Example usage for java.nio ByteBuffer allocateDirect

Introduction

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

Prototype

public static ByteBuffer allocateDirect(int capacity)

Source Link

Document

Creates a direct byte buffer based on a newly allocated memory block.

Usage

From source file:au.org.theark.core.service.ArkCommonServiceImpl.java

/**
 * {@inheritDoc}//ww w.ja  v a2 s.co m
 */
public void copyArkLargeFileAttachments(String sourceFilePath, String destinationFilePath) throws IOException {
    FileChannel source = null;
    FileChannel destination = null;

    try {
        source = new FileInputStream(new File(sourceFilePath)).getChannel();
        destination = new FileOutputStream(new File(destinationFilePath)).getChannel();

        // This fails with Map Failed exception on large files
        // destination.transferFrom(source, 0, source.size());

        ByteBuffer buf = ByteBuffer.allocateDirect(DEFAULT_BUFFER_SIZE);
        while ((source.read(buf)) != -1) {
            buf.flip();
            destination.write(buf);
            buf.clear();
        }
    } finally {
        if (source != null) {
            source.close();
        }
        if (destination != null) {
            destination.close();
        }
    }
}

From source file:org.nd4j.linalg.Nd4jTestsC.java

@Test
public void testNullPointerDataBuffer() {
    DataBuffer.Type initialType = Nd4j.dataType();

    DataTypeUtil.setDTypeForContext(DataBuffer.Type.FLOAT);

    ByteBuffer allocate = ByteBuffer.allocateDirect(10 * 4).order(ByteOrder.nativeOrder());
    allocate.asFloatBuffer().put(new float[] { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 });
    DataBuffer buff = Nd4j.createBuffer(allocate, DataBuffer.Type.FLOAT, 10);
    float sum = Nd4j.create(buff).sumNumber().floatValue();
    System.out.println(sum);// www.  j ava 2  s . c  om
    assertEquals(55f, sum, 0.001f);

    DataTypeUtil.setDTypeForContext(initialType);
}

From source file:com.sonicle.webtop.mail.Service.java

public static void fastChannelCopy(final ReadableByteChannel src, final WritableByteChannel dest)
        throws IOException {
    final ByteBuffer buffer = ByteBuffer.allocateDirect(16 * 1024);
    while (src.read(buffer) != -1) {
        // prepare the buffer to be drained
        buffer.flip();//  www  . ja  va 2  s.  co m
        // write to the channel, may block
        dest.write(buffer);
        // If partial transfer, shift remainder down
        // If buffer is empty, same as doing clear()
        buffer.compact();
    }
    // EOF will leave buffer in fill state
    buffer.flip();
    // make sure the buffer is fully drained.
    while (buffer.hasRemaining()) {
        dest.write(buffer);
    }
}