Java 类java.nio.channels.FileChannel.MapMode 实例源码

项目：MpiTaskFramework 文件：SharedSystemData.java

/**
 * Constructor.
 * @throws IOException 
 */
public SharedSystemData(String path, boolean create) throws IOException {
    File f = new File(path);

    if (create) {
        if (f.exists()) {
            System.out.println("Existing system detected, deleting");
            f.delete(); // Delete if present.
        }
    } else {
        if (!f.exists()) {
            System.err.println("ERROR, system dont exist");
            System.exit(-1);
        }
    }
    channel = FileChannel.open(f.toPath(), StandardOpenOption.READ, StandardOpenOption.WRITE, StandardOpenOption.CREATE);
    buffer = channel.map(MapMode.READ_WRITE, 0, 4000);

    if (create) {
        setNextTaskId(0);
        setShutdownSignal(false);
    }
}

项目：dataset-lib 文件：StreamThread.java

public ByteBuffer call() throws Exception {
    ServerSocketChannel serverSocketChannel = ServerSocketChannel.open();
    buff = ByteBuffer.allocate(bufferSize);
    serverSocketChannel.socket().bind(new InetSocketAddress(port));
    while (!stop.isLocked()) {
        RandomAccessFile temp = new RandomAccessFile(tempName, "rw");
        SocketChannel socketChannel = serverSocketChannel.accept();
        socketChannel.read(buff);
        FileChannel channel = temp.getChannel();
        channel.write(buff);
        if (!pause.isLocked()) {
            MappedByteBuffer b = channel.map(MapMode.READ_WRITE, 0, (long) bufferSize);
            b.clear();
        }
        temp.close();
        buff.clear();
    }

    return null;
}

项目：dataset-lib 文件：StreamThread.java

public ByteBuffer call() throws Exception {
    ServerSocketChannel serverSocketChannel = ServerSocketChannel.open();
    buff = ByteBuffer.allocate(bufferSize);
    serverSocketChannel.socket().bind(new InetSocketAddress(port));
    RandomAccessFile temp = new RandomAccessFile(tempName, "rw");
    MappedByteBuffer b;
    while (!stop.isLocked()) {
        sync=0;
        SocketChannel socketChannel = serverSocketChannel.accept();
        socketChannel.read(buff);
        FileChannel channel = temp.getChannel();
        channel.write(buff);
        if (!pause.isLocked()) {
            b = channel.map(MapMode.READ_WRITE, 0, (long) bufferSize);
            sync = 1;
            if(sync==2){
            b.clear();
            }
        }
        buff.clear();
    }
    temp.close();
    return null;
}

项目：Maxine-VM 文件：ReadOnlyTeleProcess.java

/**
 * Maps the heapPointer and code sections of the boot image in a given file into memory.
 *
 * @param bootImageFile the file containing the heapPointer and code sections to map into memory
 * @return a {@link DataAccess} object that can be used to access the mapped sections
 * @throws IOException if an IO error occurs while performing the memory mapping
 */
private DataAccess map(File bootImageFile, BootImage bootImage) throws IOException {
    final RandomAccessFile randomAccessFile = new RandomAccessFile(bootImageFile, "rwd");
    final Header header = bootImage.header;
    int heapOffset = bootImage.heapOffset();
    int heapAndCodeSize = header.heapSize + header.codeSize;
    final MappedByteBuffer bootImageBuffer = randomAccessFile.getChannel().map(MapMode.PRIVATE, heapOffset, heapAndCodeSize);
    bootImageBuffer.order(platform().endianness().asByteOrder());
    randomAccessFile.close();

    if (heapPointer.isNotZero()) {
        long address = (Long) WithoutAccessCheck.getInstanceField(bootImageBuffer, "address");
        bootImage.relocate(address, heapPointer);
    }
    return new MappedByteBufferDataAccess(bootImageBuffer, heapPointer, header.wordWidth());
}

项目：alfresco-repository 文件：IndexInfo.java

private boolean checkVersion(FileChannel channel) throws IOException
{
    if (channel.size() > 0)
    {
        channel.position(0);
        ByteBuffer buffer;

        if (useNIOMemoryMapping)
        {
            MappedByteBuffer mbb = channel.map(MapMode.READ_ONLY, 0, 8);
            mbb.load();
            buffer = mbb;
        }
        else
        {
            buffer = ByteBuffer.wrap(new byte[8]);
            channel.read(buffer);
            buffer.position(0);
        }

        buffer.position(0);
        long onDiskVersion = buffer.getLong();
        return (version == onDiskVersion);
    }
    return (version == 0);
}

