1 /*
2 * Copyright (c) 1996, 2021, 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
26 package java.io;
27
28 import java.io.ObjectStreamClass.WeakClassKey;
29 import java.lang.ref.ReferenceQueue;
30 import java.security.AccessController;
31 import java.security.PrivilegedAction;
32 import java.util.ArrayList;
33 import java.util.Arrays;
34 import java.util.List;
35 import java.util.StringJoiner;
36 import java.util.concurrent.ConcurrentHashMap;
37 import java.util.concurrent.ConcurrentMap;
38 import static java.io.ObjectStreamClass.processQueue;
39 import sun.reflect.misc.ReflectUtil;
40
41 /**
42 * An ObjectOutputStream writes primitive data types and graphs of Java objects
43 * to an OutputStream. The objects can be read (reconstituted) using an
44 * ObjectInputStream. Persistent storage of objects can be accomplished by
45 * using a file for the stream. If the stream is a network socket stream, the
46 * objects can be reconstituted on another host or in another process.
47 *
48 * <p>Only objects that support the java.io.Serializable interface can be
49 * written to streams. The class of each serializable object is encoded
50 * including the class name and signature of the class, the values of the
51 * object's fields and arrays, and the closure of any other objects referenced
52 * from the initial objects.
53 *
54 * <p>The method writeObject is used to write an object to the stream. Any
55 * object, including Strings and arrays, is written with writeObject. Multiple
56 * objects or primitives can be written to the stream. The objects must be
57 * read back from the corresponding ObjectInputstream with the same types and
58 * in the same order as they were written.
59 *
60 * <p>Primitive data types can also be written to the stream using the
61 * appropriate methods from DataOutput. Strings can also be written using the
62 * writeUTF method.
63 *
64 * <p>The default serialization mechanism for an object writes the class of the
65 * object, the class signature, and the values of all non-transient and
66 * non-static fields. References to other objects (except in transient or
67 * static fields) cause those objects to be written also. Multiple references
68 * to a single object are encoded using a reference sharing mechanism so that
69 * graphs of objects can be restored to the same shape as when the original was
70 * written.
71 *
72 * <p>For example to write an object that can be read by the example in
73 * ObjectInputStream:
74 * <br>
75 * <pre>
76 * FileOutputStream fos = new FileOutputStream("t.tmp");
77 * ObjectOutputStream oos = new ObjectOutputStream(fos);
78 *
79 * oos.writeInt(12345);
80 * oos.writeObject("Today");
81 * oos.writeObject(new Date());
82 *
83 * oos.close();
84 * </pre>
85 *
86 * <p>Classes that require special handling during the serialization and
87 * deserialization process must implement special methods with these exact
88 * signatures:
89 * <br>
90 * <pre>
91 * private void readObject(java.io.ObjectInputStream stream)
92 * throws IOException, ClassNotFoundException;
93 * private void writeObject(java.io.ObjectOutputStream stream)
94 * throws IOException
95 * private void readObjectNoData()
96 * throws ObjectStreamException;
97 * </pre>
98 *
99 * <p>The writeObject method is responsible for writing the state of the object
100 * for its particular class so that the corresponding readObject method can
101 * restore it. The method does not need to concern itself with the state
102 * belonging to the object's superclasses or subclasses. State is saved by
103 * writing the individual fields to the ObjectOutputStream using the
104 * writeObject method or by using the methods for primitive data types
105 * supported by DataOutput.
106 *
107 * <p>Serialization does not write out the fields of any object that does not
108 * implement the java.io.Serializable interface. Subclasses of Objects that
109 * are not serializable can be serializable. In this case the non-serializable
110 * class must have a no-arg constructor to allow its fields to be initialized.
111 * In this case it is the responsibility of the subclass to save and restore
112 * the state of the non-serializable class. It is frequently the case that the
113 * fields of that class are accessible (public, package, or protected) or that
114 * there are get and set methods that can be used to restore the state.
115 *
116 * <p>Serialization of an object can be prevented by implementing writeObject
117 * and readObject methods that throw the NotSerializableException. The
118 * exception will be caught by the ObjectOutputStream and abort the
119 * serialization process.
120 *
121 * <p>Implementing the Externalizable interface allows the object to assume
122 * complete control over the contents and format of the object's serialized
123 * form. The methods of the Externalizable interface, writeExternal and
124 * readExternal, are called to save and restore the objects state. When
125 * implemented by a class they can write and read their own state using all of
126 * the methods of ObjectOutput and ObjectInput. It is the responsibility of
127 * the objects to handle any versioning that occurs.
128 *
129 * <p>Enum constants are serialized differently than ordinary serializable or
130 * externalizable objects. The serialized form of an enum constant consists
131 * solely of its name; field values of the constant are not transmitted. To
132 * serialize an enum constant, ObjectOutputStream writes the string returned by
133 * the constant's name method. Like other serializable or externalizable
134 * objects, enum constants can function as the targets of back references
135 * appearing subsequently in the serialization stream. The process by which
136 * enum constants are serialized cannot be customized; any class-specific
137 * writeObject and writeReplace methods defined by enum types are ignored
138 * during serialization. Similarly, any serialPersistentFields or
139 * serialVersionUID field declarations are also ignored--all enum types have a
140 * fixed serialVersionUID of 0L.
141 *
142 * <p>Primitive data, excluding serializable fields and externalizable data, is
143 * written to the ObjectOutputStream in block-data records. A block data record
144 * is composed of a header and data. The block data header consists of a marker
145 * and the number of bytes to follow the header. Consecutive primitive data
146 * writes are merged into one block-data record. The blocking factor used for
147 * a block-data record will be 1024 bytes. Each block-data record will be
148 * filled up to 1024 bytes, or be written whenever there is a termination of
149 * block-data mode. Calls to the ObjectOutputStream methods writeObject,
150 * defaultWriteObject and writeFields initially terminate any existing
151 * block-data record.
152 *
153 * <p>Records are serialized differently than ordinary serializable or externalizable
154 * objects, see <a href="ObjectInputStream.html#record-serialization">record serialization</a>.
155 *
156 * @author Mike Warres
157 * @author Roger Riggs
158 * @see java.io.DataOutput
159 * @see java.io.ObjectInputStream
160 * @see java.io.Serializable
161 * @see java.io.Externalizable
162 * @see <a href="{@docRoot}/../specs/serialization/output.html">
163 * <cite>Java Object Serialization Specification,</cite> Section 2, "Object Output Classes"</a>
164 * @since 1.1
165 */
166 public class ObjectOutputStream
167 extends OutputStream implements ObjectOutput, ObjectStreamConstants
168 {
169
170 private static class Caches {
171 /** cache of subclass security audit results */
172 static final ConcurrentMap<WeakClassKey,Boolean> subclassAudits =
173 new ConcurrentHashMap<>();
174
175 /** queue for WeakReferences to audited subclasses */
176 static final ReferenceQueue<Class<?>> subclassAuditsQueue =
177 new ReferenceQueue<>();
178 }
179
180 /** filter stream for handling block data conversion */
181 private final BlockDataOutputStream bout;
182 /** obj -> wire handle map */
183 private final HandleTable handles;
184 /** obj -> replacement obj map */
185 private final ReplaceTable subs;
186 /** stream protocol version */
187 private int protocol = PROTOCOL_VERSION_2;
188 /** recursion depth */
189 private int depth;
190
191 /** buffer for writing primitive field values */
192 private byte[] primVals;
193
194 /** if true, invoke writeObjectOverride() instead of writeObject() */
195 private final boolean enableOverride;
196 /** if true, invoke replaceObject() */
197 private boolean enableReplace;
198
199 // values below valid only during upcalls to writeObject()/writeExternal()
200 /**
201 * Context during upcalls to class-defined writeObject methods; holds
202 * object currently being serialized and descriptor for current class.
203 * Null when not during writeObject upcall.
204 */
205 private SerialCallbackContext curContext;
206 /** current PutField object */
207 private PutFieldImpl curPut;
208
209 /** custom storage for debug trace info */
210 private final DebugTraceInfoStack debugInfoStack;
211
212 /**
213 * value of "sun.io.serialization.extendedDebugInfo" property,
214 * as true or false for extended information about exception's place
215 */
216 @SuppressWarnings("removal")
217 private static final boolean extendedDebugInfo =
218 java.security.AccessController.doPrivileged(
219 new sun.security.action.GetBooleanAction(
220 "sun.io.serialization.extendedDebugInfo")).booleanValue();
221
222 /**
223 * Creates an ObjectOutputStream that writes to the specified OutputStream.
224 * This constructor writes the serialization stream header to the
225 * underlying stream; callers may wish to flush the stream immediately to
226 * ensure that constructors for receiving ObjectInputStreams will not block
227 * when reading the header.
228 *
229 * <p>If a security manager is installed, this constructor will check for
230 * the "enableSubclassImplementation" SerializablePermission when invoked
231 * directly or indirectly by the constructor of a subclass which overrides
232 * the ObjectOutputStream.putFields or ObjectOutputStream.writeUnshared
233 * methods.
234 *
235 * @param out output stream to write to
236 * @throws IOException if an I/O error occurs while writing stream header
237 * @throws SecurityException if untrusted subclass illegally overrides
238 * security-sensitive methods
239 * @throws NullPointerException if {@code out} is {@code null}
240 * @since 1.4
241 * @see ObjectOutputStream#ObjectOutputStream()
242 * @see ObjectOutputStream#putFields()
243 * @see ObjectInputStream#ObjectInputStream(InputStream)
244 */
245 public ObjectOutputStream(OutputStream out) throws IOException {
246 verifySubclass();
247 bout = new BlockDataOutputStream(out);
248 handles = new HandleTable(10, (float) 3.00);
249 subs = new ReplaceTable(10, (float) 3.00);
250 enableOverride = false;
251 writeStreamHeader();
252 bout.setBlockDataMode(true);
253 if (extendedDebugInfo) {
254 debugInfoStack = new DebugTraceInfoStack();
255 } else {
256 debugInfoStack = null;
257 }
258 }
259
260 /**
261 * Provide a way for subclasses that are completely reimplementing
262 * ObjectOutputStream to not have to allocate private data just used by
263 * this implementation of ObjectOutputStream.
264 *
265 * <p>If there is a security manager installed, this method first calls the
266 * security manager's {@code checkPermission} method with a
267 * {@code SerializablePermission("enableSubclassImplementation")}
268 * permission to ensure it's ok to enable subclassing.
269 *
270 * @throws SecurityException if a security manager exists and its
271 * {@code checkPermission} method denies enabling
272 * subclassing.
