Examples with DirectByteBuffer java.nio.DirectByteBuffer used on opensource projects

Example 1 with DirectByteBuffer

use of java.nio.DirectByteBuffer in project j2objc by google.

the class FileChannelImpl method map.

public MappedByteBuffer map(MapMode mode, long position, long size) throws IOException {
    ensureOpen();
    if (mode == null)
        throw new NullPointerException("Mode is null");
    if (position < 0L)
        throw new IllegalArgumentException("Negative position");
    if (size < 0L)
        throw new IllegalArgumentException("Negative size");
    if (position + size < 0)
        throw new IllegalArgumentException("Position + size overflow");
    if (size > Integer.MAX_VALUE)
        throw new IllegalArgumentException("Size exceeds Integer.MAX_VALUE");
    int imode = -1;
    if (mode == MapMode.READ_ONLY)
        imode = MAP_RO;
    else if (mode == MapMode.READ_WRITE)
        imode = MAP_RW;
    else if (mode == MapMode.PRIVATE)
        imode = MAP_PV;
    assert (imode >= 0);
    if ((mode != MapMode.READ_ONLY) && !writable)
        throw new NonWritableChannelException();
    if (!readable)
        throw new NonReadableChannelException();
    long addr = -1;
    int ti = -1;
    try {
        begin();
        ti = threads.add();
        if (!isOpen())
            return null;
        long filesize;
        do {
            filesize = nd.size(fd);
        } while ((filesize == IOStatus.INTERRUPTED) && isOpen());
        if (!isOpen())
            return null;
        if (filesize < position + size) {
            // Extend file size
            if (!writable) {
                throw new IOException("Channel not open for writing " + "- cannot extend file to required size");
            }
            int rv;
            do {
                rv = nd.truncate(fd, position + size);
            } while ((rv == IOStatus.INTERRUPTED) && isOpen());
            if (!isOpen())
                return null;
        }
        if (size == 0) {
            addr = 0;
            // a valid file descriptor is not required
            FileDescriptor dummy = new FileDescriptor();
            /*
                if ((!writable) || (imode == MAP_RO))
                    return Util.newMappedByteBufferR(0, 0, dummy, null);
                else
                    return Util.newMappedByteBuffer(0, 0, dummy, null);
                */
            return new DirectByteBuffer(0, 0, dummy, null, (!writable) || (imode == MAP_RO));
        }
        int pagePosition = (int) (position % allocationGranularity);
        long mapPosition = position - pagePosition;
        long mapSize = size + pagePosition;
        try {
            // Android-added: BlockGuard support.
            BlockGuard.getThreadPolicy().onReadFromDisk();
            // If no exception was thrown from map0, the address is valid
            addr = map0(imode, mapPosition, mapSize);
        } catch (OutOfMemoryError x) {
            // An OutOfMemoryError may indicate that we've exhausted memory
            // so force gc and re-attempt map
            System.gc();
            try {
                Thread.sleep(100);
            } catch (InterruptedException y) {
                Thread.currentThread().interrupt();
            }
            try {
                addr = map0(imode, mapPosition, mapSize);
            } catch (OutOfMemoryError y) {
                // After a second OOME, fail
                throw new IOException("Map failed", y);
            }
        }
        // On Windows, and potentially other platforms, we need an open
        // file descriptor for some mapping operations.
        FileDescriptor mfd;
        try {
            mfd = nd.duplicateForMapping(fd);
        } catch (IOException ioe) {
            unmap0(addr, mapSize);
            throw ioe;
        }
        assert (IOStatus.checkAll(addr));
        assert (addr % allocationGranularity == 0);
        int isize = (int) size;
        Unmapper um = new Unmapper(addr, mapSize, isize, mfd);
        /*
            if ((!writable) || (imode == MAP_RO)) {
                return Util.newMappedByteBufferR(isize,
                                                 addr + pagePosition,
                                                 mfd,
                                                 um);
            } else {
                return Util.newMappedByteBuffer(isize,
                                                addr + pagePosition,
                                                mfd,
                                                um);
            }
            */
        return new DirectByteBuffer(isize, addr + pagePosition, mfd, um, (!writable) || (imode == MAP_RO));
    } finally {
        threads.remove(ti);
        end(IOStatus.checkAll(addr));
    }
}

Example 2 with DirectByteBuffer

use of java.nio.DirectByteBuffer in project j2objc by google.

the class DirectDoubleBufferTest method testJNIAccessByAddress.