项目：rocketmq-rocketmq-all-4.1.0-incubating 文件：StoreCheckpoint.java

public StoreCheckpoint(final String scpPath) throws IOException {
    File file = new File(scpPath);
    MappedFile.ensureDirOK(file.getParent());
    boolean fileExists = file.exists();

    this.randomAccessFile = new RandomAccessFile(file, "rw");
    this.fileChannel = this.randomAccessFile.getChannel();
    this.mappedByteBuffer = fileChannel.map(MapMode.READ_WRITE, 0, MappedFile.OS_PAGE_SIZE);

    if (fileExists) {
        log.info("store checkpoint file exists, " + scpPath);
        this.physicMsgTimestamp = this.mappedByteBuffer.getLong(0);
        this.logicsMsgTimestamp = this.mappedByteBuffer.getLong(8);
        this.indexMsgTimestamp = this.mappedByteBuffer.getLong(16);

        log.info("store checkpoint file physicMsgTimestamp " + this.physicMsgTimestamp + ", "
            + UtilAll.timeMillisToHumanString(this.physicMsgTimestamp));
        log.info("store checkpoint file logicsMsgTimestamp " + this.logicsMsgTimestamp + ", "
            + UtilAll.timeMillisToHumanString(this.logicsMsgTimestamp));
        log.info("store checkpoint file indexMsgTimestamp " + this.indexMsgTimestamp + ", "
            + UtilAll.timeMillisToHumanString(this.indexMsgTimestamp));
    } else {
        log.info("store checkpoint file not exists, " + scpPath);
    }
}

项目：guava-mock 文件：FilesTest.java

public void testMap_readWrite() throws IOException {
  // Test data
  int size = 1024;
  byte[] expectedBytes = new byte[size];
  byte[] bytes = newPreFilledByteArray(1024);

  // Setup
  File file = createTempFile();
  Files.write(bytes, file);

  Random random = new Random();
  random.nextBytes(expectedBytes);

  // Test
  MappedByteBuffer map = Files.map(file, MapMode.READ_WRITE);
  map.put(expectedBytes);

  // Verify
  byte[] actualBytes = Files.toByteArray(file);
  assertTrue(Arrays.equals(expectedBytes, actualBytes));
}

项目：guava-mock 文件：FilesTest.java

public void testMap_readWrite_creates() throws IOException {
  // Test data
  int size = 1024;
  byte[] expectedBytes = newPreFilledByteArray(1024);

  // Setup
  File file = createTempFile();
  boolean deleted = file.delete();
  assertTrue(deleted);
  assertFalse(file.exists());

  // Test
  MappedByteBuffer map = Files.map(file, MapMode.READ_WRITE, size);
  map.put(expectedBytes);

  // Verify
  assertTrue(file.exists());
  assertTrue(file.isFile());
  assertEquals(size, file.length());
  byte[] actualBytes = Files.toByteArray(file);
  assertTrue(Arrays.equals(expectedBytes, actualBytes));
}

项目：reading-and-annotate-rocketmq-3.4.6 文件：StoreCheckpoint.java

public StoreCheckpoint(final String scpPath) throws IOException {
    File file = new File(scpPath);
    MapedFile.ensureDirOK(file.getParent());
    boolean fileExists = file.exists();

    this.randomAccessFile = new RandomAccessFile(file, "rw");
    this.fileChannel = this.randomAccessFile.getChannel();
    this.mappedByteBuffer = fileChannel.map(MapMode.READ_WRITE, 0, MapedFile.OS_PAGE_SIZE);

    if (fileExists) {
        log.info("store checkpoint file exists, " + scpPath);
        this.physicMsgTimestamp = this.mappedByteBuffer.getLong(0);
        this.logicsMsgTimestamp = this.mappedByteBuffer.getLong(8);
        this.indexMsgTimestamp = this.mappedByteBuffer.getLong(16);

        log.info("store checkpoint file physicMsgTimestamp " + this.physicMsgTimestamp + ", "
                + UtilAll.timeMillisToHumanString(this.physicMsgTimestamp));
        log.info("store checkpoint file logicsMsgTimestamp " + this.logicsMsgTimestamp + ", "
                + UtilAll.timeMillisToHumanString(this.logicsMsgTimestamp));
        log.info("store checkpoint file indexMsgTimestamp " + this.indexMsgTimestamp + ", "
                + UtilAll.timeMillisToHumanString(this.indexMsgTimestamp));
    }
    else {
        log.info("store checkpoint file not exists, " + scpPath);
    }
}

项目：MetadataEditor 文件：FlacTagWriter.java

/**
 * Insert new metadata into file by using memory mapped file, and if fails write in chunks
 * <p>
 * But this is problematic on 32bit systems for large flac files may not be able to map a contiguous address space large enough
 * for a large audio size , so no longer used since better to go straight to using chunks
 *
 * @param tag
 * @param fc
 * @param blockInfo
 * @param flacStream
 * @param neededRoom
 * @param availableRoom
 * @throws IOException
 * @throws UnsupportedEncodingException
 */
private void insertTagAndShift(File file, Tag tag, FileChannel fc, MetadataBlockInfo blockInfo, FlacStreamReader flacStream, int neededRoom, int availableRoom) throws IOException, UnsupportedEncodingException {
    int headerLength = flacStream.getStartOfFlacInFile() + FlacStreamReader.FLAC_STREAM_IDENTIFIER_LENGTH + MetadataBlockHeader.HEADER_LENGTH // this should be the length of the block header for the stream info
            + MetadataBlockDataStreamInfo.STREAM_INFO_DATA_LENGTH;
    long targetSizeBeforeAudioData = headerLength + neededRoom + FlacTagCreator.DEFAULT_PADDING;
    long remainderTargetSize = fc.size() - (headerLength + availableRoom);
    long totalTargetSize = targetSizeBeforeAudioData + remainderTargetSize;

