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Java Source Code / Java Documentation » Database DBMS » Quadcap Embeddable Database » com.quadcap.sql.file 
Source Cross Referenced  Class Diagram Java Document (Java Doc) 


001:        package com.quadcap.sql.file;
002:
003:        /* Copyright 1997 - 2003 Quadcap Software.  All rights reserved.
004:         *
005:         * This software is distributed under the Quadcap Free Software License.
006:         * This software may be used or modified for any purpose, personal or
007:         * commercial.  Open Source redistributions are permitted.  Commercial
008:         * redistribution of larger works derived from, or works which bundle
009:         * this software requires a "Commercial Redistribution License"; see
010:         * http://www.quadcap.com/purchase.
011:         *
012:         * Redistributions qualify as "Open Source" under  one of the following terms:
013:         *   
014:         *    Redistributions are made at no charge beyond the reasonable cost of
015:         *    materials and delivery.
016:         *
017:         *    Redistributions are accompanied by a copy of the Source Code or by an
018:         *    irrevocable offer to provide a copy of the Source Code for up to three
019:         *    years at the cost of materials and delivery.  Such redistributions
020:         *    must allow further use, modification, and redistribution of the Source
021:         *    Code under substantially the same terms as this license.
022:         *
023:         * Redistributions of source code must retain the copyright notices as they
024:         * appear in each source code file, these license terms, and the
025:         * disclaimer/limitation of liability set forth as paragraph 6 below.
026:         *
027:         * Redistributions in binary form must reproduce this Copyright Notice,
028:         * these license terms, and the disclaimer/limitation of liability set
029:         * forth as paragraph 6 below, in the documentation and/or other materials
030:         * provided with the distribution.
031:         *
032:         * The Software is provided on an "AS IS" basis.  No warranty is
033:         * provided that the Software is free of defects, or fit for a
034:         * particular purpose.  
035:         *
036:         * Limitation of Liability. Quadcap Software shall not be liable
037:         * for any damages suffered by the Licensee or any third party resulting
038:         * from use of the Software.
039:         */
040:
041:        import java.io.ByteArrayOutputStream;
042:        import java.io.File;
043:        import java.io.FileInputStream;
044:        import java.io.IOException;
045:        import java.io.InputStream;
046:        import java.io.OutputStream;
047:        import java.io.PrintWriter;
048:
049:        import java.util.Properties;
050:
051:        import com.quadcap.util.ConfigNumber;
052:        import com.quadcap.util.Debug;
053:        import com.quadcap.util.Util;
054:
055:        import com.quadcap.util.collections.LongMap;
056:
057:        import com.quadcap.crypto.KeyFactory;
058:        import com.quadcap.crypto.SymmetricKey;
059:
060:        import com.quadcap.io.MutableByteArrayInputStream;
061:
062:        import com.quadcap.sql.io.ObjectInputStream;
063:        import com.quadcap.sql.io.ObjectOutputStream;
064:
065:        import com.quadcap.sql.Version;
066:
067:        /**
068:         * This class is used to create, modify, or read a blocked file.  The blocked
069:         * file is accessed as a number of fixed size blocks, which are accessed
070:         * through a cache of a size specified by the class user.
