alluxio.fuse

Class OpenFileEntry<T1 extends InputStream,T2 extends OutputStream>

java.lang.Object

alluxio.fuse.OpenFileEntry<T1,T2>

Type Parameters:

T1 - the concrete input stream subclass

T2 - the concrete output stream subclass

All Implemented Interfaces:

Closeable, AutoCloseable

@NotThreadSafe
public final class OpenFileEntry<T1 extends InputStream,T2 extends OutputStream>
extends Object
implements Closeable

Convenience class to encapsulate input/output streams of open alluxio files. An open file can be either write-only or read-only, never both. This means that one of getIn or getOut will be null, while the other will be non-null. It is up to the user of this class (currently, only AlluxioFuseFileSystem) to check that. This mechanism is preferred over more complex sub-classing to avoid useless casts or type checks for every read/write call, which happen quite often.

Constructor Summary

Constructors

Constructor and Description
OpenFileEntry(long id, String path, T1 in, T2 out) Constructs a new OpenFileEntry for an Alluxio file.

Method Summary

Modifier and Type	Method and Description
void	close() Closes the underlying open streams.
long	getId()
T1	getIn() Gets the opened input stream for this open file entry.
T2	getOut() Gets the opened output stream for this open file entry.
String	getPath()
long	getWriteOffset()
void	setPath(String path) Sets the path of the file.
void	setWriteOffset(long offset) Sets the offset of the next write.

Methods inherited from class java.lang.Object

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

Constructor Detail

OpenFileEntry

public OpenFileEntry(long id,
                     String path,
                     T1 in,
                     T2 out)

Constructs a new OpenFileEntry for an Alluxio file.

Parameters:

id - the id of the file

path - the path of the file

in - the input stream of the file

out - the output stream of the file

Method Detail

getId

public long getId()

Returns:

the id of the file

getPath

public String getPath()

Returns:

the path of the file

getIn

@Nullable
public T1 getIn()

Gets the opened input stream for this open file entry. The value returned can be null if the file is not open for reading.

Returns:

an opened input stream for the open alluxio file, or null

getOut

@Nullable
public T2 getOut()

Gets the opened output stream for this open file entry. The value returned can be null if the file is not open for writing.

Returns:

an opened input stream for the open alluxio file, or null

getWriteOffset

public long getWriteOffset()

Returns:

the offset of the next write

setPath

public void setPath(String path)

Sets the path of the file. The file path can be changed if fuse rename() is called.

Parameters:

path - the new path of the file

setWriteOffset

public void setWriteOffset(long offset)

Sets the offset of the next write.

Parameters:

offset - the new offset of the next write

close

public void close()
           throws IOException

Closes the underlying open streams.

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Throws:

IOException