    MappedByteBuffer mappedFile = null;
    try {
        //Use ByteBuffer
        mappedFile = fc.map(MapMode.READ_WRITE, 0, totalTargetSize);
        insertTagAndShiftViaMappedByteBuffer(tag, mappedFile, fc, targetSizeBeforeAudioData, totalTargetSize, blockInfo, flacStream, neededRoom, availableRoom);
    } catch (IOException ioe) {
        //#175: Flac Map error on write
        if (mappedFile == null) {
            insertUsingChunks(file, tag, fc, blockInfo, flacStream, neededRoom + FlacTagCreator.DEFAULT_PADDING, availableRoom);
        } else {
            logger.log(Level.SEVERE, ioe.getMessage(), ioe);
            throw ioe;
        }
    }
}

项目：MaxSim 文件：ReadOnlyTeleProcess.java

/**
 * Maps the heapPointer and code sections of the boot image in a given file into memory.
 *
 * @param bootImageFile the file containing the heapPointer and code sections to map into memory
 * @return a {@link DataAccess} object that can be used to access the mapped sections
 * @throws IOException if an IO error occurs while performing the memory mapping
 */
private DataAccess map(File bootImageFile, BootImage bootImage) throws IOException {
    final RandomAccessFile randomAccessFile = new RandomAccessFile(bootImageFile, "rwd");
    final Header header = bootImage.header;
    int heapOffset = bootImage.heapOffset();
    int heapAndCodeSize = header.heapSize + header.codeSize;
    final MappedByteBuffer bootImageBuffer = randomAccessFile.getChannel().map(MapMode.PRIVATE, heapOffset, heapAndCodeSize);
    bootImageBuffer.order(platform().endianness().asByteOrder());
    randomAccessFile.close();

    if (heapPointer.isNotZero()) {
        long address = (Long) WithoutAccessCheck.getInstanceField(bootImageBuffer, "address");
        bootImage.relocate(address, heapPointer);
    }
    return new MappedByteBufferDataAccess(bootImageBuffer, heapPointer, header.wordWidth());
}

项目：hadoop 文件：MappableBlock.java

/**
 * Load the block.
 *
 * mmap and mlock the block, and then verify its checksum.
 *
 * @param length         The current length of the block.
 * @param blockIn        The block input stream.  Should be positioned at the
 *                       start.  The caller must close this.
 * @param metaIn         The meta file input stream.  Should be positioned at
 *                       the start.  The caller must close this.
 * @param blockFileName  The block file name, for logging purposes.
 *
 * @return               The Mappable block.
 */
public static MappableBlock load(long length,
    FileInputStream blockIn, FileInputStream metaIn,
    String blockFileName) throws IOException {
  MappableBlock mappableBlock = null;
  MappedByteBuffer mmap = null;
  FileChannel blockChannel = null;
  try {
    blockChannel = blockIn.getChannel();
    if (blockChannel == null) {
      throw new IOException("Block InputStream has no FileChannel.");
    }
    mmap = blockChannel.map(MapMode.READ_ONLY, 0, length);
    NativeIO.POSIX.getCacheManipulator().mlock(blockFileName, mmap, length);
    verifyChecksum(length, metaIn, blockChannel, blockFileName);
    mappableBlock = new MappableBlock(mmap, length);
  } finally {
    IOUtils.closeQuietly(blockChannel);
    if (mappableBlock == null) {
      if (mmap != null) {
        NativeIO.POSIX.munmap(mmap); // unmapping also unlocks
      }
    }
  }
  return mappableBlock;
}

项目：jdk8u-jdk 文件：MapTest.java

/**
 * Maps blah file with a random offset and checks to see if data
 * written out to the file can be read back in
 */
private static void testWrite() throws Exception {
    StringBuilder sb = new StringBuilder();
    sb.setLength(4);

    for (int x=0; x<1000; x++) {
        try (RandomAccessFile raf = new RandomAccessFile(blah, "rw")) {
            FileChannel fc = raf.getChannel();

            long offset = generator.nextInt(1000);
            MappedByteBuffer b = fc.map(MapMode.READ_WRITE,
                                        offset, 100);

            for (int i=0; i<4; i++) {
                b.put(i, (byte)('0' + i));
            }

            for (int i=0; i<4; i++) {
                byte aByte = b.get(i);
                sb.setCharAt(i, (char)aByte);
            }
            if (!sb.toString().equals("0123"))
                throw new Exception("Write test failed");
        }
    }
}

