Java FileChannel.force方法代码示例

import java.nio.channels.FileChannel; //导入方法依赖的package包/类
/**
 * 将字节数组写入文件
 *
 * @param file    文件
 * @param bytes   字节数组
 * @param append  是否追加在文件末
 * @param isForce 是否写入文件
 * @return {@code true}: 写入成功<br>{@code false}: 写入失败
 */
public static boolean writeFileFromBytesByChannel(File file, final byte[] bytes, boolean append, boolean isForce) {
    if (bytes == null) return false;
    if (!append && !FileUtils.createFileByDeleteOldFile(file)) return false;
    FileChannel fc = null;
    try {
        fc = new RandomAccessFile(file, "rw").getChannel();
        fc.position(fc.size());
        fc.write(ByteBuffer.wrap(bytes));
        if (isForce) fc.force(true);
        return true;
    } catch (IOException e) {
        e.printStackTrace();
        return false;
    } finally {
        CloseUtils.closeIO(fc);
    }
}
 

import java.nio.channels.FileChannel; //导入方法依赖的package包/类
/**
 * 将字节数组写入文件
 *
 * @param file    文件
 * @param bytes   字节数组
 * @param append  是否追加在文件末
 * @param isForce 是否写入文件
 * @return {@code true}: 写入成功<br>{@code false}: 写入失败
 */
public static boolean writeFileFromBytesByChannel(final File file, final byte[] bytes, final boolean append, final boolean isForce) {
    if (bytes == null) return false;
    FileChannel fc = null;
    try {
        fc = new FileOutputStream(file, append).getChannel();
        fc.position(fc.size());
        fc.write(ByteBuffer.wrap(bytes));
        if (isForce) fc.force(true);
        return true;
    } catch (IOException e) {
        e.printStackTrace();
        return false;
    } finally {
        CloseUtils.closeIO(fc);
    }
}
 

import java.nio.channels.FileChannel; //导入方法依赖的package包/类
public void flush() {
    if (!needsFlush) {
        return;
    }
    needsFlush = false;
    LOGGER.info("flushing bucket {}", bucketNumber);
    try {
        synchronized (this) {
            final FileChannel openChannel = getOpenChannel();
            if (openChannel.isOpen()) {
                openChannel.force(wantsTimestampUpdate);
                if (!wantsTimestampUpdate) {
                    Files.setLastModifiedTime(filePath, lastModifiedTime);
                } else {
                    lastModifiedTime = FileTime.from(Instant.now());
                }
                wantsTimestampUpdate = false;
            }
        }
    } catch (IOException e) {
        LOGGER.warn("unable to flush file of bucket {}", bucketNumber);
    }
}
 

import java.nio.channels.FileChannel; //导入方法依赖的package包/类
/**
 * 将字节数组写入文件
 *
 * @param file    文件
 * @param bytes   字节数组
 * @param append  是否追加在文件末
 * @param isForce 是否写入文件
 * @return {@code true}: 写入成功<br>{@code false}: 写入失败
 */
public static boolean writeFileFromBytesByChannel(File file, final byte[] bytes, boolean append, boolean isForce) {
    if (bytes == null) return false;
    FileChannel fc = null;
    try {
        fc = new FileOutputStream(file, append).getChannel();
        fc.position(fc.size());
        fc.write(ByteBuffer.wrap(bytes));
        if (isForce) fc.force(true);
        return true;
    } catch (IOException e) {
        e.printStackTrace();
        return false;
    } finally {
        CloseUtils.closeIO(fc);
    }
}
 

import java.nio.channels.FileChannel; //导入方法依赖的package包/类
/**
 * 将字节数组写入文件
 *
 * @param file    文件
 * @param bytes   字节数组
 * @param append  是否追加在文件末
 * @param isForce 是否写入文件
 * @return {@code true}: 写入成功<br>{@code false}: 写入失败
 */
public static boolean writeFileFromBytesByChannel(final File file, final byte[] bytes, final boolean append, final boolean isForce) {
	if (bytes == null) {
		return false;
	}
	FileChannel fc = null;
	try {
		fc = new FileOutputStream(file, append).getChannel();
		fc.position(fc.size());
		fc.write(ByteBuffer.wrap(bytes));
		if (isForce) {
			fc.force(true);
		}
		return true;
	} catch (IOException e) {
		e.printStackTrace();
		return false;
	} finally {
		CloseUtils.closeIO(fc);
	}
}
 