071:         *
072:         * @author Stan Bailes
073:         */
074:
075:        public class BlockFile implements  PageManager, SegmentManager {
076:            /** The underlying store used by the cache to access the file.  */
077:            BlockStore store;
078:
079:            /** The cache of file blocks. */
080:            BlockCache cache;
081:
082:            /** For main-memory mode, our objects */
083:            LongMap memoryObjects = null;
084:            long memObjectCount = 100000;
085:            boolean inMemory;
086:
087:            static final int REF_SIZE = 8;
088:
089:            static final int MIN_SUBPAGE = 64;
090:
091:            static final int MAX_PAGESHIFT = 16;
092:
093:            int maxPageShift = 0; // default
094:
095:            // Block			root;
096:            // root block format:
097:            // 0: uint16                   magic (4c)
098:            // 2: uint8                    major version
099:            // 3: uint8                    minor version
100:            // 4: uint32                   blockSize
101:            static final int oBLOCKSIZE = 4;
102:
103:            // 8: uint64 freelist
104:            static final int oFREELIST = 8;
105:
106:            // 16: uint64 lastBlock
107:            static final int oLASTBLOCK = 16;
108:
109:            // 24: uint64 streams[4]
110:            static final int oSTREAM_START = 24;
111:            static final int MAX_STREAM = 4;
112:
113:            // 56: byte[20] hash password
114:            static final int oHASH_PASSWD_start = oSTREAM_START
115:                    + (REF_SIZE * MAX_STREAM);
116:            static final int oHASH_PASSWD_len = 20;
117:            // 76: uint64 subroots[16]
118:            static final int oSUBPAGE_ROOT = oHASH_PASSWD_start
119:                    + oHASH_PASSWD_len;
120:            static final int oHEADER_SIZE = (oSUBPAGE_ROOT + (MAX_PAGESHIFT * REF_SIZE));
121:
122:            int blockSize;
123:
124:            /** Cached copy of largest allocated block number. */
125:            long lastBlock = 0;
126:
127:            boolean readOnly;
128:
129:            PageManager[] pageManagers = new PageManager[MAX_PAGESHIFT];
130:            Object fileLock = new Object();
131:
132:            MutableByteArrayInputStream mbis = new MutableByteArrayInputStream();
133:            ObjectInputStream ois = new ObjectInputStream(mbis);
134:            ByteArrayOutputStream bos = new ByteArrayOutputStream();
135:            ObjectOutputStream oos;
136:
137:            /**
138:             * Create a new BlockFile, attached to the specified file.  For
139:             * an existing BlockFile, use the blocksize with which the file was
140:             * created -- for a new file, use the specified blocksize.
141:             *
142:             * @param filename the file to operate on.
143:             * @param blockSize the block size to use if we're creating a new file.
144:             * @param mode "r" (read only) or "rw" (read-write) access.
145:             */
146:            public BlockFile(String filename, String mode, Properties props,
147:                    int blocksize, int cacheSize) throws IOException {
148:                //#ifndef RELEASE
149:                if (Trace.bit(4)) {
150:                    Debug.println("BlockFile(" + filename + ", " + mode
151:                            + ", blockSize = " + blocksize + ", cacheSize = "
152:                            + cacheSize + ")");
153:                }
154:                //#endif
155:                this .inMemory = props.getProperty("memoryOnly", "")
156:                        .equalsIgnoreCase("true");
157:                pageManagers[0] = this ;
158:                int psize = blocksize;
159:                maxPageShift = 0;
160:                while (psize > MIN_SUBPAGE) {
161:                    maxPageShift++;
162:                    psize >>= 1;
163:                }
164:                this .readOnly = mode.equalsIgnoreCase("r");
165:                this .store = makeStore(props, filename, blocksize, mode);
166:                this .blockSize = store.blockSize();
167:                this .cache = new BlockCache();
168:                this .oos = new ObjectOutputStream(bos);
169:                if (inMemory) {
170:                    this .memoryObjects = new LongMap(8888);
171:                }
172:                cache.setLock(fileLock);
173:                cache.setReadOnly(readOnly);
174:                cache.init(store, cacheSize);
175:                Block root = getBlock(0);
176:                try {
177:                    this .lastBlock = root.readLong(oLASTBLOCK);
178:                } finally {
179:                    root.decrRefCount();
180:                }
181:            }
182:
183:            //#ifdef DEBUG
184:            public String signature() throws IOException {
185:                StringBuffer sb = new StringBuffer("{");
186:                for (long blk = 0; blk <= lastBlock; blk++) {
187:                    if (blk > 0)
188:                        sb.append(",");