项目：openjdk-jdk10 文件：MapTest.java

/**
 * Maps blah file with a random offset and checks to see if data
 * written out to the file can be read back in
 */
private static void testWrite() throws Exception {
    StringBuilder sb = new StringBuilder();
    sb.setLength(4);

    for (int x=0; x<1000; x++) {
        try (RandomAccessFile raf = new RandomAccessFile(blah, "rw")) {
            FileChannel fc = raf.getChannel();

            long offset = generator.nextInt(1000);
            MappedByteBuffer b = fc.map(MapMode.READ_WRITE,
                                        offset, 100);

            for (int i=0; i<4; i++) {
                b.put(i, (byte)('0' + i));
            }

            for (int i=0; i<4; i++) {
                byte aByte = b.get(i);
                sb.setCharAt(i, (char)aByte);
            }
            if (!sb.toString().equals("0123"))
                throw new Exception("Write test failed");
        }
    }
}

项目：googles-monorepo-demo 文件：FilesTest.java

public void testMap_readWrite() throws IOException {
  // Test data
  int size = 1024;
  byte[] expectedBytes = new byte[size];
  byte[] bytes = newPreFilledByteArray(1024);

  // Setup
  File file = createTempFile();
  Files.write(bytes, file);

  Random random = new Random();
  random.nextBytes(expectedBytes);

  // Test
  MappedByteBuffer map = Files.map(file, MapMode.READ_WRITE);
  map.put(expectedBytes);

  // Verify
  byte[] actualBytes = Files.toByteArray(file);
  assertTrue(Arrays.equals(expectedBytes, actualBytes));
}

项目：googles-monorepo-demo 文件：FilesTest.java

public void testMap_readWrite_creates() throws IOException {
  // Test data
  int size = 1024;
  byte[] expectedBytes = newPreFilledByteArray(1024);

  // Setup
  File file = createTempFile();
  boolean deleted = file.delete();
  assertTrue(deleted);
  assertFalse(file.exists());

  // Test
  MappedByteBuffer map = Files.map(file, MapMode.READ_WRITE, size);
  map.put(expectedBytes);

  // Verify
  assertTrue(file.exists());
  assertTrue(file.isFile());
  assertEquals(size, file.length());
  byte[] actualBytes = Files.toByteArray(file);
  assertTrue(Arrays.equals(expectedBytes, actualBytes));
}

项目：rmq4note 文件：StoreCheckpoint.java

public StoreCheckpoint(final String scpPath) throws IOException {
    File file = new File(scpPath);
    MappedFile.ensureDirOK(file.getParent());
    boolean fileExists = file.exists();

    this.randomAccessFile = new RandomAccessFile(file, "rw");
    this.fileChannel = this.randomAccessFile.getChannel();
    this.mappedByteBuffer = fileChannel.map(MapMode.READ_WRITE, 0, MappedFile.OS_PAGE_SIZE);

    if (fileExists) {
        log.info("store checkpoint file exists, " + scpPath);
        this.physicMsgTimestamp = this.mappedByteBuffer.getLong(0);
        this.logicsMsgTimestamp = this.mappedByteBuffer.getLong(8);
        this.indexMsgTimestamp = this.mappedByteBuffer.getLong(16);

        log.info("store checkpoint file physicMsgTimestamp " + this.physicMsgTimestamp + ", "
            + UtilAll.timeMillisToHumanString(this.physicMsgTimestamp));
        log.info("store checkpoint file logicsMsgTimestamp " + this.logicsMsgTimestamp + ", "
            + UtilAll.timeMillisToHumanString(this.logicsMsgTimestamp));
        log.info("store checkpoint file indexMsgTimestamp " + this.indexMsgTimestamp + ", "
            + UtilAll.timeMillisToHumanString(this.indexMsgTimestamp));
    } else {
        log.info("store checkpoint file not exists, " + scpPath);
    }
}

项目：openjdk9 文件：MapTest.java

/**
 * Maps blah file with a random offset and checks to see if data
 * written out to the file can be read back in
 */
private static void testWrite() throws Exception {
    StringBuilder sb = new StringBuilder();
    sb.setLength(4);

    for (int x=0; x<1000; x++) {
        try (RandomAccessFile raf = new RandomAccessFile(blah, "rw")) {
            FileChannel fc = raf.getChannel();

            long offset = generator.nextInt(1000);
            MappedByteBuffer b = fc.map(MapMode.READ_WRITE,
                                        offset, 100);

            for (int i=0; i<4; i++) {
                b.put(i, (byte)('0' + i));
            }

            for (int i=0; i<4; i++) {
                byte aByte = b.get(i);
                sb.setCharAt(i, (char)aByte);
            }
            if (!sb.toString().equals("0123"))
                throw new Exception("Write test failed");
        }
    }
}