import java.nio.channels.FileChannel; //导入方法依赖的package包/类
public static TranslogWriter create(Type type, ShardId shardId, String translogUUID, long fileGeneration, Path file, Callback<ChannelReference> onClose, int bufferSize, ChannelFactory channelFactory) throws IOException {
    final BytesRef ref = new BytesRef(translogUUID);
    final int headerLength = getHeaderLength(ref.length);
    final FileChannel channel = channelFactory.open(file);
    try {
        // This OutputStreamDataOutput is intentionally not closed because
        // closing it will close the FileChannel
        final OutputStreamDataOutput out = new OutputStreamDataOutput(java.nio.channels.Channels.newOutputStream(channel));
        CodecUtil.writeHeader(out, TRANSLOG_CODEC, VERSION);
        out.writeInt(ref.length);
        out.writeBytes(ref.bytes, ref.offset, ref.length);
        channel.force(true);
        writeCheckpoint(headerLength, 0, file.getParent(), fileGeneration, StandardOpenOption.WRITE);
        final TranslogWriter writer = type.create(shardId, fileGeneration, new ChannelReference(file, fileGeneration, channel, onClose), bufferSize);
        return writer;
    } catch (Throwable throwable){
        // if we fail to bake the file-generation into the checkpoint we stick with the file and once we recover and that
        // file exists we remove it. We only apply this logic to the checkpoint.generation+1 any other file with a higher generation is an error condition
        IOUtils.closeWhileHandlingException(channel);
        throw throwable;
    }
}
 

import java.nio.channels.FileChannel; //导入方法依赖的package包/类
public static void force(FileChannel fc, boolean metaData) throws IOException
{
    Preconditions.checkNotNull(fc);
    if (SKIP_SYNC)
    {
        if (!fc.isOpen())
            throw new ClosedChannelException();
    }
    else
    {
        fc.force(metaData);
    }
}
 

import java.nio.channels.FileChannel; //导入方法依赖的package包/类
private static void writeFileFromBytes(final File file, final byte[] bytes) {
    FileChannel fc = null;
    try {
        fc = new FileOutputStream(file, false).getChannel();
        fc.write(ByteBuffer.wrap(bytes));
        fc.force(true);
    } catch (IOException e) {
        e.printStackTrace();
    } finally {
        CloseUtils.closeIO(fc);
    }
}
 

import java.nio.channels.FileChannel; //导入方法依赖的package包/类
@Override
public void trim(long offset, long length) throws IOException {
    final long offsetInThisBucket = offsetInThisBucket(offset);
    final long lengthInThisBucket = calcLengthInThisBucket(offsetInThisBucket, length); //should be always equal to length since it is normalized in MineboxEport
    final FileChannel channel = getOpenChannel();
    final long fileSize = channel.size();
    if (fileSize == 0 || offsetInThisBucket >= fileSize) {
        //if the file is empty, there is nothing to trim
    } else if (lengthInThisBucket == this.bucketSize) {
        if (fileSize > 0)
        //if we are trimming the whole bucket we can truncate to 0
        {
            synchronized (this) {
                channel.truncate(0);
                channel.force(true);
            }
            needsFlush = true;
        }
    } else if (offsetInThisBucket == 0 && lengthInThisBucket >= fileSize) {
        //we are trimming the whole file, so we can truncate it.
        synchronized (this) {
            channel.truncate(0);
            channel.force(true);
        }
        needsFlush = true;
    } else if (offsetInThisBucket + lengthInThisBucket == this.bucketSize) {
        //truncating from index until end, we can shorten the file now
        synchronized (this) {
            channel.truncate(offsetInThisBucket);
            channel.force(false); //since we assume the un-truncated file was actually backed up, we don't care if this shortened file is not the one uploaded, since truncate is a "best effort" operations btrfs should tolerate those data being non-zero
        }
        needsFlush = true;
    } else {
        final int intLen = Ints.checkedCast(length); //buckets can not be bigger than 2GB right now, could be fixed
        final ByteBuffer bb = ByteBuffer.allocate(intLen);
        bb.put(new byte[intLen]);
        bb.flip();
        putBytesInternal(offset, bb, false); //sadly, this will encrypt zeroes. we need a workaround
    }
}
 

