Package alluxio.underfs

Class AtomicFileOutputStream

java.lang.Object

java.io.OutputStream

alluxio.underfs.AtomicFileOutputStream

All Implemented Interfaces:

ContentHashable, java.io.Closeable, java.io.Flushable, java.lang.AutoCloseable

@NotThreadSafe
public class AtomicFileOutputStream
extends java.io.OutputStream
implements ContentHashable

A AtomicFileOutputStream writes to a temporary file and renames on close. This ensures that writing to the stream is atomic, i.e., all writes become readable only after a close.

Constructor Summary

Constructors

Constructor	Description
AtomicFileOutputStream(java.lang.String path, AtomicFileOutputStreamCallback ufs, CreateOptions options)	Constructs a new AtomicFileOutputStream.

Method Summary

Modifier and Type	Method	Description
void	close()
java.util.Optional<java.lang.String>	getContentHash()
void	write(byte[] b)
void	write(byte[] b, int off, int len)
void	write(int b)

Methods inherited from class java.io.OutputStream

flush, nullOutputStream

Methods inherited from class java.lang.Object

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

Constructor Detail

AtomicFileOutputStream

public AtomicFileOutputStream(java.lang.String path,
                              AtomicFileOutputStreamCallback ufs,
                              CreateOptions options)
                       throws java.io.IOException

Constructs a new AtomicFileOutputStream.

Parameters:

path - path being written to

ufs - the calling UnderFileSystem

options - create options for destination file

Throws:

java.io.IOException

Method Detail

write

public void write(int b)
           throws java.io.IOException

Specified by:

write in class java.io.OutputStream

Throws:

java.io.IOException

write

public void write(byte[] b)
           throws java.io.IOException

Overrides:

write in class java.io.OutputStream

Throws:

java.io.IOException

write

public void write(byte[] b,
                  int off,
                  int len)
           throws java.io.IOException

Overrides:

write in class java.io.OutputStream

Throws:

java.io.IOException

close

public void close()
           throws java.io.IOException

Specified by:

close in interface java.lang.AutoCloseable

Specified by:

close in interface java.io.Closeable

Overrides:

close in class java.io.OutputStream

Throws:

java.io.IOException

getContentHash

public java.util.Optional<java.lang.String> getContentHash()
                                                    throws java.io.IOException

Specified by:

getContentHash in interface ContentHashable

Returns:

the content hash of the file written to the UFS if available after the stream has been closed

Throws:

java.io.IOException