alluxio.underfs

Class UfsInputStreamCache

java.lang.Object

alluxio.underfs.UfsInputStreamCache

@ThreadSafe
public final class UfsInputStreamCache
extends Object

This class implements a BlockReader to read a block directly from UFS, and optionally cache the block to the Alluxio worker if the whole block it is read.

Constructor Summary

Constructors

Constructor and Description
UfsInputStreamCache() Constructs a new UFS input stream cache.

Method Summary

Modifier and Type	Method and Description
InputStream	acquire(UnderFileSystem ufs, String path, FileId fileId, OpenOptions openOptions) Acquires an input stream.
void	release(InputStream inputStream) Releases an input stream.

Methods inherited from class java.lang.Object

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

Constructor Detail

UfsInputStreamCache

public UfsInputStreamCache()

Constructs a new UFS input stream cache.

Method Detail

release

public void release(InputStream inputStream)

Releases an input stream. The input stream is closed if it's already expired.

Parameters:

inputStream - the input stream to release

Throws:

IOException - when input stream fails to close

acquire

public InputStream acquire(UnderFileSystem ufs,
                           String path,
                           FileId fileId,
                           OpenOptions openOptions)
                    throws IOException

Acquires an input stream. For seekable input streams, if there is an available input stream in the cache, reuse it and repositions the offset, otherwise the manager opens a new input stream.

Parameters:

ufs - the under file system

path - the path to the under storage file

fileId - the file id

openOptions - the open options

Returns:

the acquired input stream

Throws:

IOException - if the input stream fails to open