import java.nio.channels.FileChannel; //导入方法依赖的package包/类
static void truncateFileToConsistentSize(FileOutputStream fos, long size) {
    try {
        FileChannel fch = fos.getChannel();
        fch.truncate(size);
        fch.force(true);
    } catch (IOException ex) {
        Logger.getLogger(DataConsistentFileOutputStream.class.getName()).log(
                Level.INFO,
                "Not able to truncate file to the data consistent size of "+size+" bytes.",
                ex);
    }
}
 

import java.nio.channels.FileChannel; //导入方法依赖的package包/类
public static TranslogWriter create(
    ShardId shardId,
    String translogUUID,
    long fileGeneration,
    Path file,
    ChannelFactory channelFactory,
    ByteSizeValue bufferSize,
    final LongSupplier globalCheckpointSupplier) throws IOException {
    final BytesRef ref = new BytesRef(translogUUID);
    final int headerLength = getHeaderLength(ref.length);
    final FileChannel channel = channelFactory.open(file);
    try {
        // This OutputStreamDataOutput is intentionally not closed because
        // closing it will close the FileChannel
        final OutputStreamDataOutput out = new OutputStreamDataOutput(java.nio.channels.Channels.newOutputStream(channel));
        writeHeader(out, ref);
        channel.force(true);
        final Checkpoint checkpoint =
                Checkpoint.emptyTranslogCheckpoint(headerLength, fileGeneration, globalCheckpointSupplier.getAsLong());
        writeCheckpoint(channelFactory, file.getParent(), checkpoint);
        return new TranslogWriter(channelFactory, shardId, checkpoint, channel, file, bufferSize, globalCheckpointSupplier);
    } catch (Exception exception) {
        // if we fail to bake the file-generation into the checkpoint we stick with the file and once we recover and that
        // file exists we remove it. We only apply this logic to the checkpoint.generation+1 any other file with a higher generation is an error condition
        IOUtils.closeWhileHandlingException(channel);
        throw exception;
    }
}
 

import java.nio.channels.FileChannel; //导入方法依赖的package包/类
private static void writeFileFromBytes(File file, byte[] bytes) {
    FileChannel fc = null;
    try {
        fc = new FileOutputStream(file, false).getChannel();
        fc.write(ByteBuffer.wrap(bytes));
        fc.force(true);
    } catch (IOException e) {
        e.printStackTrace();
    } finally {
        CloseUtils.closeIO(fc);
    }
}
 

import java.nio.channels.FileChannel; //导入方法依赖的package包/类
public void force(boolean metaData) {
    try {
        for (FileChannel file : this.files) {
            file.force(metaData);
        }
    } catch (IOException e) {
        closeFileSilently();
        throw TmpFileException.get(ErrorCode.ER_FILE_FORCE, e, name);
    }
}
 

import java.nio.channels.FileChannel; //导入方法依赖的package包/类
@Override
public synchronized void flush() throws IOException {
    super.flush();
    FileChannel fch = fos.getChannel();
    fch.force(true);
}
 

import java.nio.channels.FileChannel; //导入方法依赖的package包/类
@Test
public void testReadableByteChannel() throws Exception {
    int[] testSizes = { 0, 10, 1023, 1024, 1025, 2047, 2048, 2049 };

    for (int size : testSizes) {
        SelectorProvider sp = SelectorProvider.provider();
        Pipe p = sp.openPipe();
        Pipe.SinkChannel sink = p.sink();
        Pipe.SourceChannel source = p.source();
        sink.configureBlocking(false);

        ByteBuffer outgoingdata = ByteBuffer.allocateDirect(size + 10);
        byte[] someBytes = new byte[size + 10];
        generator.nextBytes(someBytes);
        outgoingdata.put(someBytes);
        outgoingdata.flip();

        int totalWritten = 0;
        while (totalWritten < size + 10) {
            int written = sink.write(outgoingdata);
            if (written < 0)
                throw new Exception("Write failed");
            totalWritten += written;
        }

        File f = File.createTempFile("blah"+size, null);
        f.deleteOnExit();
        RandomAccessFile raf = new RandomAccessFile(f, "rw");
        FileChannel fc = raf.getChannel();
        long oldPosition = fc.position();

        long bytesWritten = fc.transferFrom(source, 0, size);
        fc.force(true);
        if (bytesWritten != size)
            throw new RuntimeException("Transfer failed");

        if (fc.position() != oldPosition)
            throw new RuntimeException("Position changed");

        if (fc.size() != size)
            throw new RuntimeException("Unexpected sink size "+ fc.size());

        fc.close();
        sink.close();
        source.close();

        f.delete();
    }
}