189:                    Block b = getBlock(blk);
190:                    try {
191:                        sb.append(b.signature());
192:                    } finally {
193:                        b.decrRefCount();
194:                    }
195:                }
196:                sb.append("}");
197:                return sb.toString();
198:            }
199:
200:            //#endif
201:
202:            protected BlockStore makeStore(Properties props, String filename,
203:                    int blockSize, String mode) throws IOException {
204:                BlockStore s;
205:                File f = null;
206:                boolean enc = false;
207:                boolean nullStore = props.getProperty("cacheOnly", "")
208:                        .equalsIgnoreCase("true");
209:                if (inMemory || nullStore) {
210:                    if (inMemory) {
211:                        s = new MemoryBlockStore();
212:                    } else {
213:                        s = new NullStore();
214:                    }
215:                } else {
216:                    filename = new File(filename).getAbsolutePath();
217:                    f = new File(filename);
218:                    boolean exists = f.exists();
219:                    if (!exists && readOnly) {
220:                        throw new IOException("Not found: " + filename);
221:                    }
222:                    String u = props.getProperty("user", props.getProperty(
223:                            "jdbc.user", ""));
224:                    String p = props.getProperty("passwd", props.getProperty(
225:                            "jdbc.passwd", ""));
226:                    /*{com.quadcap.sql.Datafile-conn.xml-70}
227:                     * <config-var>
228:                     *   <config-name>encrypt</config-name>
229:                     *   <config-dflt>false</config-dflt>
230:                     *   <config-desc>On database creation (i.e., datafile doesn't yet
231:                     *      exist and 'create=true'), if
232:                     *      <code>encrypt == <b>true</b></code>, then a low-level
233:                     *      block encryption algorithm (the default is Rijndael)
234:                     *      will be selected, seeded with the values of the
235:                     *      <code>user</code> and <code>passwd</code> properties for
236:                     *      this, connecting, user.  The database magic code will
237:                     *      be changed from <code> 04 0c </code> to <code> 0e 0c </code>
238:                     *      to signal the encrypted content.
239:                     *      </config-desc>
240:                     * </config-var>
241:                     */
242:                    boolean encrypt = props.getProperty("encrypt", "")
243:                            .equalsIgnoreCase("true");
244:                    enc = (exists && isEncrypted(f)) || (!exists && encrypt);
245:                    if (enc) {
246:                        s = new EncryptedBlockStore();
247:                    } else {
248:                        s = new BlockStore();
249:                    }
250:                }
251:                s.init(f, mode, blockSize, fileLock);
252:                if (enc) {
253:                    String u = props.getProperty("user", props.getProperty(
254:                            "jdbc.user", ""));
255:                    String p = props.getProperty("passwd", props.getProperty(
256:                            "jdbc.passwd", ""));
257:                    SymmetricKey key = KeyFactory.createSymmetricKey(u + "/"
258:                            + p);
259:                    s.setKey(key);
260:                }
261:                return s;
262:            }
263:
264:            private boolean isEncrypted(File f) throws IOException {
265:                FileInputStream fi = new FileInputStream(f);
266:                try {
267:                    return fi.read() == 0x0e;
268:                } finally {
269:                    fi.close();
270:                }
271:            }
272:
273:            public long getUserBlock(int stream) throws IOException {
274:                synchronized (fileLock) {
275:                    if (stream > MAX_STREAM) {
276:                        throw new IOException("Invalid stream: " + stream);
277:                    }
278:                    Block root = getBlock(0);
279:                    long blockNum;
280:                    int offset = oSTREAM_START + (stream * REF_SIZE);
281:                    try {
282:                        blockNum = root.readLong(offset);
283:                        if (blockNum == 0) {
284:                            blockNum = newPage();
285:                            root.writeLong(offset, blockNum);
286:                        }
287:                    } finally {
288:                        root.decrRefCount();
289:                    }
290:                    return blockNum;
291:                }
292:            }
293:
294:            /**
295:             * Flush the cache and close the underlying file.