项目：rocketmq 文件：StoreCheckpoint.java

public StoreCheckpoint(final String scpPath) throws IOException {
    File file = new File(scpPath);
    MappedFile.ensureDirOK(file.getParent());
    boolean fileExists = file.exists();

    this.randomAccessFile = new RandomAccessFile(file, "rw");
    this.fileChannel = this.randomAccessFile.getChannel();
    this.mappedByteBuffer = fileChannel.map(MapMode.READ_WRITE, 0, MappedFile.OS_PAGE_SIZE);

    if (fileExists) {
        log.info("store checkpoint file exists, " + scpPath);
        this.physicMsgTimestamp = this.mappedByteBuffer.getLong(0);
        this.logicsMsgTimestamp = this.mappedByteBuffer.getLong(8);
        this.indexMsgTimestamp = this.mappedByteBuffer.getLong(16);

        log.info("store checkpoint file physicMsgTimestamp " + this.physicMsgTimestamp + ", "
            + UtilAll.timeMillisToHumanString(this.physicMsgTimestamp));
        log.info("store checkpoint file logicsMsgTimestamp " + this.logicsMsgTimestamp + ", "
            + UtilAll.timeMillisToHumanString(this.logicsMsgTimestamp));
        log.info("store checkpoint file indexMsgTimestamp " + this.indexMsgTimestamp + ", "
            + UtilAll.timeMillisToHumanString(this.indexMsgTimestamp));
    } else {
        log.info("store checkpoint file not exists, " + scpPath);
    }
}

项目：aliyun-oss-hadoop-fs 文件：MappableBlock.java

/**
 * Load the block.
 *
 * mmap and mlock the block, and then verify its checksum.
 *
 * @param length         The current length of the block.
 * @param blockIn        The block input stream.  Should be positioned at the
 *                       start.  The caller must close this.
 * @param metaIn         The meta file input stream.  Should be positioned at
 *                       the start.  The caller must close this.
 * @param blockFileName  The block file name, for logging purposes.
 *
 * @return               The Mappable block.
 */
public static MappableBlock load(long length,
    FileInputStream blockIn, FileInputStream metaIn,
    String blockFileName) throws IOException {
  MappableBlock mappableBlock = null;
  MappedByteBuffer mmap = null;
  FileChannel blockChannel = null;
  try {
    blockChannel = blockIn.getChannel();
    if (blockChannel == null) {
      throw new IOException("Block InputStream has no FileChannel.");
    }
    mmap = blockChannel.map(MapMode.READ_ONLY, 0, length);
    NativeIO.POSIX.getCacheManipulator().mlock(blockFileName, mmap, length);
    verifyChecksum(length, metaIn, blockChannel, blockFileName);
    mappableBlock = new MappableBlock(mmap, length);
  } finally {
    IOUtils.closeQuietly(blockChannel);
    if (mappableBlock == null) {
      if (mmap != null) {
        NativeIO.POSIX.munmap(mmap); // unmapping also unlocks
      }
    }
  }
  return mappableBlock;
}

项目：SOAPgaea 文件：BioMemoryShare.java

/**
 * load bio information;egg : chromosome or dbsnp
 */
protected void loadInformation(String path) throws IOException {
    RandomAccessFile raf = new RandomAccessFile(path, "r");
    FileChannel fc = raf.getChannel();
    fcSize = (int) (fc.size() & 0xffffffff);
    int blocks = (int) ((fcSize / Integer.MAX_VALUE) + 1);
    byteBuffer = new MappedByteBuffer[blocks];
    int start = 0;
    long remain = 0;
    int size = 0;
    for (int i = 0; i < blocks; i++) {
        start = Integer.MAX_VALUE * i;
        remain = (long) (fc.size() - start);
        size = (int) ((remain > Integer.MAX_VALUE) ? Integer.MAX_VALUE : remain);
        MappedByteBuffer mapedBB = fc.map(MapMode.READ_ONLY, start, size);
        byteBuffer[i] = mapedBB;
    }
    raf.close();
}

项目：bt 文件：AnonAllocator.java

/**
 * on posix systems: allocates disk-backed bytebuffer and immediately unlinks the file
 * on others: simply returns a direct bytebuffer
 */
public static ByteBuffer allocate(int size) {
    if(MAP_AND_UNLINK_SUPPORTED) {
        try {
            Path p = Files.createTempFile("anon-mapping", ".tmp");
            ByteBuffer mapped;
            FileChannel chan = FileChannel.open(p, StandardOpenOption.READ, StandardOpenOption.WRITE);
            chan.position(size);
            chan.write(ByteBuffer.allocate(1));
            mapped = chan.map(MapMode.READ_WRITE, 0, size);
            chan.close();
            Files.delete(p);
            return mapped;
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    return ByteBuffer.allocateDirect(size);
}

项目：baratine 文件：BootFile.java

BootFile(Path bootPath)
  throws IOException
{
  Objects.requireNonNull(bootPath);

  _bootPath = bootPath;
  long bootSize = Files.size(bootPath);

  if (bootSize <= 0) {
    throw new IllegalStateException("Unexpected boot size for " + bootPath);
  }

  if (bootSize >= Integer.MAX_VALUE - 1) {
    throw new IllegalStateException("Mmapped file is too large for " + bootPath + " " + _bootSize);
  }

  _bootSize = (int) bootSize;

  _bootChannel = (FileChannel) Files.newByteChannel(_bootPath, StandardOpenOption.READ);

