Examples with LogEntryCursor org.neo4j.kernel.impl.transaction.log.LogEntryCursor used on opensource projects

Example 6 with LogEntryCursor

use of org.neo4j.kernel.impl.transaction.log.LogEntryCursor in project neo4j by neo4j.

the class LogTestUtils method assertLogContains.

public static void assertLogContains(FileSystemAbstraction fileSystem, String logPath, LogEntry... expectedEntries) throws IOException {
    try (LogEntryCursor cursor = openLog(fileSystem, new File(logPath))) {
        int entryNo = 0;
        while (cursor.next()) {
            assertTrue("The log contained more entries than we expected!", entryNo < expectedEntries.length);
            LogEntry expectedEntry = expectedEntries[entryNo];
            assertEquals("Unexpected entry at entry number " + entryNo, cursor.get(), expectedEntry);
            entryNo++;
        }
        if (entryNo < expectedEntries.length) {
            fail("Log ended prematurely. Expected to find '" + expectedEntries[entryNo].toString() + "' as log entry number " + entryNo + ", instead there were no more log entries.");
        }
    }
}

Example 7 with LogEntryCursor

use of org.neo4j.kernel.impl.transaction.log.LogEntryCursor in project neo4j by neo4j.

the class LogMatchers method logEntries.

public static List<LogEntry> logEntries(FileSystemAbstraction fileSystem, String logPath) throws IOException {
    File logFile = new File(logPath);
    StoreChannel fileChannel = fileSystem.open(logFile, "r");
    // Always a header
    LogHeader header = readLogHeader(ByteBuffer.allocateDirect(LOG_HEADER_SIZE), fileChannel, true, logFile);
    // Read all log entries
    PhysicalLogVersionedStoreChannel versionedStoreChannel = new PhysicalLogVersionedStoreChannel(fileChannel, header.logVersion, header.logFormatVersion);
    ReadableLogChannel logChannel = new ReadAheadLogChannel(versionedStoreChannel, NO_MORE_CHANNELS);
    LogEntryCursor logEntryCursor = new LogEntryCursor(new VersionAwareLogEntryReader<>(), logChannel);
    return Iterables.asList(new IOCursorAsResourceIterable<>(logEntryCursor));
}

Example 8 with LogEntryCursor

use of org.neo4j.kernel.impl.transaction.log.LogEntryCursor in project neo4j by neo4j.

the class LatestCheckPointFinder method find.

public LatestCheckPoint find(long fromVersionBackwards) throws IOException {
    long version = fromVersionBackwards;
    long versionToSearchForCommits = fromVersionBackwards;
    LogEntryStart latestStartEntry = null;
    LogEntryStart oldestStartEntry = null;
    long oldestVersionFound = -1;
    while (version >= INITIAL_LOG_VERSION) {
        LogVersionedStoreChannel channel = PhysicalLogFile.tryOpenForVersion(logFiles, fileSystem, version, false);
        if (channel == null) {
            break;
        }
        oldestVersionFound = version;
        CheckPoint latestCheckPoint = null;
        ReadableLogChannel recoveredDataChannel = new ReadAheadLogChannel(channel, NO_MORE_CHANNELS);
        boolean firstStartEntry = true;
        try (LogEntryCursor cursor = new LogEntryCursor(logEntryReader, recoveredDataChannel)) {
            LogEntry entry;
            while (cursor.next()) {
                entry = cursor.get();
                if (entry instanceof CheckPoint) {
                    latestCheckPoint = entry.as();
                }
                if (entry instanceof LogEntryStart) {
                    LogEntryStart startEntry = entry.as();
                    if (version == versionToSearchForCommits) {
                        latestStartEntry = startEntry;
                    }
                    // Oldest start entry will be the first in the last log version scanned.
                    if (firstStartEntry) {
                        oldestStartEntry = startEntry;
                        firstStartEntry = false;
                    }
                }
            }
        }
        if (latestCheckPoint != null) {
            return latestCheckPoint(fromVersionBackwards, version, latestStartEntry, oldestVersionFound, latestCheckPoint);
        }
        version--;
        // if we have found no commits in the latest log, keep searching in the next one
        if (latestStartEntry == null) {
            versionToSearchForCommits--;
        }
    }
    boolean commitsAfterCheckPoint = oldestStartEntry != null;
    long firstTxAfterPosition = commitsAfterCheckPoint ? extractFirstTxIdAfterPosition(oldestStartEntry.getStartPosition(), fromVersionBackwards) : LatestCheckPoint.NO_TRANSACTION_ID;
    return new LatestCheckPoint(null, commitsAfterCheckPoint, firstTxAfterPosition, oldestVersionFound);
}

Example 9 with LogEntryCursor

use of org.neo4j.kernel.impl.transaction.log.LogEntryCursor in project neo4j by neo4j.

the class LatestCheckPointFinder method extractFirstTxIdAfterPosition.

