Package com.google.common.jimfs

Class JimfsFileChannel

java.lang.Object

java.nio.channels.spi.AbstractInterruptibleChannel

java.nio.channels.FileChannel

com.google.common.jimfs.JimfsFileChannel

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, java.nio.channels.ByteChannel, java.nio.channels.Channel, java.nio.channels.GatheringByteChannel, java.nio.channels.InterruptibleChannel, java.nio.channels.ReadableByteChannel, java.nio.channels.ScatteringByteChannel, java.nio.channels.SeekableByteChannel, java.nio.channels.WritableByteChannel

final class JimfsFileChannel
extends java.nio.channels.FileChannel

A FileChannel implementation that reads and writes to a RegularFile object. The read and write methods and other methods that read or change the position of the channel are locked because the ReadableByteChannel and WritableByteChannel interfaces specify that the read and write methods block when another thread is currently doing a read or write operation.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
(package private) static class	JimfsFileChannel.FakeFileLock	A file lock that does nothing, since only one JVM process has access to this file system.

Nested classes/interfaces inherited from class java.nio.channels.FileChannel

java.nio.channels.FileChannel.MapMode

Field Summary

Fields

Modifier and Type	Field	Description
private boolean	append
private java.util.Set<java.lang.Thread>	blockingThreads	Set of threads that are currently doing an interruptible blocking operation; that is, doing something that requires acquiring the file's lock.
private RegularFile	file
private FileSystemState	fileSystemState
private long	position
private boolean	read
private boolean	write

Constructor Summary

Constructors

Constructor	Description
JimfsFileChannel(RegularFile file, java.util.Set<java.nio.file.OpenOption> options, FileSystemState fileSystemState)

Method Summary

Modifier and Type	Method	Description
java.nio.channels.AsynchronousFileChannel	asAsynchronousFileChannel(java.util.concurrent.ExecutorService executor)	Returns an AsynchronousFileChannel view of this channel using the given executor for asynchronous operations.
private boolean	beginBlocking()	Begins a blocking operation, making the operation interruptible.
private void	checkLockArguments(long position, long size, boolean shared)
(package private) void	checkOpen()
(package private) void	checkReadable()
(package private) void	checkWritable()
private void	endBlocking(boolean completed)	Ends a blocking operation, throwing an exception if the thread was interrupted while blocking or if the channel was closed from another thread.
void	force(boolean metaData)
protected void	implCloseChannel()
java.nio.channels.FileLock	lock(long position, long size, boolean shared)
java.nio.MappedByteBuffer	map(java.nio.channels.FileChannel.MapMode mode, long position, long size)
long	position()
java.nio.channels.FileChannel	position(long newPosition)
int	read(java.nio.ByteBuffer dst)
long	read(java.nio.ByteBuffer[] dsts, int offset, int length)
int	read(java.nio.ByteBuffer dst, long position)
long	size()
long	transferFrom(java.nio.channels.ReadableByteChannel src, long position, long count)
long	transferTo(long position, long count, java.nio.channels.WritableByteChannel target)
java.nio.channels.FileChannel	truncate(long size)
java.nio.channels.FileLock	tryLock(long position, long size, boolean shared)
int	write(java.nio.ByteBuffer src)
long	write(java.nio.ByteBuffer[] srcs, int offset, int length)
int	write(java.nio.ByteBuffer src, long position)

Methods inherited from class java.nio.channels.FileChannel

lock, open, open, read, tryLock, write

Methods inherited from class java.nio.channels.spi.AbstractInterruptibleChannel

begin, close, end, isOpen

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.nio.channels.Channel

isOpen

Field Detail

blockingThreads

private final java.util.Set<java.lang.Thread> blockingThreads

Set of threads that are currently doing an interruptible blocking operation; that is, doing something that requires acquiring the file's lock. These threads must be interrupted if the channel is closed by another thread.

file

private final RegularFile file

fileSystemState

private final FileSystemState fileSystemState

read

private final boolean read

write

private final boolean write

append

private final boolean append

position

private long position

Constructor Detail

JimfsFileChannel

public JimfsFileChannel(RegularFile file,
                        java.util.Set<java.nio.file.OpenOption> options,
                        FileSystemState fileSystemState)

Method Detail

asAsynchronousFileChannel

public java.nio.channels.AsynchronousFileChannel asAsynchronousFileChannel(java.util.concurrent.ExecutorService executor)

Returns an AsynchronousFileChannel view of this channel using the given executor for asynchronous operations.

checkReadable

void checkReadable()

checkWritable

void checkWritable()

checkOpen

void checkOpen()
        throws java.nio.channels.ClosedChannelException

Throws:

java.nio.channels.ClosedChannelException

beginBlocking

private boolean beginBlocking()

Begins a blocking operation, making the operation interruptible. Returns true if the channel was open and the thread was added as a blocking thread; returns false if the channel was closed.

endBlocking

private void endBlocking(boolean completed)
                  throws java.nio.channels.AsynchronousCloseException

Ends a blocking operation, throwing an exception if the thread was interrupted while blocking or if the channel was closed from another thread.

