object[initialCapacity];
2241 }
2242
2243 /**
2244 * Enters mapping from object to replacement object.
2245 */
2246 void assign(Object obj, Object rep) {
2247 int index = htab.assign(obj);
2248 while (index >= reps.length) {
2249 grow();
2250 }
2251 reps[index] = rep;
2252 }
2253
2254 /**
2255 * Looks up and returns replacement for given object. If no
2256 * replacement is found, returns the lookup object itself.
2257 */
2258 Object lookup(Object obj) {
2259 int index = htab.lookup(obj);
2260 return (index >= 0) ? reps[index] : obj;
2261 }
2262
2263 /**
2264 * Resets table to its initial (empty) state.
2265 */
2266 void clear() {
2267 Arrays.fill(reps, 0, htab.size(), null);
2268 htab.clear();
2269 }
2270
2271 /**
2272 * Returns the number of mappings currently in table.
2273 */
2274 int size() {
2275 return htab.size();
2276 }
2277
2278 /**
2279 * Increases table capacity.
2280 */
2281 private void grow() {
2282 Object[] newReps = new Object[(reps.length << 1) + 1];
2283 System.arraycopy(reps, 0, newReps, 0, reps.length);
2284 reps = newReps;
2285 }
2286 }
2287
2288 /**
2289 * Stack to keep debug information about the state of the
2290 * serialization process, for embedding in exception messages.
2291 */
2292 private static final class DebugTraceInfoStack {
2293 private final List<String> stack;
2294
2295 DebugTraceInfoStack() {
2296 stack = new ArrayList<>();
2297 }
2298
2299 /**
2300 * Removes all of the elements from enclosed list.
2301 */
2302 void clear() {
2303 stack.clear();
2304 }
2305
2306 /**
2307 * Removes the object at the top of enclosed list.
2308 */
2309 void pop() {
2310 stack.remove(stack.size()-1);
2311 }
2312
2313 /**
2314 * Pushes a String onto the top of enclosed list.
2315 */
2316 void push(String entry) {
2317 stack.add("\t- " + entry);
2318 }
2319
2320 /**
2321 * Returns a string representation of this object
2322 */
2323 public String toString() {
2324 StringJoiner sj = new StringJoiner("\n");
2325 for (int i = stack.size() - 1; i >= 0; i--) {
2326 sj.add(stack.get(i));
2327 }
2328 return sj.toString();
2329 }
2330 }
2331
2332 }