296:             */
297:            public void close() throws IOException {
298:                synchronized (fileLock) {
299:                    flush(false);
300:                    store.close();
301:                }
302:            }
303:
304:            public final void flush(boolean fastSync) throws IOException {
305:                synchronized (fileLock) {
306:                    //#ifdef DEBUG
307:                    if (Trace.bit(24)) {
308:                        Debug.println(toString() + ".flush(" + fastSync + ")");
309:                    }
310:                    //#endif
311:                    if (!readOnly) {
312:                        cache.flush();
313:                        if (!fastSync) {
314:                            store.flush();
315:                        }
316:                    }
317:                }
318:            }
319:
320:            public String getName() {
321:                return store.getName();
322:            }
323:
324:            public void setLog(Log log) {
325:                store.setLog(log);
326:            }
327:
328:            Log getLog() {
329:                return store.getLog();
330:            }
331:
332:            /**
333:             * Locate the specified block and return the cache entry associated
334:             * with that block.  It needs to be the case that the cache entry is
335:             * "locked" while this returned object is active, so maybe the
336:             * <b>Block</b> class needs a <b>finalize()</b> routine.
337:             * @param i the block number
338:             * @return the cache-handle of the block.
339:             */
340:            public Page getPage(long i) throws IOException {
341:                synchronized (fileLock) {
342:                    if (i > lastBlock) {
343:                        //#ifdef DEBUG
344:                        Debug.println(toString() + ".getPage(" + i
345:                                + "): Bad Block " + " vs lastBlock = "
346:                                + lastBlock);
347:                        //#endif
348:                        throw new IOException("BlockFile(" + store
349:                                + "), Bad block: " + i + " ("
350:                                + SubPageManager.toString(i) + ")");
351:                    }
352:                    return (Page) cache.getCacheable(i);
353:                }
354:            }
355:
356:            public Block getBlock(long i) throws IOException {
357:                return (Block) getPage(i);
358:            }
359:
360:            public void restoreBlock(long b, byte[] buf, int off)
361:                    throws IOException {
362:                ensureLastBlock(b);
363:                store.restore(b, buf, off);
364:            }
365:
366:            final void ensureLastBlock(long i) throws IOException {
367:                if (i > lastBlock) {
368:                    lastBlock = i;
369:                    Block root = getBlock(0);
370:                    try {
371:                        root.writeLong(oLASTBLOCK, i);
372:                    } finally {
373:                        root.decrRefCount();
374:                    }
375:                }
376:            }
377:
378:            /**
379:             * Return the block size used in this file.
380:             */
381:            public final int getPageSize() {
382:                return this .blockSize;
383:            }
384:
385:            /**
386:             * Return a RandomAccess object which references the specified block
387:             */
388:            public RandomAccess getStream(long blockRef) throws IOException {
389:                PageManager p = getPageManagerForPage(blockRef);
390:                return new BlockAccess(p, blockRef);
391:            }
392:
393:            /**
394:             * Return the head of the free list, or grow the tail of the file.
395:             * @return the number of an available block.
396:             */
397:            public long newPage() throws IOException {
398:                synchronized (fileLock) {
399:                    Block root = getBlock(0);
400:                    long ref;
401:                    try {
402:                        ref = root.readLong(oFREELIST);
403:                        if (ref < 0 || ref > lastBlock) {
404:                            throw new IOException(this  + "newPage(), bad ref: "
405:                                    + ref + ", lastBlock = " + lastBlock);
406:                        }
407:                        if (ref != 0) {
408:                            Block newPage = getBlock(ref);
409:                            try {
410:                                root.writeLong(oFREELIST, newPage.readLong(0));
411:                                //newPage.writeLong(0, 0);
412:                                newPage.clear();
413:                            } finally {
414:                                newPage.decrRefCount();
415:                            }
416:                        } else {
417:                            ref = root.readLong(oLASTBLOCK);
418:                            Block newPage = getBlock(ref);
419:                            try {
420:                                newPage.clear();
421:                            } finally {
422:                                newPage.decrRefCount();
423:                            }
424:                            lastBlock = ref + 1;
425:                            root.writeLong(oLASTBLOCK, lastBlock);
426:                        }
427:                    } finally {
428:                        root.decrRefCount();
429:                    }
430:                    //#ifdef DEBUG
431:                    if (Trace.bit(5)) {
432:                        Debug.println(toString() + ".newPage() = " + ref + "");
433:                    }
434:                    //#endif
435:                    return ref;
436:                }
437:            }
438:
439:            /**
440:             * Add this block to the free list.
