alluxio.underfs

Class MultiRangeObjectInputStream

java.lang.Object

java.io.InputStream

alluxio.underfs.MultiRangeObjectInputStream

All Implemented Interfaces:

Closeable, AutoCloseable

Direct Known Subclasses:

COSInputStream, KodoInputStream, OSSInputStream, SwiftInputStream

@NotThreadSafe
public abstract class MultiRangeObjectInputStream
extends InputStream

A stream for reading data using range queries.

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	mClosed Has the stream been closed.
protected long	mEndPos Position the current stream was open till (exclusive).
protected long	mPos The current position of the stream.
protected InputStream	mStream The backing input stream.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	MultiRangeObjectInputStream(long multiRangeChunkSize) Creates the input stream that will perform reads with a specified chunk size.

Method Summary

Modifier and Type	Method and Description
void	close()
protected abstract InputStream	createStream(long startPos, long endPos) Opens a new stream reading a range.
int	read()
int	read(byte[] b)
int	read(byte[] b, int offset, int length)
long	skip(long n)

Methods inherited from class java.io.InputStream

available, mark, markSupported, reset

Methods inherited from class java.lang.Object

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

Field Detail

mClosed

protected boolean mClosed

Has the stream been closed.

mStream

protected InputStream mStream

The backing input stream.

mPos

protected long mPos

The current position of the stream.

mEndPos

protected long mEndPos

Position the current stream was open till (exclusive).

Constructor Detail

MultiRangeObjectInputStream

protected MultiRangeObjectInputStream(long multiRangeChunkSize)

Creates the input stream that will perform reads with a specified chunk size. Reading in chunks allows us to read in smaller portions so that we don't need to read all the way to the end of a block.

Parameters:

multiRangeChunkSize - the chunk size in bytes to read with

Method Detail

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Overrides:

close in class InputStream

Throws:

IOException

read

public int read()
         throws IOException

Specified by:

read in class InputStream

Throws:

IOException

read

public int read(byte[] b)
         throws IOException

Overrides:

read in class InputStream

Throws:

IOException

read

public int read(byte[] b,
                int offset,
                int length)
         throws IOException

Overrides:

read in class InputStream

Throws:

IOException

skip

public long skip(long n)
          throws IOException

Overrides:

skip in class InputStream

Throws:

IOException

createStream

protected abstract InputStream createStream(long startPos,
                                            long endPos)
                                     throws IOException

Opens a new stream reading a range. When endPos > content length, the returned stream should read till the last valid byte of the input. The behaviour is undefined when (startPos < 0), (startPos >= content length), or (endPos <= 0).

Parameters:

startPos - start position in bytes (inclusive)

endPos - end position in bytes (exclusive)

Returns:

a new InputStream

Throws:

IOException