Example usage for java.nio ByteBuffer flip

List of usage examples for java.nio ByteBuffer flip

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Introduction

In this page you can find the example usage for java.nio ByteBuffer flip.

Prototype

public final Buffer flip()

Source Link

Document

Flips this buffer.

Usage

From source file:com.healthmarketscience.jackcess.impl.PageChannel.java

/**
 * @param buffer Buffer to read the page into
 * @param pageNumber Number of the page to read in (starting at 0)
 *///w  w  w.j  a  v a  2 s.c  o  m
public void readPage(ByteBuffer buffer, int pageNumber) throws IOException {
    validatePageNumber(pageNumber);

    ByteBuffer inPage = buffer;
    ByteBuffer outPage = buffer;
    if ((pageNumber != 0) && !_codecHandler.canDecodeInline()) {
        inPage = _tempDecodeBufferH.getPageBuffer(this);
        outPage.clear();
    }

    inPage.clear();
    int bytesRead = _channel.read(inPage, (long) pageNumber * (long) getFormat().PAGE_SIZE);
    inPage.flip();
    if (bytesRead != getFormat().PAGE_SIZE) {
        throw new IOException("Failed attempting to read " + getFormat().PAGE_SIZE + " bytes from page "
                + pageNumber + ", only read " + bytesRead);
    }

    if (pageNumber == 0) {
        // de-mask header (note, page 0 never has additional encoding)
        applyHeaderMask(buffer);
    } else {
        _codecHandler.decodePage(inPage, outPage, pageNumber);
    }
}

From source file:com.github.ambry.utils.UtilsTest.java

@Test
public void testReadStrings() throws IOException {
    // good case//from   w  w  w.  jav a 2  s.  c  o m
    ByteBuffer buffer = ByteBuffer.allocate(10);
    buffer.putShort((short) 8);
    String s = getRandomString(8);
    buffer.put(s.getBytes());
    buffer.flip();
    String outputString = Utils.readShortString(new DataInputStream(new ByteBufferInputStream(buffer)));
    Assert.assertEquals(s, outputString);
    // 0-length
    buffer.rewind();
    buffer.putShort(0, (short) 0);
    outputString = Utils.readShortString(new DataInputStream(new ByteBufferInputStream(buffer)));
    Assert.assertTrue(outputString.isEmpty());

    // failed case
    buffer.rewind();
    buffer.putShort((short) 10);
    buffer.put(s.getBytes());
    buffer.flip();
    try {
        outputString = Utils.readShortString(new DataInputStream(new ByteBufferInputStream(buffer)));
        Assert.assertTrue(false);
    } catch (IllegalArgumentException e) {
        Assert.assertTrue(true);
    }
    buffer.rewind();
    buffer.putShort(0, (short) -1);
    try {
        outputString = Utils.readShortString(new DataInputStream(new ByteBufferInputStream(buffer)));
        Assert.fail("Should have encountered exception with negative length.");
    } catch (IllegalArgumentException e) {
    }

    // good case
    buffer = ByteBuffer.allocate(40004);
    buffer.putInt(40000);
    s = getRandomString(40000);
    buffer.put(s.getBytes());
    buffer.flip();
    outputString = Utils.readIntString(new DataInputStream(new ByteBufferInputStream(buffer)),
            StandardCharsets.UTF_8);
    Assert.assertEquals(s, outputString);
    // 0-length
    buffer.rewind();
    buffer.putInt(0, 0);
    outputString = Utils.readShortString(new DataInputStream(new ByteBufferInputStream(buffer)));
    Assert.assertTrue(outputString.isEmpty());

    // failed case
    buffer.rewind();
    buffer.putInt(50000);
    buffer.put(s.getBytes());
    buffer.flip();
    try {
        outputString = Utils.readIntString(new DataInputStream(new ByteBufferInputStream(buffer)),
                StandardCharsets.UTF_8);
        fail("Should have failed");
    } catch (IllegalArgumentException e) {
        // expected.
    }

    buffer.rewind();
    buffer.putInt(0, -1);
    try {
        Utils.readIntString(new DataInputStream(new ByteBufferInputStream(buffer)), StandardCharsets.UTF_8);
        Assert.fail("Should have encountered exception with negative length.");
    } catch (IllegalArgumentException e) {
        // expected.
    }
}