441:             *
442:             * @param ref the number of the now free block.
443:             */
444:            public void freePage(long ref) throws IOException {
445:                PageManager p = getPageManagerForPage(ref);
446:                if (p != this ) {
447:                    p.freePage(ref);
448:                } else
449:                    synchronized (fileLock) {
450:                        //#ifdef DEBUG
451:                        if (Trace.bit(5)) {
452:                            Debug
453:                                    .println(toString() + ".freePage(" + ref
454:                                            + ")");
455:                        }
456:                        //#endif
457:                        if (ref <= 0 || ref > lastBlock) {
458:                            throw new IOException("bad ref");
459:                        }
460:                        Block blk = getBlock(ref);
461:                        try {
462:                            blk.getDataAndReset();
463:
464:                            Block root = getBlock(0);
465:                            try {
466:                                long freeList = root.readLong(oFREELIST);
467:                                blk.writeLong(0, freeList);
468:                                root.writeLong(oFREELIST, ref);
469:                            } finally {
470:                                root.decrRefCount();
471:                            }
472:                        } finally {
473:                            blk.decrRefCount();
474:                        }
475:                    }
476:            }
477:
478:            static int getPageOffset(PageManager pm, long ref) {
479:                int psize = pm.getPageSize();
480:                int pnum = (int) (SubPageManager.fExt(ref,
481:                        SubPageManager.PAGE_NUM));
482:                return pnum * psize;
483:            }
484:
485:            static long getPageBlock(long ref) {
486:                return SubPageManager.pageBlock(ref);
487:            }
488:
489:            static final boolean quick = true;
490:
491:            /**
492:             * Create a new segment with the specified bytes value and return
493:             * its reference
494:             *
495:             * @param buf the value to write to the new segment
496:             * @return the segment id
497:             */
498:            public long putBytes(byte[] buf) throws IOException {
499:                PageManager pm = getPageManagerForLen(buf.length);
500:                long seg = pm.newPage();
501:                if (quick && (buf.length + 8) < pm.getPageSize()) {
502:                    int off = getPageOffset(pm, seg);
503:                    long blk = getPageBlock(seg);
504:                    synchronized (fileLock) {
505:                        Block b = getBlock(blk);
506:                        try {
507:                            b.writeLong(off, buf.length);
508:                            b.write(off + 8, buf, 0, buf.length);
509:                        } finally {
510:                            b.decrRefCount();
511:                        }
512:                    }
513:                } else {
514:                    synchronized (fileLock) {
515:                        ba.init(pm, seg);
516:                        ba.resize(buf.length);
517:                        ba.write(0, buf, 0, buf.length);
518:                    }
519:                }
520:                //         Debug.println("BlockFile.putBytes(" + SubPageManager.toString(seg) + "): " +
521:                //                       Util.strBytes(buf, 0, 16));
522:                //         Debug.println(Util.stackTrace());
523:                return seg;
524:            }
525:
526:            BlockAccess ba = new BlockAccess();
527:
528:            /**
529:             * Return the segment as a byte array
530:             *
531:             * @param seg the segment id
532:             * @return the value of the segment's bytes
533:             */
534:            public byte[] getBytes(long seg) throws IOException {
535:                PageManager pm = getPageManagerForPage(seg);
536:                byte[] buf = null;
537:                int off = getPageOffset(pm, seg);
538:                long blk = getPageBlock(seg);
539:                synchronized (fileLock) {
540:                    if (quick) {
541:                        Block b = getBlock(blk);
542:                        try {
543:                            int len = (int) b.readLong(off);
544:                            if (len + 8 < pm.getPageSize()) {
545:                                buf = new byte[len];
546:                                b.read(off + 8, buf, 0, len);
547:                            }
548:                        } finally {
549:                            b.decrRefCount();
550:                        }
551:                    }
552:                    if (buf == null) {
553:                        ba.init(pm, seg);
554:                        buf = new byte[(int) (ba.size())];
555:                        ba.read(0, buf, 0, buf.length);
556:                    }
557:                }
558:                //         Debug.println("BlockFile.getBytes(" +
559:                //                       SubPageManager.toString(seg) + "): " +
560:                //                       Util.strBytes(buf, 0, 16) + " @ " + Util.stackTrace());
561:                return buf;
562:            }
563:
564:            /**
565:             * Update a segment with new value bytes.