273 * @throws IOException if an I/O error occurs while creating this stream
274 * @see SecurityManager#checkPermission
275 * @see java.io.SerializablePermission
276 */
277 protected ObjectOutputStream() throws IOException, SecurityException {
278 @SuppressWarnings("removal")
279 SecurityManager sm = System.getSecurityManager();
280 if (sm != null) {
281 sm.checkPermission(SUBCLASS_IMPLEMENTATION_PERMISSION);
282 }
283 bout = null;
284 handles = null;
285 subs = null;
286 enableOverride = true;
287 debugInfoStack = null;
288 }
289
290 /**
291 * Specify stream protocol version to use when writing the stream.
292 *
293 * <p>This routine provides a hook to enable the current version of
294 * Serialization to write in a format that is backwards compatible to a
295 * previous version of the stream format.
296 *
297 * <p>Every effort will be made to avoid introducing additional
298 * backwards incompatibilities; however, sometimes there is no
299 * other alternative.
300 *
301 * @param version use ProtocolVersion from java.io.ObjectStreamConstants.
302 * @throws IllegalStateException if called after any objects
303 * have been serialized.
304 * @throws IllegalArgumentException if invalid version is passed in.
305 * @throws IOException if I/O errors occur
306 * @see java.io.ObjectStreamConstants#PROTOCOL_VERSION_1
307 * @see java.io.ObjectStreamConstants#PROTOCOL_VERSION_2
308 * @since 1.2
309 */
310 public void useProtocolVersion(int version) throws IOException {
311 if (handles.size() != 0) {
312 // REMIND: implement better check for pristine stream?
313 throw new IllegalStateException("stream non-empty");
314 }
315 switch (version) {
316 case PROTOCOL_VERSION_1:
317 case PROTOCOL_VERSION_2:
318 protocol = version;
319 break;
320
321 default:
322 throw new IllegalArgumentException(
323 "unknown version: " + version);
324 }
325 }
326
327 /**
328 * Write the specified object to the ObjectOutputStream. The class of the
329 * object, the signature of the class, and the values of the non-transient
330 * and non-static fields of the class and all of its supertypes are
331 * written. Default serialization for a class can be overridden using the
332 * writeObject and the readObject methods. Objects referenced by this
333 * object are written transitively so that a complete equivalent graph of
334 * objects can be reconstructed by an ObjectInputStream.
335 *
336 * <p>Exceptions are thrown for problems with the OutputStream and for
337 * classes that should not be serialized. All exceptions are fatal to the
338 * OutputStream, which is left in an indeterminate state, and it is up to
339 * the caller to ignore or recover the stream state.
340 *
341 * @throws InvalidClassException Something is wrong with a class used by
342 * serialization.
343 * @throws NotSerializableException Some object to be serialized does not
344 * implement the java.io.Serializable interface.
345 * @throws IOException Any exception thrown by the underlying
346 * OutputStream.
347 */
348 public final void writeObject(Object obj) throws IOException {
349 if (enableOverride) {
350 writeObjectOverride(obj);
351 return;
352 }
353 try {
354 writeObject0(obj, false);
355 } catch (IOException ex) {
356 if (depth == 0) {
357 writeFatalException(ex);
358 }
359 throw ex;
360 }
361 }
362
363 /**
364 * Method used by subclasses to override the default writeObject method.
365 * This method is called by trusted subclasses of ObjectOutputStream that
366 * constructed ObjectOutputStream using the protected no-arg constructor.
367 * The subclass is expected to provide an override method with the modifier
368 * "final".
369 *
370 * @param obj object to be written to the underlying stream
371 * @throws IOException if there are I/O errors while writing to the
372 * underlying stream
373 * @see #ObjectOutputStream()
374 * @see #writeObject(Object)
375 * @since 1.2
376 */
377 protected void writeObjectOverride(Object obj) throws IOException {
378 }
379
380 /**
381 * Writes an "unshared" object to the ObjectOutputStream. This method is
382 * identical to writeObject, except that it always writes the given object
383 * as a new, unique object in the stream (as opposed to a back-reference
384 * pointing to a previously serialized instance). Specifically:
385 * <ul>
386 * <li>An object written via writeUnshared is always serialized in the
387 * same manner as a newly appearing object (an object that has not
388 * been written to the stream yet), regardless of whether or not the
389 * object has been written previously.
390 *
391 * <li>If writeObject is used to write an object that has been previously
392 * written with writeUnshared, the previous writeUnshared operation
393 * is treated as if it were a write of a separate object. In other
394 * words, ObjectOutputStream will never generate back-references to
395 * object data written by calls to writeUnshared.
396 * </ul>
397 * While writing an object via writeUnshared does not in itself guarantee a
398 * unique reference to the object when it is deserialized, it allows a
399 * single object to be defined multiple times in a stream, so that multiple
400 * calls to readUnshared by the receiver will not conflict. Note that the
401 * rules described above only apply to the base-level object written with
402 * writeUnshared, and not to any transitively referenced sub-objects in the
403 * object graph to be serialized.
404 *
405 * <p>ObjectOutputStream subclasses which override this method can only be
406 * constructed in security contexts possessing the
407 * "enableSubclassImplementation" SerializablePermission; any attempt to
408 * instantiate such a subclass without this permission will cause a
409 * SecurityException to be thrown.
410 *
411 * @param obj object to write to stream
412 * @throws NotSerializableException if an object in the graph to be
413 * serialized does not implement the Serializable interface
414 * @throws InvalidClassException if a problem exists with the class of an
415 * object to be serialized
416 * @throws IOException if an I/O error occurs during serialization
417 * @since 1.4
418 */
419 public void writeUnshared(Object obj) throws IOException {
420 try {
421 writeObject0(obj, true);
422 } catch (IOException ex) {
423 if (depth == 0) {
424 writeFatalException(ex);
425 }
426 throw ex;
427 }
428 }
429
430 /**
431 * Write the non-static and non-transient fields of the current class to
432 * this stream. This may only be called from the writeObject method of the
433 * class being serialized. It will throw the NotActiveException if it is
434 * called otherwise.
435 *
436 * @throws IOException if I/O errors occur while writing to the underlying
437 * {@code OutputStream}
438 */
439 public void defaultWriteObject() throws IOException {
440 SerialCallbackContext ctx = curContext;
441 if (ctx == null) {
442 throw new NotActiveException("not in call to writeObject");
443 }
444 Object curObj = ctx.getObj();
445 ObjectStreamClass curDesc = ctx.getDesc();
446 bout.setBlockDataMode(false);
447 defaultWriteFields(curObj, curDesc);
448 bout.setBlockDataMode(true);
449 }
450
451 /**
452 * Retrieve the object used to buffer persistent fields to be written to
453 * the stream. The fields will be written to the stream when writeFields
454 * method is called.
455 *
456 * @return an instance of the class Putfield that holds the serializable
457 * fields
458 * @throws IOException if I/O errors occur
459 * @since 1.2
460 */
461 public ObjectOutputStream.PutField putFields() throws IOException {
462 if (curPut == null) {
463 SerialCallbackContext ctx = curContext;
464 if (ctx == null) {
465 throw new NotActiveException("not in call to writeObject");
466 }
467 ctx.checkAndSetUsed();
468 ObjectStreamClass curDesc = ctx.getDesc();
469 curPut = new PutFieldImpl(curDesc);
470 }
471 return curPut;
472 }
473
474 /**
475 * Write the buffered fields to the stream.
476 *
477 * @throws IOException if I/O errors occur while writing to the underlying
478 * stream
479 * @throws NotActiveException Called when a classes writeObject method was
480 * not called to write the state of the object.
481 * @since 1.2
482 */
483 public void writeFields() throws IOException {
484 if (curPut == null) {
485 throw new NotActiveException("no current PutField object");
486 }
487 bout.setBlockDataMode(false);
488 curPut.writeFields();
489 bout.setBlockDataMode(true);
490 }
491
492 /**
493 * Reset will disregard the state of any objects already written to the
494 * stream. The state is reset to be the same as a new ObjectOutputStream.
495 * The current point in the stream is marked as reset so the corresponding
496 * ObjectInputStream will be reset at the same point. Objects previously
497 * written to the stream will not be referred to as already being in the
498 * stream. They will be written to the stream again.
499 *
500 * @throws IOException if reset() is invoked while serializing an object.
501 */
502 public void reset() throws IOException {
503 if (depth != 0) {
504 throw new IOException("stream active");
505 }
506 bout.setBlockDataMode(false);
507 bout.writeByte(TC_RESET);
508 clear();
509 bout.setBlockDataMode(true);
510 }
511
512 /**
513 * Subclasses may implement this method to allow class data to be stored in
514 * the stream. By default this method does nothing. The corresponding
515 * method in ObjectInputStream is resolveClass. This method is called
516 * exactly once for each unique class in the stream. The class name and
517 * signature will have already been written to the stream. This method may
518 * make free use of the ObjectOutputStream to save any representation of
519 * the class it deems suitable (for example, the bytes of the class file).
520 * The resolveClass method in the corresponding subclass of
521 * ObjectInputStream must read and use any data or objects written by
522 * annotateClass.
523 *
524 * @param cl the class to annotate custom data for
525 * @throws IOException Any exception thrown by the underlying
526 * OutputStream.
527 */
528 protected void annotateClass(Class<?> cl) throws IOException {
529 }
530
531 /**
532 * Subclasses may implement this method to store custom data in the stream
533 * along with descriptors for dynamic proxy classes.
534 *
535 * <p>This method is called exactly once for each unique proxy class
536 * descriptor in the stream. The default implementation of this method in
537 * {@code ObjectOutputStream} does nothing.
538 *
539 * <p>The corresponding method in {@code ObjectInputStream} is
540 * {@code resolveProxyClass}. For a given subclass of
541 * {@code ObjectOutputStream} that overrides this method, the
542 * {@code resolveProxyClass} method in the corresponding subclass of
543 * {@code ObjectInputStream} must read any data or objects written by
544 * {@code annotateProxyClass}.
545 *
546 * @param cl the proxy class to annotate custom data for
547 * @throws IOException any exception thrown by the underlying
548 * {@code OutputStream}
549 * @see ObjectInputStream#resolveProxyClass(String[])
550 * @since 1.3
551 */
552 protected void annotateProxyClass(Class<?> cl) throws IOException {
553 }
554
555 /**
556 * This method will allow trusted subclasses of ObjectOutputStream to
557 * substitute one object for another during serialization. Replacing
558 * objects is disabled until enableReplaceObject is called. The
559 * enableReplaceObject method checks that the stream requesting to do
560 * replacement can be trusted. The first occurrence of each object written
561 * into the serialization stream is passed to replaceObject. Subsequent
562 * references to the object are replaced by the object returned by the
563 * original call to replaceObject. To ensure that the private state of
564 * objects is not unintentionally exposed, only trusted streams may use
565 * replaceObject.