From source file:org.sglover.checksum.ChecksumServiceImpl.java

@Override
public NodeChecksums getChecksums(final Node node, final InputStream in) {
    final String nodeId = node.getNodeId();
    final Long nodeVersion = node.getNodeVersion();
    final Long nodeInternalId = node.getNodeInternalId();
    final String versionLabel = node.getVersionLabel();
    int x = 0;// www  . ja v a 2 s .  com

    NodeChecksums documentChecksums = new NodeChecksums(nodeId, nodeInternalId, nodeVersion, versionLabel,
            blockSize);

    try (ReadableByteChannel fc = getChannel(in)) {
        ByteBuffer data = ByteBuffer.allocate(blockSize * 20);
        int bytesRead = -1;
        int blockNum = 1; // starts at 1

        do {
            bytesRead = fc.read(data);
            if (bytesRead > 0) {
                x += bytesRead;

                data.flip();

                long numBlocks = data.limit() / blockSize + (data.limit() % blockSize > 0 ? 1 : 0);

                // spin through the data and create checksums for each block
                for (int i = 0; i < numBlocks; i++) {
                    int start = i * blockSize;
                    int end = start + blockSize - 1;

                    if (end >= data.limit()) {
                        end = data.limit() - 1;
                    }

                    // calculate the adler32 checksum
                    Adler32 adlerInfo = new Adler32(data, start, end, hasher);

                    // calculate the full md5 checksum
                    String md5sum = hasher.md5(data, start, end);
                    Checksum checksum = new Checksum(blockNum, start, end, adlerInfo.getHash(),
                            adlerInfo.getAdler32(), md5sum);
                    if (blockNum < 2) {
                        System.out.println(checksum);
                    }
                    documentChecksums.addChecksum(checksum);

                    blockNum++;
                }

                data.clear();
            }
        } while (bytesRead > 0);
    } catch (NoSuchAlgorithmException | IOException e) {
        throw new RuntimeException(e);
    }

    return documentChecksums;
}

From source file:net.timewalker.ffmq4.transport.tcp.nio.NIOTcpMultiplexer.java

protected boolean readAndProcessChannelData(NIOClientSocketHandler clientHandler) {
    try {//  w  w  w .  j ava  2s  . c o  m
        ByteBuffer inputBuffer = clientHandler.getInputBuffer();
        int readAmount = clientHandler.getSocketChannel().read(inputBuffer);
        if (readAmount <= 0) {
            log.debug("[" + clientHandler.getId() + "] Cannot read, channel socket was closed");
            return false;
        }

        inputBuffer.flip(); // Prepare for reading
        boolean status = clientHandler.handleIncomingData();
        inputBuffer.compact(); // Restore pointers

        return status;
    } catch (IOException e) {
        log.debug("[" + clientHandler.getId() + "] Read failed : " + e.getMessage());
        return false;
    } catch (Exception e) {
        log.error("[" + clientHandler.getId() + "] Could not read channel data", e);
        return false;
    }
}

From source file:org.apache.hadoop.hbase.client.TestResult.java

/**
 * Microbenchmark that compares {@link Result#getValue} and {@link Result#loadValue} performance.
 *
 * @throws Exception//from   w w w . j a va2  s.  c  o  m
 */
public void doReadBenchmark() throws Exception {

    final int n = 5;
    final int m = 100000000;

    StringBuilder valueSB = new StringBuilder();
    for (int i = 0; i < 100; i++) {
        valueSB.append((byte) (Math.random() * 10));
    }

    StringBuilder rowSB = new StringBuilder();
    for (int i = 0; i < 50; i++) {
        rowSB.append((byte) (Math.random() * 10));
    }

    KeyValue[] kvs = genKVs(Bytes.toBytes(rowSB.toString()), family, Bytes.toBytes(valueSB.toString()), 1, n);
    Arrays.sort(kvs, KeyValue.COMPARATOR);
    ByteBuffer loadValueBuffer = ByteBuffer.allocate(1024);
    Result r = Result.create(kvs);

    byte[][] qfs = new byte[n][Bytes.SIZEOF_INT];
    for (int i = 0; i < n; ++i) {
        System.arraycopy(qfs[i], 0, Bytes.toBytes(i), 0, Bytes.SIZEOF_INT);
    }

