LogFileManager xref

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    1   /***
    2    *
    3    * Copyright 2004 Hiram Chirino
    4    *
    5    * Licensed under the Apache License, Version 2.0 (the "License");
    6    * you may not use this file except in compliance with the License.
    7    * You may obtain a copy of the License at
    8    *
    9    * http://www.apache.org/licenses/LICENSE-2.0
    10   *
    11   * Unless required by applicable law or agreed to in writing, software
    12   * distributed under the License is distributed on an "AS IS" BASIS,
    13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    14   * See the License for the specific language governing permissions and
    15   * limitations under the License.
    16   *
    17   **/
    18  package org.activeio.journal.active;
    19
    20  import java.io.DataInput;
    21  import java.io.DataInputStream;
    22  import java.io.DataOutput;
    23  import java.io.DataOutputStream;
    24  import java.io.File;
    25  import java.io.IOException;
    26  import java.nio.ByteBuffer;
    27  import java.text.NumberFormat;
    28
    29  import org.activeio.Packet;
    30  import org.activeio.adapter.PacketInputStream;
    31  import org.activeio.adapter.PacketOutputStream;
    32  import org.activeio.journal.InvalidRecordLocationException;
    33  import org.activeio.packet.ByteArrayPacket;
    34  import org.activeio.packet.ByteBufferPacket;
    35
    36  import EDU.oswego.cs.dl.util.concurrent.SynchronizedInt;
    37
    38  /***
    39   * Provides a logical view of many seperate files as one single long log file.
    40   * The seperate files that compose the LogFile are Segements of the LogFile.
    41   * <p/>This class is not thread safe.
    42   *
    43   * @version $Revision: 1.1 $
    44   */
    45  final public class LogFileManager {
    46
    47      public static final int DEFAULT_LOGFILE_COUNT = Integer.parseInt(System.getProperty("org.activeio.journal.active.DefaultLogFileCount", ""+(2)));
    48      public static final int DEFAULT_LOGFILE_SIZE = Integer.parseInt(System.getProperty("org.activeio.journal.active.DefaultLogFileSize", ""+(1024*1024*20)));
    49
    50      static final public int SERIALIZED_SIZE = 6+Location.SERIALIZED_SIZE;
    51
    52      static final public byte DATA_RECORD_TYPE = 1;
    53      static final public byte MARK_RECORD_TYPE = 2;
    54      static final private NumberFormat onlineLogNameFormat = NumberFormat.getNumberInstance();
    55      static {
    56          onlineLogNameFormat.setMinimumIntegerDigits(3);
    57          onlineLogNameFormat.setMaximumIntegerDigits(3);
    58          onlineLogNameFormat.setGroupingUsed(false);
    59          onlineLogNameFormat.setParseIntegerOnly(true);
    60          onlineLogNameFormat.setMaximumFractionDigits(0);
    61      }
    62
    63      // Config
    64      private final File logDirectory;
    65      private final int initialLogFileSize;
    66      private final int onlineLogFileCount;
    67      private final SynchronizedInt activeLogFileCount = new SynchronizedInt(0);
    68
    69      // Keeps track of the online log file.
    70      private LogFileNode firstNode;
    71      private LogFileNode firstActiveNode;
    72      private LogFileNode firstInactiveNode;
    73      private LogFileNode appendNode;
    74
    75      private ControlFile controlFile;
    76      private int lastLogFileId = -1;
    77      private Location lastMark;
    78      private boolean disposed;
    79      private boolean loadedFromCleanShutDown;
    80
    81
    82      public LogFileManager(File logDirectory) throws IOException {
    83          this(logDirectory, DEFAULT_LOGFILE_COUNT, DEFAULT_LOGFILE_SIZE);
    84      }
    85
    86      public LogFileManager(File logDirectory, int onlineLogFileCount, int initialLogFileSize) throws IOException {
    87          this.logDirectory = logDirectory;
    88          this.onlineLogFileCount = onlineLogFileCount;
    89          this.initialLogFileSize = initialLogFileSize;
    90          initialize(onlineLogFileCount);
    91      }
    92
    93      void initialize(int onlineLogFileCount) throws IOException {
    94
    95          LogFileNode logFiles[] = new LogFileNode[onlineLogFileCount];
    96
    97          // Create the log directory if it does not exist.