// http://b/28964300
public void testJNIAccessByAddress() throws Exception {
    DirectByteBuffer directByteBuffer = (DirectByteBuffer) ByteBuffer.allocateDirect(10);
    directByteBuffer.put((byte) 'a');
    DoubleBuffer doubleBuffer = directByteBuffer.asDoubleBuffer();
    long byteBufferBasePointer = NIOAccess.getBasePointer(directByteBuffer);
    long doubleBufferBasePointer = NIOAccess.getBasePointer(doubleBuffer);
    assertEquals(byteBufferBasePointer, doubleBufferBasePointer);
    // Check if the NIOAccess method adds up the current position value.
    doubleBuffer.put(1.0);
    assertEquals(doubleBufferBasePointer + Double.BYTES, NIOAccess.getBasePointer(doubleBuffer));
}

Example 3 with DirectByteBuffer

use of java.nio.DirectByteBuffer in project j2objc by google.

the class DirectIntBufferTest method testJNIAccessByAddress.

// http://b/28964300
public void testJNIAccessByAddress() throws Exception {
    DirectByteBuffer directByteBuffer = (DirectByteBuffer) ByteBuffer.allocateDirect(10);
    directByteBuffer.put((byte) 'a');
    IntBuffer intBuffer = directByteBuffer.asIntBuffer();
    long byteBufferBasePointer = NIOAccess.getBasePointer(directByteBuffer);
    long intBufferBasePointer = NIOAccess.getBasePointer(intBuffer);
    assertEquals(byteBufferBasePointer, intBufferBasePointer);
    // Check if the NIOAccess method adds up the current position value.
    intBuffer.put(1);
    assertEquals(intBufferBasePointer + Integer.BYTES, NIOAccess.getBasePointer(intBuffer));
}

Example 4 with DirectByteBuffer

use of java.nio.DirectByteBuffer in project j2objc by google.

the class DirectShortBufferTest method testJNIAccessByAddress.

// http://b/28964300
public void testJNIAccessByAddress() {
    DirectByteBuffer directByteBuffer = (DirectByteBuffer) ByteBuffer.allocateDirect(10);
    directByteBuffer.put((byte) 'a');
    ShortBuffer shortBuffer = directByteBuffer.asShortBuffer();
    long byteBufferBasePointer = NIOAccess.getBasePointer(directByteBuffer);
    long shortBufferBasePointer = NIOAccess.getBasePointer(shortBuffer);
    assertEquals(byteBufferBasePointer, shortBufferBasePointer);
    // Check if the NIOAccess method adds up the current position value.
    shortBuffer.put((short) 1);
    assertEquals(shortBufferBasePointer + Short.BYTES, NIOAccess.getBasePointer(shortBuffer));
}

Example 5 with DirectByteBuffer

use of java.nio.DirectByteBuffer in project j2objc by google.

the class DirectCharBufferTest method testJNIAccessByAddress.

// http://b/28964300
public void testJNIAccessByAddress() throws Exception {
    DirectByteBuffer directByteBuffer = (DirectByteBuffer) ByteBuffer.allocateDirect(10);
    directByteBuffer.put((byte) 'a');
    CharBuffer charBuffer = directByteBuffer.asCharBuffer();
    long byteBufferBasePointer = NIOAccess.getBasePointer(directByteBuffer);
    long charBufferBasePointer = NIOAccess.getBasePointer(charBuffer);
    assertEquals(byteBufferBasePointer, charBufferBasePointer);
    // Check if the NIOAccess method adds up the current position value.
    charBuffer.put('b');
    assertEquals(charBufferBasePointer + Character.BYTES, NIOAccess.getBasePointer(charBuffer));
}