  _bootMap = _bootChannel.map(MapMode.READ_ONLY, 0, _bootSize);

  readJar();

  readManifest();
}

项目：big-c 文件：MappableBlock.java

/**
 * Load the block.
 *
 * mmap and mlock the block, and then verify its checksum.
 *
 * @param length         The current length of the block.
 * @param blockIn        The block input stream.  Should be positioned at the
 *                       start.  The caller must close this.
 * @param metaIn         The meta file input stream.  Should be positioned at
 *                       the start.  The caller must close this.
 * @param blockFileName  The block file name, for logging purposes.
 *
 * @return               The Mappable block.
 */
public static MappableBlock load(long length,
    FileInputStream blockIn, FileInputStream metaIn,
    String blockFileName) throws IOException {
  MappableBlock mappableBlock = null;
  MappedByteBuffer mmap = null;
  FileChannel blockChannel = null;
  try {
    blockChannel = blockIn.getChannel();
    if (blockChannel == null) {
      throw new IOException("Block InputStream has no FileChannel.");
    }
    mmap = blockChannel.map(MapMode.READ_ONLY, 0, length);
    NativeIO.POSIX.getCacheManipulator().mlock(blockFileName, mmap, length);
    verifyChecksum(length, metaIn, blockChannel, blockFileName);
    mappableBlock = new MappableBlock(mmap, length);
  } finally {
    IOUtils.closeQuietly(blockChannel);
    if (mappableBlock == null) {
      if (mmap != null) {
        NativeIO.POSIX.munmap(mmap); // unmapping also unlocks
      }
    }
  }
  return mappableBlock;
}

项目：minperf 文件：LargeLongList.java

static LargeLongArray create(Iterator<Long> iterator, int size) {
    try {
        File file = File.createTempFile("list", ".tmp");
        file.deleteOnExit();
        try (RandomAccessFile raf = new RandomAccessFile(file, "rw")) {
            FileChannel channel = raf.getChannel();
            MappedByteBuffer map = channel
                    .map(MapMode.READ_WRITE, 0, size * 8L);
            for (int i = 0; i < size; i++) {
                long x = iterator.next();
                map.putLong(x);
            }
            return new LargeLongArray(size, file, channel, map);
        }
    } catch (IOException e) {
        throw new RuntimeException(e);
    }
}

项目：fastcatsearch3 文件：MMapDirectory.java

/** Maps a file into a set of buffers */
ByteBuffer[] map(RandomAccessFile raf, long offset, long length) throws IOException {
  if ((length >>> chunkSizePower) >= Integer.MAX_VALUE)
    throw new IllegalArgumentException("RandomAccessFile too big for chunk size: " + raf.toString());

  final long chunkSize = 1L << chunkSizePower;

  // we always allocate one more buffer, the last one may be a 0 byte one
  final int nrBuffers = (int) (length >>> chunkSizePower) + 1;

  ByteBuffer buffers[] = new ByteBuffer[nrBuffers];

  long bufferStart = 0L;
  FileChannel rafc = raf.getChannel();
  for (int bufNr = 0; bufNr < nrBuffers; bufNr++) { 
    int bufSize = (int) ( (length > (bufferStart + chunkSize))
        ? chunkSize
            : (length - bufferStart)
        );
    buffers[bufNr] = rafc.map(MapMode.READ_ONLY, offset + bufferStart, bufSize);
    bufferStart += bufSize;
  }

  return buffers;
}

项目：rocketmq-commet 文件：StoreCheckpoint.java

public StoreCheckpoint(final String scpPath) throws IOException {
    File file = new File(scpPath);
    MapedFile.ensureDirOK(file.getParent());
    boolean fileExists = file.exists();

    this.randomAccessFile = new RandomAccessFile(file, "rw");
    this.fileChannel = this.randomAccessFile.getChannel();
    this.mappedByteBuffer = fileChannel.map(MapMode.READ_WRITE, 0, MapedFile.OS_PAGE_SIZE);

    if (fileExists) {
        log.info("store checkpoint file exists, " + scpPath);
        this.physicMsgTimestamp = this.mappedByteBuffer.getLong(0);
        this.logicsMsgTimestamp = this.mappedByteBuffer.getLong(8);
        this.indexMsgTimestamp = this.mappedByteBuffer.getLong(16);

        log.info("store checkpoint file physicMsgTimestamp " + this.physicMsgTimestamp + ", "
                + UtilAll.timeMillisToHumanString(this.physicMsgTimestamp));
        log.info("store checkpoint file logicsMsgTimestamp " + this.logicsMsgTimestamp + ", "
                + UtilAll.timeMillisToHumanString(this.logicsMsgTimestamp));
        log.info("store checkpoint file indexMsgTimestamp " + this.indexMsgTimestamp + ", "
                + UtilAll.timeMillisToHumanString(this.indexMsgTimestamp));
    }
    else {
        log.info("store checkpoint file not exists, " + scpPath);
    }
}