Throws:

java.nio.channels.AsynchronousCloseException

read

public int read(java.nio.ByteBuffer dst)
         throws java.io.IOException

Specified by:

read in interface java.nio.channels.ReadableByteChannel

Specified by:

read in interface java.nio.channels.SeekableByteChannel

Specified by:

read in class java.nio.channels.FileChannel

Throws:

java.io.IOException

read

public long read(java.nio.ByteBuffer[] dsts,
                 int offset,
                 int length)
          throws java.io.IOException

Specified by:

read in interface java.nio.channels.ScatteringByteChannel

Specified by:

read in class java.nio.channels.FileChannel

Throws:

java.io.IOException

read

public int read(java.nio.ByteBuffer dst,
                long position)
         throws java.io.IOException

Specified by:

read in class java.nio.channels.FileChannel

Throws:

java.io.IOException

write

public int write(java.nio.ByteBuffer src)
          throws java.io.IOException

Specified by:

write in interface java.nio.channels.SeekableByteChannel

Specified by:

write in interface java.nio.channels.WritableByteChannel

Specified by:

write in class java.nio.channels.FileChannel

Throws:

java.io.IOException

write

public long write(java.nio.ByteBuffer[] srcs,
                  int offset,
                  int length)
           throws java.io.IOException

Specified by:

write in interface java.nio.channels.GatheringByteChannel

Specified by:

write in class java.nio.channels.FileChannel

Throws:

java.io.IOException

write

public int write(java.nio.ByteBuffer src,
                 long position)
          throws java.io.IOException

Specified by:

write in class java.nio.channels.FileChannel

Throws:

java.io.IOException

position

public long position()
              throws java.io.IOException

Specified by:

position in interface java.nio.channels.SeekableByteChannel

Specified by:

position in class java.nio.channels.FileChannel

Throws:

java.io.IOException

position

@CanIgnoreReturnValue
public java.nio.channels.FileChannel position(long newPosition)
                                       throws java.io.IOException

Specified by:

position in interface java.nio.channels.SeekableByteChannel

Specified by:

position in class java.nio.channels.FileChannel

Throws:

java.io.IOException

size

public long size()
          throws java.io.IOException

Specified by:

size in interface java.nio.channels.SeekableByteChannel

Specified by:

size in class java.nio.channels.FileChannel

Throws:

java.io.IOException

truncate

@CanIgnoreReturnValue
public java.nio.channels.FileChannel truncate(long size)
                                       throws java.io.IOException

Specified by:

truncate in interface java.nio.channels.SeekableByteChannel

Specified by:

truncate in class java.nio.channels.FileChannel

Throws:

java.io.IOException

force

public void force(boolean metaData)
           throws java.io.IOException

Specified by:

force in class java.nio.channels.FileChannel

Throws:

java.io.IOException

transferTo

public long transferTo(long position,
                       long count,
                       java.nio.channels.WritableByteChannel target)
                throws java.io.IOException

Specified by:

transferTo in class java.nio.channels.FileChannel

Throws:

java.io.IOException

transferFrom

public long transferFrom(java.nio.channels.ReadableByteChannel src,
                         long position,
                         long count)
                  throws java.io.IOException

Specified by:

transferFrom in class java.nio.channels.FileChannel

Throws:

java.io.IOException

map

public java.nio.MappedByteBuffer map(java.nio.channels.FileChannel.MapMode mode,
                                     long position,
                                     long size)
                              throws java.io.IOException

Specified by:

map in class java.nio.channels.FileChannel

Throws:

java.io.IOException

lock

public java.nio.channels.FileLock lock(long position,
                                       long size,
                                       boolean shared)
                                throws java.io.IOException

Specified by:

lock in class java.nio.channels.FileChannel

Throws:

java.io.IOException

tryLock

public java.nio.channels.FileLock tryLock(long position,
                                          long size,
                                          boolean shared)
                                   throws java.io.IOException

Specified by:

tryLock in class java.nio.channels.FileChannel

Throws:

java.io.IOException

checkLockArguments

private void checkLockArguments(long position,
                                long size,
                                boolean shared)
                         throws java.io.IOException

Throws:

java.io.IOException

implCloseChannel

protected void implCloseChannel()

Specified by:

implCloseChannel in class java.nio.channels.spi.AbstractInterruptibleChannel