566:             *
567:             * @param buf the value to write to the segment
568:             * @param seg the segment id
569:             */
570:            public void updateBytes(long seg, byte[] buf) throws IOException {
571:                //         Debug.println("BlockFile.updateBytes(" + SubPageManager.toString(seg) +
572:                //                       "): " + Util.strBytes(buf, 0, 16));
573:                //         Debug.println(Util.stackTrace());
574:                PageManager pm = getPageManagerForPage(seg);
575:                synchronized (fileLock) {
576:                    if (quick && (buf.length + 8) < pm.getPageSize()) {
577:                        Block b = getBlock(getPageBlock(seg));
578:                        try {
579:                            int off = getPageOffset(pm, seg);
580:                            long oldLen = b.readLong(off);
581:                            if ((oldLen + 8) < pm.getPageSize()) {
582:                                b.writeLong(off, buf.length);
583:                                b.write(off + 8, buf, 0, buf.length);
584:                                return;
585:                            }
586:                        } finally {
587:                            b.decrRefCount();
588:                        }
589:                    }
590:
591:                    ba.init(pm, seg);
592:                    if (ba.size() != buf.length) {
593:                        ba.resize(buf.length);
594:                    }
595:                    ba.write(0, buf, 0, buf.length);
596:                }
597:            }
598:
599:            /**
600:             * Destroy the stream with the specified root page and free up the
601:             * storage it was using.
602:             *
603:             * @param page the root page of the region
604:             *
605:             * @exception IOException if the page number isn't valid, or if another
606:             *		error is detected trying to access the region.
607:             */
608:            public void freeStream(long page) throws IOException {
609:                synchronized (fileLock) {
610:                    getStream(page).resize(0);
611:                    freePage(page);
612:                }
613:            }
614:
615:            public void freeSegment(long seg) throws IOException {
616:                freeStream(seg);
617:            }
618:
619:            /**
620:             * Return a new input stream, reading from the region with the specified
621:             * root block.
622:             *
623:             * @param block the root block of the region
624:             * @return an InputStream bound to the region.
625:             * @exception IOException if the block number isn't valid, or if another
626:             *		error is detected trying to access the region.
627:             */
628:            public RandomAccessInputStream getInputStream(long block)
629:                    throws IOException {
630:                return new RandomAccessInputStream(getStream(block));
631:            }
632:
633:            /**
634:             * Return a new output stream, writing to the region with the specified
635:             * root block.
636:             *
637:             * @param block the root block of the region
638:             * @return an OutputStream bound to the region.
639:             * @exception IOException if the block number isn't valid, or if another
640:             *		error is detected trying to access the region.