项目：jdk8u_jdk 文件：MapTest.java

/**
 * Maps blah file with a random offset and checks to see if data
 * written out to the file can be read back in
 */
private static void testWrite() throws Exception {
    StringBuilder sb = new StringBuilder();
    sb.setLength(4);

    for (int x=0; x<1000; x++) {
        try (RandomAccessFile raf = new RandomAccessFile(blah, "rw")) {
            FileChannel fc = raf.getChannel();

            long offset = generator.nextInt(1000);
            MappedByteBuffer b = fc.map(MapMode.READ_WRITE,
                                        offset, 100);

            for (int i=0; i<4; i++) {
                b.put(i, (byte)('0' + i));
            }

            for (int i=0; i<4; i++) {
                byte aByte = b.get(i);
                sb.setCharAt(i, (char)aByte);
            }
            if (!sb.toString().equals("0123"))
                throw new Exception("Write test failed");
        }
    }
}

项目：SilverKing 文件：FileSegment.java

static final FileSegment create(File nsDir, int segmentNumber, int dataSegmentSize, SyncMode syncMode, 
                                NamespaceOptions nsOptions) throws IOException {
    RandomAccessFile    raFile;
    byte[]              header;
    ByteBuffer          dataBuf;
    int                 indexOffset;

    indexOffset = dataSegmentSize;
    raFile = new RandomAccessFile(fileForSegment(nsDir, segmentNumber), syncModeToFileOpenMode(syncMode));
    header = SegmentFormat.newHeader(segmentNumber, dataOffset, indexOffset);

    dataBuf = raFile.getChannel().map(MapMode.READ_WRITE, 0, dataSegmentSize);
    dataBuf.put(header);
    //raFile.getFD().sync(); // For now we leave this out and let SyncMode cover this
    return new FileSegment(nsDir, segmentNumber, raFile, dataBuf, dataSegmentSize, nsOptions);
}

项目：lookaside_java-1.8.0-openjdk 文件：MapTest.java

/**
 * Maps blah file with a random offset and checks to see if data
 * written out to the file can be read back in
 */
private static void testWrite() throws Exception {
    StringBuilder sb = new StringBuilder();
    sb.setLength(4);

    for (int x=0; x<1000; x++) {
        try (RandomAccessFile raf = new RandomAccessFile(blah, "rw")) {
            FileChannel fc = raf.getChannel();

            long offset = generator.nextInt(1000);
            MappedByteBuffer b = fc.map(MapMode.READ_WRITE,
                                        offset, 100);

            for (int i=0; i<4; i++) {
                b.put(i, (byte)('0' + i));
            }

            for (int i=0; i<4; i++) {
                byte aByte = b.get(i);
                sb.setCharAt(i, (char)aByte);
            }
            if (!sb.toString().equals("0123"))
                throw new Exception("Write test failed");
        }
    }
}

项目：SEANLP 文件：IOUtil.java

public static byte[] readBytesByMapped(String path) {
    FileChannel fc = null;
    try {
        fc = new RandomAccessFile(path, "r").getChannel();
        MappedByteBuffer byteBuffer = fc.map(MapMode.READ_ONLY, 0, fc.size()).load();
        byte[] bytes = new byte[(int) fc.size()];
        if (byteBuffer.remaining() > 0) {
            byteBuffer.get(bytes, 0, byteBuffer.remaining());
        }
        fc.close();
        return bytes;
    } catch (Exception e) {
        Log.logger.warning("读取" + path + "时发生异常" + e.getMessage());
    }
    return null;
}

项目：antsdb 文件：Space.java

public void open(MapMode mode, int fileSize) throws IOException {
       int fileLength = (int)this.file.length();
       int size = (mode == MapMode.READ_WRITE) ? fileSize : fileLength;
    this.mmf = new MemoryMappedFile(this.file, size, mode == MapMode.READ_WRITE ? "rw" : "r");
       if (mode == MapMode.READ_WRITE) {
           File parent = file.getAbsoluteFile().getParentFile();
           long free = parent.getUsableSpace();
           if ((fileSize * 4) > free) {
               throw new HumpbackException("out of storage space: " + this.file.toString() + ' ' + free);
           }
       }
       if (mode == MapMode.READ_WRITE) {
           this.mmf.buf.load();
       }
       this.mmf.buf.order(ByteOrder.LITTLE_ENDIAN);
       this.addr = this.mmf.getAddress();
       this.spStart = SpaceManager.makeSpacePointer(this.id, 0);
       this.spEnd = fileSize + this.spStart;
       this.allocPointer = new AtomicInteger(fileLength);
       this.capacity = this.mmf.buf.capacity();
}

项目：crail 文件：MappedBufferCache.java

private CrailBuffer allocateRegion() throws IOException {
    if (currentRegion >= allocationCount){
        return null;
    }

    String path = directory + "/" + currentRegion++;
    RandomAccessFile randomFile = new RandomAccessFile(path, "rw");
    randomFile.setLength(CrailConstants.REGION_SIZE);
    FileChannel channel = randomFile.getChannel();
    MappedByteBuffer _mappedBuffer = channel.map(MapMode.READ_WRITE, 0,
            CrailConstants.REGION_SIZE);
    CrailBuffer mappedBuffer = OffHeapBuffer.wrap(_mappedBuffer);
    randomFile.close();
    channel.close();