566 *
567 * <p>The ObjectOutputStream.writeObject method takes a parameter of type
568 * Object (as opposed to type Serializable) to allow for cases where
569 * non-serializable objects are replaced by serializable ones.
570 *
571 * <p>When a subclass is replacing objects it must ensure that either a
572 * complementary substitution must be made during deserialization or that
573 * the substituted object is compatible with every field where the
574 * reference will be stored. Objects whose type is not a subclass of the
575 * type of the field or array element abort the serialization by raising an
576 * exception and the object is not be stored.
577 *
578 * <p>This method is called only once when each object is first
579 * encountered. All subsequent references to the object will be redirected
580 * to the new object. This method should return the object to be
581 * substituted or the original object.
582 *
583 * <p>Null can be returned as the object to be substituted, but may cause
584 * NullReferenceException in classes that contain references to the
585 * original object since they may be expecting an object instead of
586 * null.
587 *
588 * @param obj the object to be replaced
589 * @return the alternate object that replaced the specified one
590 * @throws IOException Any exception thrown by the underlying
591 * OutputStream.
592 */
593 protected Object replaceObject(Object obj) throws IOException {
594 return obj;
595 }
596
597 /**
598 * Enables the stream to do replacement of objects written to the stream. When
599 * enabled, the {@link #replaceObject} method is called for every object being
600 * serialized.
601 *
602 * <p>If object replacement is currently not enabled, and
603 * {@code enable} is true, and there is a security manager installed,
604 * this method first calls the security manager's
605 * {@code checkPermission} method with the
606 * {@code SerializablePermission("enableSubstitution")} permission to
607 * ensure that the caller is permitted to enable the stream to do replacement
608 * of objects written to the stream.
609 *
610 * @param enable true for enabling use of {@code replaceObject} for
611 * every object being serialized
612 * @return the previous setting before this method was invoked
613 * @throws SecurityException if a security manager exists and its
614 * {@code checkPermission} method denies enabling the stream
615 * to do replacement of objects written to the stream.
616 * @see SecurityManager#checkPermission
617 * @see java.io.SerializablePermission
618 */
619 protected boolean enableReplaceObject(boolean enable)
620 throws SecurityException
621 {
622 if (enable == enableReplace) {
623 return enable;
624 }
625 if (enable) {
626 @SuppressWarnings("removal")
627 SecurityManager sm = System.getSecurityManager();
628 if (sm != null) {
629 sm.checkPermission(SUBSTITUTION_PERMISSION);
630 }
631 }
632 enableReplace = enable;
633 return !enableReplace;
634 }
635
636 /**
637 * The writeStreamHeader method is provided so subclasses can append or
638 * prepend their own header to the stream. It writes the magic number and
639 * version to the stream.
640 *
641 * @throws IOException if I/O errors occur while writing to the underlying
642 * stream
643 */
644 protected void writeStreamHeader() throws IOException {
645 bout.writeShort(STREAM_MAGIC);
646 bout.writeShort(STREAM_VERSION);
647 }
648
649 /**
650 * Write the specified class descriptor to the ObjectOutputStream. Class
651 * descriptors are used to identify the classes of objects written to the
652 * stream. Subclasses of ObjectOutputStream may override this method to
653 * customize the way in which class descriptors are written to the
654 * serialization stream. The corresponding method in ObjectInputStream,
655 * {@code readClassDescriptor}, should then be overridden to
656 * reconstitute the class descriptor from its custom stream representation.
657 * By default, this method writes class descriptors according to the format
658 * defined in the Object Serialization specification.
659 *
660 * <p>Note that this method will only be called if the ObjectOutputStream
661 * is not using the old serialization stream format (set by calling
662 * ObjectOutputStream's {@code useProtocolVersion} method). If this
663 * serialization stream is using the old format
664 * ({@code PROTOCOL_VERSION_1}), the class descriptor will be written
665 * internally in a manner that cannot be overridden or customized.
666 *
667 * @param desc class descriptor to write to the stream
668 * @throws IOException If an I/O error has occurred.
669 * @see java.io.ObjectInputStream#readClassDescriptor()
670 * @see #useProtocolVersion(int)
671 * @see java.io.ObjectStreamConstants#PROTOCOL_VERSION_1
672 * @since 1.3
673 */
674 protected void writeClassDescriptor(ObjectStreamClass desc)
675 throws IOException
676 {
677 desc.writeNonProxy(this);
678 }
679
680 /**
681 * Writes a byte. This method will block until the byte is actually
682 * written.
683 *
684 * @param val the byte to be written to the stream
685 * @throws IOException If an I/O error has occurred.
686 */
687 public void write(int val) throws IOException {
688 bout.write(val);
689 }
690
691 /**
692 * Writes an array of bytes. This method will block until the bytes are
693 * actually written.
694 *
695 * @param buf the data to be written
696 * @throws IOException If an I/O error has occurred.
697 */
698 public void write(byte[] buf) throws IOException {
699 bout.write(buf, 0, buf.length, false);
700 }
701
702 /**
703 * Writes a sub array of bytes.
704 *
705 * @param buf the data to be written
706 * @param off the start offset in the data
707 * @param len the number of bytes that are written
708 * @throws IOException If an I/O error has occurred.
709 */
710 public void write(byte[] buf, int off, int len) throws IOException {
711 if (buf == null) {
712 throw new NullPointerException();
713 }
714 int endoff = off + len;
715 if (off < 0 || len < 0 || endoff > buf.length || endoff < 0) {
716 throw new IndexOutOfBoundsException();
717 }
718 bout.write(buf, off, len, false);
719 }
720
721 /**
722 * Flushes the stream. This will write any buffered output bytes and flush
723 * through to the underlying stream.
724 *
725 * @throws IOException If an I/O error has occurred.
726 */
727 public void flush() throws IOException {
728 bout.flush();
729 }
730
731 /**
732 * Drain any buffered data in ObjectOutputStream. Similar to flush but
733 * does not propagate the flush to the underlying stream.
734 *
735 * @throws IOException if I/O errors occur while writing to the underlying
736 * stream
737 */
738 protected void drain() throws IOException {
739 bout.drain();
740 }
741
742 /**
743 * Closes the stream. This method must be called to release any resources
744 * associated with the stream.
745 *
746 * @throws IOException If an I/O error has occurred.
747 */
748 public void close() throws IOException {
749 flush();
750 clear();
751 bout.close();
752 }
753
754 /**
755 * Writes a boolean.
756 *
757 * @param val the boolean to be written
758 * @throws IOException if I/O errors occur while writing to the underlying
759 * stream
760 */
761 public void writeBoolean(boolean val) throws IOException {
762 bout.writeBoolean(val);
763 }
764
765 /**
766 * Writes an 8 bit byte.
767 *
768 * @param val the byte value to be written
769 * @throws IOException if I/O errors occur while writing to the underlying
770 * stream
771 */
772 public void writeByte(int val) throws IOException {
773 bout.writeByte(val);
774 }
775
776 /**
777 * Writes a 16 bit short.
778 *
779 * @param val the short value to be written
780 * @throws IOException if I/O errors occur while writing to the underlying
781 * stream
782 */
783 public void writeShort(int val) throws IOException {
784 bout.writeShort(val);
785 }
786
787 /**
788 * Writes a 16 bit char.
789 *
790 * @param val the char value to be written
791 * @throws IOException if I/O errors occur while writing to the underlying
792 * stream
793 */
794 public void writeChar(int val) throws IOException {
795 bout.writeChar(val);
796 }
797
798 /**
799 * Writes a 32 bit int.
800 *
801 * @param val the integer value to be written
802 * @throws IOException if I/O errors occur while writing to the underlying
803 * stream
804 */
805 public void writeInt(int val) throws IOException {
806 bout.writeInt(val);
807 }
808
809 /**
810 * Writes a 64 bit long.
811 *
812 * @param val the long value to be written
813 * @throws IOException if I/O errors occur while writing to the underlying
814 * stream
815 */
816 public void writeLong(long val) throws IOException {
817 bout.writeLong(val);
818 }
819
820 /**
821 * Writes a 32 bit float.
822 *
823 * @param val the float value to be written
824 * @throws IOException if I/O errors occur while writing to the underlying
825 * stream
826 */
827 public void writeFloat(float val) throws IOException {
828 bout.writeFloat(val);
829 }
830
831 /**
832 * Writes a 64 bit double.
833 *
834 * @param val the double value to be written
835 * @throws IOException if I/O errors occur while writing to the underlying
836 * stream
837 */
838 public void writeDouble(double val) throws IOException {
839 bout.writeDouble(val);
840 }
841
842 /**
843 * Writes a String as a sequence of bytes.
844 *
845 * @param str the String of bytes to be written
846 * @throws IOException if I/O errors occur while writing to the underlying
847 * stream
848 */
849 public void writeBytes(String str) throws IOException {
850 bout.writeBytes(str);
851 }
852
853 /**
854 * Writes a String as a sequence of chars.
855 *
856 * @param str the String of chars to be written
857 * @throws IOException if I/O errors occur while writing to the underlying
858 * stream
859 */
860 public void writeChars(String str) throws IOException {
861 bout.writeChars(str);
862 }
863
864 /**
865 * Primitive data write of this String in
866 * <a href="DataInput.html#modified-utf-8">modified UTF-8</a>
867 * format. Note that there is a
868 * significant difference between writing a String into the stream as
869 * primitive data or as an Object. A String instance written by writeObject
870 * is written into the stream as a String initially. Future writeObject()
871 * calls write references to the string into the stream.
872 *
873 * @param str the String to be written
874 * @throws IOException if I/O errors occur while writing to the underlying
875 * stream
876 */
877 public void writeUTF(String str) throws IOException {
878 bout.writeUTF(str);
879 }
880
881 /**
882 * Provide programmatic access to the persistent fields to be written
883 * to ObjectOutput.
884 *
885 * @since 1.2
886 */
887 public abstract static class PutField {
888 /**
889 * Constructor for subclasses to call.
890 */
891 public PutField() {}
892
893 /**
894 * Put the value of the named boolean field into the persistent field.
895 *
896 * @param name the name of the serializable field
897 * @param val the value to assign to the field
898 * @throws IllegalArgumentException if {@code name} does not
899 * match the name of a serializable field for the class whose fields
900 * are being written, or if the type of the named field is not
901 * {@code boolean}
902 */
903 public abstract void put(String name, boolean val);
904
905 /**
906 * Put the value of the named byte field into the persistent field.
907 *
908 * @param name the name of the serializable field
909 * @param val the value to assign to the field
910 * @throws IllegalArgumentException if {@code name} does not
911 * match the name of a serializable field for the class whose fields
912 * are being written, or if the type of the named field is not
913 * {@code byte}
914 */
915 public abstract void put(String name, byte val);
916
917 /**
918 * Put the value of the named char field into the persistent field.