641:             */
642:            public RandomAccessOutputStream getOutputStream(long block)
643:                    throws IOException {
644:                return new RandomAccessOutputStream(getStream(block));
645:            }
646:
647:            /**
648:             * Return the specified sub-page manager
649:             */
650:            public PageManager getPageManager(int i) throws IOException {
651:                if (i < 0 || i > maxPageShift) {
652:                    throw new IOException("Bad page shift: " + i);
653:                }
654:                PageManager pm = pageManagers[i];
655:                if (pm == null) {
656:                    pageManagers[i] = pm = new SubPageManager(this , i, 0);
657:                }
658:                return pm;
659:            }
660:
661:            public PageManager getPageManagerForPage(long page)
662:                    throws IOException {
663:                return getPageManager(SubPageManager.pageShift(page));
664:            }
665:
666:            public PageManager getPageManagerForLen(long len)
667:                    throws IOException {
668:                int pageShift = 0;
669:                int siz = blockSize >> 1;
670:                while (len < siz && pageShift < maxPageShift - 1) {
671:                    siz >>= 1;
672:                    pageShift++;
673:                }
674:                if (pageShift > 0) {
675:                    pageShift--;
676:                }
677:                return getPageManager(pageShift);
678:            }
679:
680:            public void revert() throws IOException {
681:                cache.revert();
682:                Block root = getBlock(0);
683:                try {
684:                    this .lastBlock = root.readLong(oLASTBLOCK);
685:                } finally {
686:                    root.decrRefCount();
687:                }
688:                store.setLength(this .lastBlock * blockSize);
689:            }
690:
691:            public void showCache(PrintWriter os) {
692:                cache.show(os);
693:            }
694:
695:            public String toString() {
696:                return "BlockFile(" + store + ")";
697:            }
698:
699:            public void clearModified() throws IOException {
700:                store.clearModified();
701:            }
702:
703:            public long getSize() {
704:                return lastBlock * blockSize;
705:            }
706:
707:            public Object getLock() {
708:                return fileLock;
709:            }
710:
711:            public int getBlockSize() {
712:                return blockSize;
713:            }
714:
715:            /**
716:             * Return the specified persistent object from the store
717:             * @param ref the block number of the object's root
718:             * @return the object
719:             * @exception IOException may be thrown
720:             */
721:            public Object getObject(long ref) throws IOException {
722:                Object ret = null;
723:                synchronized (fileLock) {
724:                    if (inMemory) {
725:                        ret = memoryObjects.get(ref);
726:                    } else {
727:                        try {
728:                            byte[] buf = getBytes(ref);
729:                            mbis.reset(buf);
730:                            ret = ois.readObject();
731:                        } catch (ClassNotFoundException e) {
732:                            throw new DatafileException(e);
733:                        }
734:                    }
735:                }
736:                //Debug.println(this + ".getObject(" + ref + "): " + ret);
737:                return ret;
738:            }
739:
740:            /**
741:             * Write a new object to the store and return its reference
742:             * @param obj the object
743:             * @return the block number of the object's root
744:             * @exception IOException may be thrown
745:             */
746:            public long putObject(Object obj) throws IOException {
747:                synchronized (fileLock) {
748:                    if (inMemory) {
749:                        memoryObjects.put(++memObjectCount, obj);
750:                        //Debug.println(this + ".put(" + obj + ") = " + memObjectCount);
751:                        return memObjectCount;
752:                    }
753:                    bos.reset();
754:                    oos.writeObject(obj);
755:                    oos.flush();
756:                    byte[] buf = bos.toByteArray();
757:                    long ret = putBytes(buf);
758:                    return ret;
759:                }
760:            }
761:
762:            /**
763:             * Write a new version of a persistent object to the store.
