Examples with StoreChannel org.neo4j.io.fs.StoreChannel used on opensource projects

Example 16 with StoreChannel

use of org.neo4j.io.fs.StoreChannel in project neo4j by neo4j.

the class SegmentedRaftLogPartialEntryRecoveryTest method truncateAndRecover.

/**
     * Truncates and recovers the log file provided, one byte at a time until it reaches the header.
     * The reason the header is not truncated (and instead has its own test) is that if the log consists of
     * only one file (Segment) and the header is incomplete, that is correctly an exceptional circumstance and
     * is tested elsewhere.
     */
private void truncateAndRecover(File logFile, long truncateDownToSize) throws IOException, DamagedLogStorageException, DisposedException {
    StoreChannel lastFile = fsRule.get().open(logFile, "rw");
    long currentSize = lastFile.size();
    lastFile.close();
    RecoveryProtocol recovery;
    while (currentSize-- > truncateDownToSize) {
        lastFile = fsRule.get().open(logFile, "rw");
        lastFile.truncate(currentSize);
        lastFile.close();
        recovery = createRecoveryProtocol();
        recovery.run();
    }
}

Example 17 with StoreChannel

use of org.neo4j.io.fs.StoreChannel in project neo4j by neo4j.

the class RecoveryProtocolTest method createEmptyLogFile.

private void createEmptyLogFile(EphemeralFileSystemAbstraction fsa, long fileNameVersion) throws IOException {
    StoreChannel channel = fsa.open(fileNames.getForVersion(fileNameVersion), "w");
    channel.close();
}

Example 18 with StoreChannel

use of org.neo4j.io.fs.StoreChannel in project neo4j by neo4j.

the class SegmentedRaftLogPartialEntryRecoveryTest method shouldNotAppendAtTheEndOfLogFileWithIncompleteEntries.

@Test
public void shouldNotAppendAtTheEndOfLogFileWithIncompleteEntries() throws Throwable {
    // Given
    // we use a RaftLog to create a raft log file and then we will chop some bits off the end
    SegmentedRaftLog raftLog = createRaftLog(100_000);
    raftLog.start();
    raftLog.append(new RaftLogEntry(4, new NewLeaderBarrier()));
    raftLog.stop();
    // We use a temporary RecoveryProtocol to get the file to chop
    RecoveryProtocol recovery = createRecoveryProtocol();
    State recoveryState = recovery.run();
    String logFilename = recoveryState.segments.last().getFilename();
    File logFile = new File(logDirectory, logFilename);
    StoreChannel lastFile = fsRule.get().open(logFile, "rw");
    long currentSize = lastFile.size();
    lastFile.close();
    // When
    // We induce an incomplete entry at the end of the last file
    lastFile = fsRule.get().open(logFile, "rw");
    lastFile.truncate(currentSize - 1);
    lastFile.close();
    // We start the raft log again, on the previous log file with truncated last entry.
    raftLog = createRaftLog(100_000);
    //  Recovery will run here
    raftLog.start();
    // Append an entry
    raftLog.append(new RaftLogEntry(4, new NewLeaderBarrier()));
    // The log should report as containing only the last entry we've appended
    try (RaftLogCursor entryCursor = raftLog.getEntryCursor(0)) {
        // There should be exactly one entry, of type NewLeaderBarrier
        assertTrue(entryCursor.next());
        RaftLogEntry raftLogEntry = entryCursor.get();
        assertEquals(NewLeaderBarrier.class, raftLogEntry.content().getClass());
        assertFalse(entryCursor.next());
    }
}

Example 19 with StoreChannel

use of org.neo4j.io.fs.StoreChannel in project neo4j by neo4j.

the class PhysicalFlushableChannel method prepareForFlush.

/**
     * External synchronization between this method and close is required so that they aren't called concurrently.
     * Currently that's done by acquiring the PhysicalLogFile monitor.
     */
@Override
public Flushable prepareForFlush() throws IOException {
    buffer.flip();
    StoreChannel channel = this.channel;
    try {
        channel.writeAll(buffer);
    } catch (ClosedChannelException e) {
        handleClosedChannelException(e);
    }
    buffer.clear();
    return channel;
}

Example 20 with StoreChannel

use of org.neo4j.io.fs.StoreChannel in project neo4j by neo4j.

the class PhysicalLogFile method createLogChannelForVersion.

/**
     * Creates a new channel for the specified version, creating the backing file if it doesn't already exist.
     * If the file exists then the header is verified to be of correct version. Having an existing file there
     * could happen after a previous crash in the middle of rotation, where the new file was created,
     * but the incremented log version changed hadn't made it to persistent storage.
     *
     * @param forVersion log version for the file/channel to create.
     * @return {@link PhysicalLogVersionedStoreChannel} for newly created/opened log file.
     * @throws IOException if there's any I/O related error.
     */
private PhysicalLogVersionedStoreChannel createLogChannelForVersion(long forVersion) throws IOException {
    File toOpen = logFiles.getLogFileForVersion(forVersion);
    StoreChannel storeChannel = fileSystem.open(toOpen, "rw");
    LogHeader header = readLogHeader(headerBuffer, storeChannel, false, toOpen);
    if (header == null) {
        // Either the header is not there in full or the file was new. Don't care
        long lastTxId = lastCommittedId.get();
        writeLogHeader(headerBuffer, forVersion, lastTxId);
        logHeaderCache.putHeader(forVersion, lastTxId);
        storeChannel.writeAll(headerBuffer);
        monitor.opened(toOpen, forVersion, lastTxId, true);
    }
    byte formatVersion = header == null ? CURRENT_LOG_VERSION : header.logFormatVersion;
    return new PhysicalLogVersionedStoreChannel(storeChannel, forVersion, formatVersion);
}