919 *
920 * @param name the name of the serializable field
921 * @param val the value to assign to the field
922 * @throws IllegalArgumentException if {@code name} does not
923 * match the name of a serializable field for the class whose fields
924 * are being written, or if the type of the named field is not
925 * {@code char}
926 */
927 public abstract void put(String name, char val);
928
929 /**
930 * Put the value of the named short field into the persistent field.
931 *
932 * @param name the name of the serializable field
933 * @param val the value to assign to the field
934 * @throws IllegalArgumentException if {@code name} does not
935 * match the name of a serializable field for the class whose fields
936 * are being written, or if the type of the named field is not
937 * {@code short}
938 */
939 public abstract void put(String name, short val);
940
941 /**
942 * Put the value of the named int field into the persistent field.
943 *
944 * @param name the name of the serializable field
945 * @param val the value to assign to the field
946 * @throws IllegalArgumentException if {@code name} does not
947 * match the name of a serializable field for the class whose fields
948 * are being written, or if the type of the named field is not
949 * {@code int}
950 */
951 public abstract void put(String name, int val);
952
953 /**
954 * Put the value of the named long field into the persistent field.
955 *
956 * @param name the name of the serializable field
957 * @param val the value to assign to the field
958 * @throws IllegalArgumentException if {@code name} does not
959 * match the name of a serializable field for the class whose fields
960 * are being written, or if the type of the named field is not
961 * {@code long}
962 */
963 public abstract void put(String name, long val);
964
965 /**
966 * Put the value of the named float field into the persistent field.
967 *
968 * @param name the name of the serializable field
969 * @param val the value to assign to the field
970 * @throws IllegalArgumentException if {@code name} does not
971 * match the name of a serializable field for the class whose fields
972 * are being written, or if the type of the named field is not
973 * {@code float}
974 */
975 public abstract void put(String name, float val);
976
977 /**
978 * Put the value of the named double field into the persistent field.
979 *
980 * @param name the name of the serializable field
981 * @param val the value to assign to the field
982 * @throws IllegalArgumentException if {@code name} does not
983 * match the name of a serializable field for the class whose fields
984 * are being written, or if the type of the named field is not
985 * {@code double}
986 */
987 public abstract void put(String name, double val);
988
989 /**
990 * Put the value of the named Object field into the persistent field.
991 *
992 * @param name the name of the serializable field
993 * @param val the value to assign to the field
994 * (which may be {@code null})
995 * @throws IllegalArgumentException if {@code name} does not
996 * match the name of a serializable field for the class whose fields
997 * are being written, or if the type of the named field is not a
998 * reference type
999 */
1000 public abstract void put(String name, Object val);
1001
1002 /**
1003 * Write the data and fields to the specified ObjectOutput stream,
1004 * which must be the same stream that produced this
1005 * {@code PutField} object.
1006 *
1007 * @param out the stream to write the data and fields to
1008 * @throws IOException if I/O errors occur while writing to the
1009 * underlying stream
1010 * @throws IllegalArgumentException if the specified stream is not
1011 * the same stream that produced this {@code PutField}
1012 * object
1013 * @deprecated This method does not write the values contained by this
1014 * {@code PutField} object in a proper format, and may
1015 * result in corruption of the serialization stream. The
1016 * correct way to write {@code PutField} data is by
1017 * calling the {@link java.io.ObjectOutputStream#writeFields()}
1018 * method.
1019 */
1020 @Deprecated
1021 public abstract void write(ObjectOutput out) throws IOException;
1022 }
1023
1024
1025 /**
1026 * Returns protocol version in use.
1027 */
1028 int getProtocolVersion() {
1029 return protocol;
1030 }
1031
1032 /**
1033 * Writes string without allowing it to be replaced in stream. Used by
1034 * ObjectStreamClass to write class descriptor type strings.
1035 */
1036 void writeTypeString(String str) throws IOException {
1037 int handle;
1038 if (str == null) {
1039 writeNull();
1040 } else if ((handle = handles.lookup(str)) != -1) {
1041 writeHandle(handle);
1042 } else {
1043 writeString(str, false);
1044 }
1045 }
1046
1047 /**
1048 * Verifies that this (possibly subclass) instance can be constructed
1049 * without violating security constraints: the subclass must not override
1050 * security-sensitive non-final methods, or else the
1051 * "enableSubclassImplementation" SerializablePermission is checked.
1052 */
1053 private void verifySubclass() {
1054 Class<?> cl = getClass();
1055 if (cl == ObjectOutputStream.class) {
1056 return;
1057 }
1058 @SuppressWarnings("removal")
1059 SecurityManager sm = System.getSecurityManager();
1060 if (sm == null) {
1061 return;
1062 }
1063 processQueue(Caches.subclassAuditsQueue, Caches.subclassAudits);
1064 WeakClassKey key = new WeakClassKey(cl, Caches.subclassAuditsQueue);
1065 Boolean result = Caches.subclassAudits.get(key);
1066 if (result == null) {
1067 result = auditSubclass(cl);
1068 Caches.subclassAudits.putIfAbsent(key, result);
1069 }
1070 if (!result) {
1071 sm.checkPermission(SUBCLASS_IMPLEMENTATION_PERMISSION);
1072 }
1073 }
1074
1075 /**
1076 * Performs reflective checks on given subclass to verify that it doesn't
1077 * override security-sensitive non-final methods. Returns TRUE if subclass
1078 * is "safe", FALSE otherwise.
1079 */
1080 @SuppressWarnings("removal")
1081 private static Boolean auditSubclass(Class<?> subcl) {
1082 return AccessController.doPrivileged(
1083 new PrivilegedAction<>() {
1084 public Boolean run() {
1085 for (Class<?> cl = subcl;
1086 cl != ObjectOutputStream.class;
1087 cl = cl.getSuperclass())
1088 {
1089 try {
1090 cl.getDeclaredMethod(
1091 "writeUnshared", new Class<?>[] { Object.class });
1092 return Boolean.FALSE;
1093 } catch (NoSuchMethodException ex) {
1094 }
1095 try {
1096 cl.getDeclaredMethod("putFields", (Class<?>[]) null);
1097 return Boolean.FALSE;
1098 } catch (NoSuchMethodException ex) {
1099 }
1100 }
1101 return Boolean.TRUE;
1102 }
1103 }
1104 );
1105 }
1106
1107 /**
1108 * Clears internal data structures.
1109 */
1110 private void clear() {
1111 subs.clear();
1112 handles.clear();
1113 }
1114
1115 /**
1116 * Underlying writeObject/writeUnshared implementation.
1117 */
1118 private void writeObject0(Object obj, boolean unshared)
1119 throws IOException
1120 {
1121 boolean oldMode = bout.setBlockDataMode(false);
1122 depth++;
1123 try {
1124 // handle previously written and non-replaceable objects
1125 int h;
1126 if ((obj = subs.lookup(obj)) == null) {
1127 writeNull();
1128 return;
1129 } else if (!unshared && (h = handles.lookup(obj)) != -1) {
1130 writeHandle(h);
1131 return;
1132 } else if (obj instanceof Class) {
1133 writeClass((Class) obj, unshared);
1134 return;
1135 } else if (obj instanceof ObjectStreamClass) {
1136 writeClassDesc((ObjectStreamClass) obj, unshared);
1137 return;
1138 }
1139
1140 // check for replacement object
1141 Object orig = obj;
1142 Class<?> cl = obj.getClass();
1143 ObjectStreamClass desc;
1144 for (;;) {
1145 // REMIND: skip this check for strings/arrays?
1146 Class<?> repCl;
1147 desc = ObjectStreamClass.lookup(cl, true);
1148 if (!desc.hasWriteReplaceMethod() ||
1149 (obj = desc.invokeWriteReplace(obj)) == null ||
1150 (repCl = obj.getClass()) == cl)
1151 {
1152 break;
1153 }
1154 cl = repCl;
1155 }
1156 if (enableReplace) {
1157 Object rep = replaceObject(obj);
1158 if (rep != obj && rep != null) {
1159 cl = rep.getClass();
1160 desc = ObjectStreamClass.lookup(cl, true);
1161 }
1162 obj = rep;
1163 }
1164
1165 // if object replaced, run through original checks a second time
1166 if (obj != orig) {
1167 subs.assign(orig, obj);
1168 if (obj == null) {
1169 writeNull();
1170 return;
1171 } else if (!unshared && (h = handles.lookup(obj)) != -1) {
1172 writeHandle(h);
1173 return;
1174 } else if (obj instanceof Class) {
1175 writeClass((Class) obj, unshared);
1176 return;
1177 } else if (obj instanceof ObjectStreamClass) {
1178 writeClassDesc((ObjectStreamClass) obj, unshared);
1179 return;
1180 }
1181 }
1182
1183 // remaining cases
1184 if (obj instanceof String) {
1185 writeString((String) obj, unshared);
1186 } else if (cl.isArray()) {
1187 writeArray(obj, desc, unshared);
1188 } else if (obj instanceof Enum) {
1189 writeEnum((Enum<?>) obj, desc, unshared);
1190 } else if (obj instanceof Serializable) {
1191 writeOrdinaryObject(obj, desc, unshared);
1192 } else {
1193 if (extendedDebugInfo) {
1194 throw new NotSerializableException(
1195 cl.getName() + "\n" + debugInfoStack.toString());
1196 } else {
1197 throw new NotSerializableException(cl.getName());
1198 }
1199 }
1200 } finally {
1201 depth--;
1202 bout.setBlockDataMode(oldMode);
1203 }
1204 }
1205
1206 /**
1207 * Writes null code to stream.
1208 */
1209 private void writeNull() throws IOException {
1210 bout.writeByte(TC_NULL);
1211 }
1212
1213 /**
1214 * Writes given object handle to stream.
1215 */
1216 private void writeHandle(int handle) throws IOException {
1217 bout.writeByte(TC_REFERENCE);
1218 bout.writeInt(baseWireHandle + handle);
1219 }
1220
1221 /**
1222 * Writes representation of given class to stream.
1223 */
1224 private void writeClass(Class<?> cl, boolean unshared) throws IOException {
1225 bout.writeByte(TC_CLASS);
1226 writeClassDesc(ObjectStreamClass.lookup(cl, true), false);
1227 handles.assign(unshared ? null : cl);
1228 }
1229
1230 /**
1231 * Writes representation of given class descriptor to stream.