    // warm up
    for (int k = 0; k < 100000; k++) {
        for (int i = 0; i < n; ++i) {
            r.getValue(family, qfs[i]);
            loadValueBuffer.clear();
            r.loadValue(family, qfs[i], loadValueBuffer);
            loadValueBuffer.flip();
        }
    }

    System.gc();
    long start = System.nanoTime();
    for (int k = 0; k < m; k++) {
        for (int i = 0; i < n; ++i) {
            loadValueBuffer.clear();
            r.loadValue(family, qfs[i], loadValueBuffer);
            loadValueBuffer.flip();
        }
    }
    long stop = System.nanoTime();
    System.out.println("loadValue(): " + (stop - start));

    System.gc();
    start = System.nanoTime();
    for (int k = 0; k < m; k++) {
        for (int i = 0; i < n; i++) {
            r.getValue(family, qfs[i]);
        }
    }
    stop = System.nanoTime();
    System.out.println("getValue():  " + (stop - start));
}

From source file:co.paralleluniverse.galaxy.core.BackupImpl.java

private Message.BACKUP makeBackup(CacheLine line, long version) {
    if (line.getVersion() != version)
        return null;
    final Message.BACKUP backup;
    if (line.getData() == null) {
        backup = Message.BACKUP(line.getId(), line.getVersion(), null);
    } else {//  ww w.j  av a2 s. co  m
        final ByteBuffer buffer = ByteBuffer.allocate(line.getData().limit()); // storage.allocateStorage(line.getData().limit());
        line.rewind();
        buffer.put(line.getData());
        line.rewind();
        buffer.flip();
        backup = Message.BACKUP(line.getId(), line.getVersion(), buffer);
    }
    LOG.debug("Copying version {} of line {} data: {}",
            new Object[] { backup.getVersion(), hex(backup.getLine()),
                    backup.getData() != null ? "(" + backup.getData().remaining() + " bytes)" : "null" });
    return backup;
}

From source file:com.clustercontrol.agent.job.PublicKeyThread.java

/**
 *  ?Authorized_key????<BR>//w w  w .  j a v  a 2 s .c o m
 * 
 * @param publicKey
 * @return true : ?false:
 */
private synchronized boolean deleteKey(String publicKey) {
    m_log.debug("delete key start");

    if (SKIP_KEYFILE_UPDATE) {
        m_log.info("skipped deleting publicKey");
        return true;
    }

    Charset charset = Charset.forName("UTF-8");
    CharsetEncoder encoder = charset.newEncoder();
    CharsetDecoder decoder = charset.newDecoder();

    //???
    String fileName = AgentProperties.getProperty(execUser.toLowerCase() + AUTHORIZED_KEY_PATH);
    if (fileName == null || fileName.length() == 0)
        return false;

    //File?
    File fi = new File(fileName);

    RandomAccessFile randomAccessFile = null;
    FileChannel channel = null;
    FileLock lock = null;
    boolean delete = false;
    try {
        //RandomAccessFile?
        randomAccessFile = new RandomAccessFile(fi, "rw");
        //FileChannel?
        channel = randomAccessFile.getChannel();

        // 
        for (int i = 0; i < (FILELOCK_TIMEOUT / FILELOCK_WAIT); i++) {
            if (null != (lock = channel.tryLock())) {
                break;
            }
            m_log.info("waiting for locked file... [" + (i + 1) + "/" + (FILELOCK_TIMEOUT / FILELOCK_WAIT)
                    + " : " + fileName + "]");
            Thread.sleep(FILELOCK_WAIT);
        }
        if (null == lock) {
            m_log.warn("file locking timeout.");
            return false;
        }

        // (?)
        synchronized (authKeyLock) {
            //??
            ByteBuffer buffer = ByteBuffer.allocate((int) channel.size());

            //??
            channel.read(buffer);

            // ???????????0?
            buffer.flip();

            //??
            String contents = decoder.decode(buffer).toString();

            // ?
            m_log.debug("contents " + contents.length() + " : " + contents);

            //??
            List<String> keyCheck = new ArrayList<String>();
            StringTokenizer tokenizer = new StringTokenizer(contents, "\n");
            while (tokenizer.hasMoreTokens()) {
                keyCheck.add(tokenizer.nextToken());
            }

            //??????
            int s = keyCheck.lastIndexOf(publicKey);
            if (s != -1) {
                // ?
                m_log.debug("remobe key : " + keyCheck.get(s));
                keyCheck.remove(s);
            }

