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

Example 26 with StoreChannel

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

the class StoreMigratorCheckPointer method checkPoint.

/**
     * Write a check point in the log file with the given version
     * <p>
     * It will create the file with header containing the log version and lastCommittedTx given as arguments
     *
     * @param logVersion the log version to open
     * @param lastCommittedTx the last committed tx id
     */
public void checkPoint(long logVersion, long lastCommittedTx) throws IOException {
    PhysicalLogFiles logFiles = new PhysicalLogFiles(storeDir, fileSystem);
    File logFileForVersion = logFiles.getLogFileForVersion(logVersion);
    if (!fileSystem.fileExists(logFileForVersion)) {
        try (StoreChannel channel = fileSystem.create(logFileForVersion)) {
            writeLogHeader(channel, logVersion, lastCommittedTx);
        }
    }
    try (LogVersionedStoreChannel storeChannel = PhysicalLogFile.openForVersion(logFiles, fileSystem, logVersion, true)) {
        long offset = storeChannel.size();
        storeChannel.position(offset);
        try (PositionAwarePhysicalFlushableChannel channel = new PositionAwarePhysicalFlushableChannel(storeChannel)) {
            TransactionLogWriter writer = new TransactionLogWriter(new LogEntryWriter(channel));
            writer.checkPoint(new LogPosition(logVersion, offset));
        }
    }
}

Example 27 with StoreChannel

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

the class LegacyLogEntryReader method openReadableChannel.

public Pair<LogHeader, IOCursor<LogEntry>> openReadableChannel(File logFile) throws IOException {
    final StoreChannel rawChannel = fs.open(logFile, "r");
    final LogHeader header = readLogHeader(ByteBuffer.allocate(LOG_HEADER_SIZE), rawChannel, false, logFile);
    LogEntryReader<ReadableLogChannel> reader = readerFactory.apply(header);
    // this ensures that the last committed txId field in the header is initialized properly
    long lastCommittedTxId = Math.max(BASE_TX_ID, header.lastCommittedTxId);
    final PhysicalLogVersionedStoreChannel channel = new PhysicalLogVersionedStoreChannel(rawChannel, header.logVersion, header.logFormatVersion);
    final ReadableLogChannel readableChannel = new ReadAheadLogChannel(channel, NO_MORE_CHANNELS);
    final IOCursor<LogEntry> cursor = new LogEntrySortingCursor(reader, readableChannel);
    return Pair.of(new LogHeader(CURRENT_LOG_VERSION, header.logVersion, lastCommittedTxId), cursor);
}

Example 28 with StoreChannel

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

the class IdGeneratorImpl method createGenerator.

/**
     * Creates a new id generator.
     *
     * @param fileName The name of the id generator
     * @param throwIfFileExists if {@code true} will cause an {@link UnderlyingStorageException} to be thrown if
     * the file already exists. if {@code false} will truncate the file writing the header in it.
     */
public static void createGenerator(FileSystemAbstraction fs, File fileName, long highId, boolean throwIfFileExists) {
    // sanity checks
    if (fs == null) {
        throw new IllegalArgumentException("Null filesystem");
    }
    if (fileName == null) {
        throw new IllegalArgumentException("Null filename");
    }
    if (throwIfFileExists && fs.fileExists(fileName)) {
        throw new IllegalStateException("Can't create IdGeneratorFile[" + fileName + "], file already exists");
    }
    try (StoreChannel channel = fs.create(fileName)) {
        // write the header
        channel.truncate(0);
        ByteBuffer buffer = ByteBuffer.allocate(HEADER_SIZE);
        buffer.put(CLEAN_GENERATOR).putLong(highId).flip();
        channel.write(buffer);
        channel.force(false);
    } catch (IOException e) {
        throw new UnderlyingStorageException("Unable to create id generator" + fileName, e);
    }
}

Example 29 with StoreChannel

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

the class KeyValueStoreFileFormat method open.

/**
     * Opens an existing store file.
     *
     * @param fs    the file system which holds the store file.
     * @param path  the location in the file system where the store file resides.
     * @param pages the page cache to use for opening the store file.
     * @return the opened store file.
     */
private KeyValueStoreFile open(FileSystemAbstraction fs, File path, PageCache pages) throws IOException {
    ByteBuffer buffer = ByteBuffer.wrap(new byte[maxSize * 4]);
    try (StoreChannel file = fs.open(path, "r")) {
        while (buffer.hasRemaining()) {
            int bytes = file.read(buffer);
            if (bytes == -1) {
                break;
            }
        }
    }
    buffer.flip();
    // compute the key sizes
    int keySize = 0;
    while (buffer.hasRemaining() && buffer.get() == 0) {
        if (++keySize > maxSize) {
            throw new IOException("Invalid header, key size too large.");
        }
    }
    // compute the value size
    // start at 1, since we've seen the first non-zero byte
    int valueSize = 1;
    for (int zeros = 0; zeros <= keySize; zeros++) {
        if (!buffer.hasRemaining()) {
            throw new IOException("Invalid value size: " + valueSize);
        }
        if (buffer.get() != 0) {
            zeros = 0;
        }
        if (++valueSize - keySize > maxSize) {
            throw new IOException("Invalid header, value size too large.");
        }
    }
    // we read in the next zero-key
    valueSize -= keySize;
    // compute a page size that aligns with the <key,value>-tuple size
    int pageSize = pageSize(pages, keySize, valueSize);
    // read the store metadata
    {
        BigEndianByteArrayBuffer formatSpecifier = new BigEndianByteArrayBuffer(new byte[valueSize]);
        writeFormatSpecifier(formatSpecifier);
        PagedFile file = pages.map(path, pageSize);
        try {
            BigEndianByteArrayBuffer key = new BigEndianByteArrayBuffer(new byte[keySize]);
            BigEndianByteArrayBuffer value = new BigEndianByteArrayBuffer(new byte[valueSize]);
            // the first value is the format identifier, pass it along
            buffer.position(keySize);
            buffer.limit(keySize + valueSize);
            value.dataFrom(buffer);
            MetadataCollector metadata = metadata(formatSpecifier, pageSize, keySize, valueSize);
            // scan and catalogue all entries in the file
            KeyValueStoreFile.scanAll(file, 0, metadata, key, value);
            KeyValueStoreFile storeFile = new KeyValueStoreFile(file, keySize, valueSize, metadata);
            file = null;
            return storeFile;
        } finally {
            if (file != null) {
                file.close();
            }
        }
    }
}

Example 30 with StoreChannel

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

the class StateRecoveryManagerTest method writeSomeGarbage.

private void writeSomeGarbage(EphemeralFileSystemAbstraction fsa, File file) throws IOException {
    final StoreChannel channel = fsa.open(file, "rw");
    ByteBuffer buffer = ByteBuffer.allocate(4);
    buffer.putInt(9876);
    buffer.flip();
    channel.writeAll(buffer);
    channel.force(false);
    channel.close();
}