1232 */
1233 private void writeClassDesc(ObjectStreamClass desc, boolean unshared)
1234 throws IOException
1235 {
1236 int handle;
1237 if (desc == null) {
1238 writeNull();
1239 } else if (!unshared && (handle = handles.lookup(desc)) != -1) {
1240 writeHandle(handle);
1241 } else if (desc.isProxy()) {
1242 writeProxyDesc(desc, unshared);
1243 } else {
1244 writeNonProxyDesc(desc, unshared);
1245 }
1246 }
1247
1248 private boolean isCustomSubclass() {
1249 // Return true if this class is a custom subclass of ObjectOutputStream
1250 return getClass().getClassLoader()
1251 != ObjectOutputStream.class.getClassLoader();
1252 }
1253
1254 /**
1255 * Writes class descriptor representing a dynamic proxy class to stream.
1256 */
1257 private void writeProxyDesc(ObjectStreamClass desc, boolean unshared)
1258 throws IOException
1259 {
1260 bout.writeByte(TC_PROXYCLASSDESC);
1261 handles.assign(unshared ? null : desc);
1262
1263 Class<?> cl = desc.forClass();
1264 Class<?>[] ifaces = cl.getInterfaces();
1265 bout.writeInt(ifaces.length);
1266 for (int i = 0; i < ifaces.length; i++) {
1267 bout.writeUTF(ifaces[i].getName());
1268 }
1269
1270 bout.setBlockDataMode(true);
1271 if (cl != null && isCustomSubclass()) {
1272 ReflectUtil.checkPackageAccess(cl);
1273 }
1274 annotateProxyClass(cl);
1275 bout.setBlockDataMode(false);
1276 bout.writeByte(TC_ENDBLOCKDATA);
1277
1278 writeClassDesc(desc.getSuperDesc(), false);
1279 }
1280
1281 /**
1282 * Writes class descriptor representing a standard (i.e., not a dynamic
1283 * proxy) class to stream.
1284 */
1285 private void writeNonProxyDesc(ObjectStreamClass desc, boolean unshared)
1286 throws IOException
1287 {
1288 bout.writeByte(TC_CLASSDESC);
1289 handles.assign(unshared ? null : desc);
1290
1291 if (protocol == PROTOCOL_VERSION_1) {
1292 // do not invoke class descriptor write hook with old protocol
1293 desc.writeNonProxy(this);
1294 } else {
1295 writeClassDescriptor(desc);
1296 }
1297
1298 Class<?> cl = desc.forClass();
1299 bout.setBlockDataMode(true);
1300 if (cl != null && isCustomSubclass()) {
1301 ReflectUtil.checkPackageAccess(cl);
1302 }
1303 annotateClass(cl);
1304 bout.setBlockDataMode(false);
1305 bout.writeByte(TC_ENDBLOCKDATA);
1306
1307 writeClassDesc(desc.getSuperDesc(), false);
1308 }
1309
1310 /**
1311 * Writes given string to stream, using standard or long UTF format
1312 * depending on string length.
1313 */
1314 private void writeString(String str, boolean unshared) throws IOException {
1315 handles.assign(unshared ? null : str);
1316 long utflen = bout.getUTFLength(str);
1317 if (utflen <= 0xFFFF) {
1318 bout.writeByte(TC_STRING);
1319 bout.writeUTF(str, utflen);
1320 } else {
1321 bout.writeByte(TC_LONGSTRING);
1322 bout.writeLongUTF(str, utflen);
1323 }
1324 }
1325
1326 /**
1327 * Writes given array object to stream.
1328 */
1329 private void writeArray(Object array,
1330 ObjectStreamClass desc,
1331 boolean unshared)
1332 throws IOException
1333 {
1334 bout.writeByte(TC_ARRAY);
1335 writeClassDesc(desc, false);
1336 handles.assign(unshared ? null : array);
1337
1338 Class<?> ccl = desc.forClass().getComponentType();
1339 if (ccl.isPrimitive()) {
1340 if (ccl == Integer.TYPE) {
1341 int[] ia = (int[]) array;
1342 bout.writeInt(ia.length);
1343 bout.writeInts(ia, 0, ia.length);
1344 } else if (ccl == Byte.TYPE) {
1345 byte[] ba = (byte[]) array;
1346 bout.writeInt(ba.length);
1347 bout.write(ba, 0, ba.length, true);
1348 } else if (ccl == Long.TYPE) {
1349 long[] ja = (long[]) array;
1350 bout.writeInt(ja.length);
1351 bout.writeLongs(ja, 0, ja.length);
1352 } else if (ccl == Float.TYPE) {
1353 float[] fa = (float[]) array;
1354 bout.writeInt(fa.length);
1355 bout.writeFloats(fa, 0, fa.length);
1356 } else if (ccl == Double.TYPE) {
1357 double[] da = (double[]) array;
1358 bout.writeInt(da.length);
1359 bout.writeDoubles(da, 0, da.length);
1360 } else if (ccl == Short.TYPE) {
1361 short[] sa = (short[]) array;
1362 bout.writeInt(sa.length);
1363 bout.writeShorts(sa, 0, sa.length);
1364 } else if (ccl == Character.TYPE) {
1365 char[] ca = (char[]) array;
1366 bout.writeInt(ca.length);
1367 bout.writeChars(ca, 0, ca.length);
1368 } else if (ccl == Boolean.TYPE) {
1369 boolean[] za = (boolean[]) array;
1370 bout.writeInt(za.length);
1371 bout.writeBooleans(za, 0, za.length);
1372 } else {
1373 throw new InternalError();
1374 }
1375 } else {
1376 Object[] objs = (Object[]) array;
1377 int len = objs.length;
1378 bout.writeInt(len);
1379 if (extendedDebugInfo) {
1380 debugInfoStack.push(
1381 "array (class \"" + array.getClass().getName() +
1382 "\", size: " + len + ")");
1383 }
1384 try {
1385 for (int i = 0; i < len; i++) {
1386 if (extendedDebugInfo) {
1387 debugInfoStack.push(
1388 "element of array (index: " + i + ")");
1389 }
1390 try {
1391 writeObject0(objs[i], false);
1392 } finally {
1393 if (extendedDebugInfo) {
1394 debugInfoStack.pop();
1395 }
1396 }
1397 }
1398 } finally {
1399 if (extendedDebugInfo) {
1400 debugInfoStack.pop();
1401 }
1402 }
1403 }
1404 }
1405
1406 /**
1407 * Writes given enum constant to stream.
1408 */
1409 private void writeEnum(Enum<?> en,
1410 ObjectStreamClass desc,
1411 boolean unshared)
1412 throws IOException
1413 {
1414 bout.writeByte(TC_ENUM);
1415 ObjectStreamClass sdesc = desc.getSuperDesc();
1416 writeClassDesc((sdesc.forClass() == Enum.class) ? desc : sdesc, false);
1417 handles.assign(unshared ? null : en);
1418 writeString(en.name(), false);
1419 }
1420
1421 /**
1422 * Writes representation of an "ordinary" (i.e., not a String, Class,
1423 * ObjectStreamClass, array, or enum constant) serializable object to the
1424 * stream.
1425 */
1426 private void writeOrdinaryObject(Object obj,
1427 ObjectStreamClass desc,
1428 boolean unshared)
1429 throws IOException
1430 {
1431 if (extendedDebugInfo) {
1432 debugInfoStack.push(
1433 (depth == 1 ? "root " : "") + "object (class \"" +
1434 obj.getClass().getName() + "\", " + obj.toString() + ")");
1435 }
1436 try {
1437 desc.checkSerialize();
1438
1439 bout.writeByte(TC_OBJECT);
1440 writeClassDesc(desc, false);
1441 handles.assign(unshared ? null : obj);
1442
1443 if (desc.isRecord()) {
1444 writeRecordData(obj, desc);
1445 } else if (desc.isExternalizable() && !desc.isProxy()) {
1446 writeExternalData((Externalizable) obj);
1447 } else {
1448 writeSerialData(obj, desc);
1449 }
1450 } finally {
1451 if (extendedDebugInfo) {
1452 debugInfoStack.pop();
1453 }
1454 }
1455 }
1456
1457 /**
1458 * Writes externalizable data of given object by invoking its
1459 * writeExternal() method.
1460 */
1461 private void writeExternalData(Externalizable obj) throws IOException {
1462 PutFieldImpl oldPut = curPut;
1463 curPut = null;
1464
1465 if (extendedDebugInfo) {
1466 debugInfoStack.push("writeExternal data");
1467 }
1468 SerialCallbackContext oldContext = curContext;
1469 try {
1470 curContext = null;
1471 if (protocol == PROTOCOL_VERSION_1) {
1472 obj.writeExternal(this);
1473 } else {
1474 bout.setBlockDataMode(true);
1475 obj.writeExternal(this);
1476 bout.setBlockDataMode(false);
1477 bout.writeByte(TC_ENDBLOCKDATA);
1478 }
1479 } finally {
1480 curContext = oldContext;
1481 if (extendedDebugInfo) {
1482 debugInfoStack.pop();
1483 }
1484 }
1485
1486 curPut = oldPut;
1487 }
1488
1489 /** Writes the record component values for the given record object. */
1490 private void writeRecordData(Object obj, ObjectStreamClass desc)
1491 throws IOException
1492 {
1493 assert obj.getClass().isRecord();
1494 ObjectStreamClass.ClassDataSlot[] slots = desc.getClassDataLayout();
1495 if (slots.length != 1) {
1496 throw new InvalidClassException(
1497 "expected a single record slot length, but found: " + slots.length);
1498 }
1499
1500 defaultWriteFields(obj, desc); // #### seems unnecessary to use the accessors
1501 }
1502
1503 /**
1504 * Writes instance data for each serializable class of given object, from
1505 * superclass to subclass.
1506 */
1507 private void writeSerialData(Object obj, ObjectStreamClass desc)
1508 throws IOException
1509 {
1510 ObjectStreamClass.ClassDataSlot[] slots = desc.getClassDataLayout();
1511 for (int i = 0; i < slots.length; i++) {
1512 ObjectStreamClass slotDesc = slots[i].desc;
1513 if (slotDesc.hasWriteObjectMethod()) {
1514 PutFieldImpl oldPut = curPut;
1515 curPut = null;
1516 SerialCallbackContext oldContext = curContext;
1517
1518 if (extendedDebugInfo) {
1519 debugInfoStack.push(
1520 "custom writeObject data (class \"" +
1521 slotDesc.getName() + "\")");
1522 }
1523 try {
1524 curContext = new SerialCallbackContext(obj, slotDesc);
1525 bout.setBlockDataMode(true);
1526 slotDesc.invokeWriteObject(obj, this);
1527 bout.setBlockDataMode(false);
1528 bout.writeByte(TC_ENDBLOCKDATA);
1529 } finally {
1530 curContext.setUsed();
1531 curContext = oldContext;
1532 if (extendedDebugInfo) {
1533 debugInfoStack.pop();
1534 }
1535 }
1536
1537 curPut = oldPut;
1538 } else {
1539 defaultWriteFields(obj, slotDesc);
1540 }
1541 }
1542 }
1543
1544 /**
1545 * Fetches and writes values of serializable fields of given object to
1546 * stream. The given class descriptor specifies which field values to
1547 * write, and in which order they should be written.