            //?????
            encoder.reset();
            buffer.clear();

            int i;
            if (keyCheck.size() > 0) {
                for (i = 0; i < keyCheck.size() - 1; i++) {
                    encoder.encode(CharBuffer.wrap(keyCheck.get(i) + "\n"), buffer, false);
                }
                encoder.encode(CharBuffer.wrap(keyCheck.get(i)), buffer, true);
            }

            //???
            buffer.flip();
            channel.truncate(0);
            channel.position(0);
            channel.write(buffer);
        }

        delete = true;
    } catch (IOException e) {
        m_log.error(e.getMessage(), e);
    } catch (RuntimeException e) {
        m_log.error(e.getMessage(), e);
    } catch (InterruptedException e) {
        m_log.error(e.getMessage(), e);
    } finally {
        try {
            if (channel != null) {
                channel.close();
            }
            if (randomAccessFile != null) {
                randomAccessFile.close();
            }
            //?
            if (lock != null) {
                lock.release();
            }
        } catch (Exception e) {
        }
    }

    return delete;
}

From source file:com.google.cloud.hadoop.gcsio.GoogleCloudStorageIntegrationHelper.java

/**
 * Helper which reads the entire file as a String.
 *//*from  w  ww. j  ava  2s. c o m*/
protected String readTextFile(String bucketName, String objectName) throws IOException {
    SeekableReadableByteChannel readChannel = null;
    ByteBuffer readBuffer = ByteBuffer.allocate(1024);
    StringBuffer returnBuffer = new StringBuffer();

    try {
        readChannel = open(bucketName, objectName);
        int numBytesRead = readChannel.read(readBuffer);
        while (numBytesRead > 0) {
            readBuffer.flip();
            returnBuffer.append(StandardCharsets.UTF_8.decode(readBuffer));
            readBuffer.clear();
            numBytesRead = readChannel.read(readBuffer);
        }
    } finally {
        if (readChannel != null) {
            readChannel.close();
        }
    }
    return returnBuffer.toString();
}

From source file:org.apache.bookkeeper.bookie.BookieJournalTest.java

private void writePreV2Journal(File journalDir, int numEntries) throws Exception {
    long logId = System.currentTimeMillis();
    File fn = new File(journalDir, Long.toHexString(logId) + ".txn");

    FileChannel fc = new RandomAccessFile(fn, "rw").getChannel();

    ByteBuffer zeros = ByteBuffer.allocate(512);
    fc.write(zeros, 4 * 1024 * 1024);//from w w w  . ja v  a2 s .c  o  m
    fc.position(0);

    byte[] data = "JournalTestData".getBytes();
    long lastConfirmed = LedgerHandle.INVALID_ENTRY_ID;
    for (int i = 1; i <= numEntries; i++) {
        ByteBuffer packet = ClientUtil.generatePacket(1, i, lastConfirmed, i * data.length, data)
                .toByteBuffer();
        lastConfirmed = i;
        ByteBuffer lenBuff = ByteBuffer.allocate(4);
        lenBuff.putInt(packet.remaining());
        lenBuff.flip();

        fc.write(lenBuff);
        fc.write(packet);
    }
}

From source file:com.serenegiant.media.TLMediaEncoder.java

/**
 * read raw bit stream from specific intermediate file
 * @param in//from w w  w.ja  v  a2s .c  om
 * @param header
 * @param buffer
 * @param readBuffer
 * @throws IOException
 * @throws BufferOverflowException
 */
/*package*/static ByteBuffer readStream(final DataInputStream in, final TLMediaFrameHeader header,
        ByteBuffer buffer, final byte[] readBuffer) throws IOException {

    readHeader(in, header);
    if ((buffer == null) || header.size > buffer.capacity()) {
        buffer = ByteBuffer.allocateDirect(header.size);
    }
    buffer.clear();
    final int max_bytes = Math.min(readBuffer.length, header.size);
    int read_bytes;
    for (int i = header.size; i > 0; i -= read_bytes) {
        read_bytes = in.read(readBuffer, 0, Math.min(i, max_bytes));
        if (read_bytes <= 0)
            break;
        buffer.put(readBuffer, 0, read_bytes);
    }
    buffer.flip();
    return buffer;
}