    CrailBuffer firstBuffer = slice(mappedBuffer, 0);

    for (int j = 1; j < bufferCount; j++) {
        int position = j * CrailConstants.BUFFER_SIZE;
        CrailBuffer sliceBuffer = slice(mappedBuffer, position);
        this.putBufferInternal(sliceBuffer);
    }
    mappedBuffer.clear();

    return firstBuffer;
}

项目：incubator-netbeans 文件：TrieDictionary.java

private TrieDictionary(File data) throws IOException {
    this.array = null;

    FileInputStream ins = new FileInputStream(data);
    FileChannel channel = ins.getChannel();

    try {
        this.buffer = channel.map(MapMode.READ_ONLY, 0, channel.size());
    } finally {
        channel.close();
        ins.close();
    }
}

项目：OpenDiabetes 文件：RAFileNIO.java

private boolean enlargeFile(long newFileLength) {

        try {
            long newBufferLength = newFileLength;

            if (!readOnly) {
                newBufferLength = largeBufferSize;
            }

            MapMode mapMode = readOnly ? FileChannel.MapMode.READ_ONLY
                                       : FileChannel.MapMode.READ_WRITE;

            if (!readOnly && file.length() < fileLength + newBufferLength) {
                file.seek(fileLength + newBufferLength - 1);
                file.writeByte(0);
            }

            MappedByteBuffer[] newBuffers =
                new MappedByteBuffer[buffers.length + 1];
            MappedByteBuffer newBuffer = channel.map(mapMode, fileLength,
                newBufferLength);

            System.arraycopy(buffers, 0, newBuffers, 0, buffers.length);

            newBuffers[buffers.length] = newBuffer;
            buffers                    = newBuffers;
            fileLength                 += newBufferLength;

            logger.logDetailEvent("NIO buffer instance, file size "
                                  + fileLength);
        } catch (Throwable e) {
            logger.logDetailEvent("NOI buffer allocate failed, file size "
                                  + newFileLength);

            return false;
        }

        return true;
    }

项目：qrcode-utils 文件：QrcodeUtils.java

/**
 * 将文件转换为字节数组，
 * 使用MappedByteBuffer，可以在处理大文件时，提升性能
 *
 * @param file 文件
 * @return 二维码图片的字节数组
 */
private static byte[] toByteArray(File file) {
  try (FileChannel fc = new RandomAccessFile(file, "r").getChannel();) {
    MappedByteBuffer byteBuffer = fc.map(MapMode.READ_ONLY, 0, fc.size()).load();
    byte[] result = new byte[(int) fc.size()];
    if (byteBuffer.remaining() > 0) {
      byteBuffer.get(result, 0, byteBuffer.remaining());
    }
    return result;
  } catch (Exception e) {
    logger.warn("文件转换成byte[]发生异常！", e);
    return null;
  }
}

项目：SubtitleDownloader 文件：OpenSubtitlesHasher.java

public static String computeHash(File file) throws IOException {
    if (!file.isFile()) {
        return "";
    }
    long size = file.length();
    long chunkSizeForFile = Math.min(HASH_CHUNK_SIZE, size);

    try (FileChannel fileChannel = new FileInputStream(file).getChannel()) {
        long head = computeHashForChunk(fileChannel.map(MapMode.READ_ONLY, 0, chunkSizeForFile));
        long tail = computeHashForChunk(fileChannel.map(MapMode.READ_ONLY, Math.max(size - HASH_CHUNK_SIZE, 0), chunkSizeForFile));

        return String.format("%016x", size + head + tail);
    }
}

项目：guava-mock 文件：Files.java

private static MappedByteBuffer map(RandomAccessFile raf, MapMode mode, long size)
    throws IOException {
  Closer closer = Closer.create();
  try {
    FileChannel channel = closer.register(raf.getChannel());
    return channel.map(mode, 0, size);
  } catch (Throwable e) {
    throw closer.rethrow(e);
  } finally {
    closer.close();
  }
}

项目：guava-mock 文件：PackageSanityTests.java

public PackageSanityTests() {
  setDefault(BaseEncoding.class, BaseEncoding.base64());
  setDefault(int.class, 32);
  setDefault(String.class, "abcd");
  setDefault(Method.class, AbstractPackageSanityTests.class.getDeclaredMethods()[0]);
  setDefault(MapMode.class, MapMode.READ_ONLY);
  setDefault(CharsetEncoder.class, Charsets.UTF_8.newEncoder());
}

项目：guava-mock 文件：FilesTest.java

public void testMap_readWrite_max_value_plus_1() throws IOException {
  // Setup
  File file = createTempFile();
  // Test
  try {
    Files.map(file, MapMode.READ_WRITE, (long) Integer.MAX_VALUE + 1);
    fail("Should throw when size exceeds Integer.MAX_VALUE");
  } catch (IllegalArgumentException expected) {
  }
}