org.apache.hadoop.fs.s3a.prefetch

Class S3ABlockManager

java.lang.Object

org.apache.hadoop.fs.impl.prefetch.BlockManager

org.apache.hadoop.fs.s3a.prefetch.S3ABlockManager

All Implemented Interfaces:

Closeable, AutoCloseable

public class S3ABlockManager
extends org.apache.hadoop.fs.impl.prefetch.BlockManager

Provides read access to S3 file one block at a time. A naive implementation of a BlockManager that provides no prefetching or caching. Useful baseline for comparing performance difference against S3ACachingBlockManager.

Constructor Summary

Constructors

Constructor and Description
S3ABlockManager(S3ARemoteObjectReader reader, org.apache.hadoop.fs.impl.prefetch.BlockData blockData) Constructs an instance of S3ABlockManager.

Method Summary

Modifier and Type	Method and Description
void	close()
int	read(ByteBuffer buffer, long startOffset, int size) Reads into the given buffer size bytes from the underlying file starting at startOffset.

Methods inherited from class org.apache.hadoop.fs.impl.prefetch.BlockManager

cancelPrefetches, get, getBlockData, release, requestCaching, requestPrefetch

Methods inherited from class java.lang.Object

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

Constructor Detail

S3ABlockManager

public S3ABlockManager(S3ARemoteObjectReader reader,
                       org.apache.hadoop.fs.impl.prefetch.BlockData blockData)

Constructs an instance of S3ABlockManager.

Parameters:

reader - a reader that reads from S3 file.

blockData - information about each block of the S3 file.

Throws:

IllegalArgumentException - if reader is null.

IllegalArgumentException - if blockData is null.

Method Detail

read

public int read(ByteBuffer buffer,
                long startOffset,
                int size)
         throws IOException

Reads into the given buffer size bytes from the underlying file starting at startOffset.

Specified by:

read in class org.apache.hadoop.fs.impl.prefetch.BlockManager

Parameters:

buffer - the buffer to read data in to.

startOffset - the offset at which reading starts.

size - the number bytes to read.

Returns:

number of bytes read.

Throws:

IOException

close

public void close()

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Overrides:

close in class org.apache.hadoop.fs.impl.prefetch.BlockManager