    98          if (!logDirectory.exists()) {
    99              if (!logDirectory.mkdirs()) {
    100                 throw new IOException("Could not create directory: " + logDirectory);
    101             }
    102         }
    103
    104         // Open the control file.
    105         int controlDataSize = SERIALIZED_SIZE + (LogFileNode.SERIALIZED_SIZE*onlineLogFileCount);
    106         controlFile = new ControlFile(new File(logDirectory, "control.dat"),  controlDataSize);
    107         // Make sure we are the only process using the control file.
    108         controlFile.lock();
    109
    110         // Initialize the nodes.
    111         for (int i = 0; i < onlineLogFileCount; i++) {
    112             LogFile file = new LogFile(new File(logDirectory, "log-" + onlineLogNameFormat.format(i) + ".dat"),
    113                     initialLogFileSize);
    114             logFiles[i] = new LogFileNode(file);
    115         }
    116
    117         // Link the nodes together.
    118         for (int i = 0; i < onlineLogFileCount; i++) {
    119             if (i == (onlineLogFileCount - 1)) {
    120                 logFiles[i].setNext(logFiles[0]);
    121             } else {
    122                 logFiles[i].setNext(logFiles[i + 1]);
    123             }
    124         }
    125
    126         firstNode = logFiles[0];
    127         loadState();
    128
    129         // Find the first active node
    130         for (int i = 0; i < onlineLogFileCount; i++) {
    131             if( logFiles[i].isActive() ) {
    132                 if( firstActiveNode == null || logFiles[i].getId() < firstActiveNode.getId() ) {
    133                     firstActiveNode = logFiles[i];
    134                 }
    135             }
    136         }
    137
    138         // None was active? activate one.
    139         if ( firstActiveNode == null ) {
    140             firstInactiveNode = logFiles[0];
    141             activateNextLogFile();
    142         } else {
    143             // Find the append log and the first inactive node
    144             firstInactiveNode = null;
    145             LogFileNode log = firstActiveNode;
    146             do {
    147                 if( !log.isActive() ) {
    148                     firstInactiveNode = log;
    149                     break;
    150                 } else {
    151                     appendNode = log;
    152                 }
    153                 log = log.getNext();
    154             } while (log != firstActiveNode);
    155         }
    156
    157         // If we did not have a clean shut down then we have to check the state
    158         // of the append log.
    159         if( !this.loadedFromCleanShutDown ) {
    160             checkAppendLog();
    161         }
    162
    163         loadedFromCleanShutDown = false;
    164         storeState();
    165     }
    166
    167     private void checkAppendLog() throws IOException {
    168
    169         // We are trying to get the true append offset and the last Mark that was written in
    170         // the append log.
    171
    172         int offset = 0;
    173         Record record = new Record();
    174         LogFile logFile = appendNode.getLogFile();
    175         Location markLocation=null;
    176
    177         while( logFile.loadAndCheckRecord(offset, record) ) {
    178
    179             if( record.getLocation().getLogFileId()!= appendNode.getId() || record.getLocation().getLogFileOffset()!=offset ) {
    180                 // We must have run past the end of the append location.
    181                 break;
    182             }
    183
    184             if ( record.getRecordType()==LogFileManager.MARK_RECORD_TYPE) {
    185                 markLocation = record.getLocation();
    186             }
    187
    188             offset += record.getRecordLength();
    189         }
    190
    191         appendNode.setAppendOffset(offset);
    192
    193         if( markLocation!=null ) {
    194             try {
    195                 Packet packet = readPacket(markLocation);
    196                 markLocation = Location.readFromPacket(packet);
    197             } catch (InvalidRecordLocationException e) {
    198                 throw (IOException)new IOException(e.getMessage()).initCause(e);
    199             }
    200             updateMark(markLocation);
    201         }
    202
    203     }
    204
    205     private void storeState() throws IOException {
    206         Packet controlData = controlFile.getControlData();
    207         if( controlData.remaining() == 0 )
    208             return;
    209
    210         DataOutput data = new DataOutputStream(new PacketOutputStream(controlData));
    211
    212         data.writeInt(lastLogFileId);
    213         data.writeBoolean(lastMark!=null);
    214         if( lastMark!=null )
    215             lastMark.writeToDataOutput(data);
    216         data.writeBoolean(loadedFromCleanShutDown);
    217
    218         // Load each node's state
    219         LogFileNode log = firstNode;
    220         do {
    221             log.writeExternal( data );
    222             log = log.getNext();
    223         } while (log != firstNode);
    224
    225         controlFile.store();
    226     }
    227
    228     private void loadState() throws IOException {
    229         if( controlFile.load() ) {
    230             Packet controlData = controlFile.getControlData();
    231             if( controlData.remaining() == 0 )
    232                 return;
    233
    234             DataInput data = new DataInputStream(new PacketInputStream(controlData));
    235
    236             lastLogFileId =data.readInt();
    237             if( data.readBoolean() )
    238                 lastMark = Location.readFromDataInput(data);
    239             else
    240                 lastMark = null;
    241             loadedFromCleanShutDown = data.readBoolean();
    242
    243             // Load each node's state
    244             LogFileNode log = firstNode;
    245             do {
    246                 log.readExternal( data );
    247                 log = log.getNext();
    248             } while (log != firstNode);
    249         }
    250     }
    251
    252     public void dispose() {
    253
    254         if (disposed)
    255             return;
    256         this.disposed = true;
    257
    258         try {
    259 	        // Close all the opened log files.