764:             * @param blockNum the address of the object's root page in the store
765:             * @param obj the new object value
766:             *
767:             * @exception IOException may be thrown
768:             */
769:            public void updateObject(long seg, Object obj) throws IOException {
770:                //Debug.println(this + ".updateObject(" + seg + "): " + obj);
771:                synchronized (fileLock) {
772:                    if (inMemory) {
773:                        memoryObjects.put(seg, obj);
774:                    } else {
775:                        bos.reset();
776:                        oos.writeObject(obj);
777:                        oos.flush();
778:                        byte[] buf = bos.toByteArray();
779:                        updateBytes(seg, buf);
780:                    }
781:                }
782:            }
783:
784:            /**
785:             * Remove an object from the store
786:             * @param ref the block number of the object's root
787:             *
788:             * @exception IOException may be thrown
789:             */
790:            public void removeObject(long ref) throws IOException {
791:                //Debug.println(toString() + ".removeObject(" + ref + ")");
792:                synchronized (fileLock) {
793:                    if (inMemory) {
794:                        memoryObjects.remove(ref);
795:                    } else {
796:                        freeSegment(ref);
797:                    }
798:                }
799:            }
800:
801:            //#ifdef DEBUG
802:            public void dump() throws IOException {
803:                Block root = getBlock(0);
804:                try {
805:                    Debug.println("Magic:         "
806:                            + Integer.toHexString(root.readShort(0)));
807:                    Debug.println("Major version: " + root.readByte(2));
808:                    Debug.println("Minor version: " + root.readByte(3));
809:                    Debug.println("Block Size:    " + root.readInt(oBLOCKSIZE));
810:                    Debug.println("FreeList:      " + root.readLong(oFREELIST));
811:                    java.util.BitSet free = new java.util.BitSet();
812:                    for (long ref = root.readLong(oFREELIST); ref != 0;) {
813:                        free.set((int) ref);
814:                        Block newPage = getBlock(ref);
815:                        try {
816:                            ref = newPage.readLong(0);
817:                        } finally {
818:                            newPage.decrRefCount();
819:                        }
820:                    }
821:                    int first = -2;
822:                    int last = -2;
823:                    for (int i = free.nextSetBit(0); i >= 0; i = free
824:                            .nextSetBit(i + 1)) {
825:                        if (i != last + 1) {
826:                            if (first >= 0) {
827:                                if (first == last) {
828:                                    Debug.println("Free: " + first);
829:                                } else {
830:                                    Debug.println("Free: " + first + " - "
831:                                            + last);
832:                                }
833:                            }
834:                            first = i;
835:                            last = i;
836:                        }
837:                    }
838:                    if (first >= 0) {
839:                        if (first == last) {
840:                            Debug.println("Free: " + first);
841:                        } else {
842:                            Debug.println("Free: " + first + " - " + last);
843:                        }
844:                    }
845:                    long lastBlock_ = root.readLong(oLASTBLOCK);
846:                    Debug
847:                            .println("Last Block:    "
848:                                    + root.readLong(oLASTBLOCK));
849:                    long waste = free.cardinality() * blockSize;
850:                    long total = lastBlock_ * blockSize;
851:                    double pct = 100 * ((double) waste) / ((double) total);
852:                    String pcts = java.text.NumberFormat.getInstance().format(
853:                            pct);
854:                    Debug.println("Fragmentation: " + free.cardinality()
855:                            + " of " + lastBlock_ + " blocks =  " + pcts
856:                            + "% waste");
857:                    Debug
858:                            .println("Last Block:    "
859:                                    + root.readLong(oLASTBLOCK));
860:                    for (int i = 0; i < MAX_STREAM; i++) {
861:                        Debug.println("Stream " + i + ":      "
862:                                + root.readLong(oSTREAM_START + i * REF_SIZE));
863:                    }
864:                    byte[] hp = new byte[oHASH_PASSWD_len];
865:                    root.read(oHASH_PASSWD_start, hp, 0, oHASH_PASSWD_len);
866:                    Debug.println("Hash Passwd:   " + Util.hexBytes(hp));
867:                    for (int i = 0; i < 16; i++) {
868:                        Debug.println("PM "
869:                                + i
870:                                + " root:    "
871:                                + SubPageManager
872:                                        .toString(root.readLong(oSUBPAGE_ROOT
873:                                                + i * REF_SIZE)));
874:                    }
875:                } finally {
876:                    root.decrRefCount();
877:                }
878:            }
879:
880:            public static void main(String[] args) {
881:                try {
882:                    BlockFile f = new BlockFile(args[0], "r", new Properties(),
883:                            8192, 256);
884:                    f.dump();
885:                } catch (Throwable t) {
886:                    Debug.print(t);
887:                }
888:            }
889:
890:            //#endif
891:        }
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