/**
     * Extracts txId from first commit entry, when starting reading at the given {@code position}.
     * If no commit entry found in the version, the reader will continue into next version(s) up till
     * {@code maxLogVersion} until finding one.
     *
     * @param initialPosition {@link LogPosition} to start scan from.
     * @param maxLogVersion max log version to scan.
     * @return txId of closes commit entry to {@code initialPosition}, or {@link LatestCheckPoint#NO_TRANSACTION_ID}
     * if not found.
     * @throws IOException on I/O error.
     */
private long extractFirstTxIdAfterPosition(LogPosition initialPosition, long maxLogVersion) throws IOException {
    LogPosition currentPosition = initialPosition;
    while (currentPosition.getLogVersion() <= maxLogVersion) {
        LogVersionedStoreChannel storeChannel = PhysicalLogFile.tryOpenForVersion(logFiles, fileSystem, currentPosition.getLogVersion(), false);
        if (storeChannel != null) {
            try {
                storeChannel.position(currentPosition.getByteOffset());
                try (ReadAheadLogChannel logChannel = new ReadAheadLogChannel(storeChannel, NO_MORE_CHANNELS);
                    LogEntryCursor cursor = new LogEntryCursor(logEntryReader, logChannel)) {
                    while (cursor.next()) {
                        LogEntry entry = cursor.get();
                        if (entry instanceof LogEntryCommit) {
                            return ((LogEntryCommit) entry).getTxId();
                        }
                    }
                }
            } finally {
                storeChannel.close();
            }
        }
        currentPosition = LogPosition.start(currentPosition.getLogVersion() + 1);
    }
    return LatestCheckPoint.NO_TRANSACTION_ID;
}

Example 10 with LogEntryCursor

use of org.neo4j.kernel.impl.transaction.log.LogEntryCursor in project neo4j by neo4j.

the class CheckTxLogs method scan.

private <C extends Command, R extends AbstractBaseRecord> boolean scan(PhysicalLogFiles logFiles, InconsistenciesHandler handler, CheckType<C, R> check, boolean checkTxIds) throws IOException {
    out.println("Checking logs for " + check.name() + " inconsistencies");
    CommittedRecords<R> state = new CommittedRecords<>(check);
    List<CommandAndLogVersion> txCommands = new ArrayList<>();
    boolean validLogs = true;
    long commandsRead = 0;
    long lastSeenTxId = BASE_TX_ID;
    try (LogEntryCursor logEntryCursor = LogTestUtils.openLogs(fs, logFiles)) {
        while (logEntryCursor.next()) {
            LogEntry entry = logEntryCursor.get();
            if (entry instanceof LogEntryCommand) {
                StorageCommand command = ((LogEntryCommand) entry).getXaCommand();
                if (check.commandClass().isInstance(command)) {
                    long logVersion = logEntryCursor.getCurrentLogVersion();
                    txCommands.add(new CommandAndLogVersion(command, logVersion));
                }
            } else if (entry instanceof LogEntryCommit) {
                long txId = ((LogEntryCommit) entry).getTxId();
                if (checkTxIds) {
                    validLogs &= checkNoDuplicatedTxsInTheLog(lastSeenTxId, txId, handler);
                    lastSeenTxId = txId;
                }
                for (CommandAndLogVersion txCommand : txCommands) {
                    validLogs &= checkAndHandleInconsistencies(txCommand, check, state, txId, handler);
                }
                txCommands.clear();
            }
            commandsRead++;
        }
    }
    out.println("Processed " + commandsRead + " commands");
    out.println(state);
    if (!txCommands.isEmpty()) {
        out.println("Found " + txCommands.size() + " uncommitted commands at the end.");
        for (CommandAndLogVersion txCommand : txCommands) {
            validLogs &= checkAndHandleInconsistencies(txCommand, check, state, -1, handler);
        }
        txCommands.clear();
    }
    return validLogs;
}