1548 */
1549 private void defaultWriteFields(Object obj, ObjectStreamClass desc)
1550 throws IOException
1551 {
1552 Class<?> cl = desc.forClass();
1553 if (cl != null && obj != null && !cl.isInstance(obj)) {
1554 throw new ClassCastException();
1555 }
1556
1557 desc.checkDefaultSerialize();
1558
1559 int primDataSize = desc.getPrimDataSize();
1560 if (primDataSize > 0) {
1561 if (primVals == null || primVals.length < primDataSize) {
1562 primVals = new byte[primDataSize];
1563 }
1564 desc.getPrimFieldValues(obj, primVals);
1565 bout.write(primVals, 0, primDataSize, false);
1566 }
1567
1568 int numObjFields = desc.getNumObjFields();
1569 if (numObjFields > 0) {
1570 ObjectStreamField[] fields = desc.getFields(false);
1571 Object[] objVals = new Object[numObjFields];
1572 int numPrimFields = fields.length - objVals.length;
1573 desc.getObjFieldValues(obj, objVals);
1574 for (int i = 0; i < objVals.length; i++) {
1575 if (extendedDebugInfo) {
1576 debugInfoStack.push(
1577 "field (class \"" + desc.getName() + "\", name: \"" +
1578 fields[numPrimFields + i].getName() + "\", type: \"" +
1579 fields[numPrimFields + i].getType() + "\")");
1580 }
1581 try {
1582 writeObject0(objVals[i],
1583 fields[numPrimFields + i].isUnshared());
1584 } finally {
1585 if (extendedDebugInfo) {
1586 debugInfoStack.pop();
1587 }
1588 }
1589 }
1590 }
1591 }
1592
1593 /**
1594 * Attempts to write to stream fatal IOException that has caused
1595 * serialization to abort.
1596 */
1597 private void writeFatalException(IOException ex) throws IOException {
1598 /*
1599 * Note: the serialization specification states that if a second
1600 * IOException occurs while attempting to serialize the original fatal
1601 * exception to the stream, then a StreamCorruptedException should be
1602 * thrown (section 2.1). However, due to a bug in previous
1603 * implementations of serialization, StreamCorruptedExceptions were
1604 * rarely (if ever) actually thrown--the "root" exceptions from
1605 * underlying streams were thrown instead. This historical behavior is
1606 * followed here for consistency.
1607 */
1608 clear();
1609 boolean oldMode = bout.setBlockDataMode(false);
1610 try {
1611 bout.writeByte(TC_EXCEPTION);
1612 writeObject0(ex, false);
1613 clear();
1614 } finally {
1615 bout.setBlockDataMode(oldMode);
1616 }
1617 }
1618
1619 /**
1620 * Default PutField implementation.
1621 */
1622 private class PutFieldImpl extends PutField {
1623
1624 /** class descriptor describing serializable fields */
1625 private final ObjectStreamClass desc;
1626 /** primitive field values */
1627 private final byte[] primVals;
1628 /** object field values */
1629 private final Object[] objVals;
1630
1631 /**
1632 * Creates PutFieldImpl object for writing fields defined in given
1633 * class descriptor.
1634 */
1635 PutFieldImpl(ObjectStreamClass desc) {
1636 this.desc = desc;
1637 primVals = new byte[desc.getPrimDataSize()];
1638 objVals = new Object[desc.getNumObjFields()];
1639 }
1640
1641 public void put(String name, boolean val) {
1642 Bits.putBoolean(primVals, getFieldOffset(name, Boolean.TYPE), val);
1643 }
1644
1645 public void put(String name, byte val) {
1646 primVals[getFieldOffset(name, Byte.TYPE)] = val;
1647 }
1648
1649 public void put(String name, char val) {
1650 Bits.putChar(primVals, getFieldOffset(name, Character.TYPE), val);
1651 }
1652
1653 public void put(String name, short val) {
1654 Bits.putShort(primVals, getFieldOffset(name, Short.TYPE), val);
1655 }
1656
1657 public void put(String name, int val) {
1658 Bits.putInt(primVals, getFieldOffset(name, Integer.TYPE), val);
1659 }
1660
1661 public void put(String name, float val) {
1662 Bits.putFloat(primVals, getFieldOffset(name, Float.TYPE), val);
1663 }
1664
1665 public void put(String name, long val) {
1666 Bits.putLong(primVals, getFieldOffset(name, Long.TYPE), val);
1667 }
1668
1669 public void put(String name, double val) {
1670 Bits.putDouble(primVals, getFieldOffset(name, Double.TYPE), val);
1671 }
1672
1673 public void put(String name, Object val) {
1674 objVals[getFieldOffset(name, Object.class)] = val;
1675 }
1676
1677 // deprecated in ObjectOutputStream.PutField
1678 public void write(ObjectOutput out) throws IOException {
1679 /*
1680 * Applications should *not* use this method to write PutField
1681 * data, as it will lead to stream corruption if the PutField
1682 * object writes any primitive data (since block data mode is not
1683 * unset/set properly, as is done in OOS.writeFields()). This
1684 * broken implementation is being retained solely for behavioral
1685 * compatibility, in order to support applications which use
1686 * OOS.PutField.write() for writing only non-primitive data.
1687 *
1688 * Serialization of unshared objects is not implemented here since
1689 * it is not necessary for backwards compatibility; also, unshared
1690 * semantics may not be supported by the given ObjectOutput
1691 * instance. Applications which write unshared objects using the
1692 * PutField API must use OOS.writeFields().
1693 */
1694 if (ObjectOutputStream.this != out) {
1695 throw new IllegalArgumentException("wrong stream");
1696 }
1697 out.write(primVals, 0, primVals.length);
1698
1699 ObjectStreamField[] fields = desc.getFields(false);
1700 int numPrimFields = fields.length - objVals.length;
1701 // REMIND: warn if numPrimFields > 0?
1702 for (int i = 0; i < objVals.length; i++) {
1703 if (fields[numPrimFields + i].isUnshared()) {
1704 throw new IOException("cannot write unshared object");
1705 }
1706 out.writeObject(objVals[i]);
1707 }
1708 }
1709
1710 /**
1711 * Writes buffered primitive data and object fields to stream.
1712 */
1713 void writeFields() throws IOException {
1714 bout.write(primVals, 0, primVals.length, false);
1715
1716 ObjectStreamField[] fields = desc.getFields(false);
1717 int numPrimFields = fields.length - objVals.length;
1718 for (int i = 0; i < objVals.length; i++) {
1719 if (extendedDebugInfo) {
1720 debugInfoStack.push(
1721 "field (class \"" + desc.getName() + "\", name: \"" +
1722 fields[numPrimFields + i].getName() + "\", type: \"" +
1723 fields[numPrimFields + i].getType() + "\")");
1724 }
1725 try {
1726 writeObject0(objVals[i],
1727 fields[numPrimFields + i].isUnshared());
1728 } finally {
1729 if (extendedDebugInfo) {
1730 debugInfoStack.pop();
1731 }
1732 }
1733 }
1734 }
1735
1736 /**
1737 * Returns offset of field with given name and type. A specified type
1738 * of null matches all types, Object.class matches all non-primitive
1739 * types, and any other non-null type matches assignable types only.
1740 * Throws IllegalArgumentException if no matching field found.
1741 */
1742 private int getFieldOffset(String name, Class<?> type) {
1743 ObjectStreamField field = desc.getField(name, type);
1744 if (field == null) {
1745 throw new IllegalArgumentException("no such field " + name +
1746 " with type " + type);
1747 }
1748 return field.getOffset();
1749 }
1750 }
1751
1752 /**
1753 * Buffered output stream with two modes: in default mode, outputs data in
1754 * same format as DataOutputStream; in "block data" mode, outputs data
1755 * bracketed by block data markers (see object serialization specification
1756 * for details).
1757 */
1758 private static class BlockDataOutputStream
1759 extends OutputStream implements DataOutput
1760 {
1761 /** maximum data block length */
1762 private static final int MAX_BLOCK_SIZE = 1024;
1763 /** maximum data block header length */
1764 private static final int MAX_HEADER_SIZE = 5;
1765 /** (tunable) length of char buffer (for writing strings) */
1766 private static final int CHAR_BUF_SIZE = 256;
1767
1768 /** buffer for writing general/block data */
1769 private final byte[] buf = new byte[MAX_BLOCK_SIZE];
1770 /** buffer for writing block data headers */
1771 private final byte[] hbuf = new byte[MAX_HEADER_SIZE];
1772 /** char buffer for fast string writes */
1773 private final char[] cbuf = new char[CHAR_BUF_SIZE];
1774
1775 /** block data mode */
1776 private boolean blkmode = false;
1777 /** current offset into buf */
1778 private int pos = 0;
1779
1780 /** underlying output stream */
1781 private final OutputStream out;
1782 /** loopback stream (for data writes that span data blocks) */
1783 private final DataOutputStream dout;
1784
1785 /**
1786 * Creates new BlockDataOutputStream on top of given underlying stream.
1787 * Block data mode is turned off by default.
1788 */
1789 BlockDataOutputStream(OutputStream out) {
1790 this.out = out;
1791 dout = new DataOutputStream(this);
1792 }
1793
1794 /**
1795 * Sets block data mode to the given mode (true == on, false == off)
1796 * and returns the previous mode value. If the new mode is the same as
1797 * the old mode, no action is taken. If the new mode differs from the
1798 * old mode, any buffered data is flushed before switching to the new
1799 * mode.
1800 */
1801 boolean setBlockDataMode(boolean mode) throws IOException {
1802 if (blkmode == mode) {
1803 return blkmode;
1804 }
1805 drain();
1806 blkmode = mode;
1807 return !blkmode;
1808 }
1809
1810 /**
1811 * Returns true if the stream is currently in block data mode, false
1812 * otherwise.
1813 */
1814 boolean getBlockDataMode() {
1815 return blkmode;
1816 }
1817
1818 /* ----------------- generic output stream methods ----------------- */
1819 /*
1820 * The following methods are equivalent to their counterparts in
1821 * OutputStream, except that they partition written data into data
1822 * blocks when in block data mode.