    260 	        LogFileNode log = firstNode;
    261 	        do {
    262 	            log.getLogFile().dispose();
    263 	            log = log.getNext();
    264 	        } while (log != firstNode);
    265
    266 	        loadedFromCleanShutDown=true;
    267 	        storeState();
    268 	        controlFile.dispose();
    269         } catch ( IOException e ) {
    270         }
    271
    272     }
    273
    274     private int getNextLogFileId() {
    275         return ++lastLogFileId;
    276     }
    277
    278     /***
    279      * @param write
    280      * @throws IOException
    281      */
    282     public void append(BatchedWrite write) throws IOException {
    283
    284         if (!appendNode.isActive())
    285             throw new IllegalStateException("Log file is not active.  Writes are not allowed");
    286         if (appendNode.isReadOnly())
    287             throw new IllegalStateException("Log file has been marked Read Only.  Writes are not allowed");
    288
    289         // Write and force the data to disk.
    290         LogFile logFile = appendNode.getLogFile();
    291         ByteBuffer buffer = ((ByteBufferPacket)write.getPacket().narrow(ByteBufferPacket.class)).getByteBuffer();
    292         int size = buffer.remaining();
    293         logFile.write(appendNode.getAppendOffset(), buffer);
    294         if( write.getForce() )
    295             logFile.force();
    296
    297         // Update state
    298         appendNode.appended(size);
    299         if (write.getMark() != null) {
    300             updateMark(write.getMark());
    301         }
    302     }
    303
    304     /***
    305      * @param write
    306      * @throws IOException
    307      */
    308     synchronized private void updateMark(Location mark) throws IOException {
    309         // If we wrote a mark we may need to deactivate some log files.
    310         this.lastMark = mark;
    311         while (firstActiveNode != appendNode) {
    312             if (firstActiveNode.getId() < lastMark.getLogFileId()) {
    313                 firstActiveNode.setActive(false);
    314                 activeLogFileCount.decrement();
    315                 if( firstInactiveNode ==null )
    316                     firstInactiveNode = firstActiveNode;
    317                 firstActiveNode = firstActiveNode.getNextActive();
    318             } else {
    319                 break;
    320             }
    321         }
    322     }
    323
    324     RecordInfo readRecordInfo(Location location) throws IOException, InvalidRecordLocationException {
    325
    326         LogFileNode logFileState = getLogFileWithId(location.getLogFileId());
    327         // There can be no record at the append offset.
    328         if (logFileState.getAppendOffset() == location.getLogFileOffset()) {
    329             throw new InvalidRecordLocationException("No record at (" + location
    330                     + ") found.  Location past end of logged data.");
    331         }
    332
    333         // Is there a record header at the seeked location?