1823 */
1824
1825 public void write(int b) throws IOException {
1826 if (pos >= MAX_BLOCK_SIZE) {
1827 drain();
1828 }
1829 buf[pos++] = (byte) b;
1830 }
1831
1832 public void write(byte[] b) throws IOException {
1833 write(b, 0, b.length, false);
1834 }
1835
1836 public void write(byte[] b, int off, int len) throws IOException {
1837 write(b, off, len, false);
1838 }
1839
1840 public void flush() throws IOException {
1841 drain();
1842 out.flush();
1843 }
1844
1845 public void close() throws IOException {
1846 flush();
1847 out.close();
1848 }
1849
1850 /**
1851 * Writes specified span of byte values from given array. If copy is
1852 * true, copies the values to an intermediate buffer before writing
1853 * them to underlying stream (to avoid exposing a reference to the
1854 * original byte array).
1855 */
1856 void write(byte[] b, int off, int len, boolean copy)
1857 throws IOException
1858 {
1859 if (!(copy || blkmode)) { // write directly
1860 drain();
1861 out.write(b, off, len);
1862 return;
1863 }
1864
1865 while (len > 0) {
1866 if (pos >= MAX_BLOCK_SIZE) {
1867 drain();
1868 }
1869 if (len >= MAX_BLOCK_SIZE && !copy && pos == 0) {
1870 // avoid unnecessary copy
1871 writeBlockHeader(MAX_BLOCK_SIZE);
1872 out.write(b, off, MAX_BLOCK_SIZE);
1873 off += MAX_BLOCK_SIZE;
1874 len -= MAX_BLOCK_SIZE;
1875 } else {
1876 int wlen = Math.min(len, MAX_BLOCK_SIZE - pos);
1877 System.arraycopy(b, off, buf, pos, wlen);
1878 pos += wlen;
1879 off += wlen;
1880 len -= wlen;
1881 }
1882 }
1883 }
1884
1885 /**
1886 * Writes all buffered data from this stream to the underlying stream,
1887 * but does not flush underlying stream.
1888 */
1889 void drain() throws IOException {
1890 if (pos == 0) {
1891 return;
1892 }
1893 if (blkmode) {
1894 writeBlockHeader(pos);
1895 }
1896 out.write(buf, 0, pos);
1897 pos = 0;
1898 }
1899
1900 /**
1901 * Writes block data header. Data blocks shorter than 256 bytes are
1902 * prefixed with a 2-byte header; all others start with a 5-byte
1903 * header.
1904 */
1905 private void writeBlockHeader(int len) throws IOException {
1906 if (len <= 0xFF) {
1907 hbuf[0] = TC_BLOCKDATA;
1908 hbuf[1] = (byte) len;
1909 out.write(hbuf, 0, 2);
1910 } else {
1911 hbuf[0] = TC_BLOCKDATALONG;
1912 Bits.putInt(hbuf, 1, len);
1913 out.write(hbuf, 0, 5);
1914 }
1915 }
1916
1917
1918 /* ----------------- primitive data output methods ----------------- */
1919 /*
1920 * The following methods are equivalent to their counterparts in
1921 * DataOutputStream, except that they partition written data into data
1922 * blocks when in block data mode.
1923 */
1924
1925 public void writeBoolean(boolean v) throws IOException {
1926 if (pos >= MAX_BLOCK_SIZE) {
1927 drain();
1928 }
1929 Bits.putBoolean(buf, pos++, v);
1930 }
1931
1932 public void writeByte(int v) throws IOException {
1933 if (pos >= MAX_BLOCK_SIZE) {
1934 drain();
1935 }
1936 buf[pos++] = (byte) v;
1937 }
1938
1939 public void writeChar(int v) throws IOException {
1940 if (pos + 2 <= MAX_BLOCK_SIZE) {
1941 Bits.putChar(buf, pos, (char) v);
1942 pos += 2;
1943 } else {
1944 dout.writeChar(v);
1945 }
1946 }
1947
1948 public void writeShort(int v) throws IOException {
1949 if (pos + 2 <= MAX_BLOCK_SIZE) {
1950 Bits.putShort(buf, pos, (short) v);
1951 pos += 2;
1952 } else {
1953 dout.writeShort(v);
1954 }
1955 }
1956
1957 public void writeInt(int v) throws IOException {
1958 if (pos + 4 <= MAX_BLOCK_SIZE) {
1959 Bits.putInt(buf, pos, v);
1960 pos += 4;
1961 } else {
1962 dout.writeInt(v);
1963 }
1964 }
1965
1966 public void writeFloat(float v) throws IOException {
1967 if (pos + 4 <= MAX_BLOCK_SIZE) {
1968 Bits.putFloat(buf, pos, v);
1969 pos += 4;
1970 } else {
1971 dout.writeFloat(v);
1972 }
1973 }
1974
1975 public void writeLong(long v) throws IOException {
1976 if (pos + 8 <= MAX_BLOCK_SIZE) {
1977 Bits.putLong(buf, pos, v);
1978 pos += 8;
1979 } else {
1980 dout.writeLong(v);
1981 }
1982 }
1983
1984 public void writeDouble(double v) throws IOException {
1985 if (pos + 8 <= MAX_BLOCK_SIZE) {
1986 Bits.putDouble(buf, pos, v);
1987 pos += 8;
1988 } else {
1989 dout.writeDouble(v);
1990 }
1991 }
1992
1993 public void writeBytes(String s) throws IOException {
1994 int endoff = s.length();
1995 int cpos = 0;
1996 int csize = 0;
1997 for (int off = 0; off < endoff; ) {
1998 if (cpos >= csize) {
1999 cpos = 0;
2000 csize = Math.min(endoff - off, CHAR_BUF_SIZE);
2001 s.getChars(off, off + csize, cbuf, 0);
2002 }
2003 if (pos >= MAX_BLOCK_SIZE) {
2004 drain();
2005 }
2006 int n = Math.min(csize - cpos, MAX_BLOCK_SIZE - pos);
2007 int stop = pos + n;
2008 while (pos < stop) {
2009 buf[pos++] = (byte) cbuf[cpos++];
2010 }
2011 off += n;
2012 }
2013 }
2014
2015 public void writeChars(String s) throws IOException {
2016 int endoff = s.length();
2017 for (int off = 0; off < endoff; ) {
2018 int csize = Math.min(endoff - off, CHAR_BUF_SIZE);
2019 s.getChars(off, off + csize, cbuf, 0);
2020 writeChars(cbuf, 0, csize);
2021 off += csize;
2022 }
2023 }
2024
2025 public void writeUTF(String s) throws IOException {
2026 writeUTF(s, getUTFLength(s));
2027 }
2028
2029
2030 /* -------------- primitive data array output methods -------------- */
2031 /*
2032 * The following methods write out spans of primitive data values.
2033 * Though equivalent to calling the corresponding primitive write
2034 * methods repeatedly, these methods are optimized for writing groups
2035 * of primitive data values more efficiently.
2036 */
2037
2038 void writeBooleans(boolean[] v, int off, int len) throws IOException {
2039 int endoff = off + len;
2040 while (off < endoff) {
2041 if (pos >= MAX_BLOCK_SIZE) {
2042 drain();
2043 }
2044 int stop = Math.min(endoff, off + (MAX_BLOCK_SIZE - pos));
2045 while (off < stop) {
2046 Bits.putBoolean(buf, pos++, v[off++]);
2047 }
2048 }
2049 }
2050
2051 void writeChars(char[] v, int off, int len) throws IOException {
2052 int limit = MAX_BLOCK_SIZE - 2;
2053 int endoff = off + len;
2054 while (off < endoff) {
2055 if (pos <= limit) {
2056 int avail = (MAX_BLOCK_SIZE - pos) >> 1;
2057 int stop = Math.min(endoff, off + avail);
2058 while (off < stop) {
2059 Bits.putChar(buf, pos, v[off++]);
2060 pos += 2;
2061 }
2062 } else {
2063 dout.writeChar(v[off++]);
2064 }
2065 }
2066 }
2067
2068 void writeShorts(short[] v, int off, int len) throws IOException {
2069 int limit = MAX_BLOCK_SIZE - 2;
2070 int endoff = off + len;
2071 while (off < endoff) {
2072 if (pos <= limit) {
2073 int avail = (MAX_BLOCK_SIZE - pos) >> 1;
2074 int stop = Math.min(endoff, off + avail);
2075 while (off < stop) {
2076 Bits.putShort(buf, pos, v[off++]);
2077 pos += 2;
2078 }
2079 } else {
2080 dout.writeShort(v[off++]);
2081 }
2082 }
2083 }
2084
2085 void writeInts(int[] v, int off, int len) throws IOException {
2086 int limit = MAX_BLOCK_SIZE - 4;
2087 int endoff = off + len;
2088 while (off < endoff) {
2089 if (pos <= limit) {
2090 int avail = (MAX_BLOCK_SIZE - pos) >> 2;
2091 int stop = Math.min(endoff, off + avail);
2092 while (off < stop) {
2093 Bits.putInt(buf, pos, v[off++]);
2094 pos += 4;
2095 }
2096 } else {
2097 dout.writeInt(v[off++]);
2098 }
2099 }
2100 }
2101
2102 void writeFloats(float[] v, int off, int len) throws IOException {
2103 int limit = MAX_BLOCK_SIZE - 4;
2104 int endoff = off + len;
2105 while (off < endoff) {
2106 if (pos <= limit) {
2107 int avail = (MAX_BLOCK_SIZE - pos) >> 2;
2108 int stop = Math.min(endoff, off + avail);
2109 while (off < stop) {
2110 Bits.putFloat(buf, pos, v[off++]);
2111 pos += 4;
2112 }
2113 } else {
2114 dout.writeFloat(v[off++]);
2115 }
2116 }
2117 }
2118
2119 void writeLongs(long[] v, int off, int len) throws IOException {
2120 int limit = MAX_BLOCK_SIZE - 8;
2121 int endoff = off + len;
2122 while (off < endoff) {
2123 if (pos <= limit) {
2124 int avail = (MAX_BLOCK_SIZE - pos) >> 3;
2125 int stop = Math.min(endoff, off + avail);
2126 while (off < stop) {
2127 Bits.putLong(buf, pos, v[off++]);
2128 pos += 8;
2129 }
2130 } else {
2131 dout.writeLong(v[off++]);
2132 }
2133 }
2134 }
2135
2136 void writeDoubles(double[] v, int off, int len) throws IOException {
2137 int limit = MAX_BLOCK_SIZE - 8;
2138 int endoff = off + len;
2139 while (off < endoff) {
2140 if (pos <= limit) {
2141 int avail = (MAX_BLOCK_SIZE - pos) >> 3;
2142 int stop = Math.min(endoff, off + avail);
2143 while (off < stop) {
2144 Bits.putDouble(buf, pos, v[off++]);
2145 pos += 8;
2146 }
2147 } else {
2148 dout.writeDouble(v[off++]);
2149 }
2150 }
2151 }
2152
2153 /**
2154 * Returns the length in bytes of the UTF encoding of the given string.