    334         try {
    335             LogFile logFile = logFileState.getLogFile();
    336             Record header = new Record();
    337             logFile.readRecordHeader(location.getLogFileOffset(), header);
    338             return new RecordInfo(location, header, logFileState);
    339         } catch (IOException e) {
    340             throw new InvalidRecordLocationException("No record at (" + location + ") found.");
    341         }
    342     }
    343
    344     LogFileNode getLogFileWithId(int logFileId) throws InvalidRecordLocationException {
    345         for (LogFileNode lf = firstActiveNode; lf != null; lf = lf.getNextActive()) {
    346             if (lf.getId() == logFileId) {
    347                 return lf;
    348             }
    349
    350             // Short cut since id's will only increment
    351             if (logFileId < lf.getId())
    352                 break;
    353         }
    354         throw new InvalidRecordLocationException("Log file with id;" + logFileId + " is not active.");
    355     }
    356
    357     /***
    358      * @param lastLocation
    359      * @return
    360      */
    361     public Location getNextDataRecordLocation(Location lastLocation) throws IOException, InvalidRecordLocationException {
    362         RecordInfo ri = readRecordInfo(lastLocation);
    363         while (true) {
    364
    365             int logFileId = ri.getLocation().getLogFileId();
    366             int offset = ri.getNextLocation();
    367
    368             // Are we overflowing into next logFile?
    369             if (offset >= ri.getLogFileState().getAppendOffset()) {
    370                 LogFileNode nextActive = ri.getLogFileState().getNextActive();
    371                 if (nextActive == null) {
    372                     return null;
    373                 }
    374                 logFileId = nextActive.getId();
    375                 offset = 0;
    376             }
    377
    378             try {
    379                 ri = readRecordInfo(new Location(logFileId, offset));
    380             } catch (InvalidRecordLocationException e) {
    381                 return null;
    382             }
    383
    384             // Is the next record the right record type?
    385             if (ri.getHeader().getRecordType() == DATA_RECORD_TYPE) {
    386                 return ri.getLocation();
    387             }
    388             // No? go onto the next record.
    389         }
    390     }
    391
    392     /***
    393      * @param logFileIndex
    394      * @param logFileOffset
    395      * @return
    396      * @throws IOException
    397      * @throws InvalidRecordLocationException
    398      */
    399     public Packet readPacket(Location location) throws IOException, InvalidRecordLocationException {
    400
    401         // Is there a record header at the seeked location?
    402         RecordInfo recordInfo = readRecordInfo(location);
    403
    404         byte data[] = new byte[recordInfo.getHeader().getPayloadLength()];
    405
    406         LogFile logFile = recordInfo.getLogFileState().getLogFile();
    407         logFile.read(recordInfo.getDataOffset(), data);
    408
    409         return new ByteArrayPacket(data);
    410
    411     }
    412
    413     public int getInitialLogFileSize() {
    414         return initialLogFileSize;
    415     }
    416
    417     public Location getFirstActiveLogLocation() {
    418         if (firstActiveNode == null)
    419             return null;
    420         if (firstActiveNode.getAppendOffset() == 0)
    421             return null;
    422         return new Location(firstActiveNode.getId(), 0);
    423     }
    424
    425     void activateNextLogFile() throws IOException {
    426
    427         // The current append logFile becomes readonly
    428         if (appendNode != null) {
    429             appendNode.setReadOnly(true);
    430         }
    431
    432         LogFileNode next = firstInactiveNode;
    433         synchronized (this) {
    434             firstInactiveNode = firstInactiveNode.getNextInactive();
    435             next.activate(getNextLogFileId());
    436             if (firstActiveNode == null) {
    437                 firstActiveNode = next;
    438             }
    439         }
    440         activeLogFileCount.increment();
    441         appendNode = next;
    442
    443         storeState();
    444     }
    445
    446     /***
    447      * @return Returns the logDirectory.
    448      */
    449     public File getLogDirectory() {
    450         return logDirectory;
    451     }
    452
    453     /***
    454      * @return Returns the lastMark.
    455      */
    456     public Location getLastMarkedRecordLocation() {
    457         return lastMark;
    458     }
    459
    460     public Location getNextAppendLocation() {
    461         return new Location(appendNode.getId(), appendNode.getAppendOffset());
    462     }
    463
    464     /***
    465      * @return Returns the onlineLogFileCount.
    466      */
    467     public int getOnlineLogFileCount() {
    468         return onlineLogFileCount;
    469     }
    470
    471     public boolean isPastHalfActive() {
    472         return (onlineLogFileCount/2.f) < activeLogFileCount.get();
    473     }
    474
    475     synchronized  public Location getFirstRecordLocationOfSecondActiveLogFile() {
    476         return firstActiveNode.getNextActive().getFirstRecordLocation();
    477     }
    478
    479     synchronized public boolean canActivateNextLogFile() {
    480         return firstInactiveNode!=null;
    481     }
    482
    483 }