2155 */
2156 long getUTFLength(String s) {
2157 int len = s.length();
2158 long utflen = 0;
2159 for (int off = 0; off < len; ) {
2160 int csize = Math.min(len - off, CHAR_BUF_SIZE);
2161 s.getChars(off, off + csize, cbuf, 0);
2162 for (int cpos = 0; cpos < csize; cpos++) {
2163 char c = cbuf[cpos];
2164 if (c >= 0x0001 && c <= 0x007F) {
2165 utflen++;
2166 } else if (c > 0x07FF) {
2167 utflen += 3;
2168 } else {
2169 utflen += 2;
2170 }
2171 }
2172 off += csize;
2173 }
2174 return utflen;
2175 }
2176
2177 /**
2178 * Writes the given string in UTF format. This method is used in
2179 * situations where the UTF encoding length of the string is already
2180 * known; specifying it explicitly avoids a prescan of the string to
2181 * determine its UTF length.
2182 */
2183 void writeUTF(String s, long utflen) throws IOException {
2184 if (utflen > 0xFFFFL) {
2185 throw new UTFDataFormatException();
2186 }
2187 writeShort((int) utflen);
2188 if (utflen == (long) s.length()) {
2189 writeBytes(s);
2190 } else {
2191 writeUTFBody(s);
2192 }
2193 }
2194
2195 /**
2196 * Writes given string in "long" UTF format. "Long" UTF format is
2197 * identical to standard UTF, except that it uses an 8 byte header
2198 * (instead of the standard 2 bytes) to convey the UTF encoding length.
2199 */
2200 void writeLongUTF(String s) throws IOException {
2201 writeLongUTF(s, getUTFLength(s));
2202 }
2203
2204 /**
2205 * Writes given string in "long" UTF format, where the UTF encoding
2206 * length of the string is already known.
2207 */
2208 void writeLongUTF(String s, long utflen) throws IOException {
2209 writeLong(utflen);
2210 if (utflen == (long) s.length()) {
2211 writeBytes(s);
2212 } else {
2213 writeUTFBody(s);
2214 }
2215 }
2216
2217 /**
2218 * Writes the "body" (i.e., the UTF representation minus the 2-byte or
2219 * 8-byte length header) of the UTF encoding for the given string.
2220 */
2221 private void writeUTFBody(String s) throws IOException {
2222 int limit = MAX_BLOCK_SIZE - 3;
2223 int len = s.length();
2224 for (int off = 0; off < len; ) {
2225 int csize = Math.min(len - off, CHAR_BUF_SIZE);
2226 s.getChars(off, off + csize, cbuf, 0);
2227 for (int cpos = 0; cpos < csize; cpos++) {
2228 char c = cbuf[cpos];
2229 if (pos <= limit) {
2230 if (c <= 0x007F && c != 0) {
2231 buf[pos++] = (byte) c;
2232 } else if (c > 0x07FF) {
2233 buf[pos + 2] = (byte) (0x80 | ((c >> 0) & 0x3F));
2234 buf[pos + 1] = (byte) (0x80 | ((c >> 6) & 0x3F));
2235 buf[pos + 0] = (byte) (0xE0 | ((c >> 12) & 0x0F));
2236 pos += 3;
2237 } else {
2238 buf[pos + 1] = (byte) (0x80 | ((c >> 0) & 0x3F));
2239 buf[pos + 0] = (byte) (0xC0 | ((c >> 6) & 0x1F));
2240 pos += 2;
2241 }
2242 } else { // write one byte at a time to normalize block
2243 if (c <= 0x007F && c != 0) {
2244 write(c);
2245 } else if (c > 0x07FF) {
2246 write(0xE0 | ((c >> 12) & 0x0F));
2247 write(0x80 | ((c >> 6) & 0x3F));
2248 write(0x80 | ((c >> 0) & 0x3F));
2249 } else {
2250 write(0xC0 | ((c >> 6) & 0x1F));
2251 write(0x80 | ((c >> 0) & 0x3F));
2252 }
2253 }
2254 }
2255 off += csize;
2256 }
2257 }
2258 }
2259
2260 /**
2261 * Lightweight identity hash table which maps objects to integer handles,
2262 * assigned in ascending order.
2263 */
2264 private static class HandleTable {
2265
2266 /* number of mappings in table/next available handle */
2267 private int size;
2268 /* size threshold determining when to expand hash spine */
2269 private int threshold;
2270 /* factor for computing size threshold */
2271 private final float loadFactor;
2272 /* maps hash value -> candidate handle value */
2273 private int[] spine;
2274 /* maps handle value -> next candidate handle value */
2275 private int[] next;
2276 /* maps handle value -> associated object */
2277 private Object[] objs;
2278
2279 /**
2280 * Creates new HandleTable with given capacity and load factor.
2281 */
2282 HandleTable(int initialCapacity, float loadFactor) {
2283 this.loadFactor = loadFactor;
2284 spine = new int[initialCapacity];
2285 next = new int[initialCapacity];
2286 objs = new Object[initialCapacity];
2287 threshold = (int) (initialCapacity * loadFactor);
2288 clear();
2289 }
2290
2291 /**
2292 * Assigns next available handle to given object, and returns handle
2293 * value. Handles are assigned in ascending order starting at 0.
2294 */
2295 int assign(Object obj) {
2296 if (size >= next.length) {
2297 growEntries();
2298 }
2299 if (size >= threshold) {
2300 growSpine();
2301 }
2302 insert(obj, size);
2303 return size++;
2304 }
2305
2306 /**
2307 * Looks up and returns handle associated with given object, or -1 if
2308 * no mapping found.
2309 */
2310 int lookup(Object obj) {
2311 if (size == 0) {
2312 return -1;
2313 }
2314 int index = hash(obj) % spine.length;
2315 for (int i = spine[index]; i >= 0; i = next[i]) {
2316 if (objs[i] == obj) {
2317 return i;
2318 }
2319 }
2320 return -1;
2321 }
2322
2323 /**
2324 * Resets table to its initial (empty) state.
2325 */
2326 void clear() {
2327 Arrays.fill(spine, -1);
2328 Arrays.fill(objs, 0, size, null);
2329 size = 0;
2330 }
2331
2332 /**
2333 * Returns the number of mappings currently in table.
2334 */
2335 int size() {
2336 return size;
2337 }
2338
2339 /**
2340 * Inserts mapping object -> handle mapping into table. Assumes table
2341 * is large enough to accommodate new mapping.
2342 */
2343 private void insert(Object obj, int handle) {
2344 int index = hash(obj) % spine.length;
2345 objs[handle] = obj;
2346 next[handle] = spine[index];
2347 spine[index] = handle;
2348 }
2349
2350 /**
2351 * Expands the hash "spine" -- equivalent to increasing the number of
2352 * buckets in a conventional hash table.
2353 */
2354 private void growSpine() {
2355 spine = new int[(spine.length << 1) + 1];
2356 threshold = (int) (spine.length * loadFactor);
2357 Arrays.fill(spine, -1);
2358 for (int i = 0; i < size; i++) {
2359 insert(objs[i], i);
2360 }
2361 }
2362
2363 /**
2364 * Increases hash table capacity by lengthening entry arrays.
2365 */
2366 private void growEntries() {
2367 int newLength = (next.length << 1) + 1;
2368 int[] newNext = new int[newLength];
2369 System.arraycopy(next, 0, newNext, 0, size);
2370 next = newNext;
2371
2372 Object[] newObjs = new Object[newLength];
2373 System.arraycopy(objs, 0, newObjs, 0, size);
2374 objs = newObjs;
2375 }
2376
2377 /**
2378 * Returns hash value for given object.
2379 */
2380 private int hash(Object obj) {
2381 return System.identityHashCode(obj) & 0x7FFFFFFF;
2382 }
2383 }
2384
2385 /**
2386 * Lightweight identity hash table which maps objects to replacement
2387 * objects.
2388 */
2389 private static class ReplaceTable {
2390
2391 /* maps object -> index */
2392 private final HandleTable htab;
2393 /* maps index -> replacement object */
2394 private Object[] reps;
2395
2396 /**
2397 * Creates new ReplaceTable with given capacity and load factor.
2398 */
2399 ReplaceTable(int initialCapacity, float loadFactor) {
2400 htab = new HandleTable(initialCapacity, loadFactor);
2401 reps = new Object[initialCapacity];
2402 }
2403
2404 /**
2405 * Enters mapping from object to replacement object.
2406 */
2407 void assign(Object obj, Object rep) {
2408 int index = htab.assign(obj);
2409 while (index >= reps.length) {
2410 grow();
2411 }
2412 reps[index] = rep;
2413 }
2414
2415 /**
2416 * Looks up and returns replacement for given object. If no
2417 * replacement is found, returns the lookup object itself.
2418 */
2419 Object lookup(Object obj) {
2420 int index = htab.lookup(obj);
2421 return (index >= 0) ? reps[index] : obj;
2422 }
2423
2424 /**
2425 * Resets table to its initial (empty) state.
2426 */
2427 void clear() {
2428 Arrays.fill(reps, 0, htab.size(), null);
2429 htab.clear();
2430 }
2431
2432 /**
2433 * Returns the number of mappings currently in table.
2434 */
2435 int size() {
2436 return htab.size();
2437 }
2438
2439 /**
2440 * Increases table capacity.
2441 */
2442 private void grow() {
2443 Object[] newReps = new Object[(reps.length << 1) + 1];
2444 System.arraycopy(reps, 0, newReps, 0, reps.length);
2445 reps = newReps;
2446 }
2447 }
2448
2449 /**
2450 * Stack to keep debug information about the state of the
2451 * serialization process, for embedding in exception messages.
2452 */
2453 private static class DebugTraceInfoStack {
2454 private final List<String> stack;
2455
2456 DebugTraceInfoStack() {
2457 stack = new ArrayList<>();
2458 }
2459
2460 /**
2461 * Removes all of the elements from enclosed list.
2462 */
2463 void clear() {
2464 stack.clear();
2465 }
2466
2467 /**
2468 * Removes the object at the top of enclosed list.
2469 */
2470 void pop() {
2471 stack.remove(stack.size()-1);
2472 }
2473
2474 /**
2475 * Pushes a String onto the top of enclosed list.
2476 */
2477 void push(String entry) {
2478 stack.add("\t- " + entry);
2479 }
2480
2481 /**
2482 * Returns a string representation of this object
2483 */
2484 public String toString() {
2485 StringJoiner sj = new StringJoiner("\n");
2486 for (int i = stack.size() - 1; i >= 0; i--) {
2487 sj.add(stack.get(i));
2488 }
2489 return sj.toString();
2490 }
2491 }
2492
2493 }