Package org.apache.hadoop.fs.impl.prefetch

Class BlockData

java.lang.Object

org.apache.hadoop.fs.impl.prefetch.BlockData

public final class BlockData
extends java.lang.Object

Holds information about blocks of data in a file.

Constructor Summary

Constructors

Constructor	Description
BlockData(long fileSize, int blockSize)	Constructs an instance of BlockData.

Method Summary

Modifier and Type	Method	Description
int	getBlockNumber(long offset)	Gets the id of the block that contains the given absolute offset.
int	getBlockSize()	Gets the size of each block.
long	getFileSize()	Gets the size of the associated file.
int	getNumBlocks()	Gets the number of blocks in the associated file.
int	getRelativeOffset(int blockNumber, long offset)	Gets the relative offset corresponding to the given block and the absolute offset.
int	getSize(int blockNumber)	Gets the size of the given block.
long	getStartOffset(int blockNumber)	Gets the start offset of the given block.
org.apache.hadoop.fs.impl.prefetch.BlockData.State	getState(int blockNumber)	Gets the state of the given block.
java.lang.String	getStateString()
boolean	isLastBlock(int blockNumber)	Indicates whether the given block is the last block in the associated file.
boolean	isValidOffset(long offset)	Indicates whether the given absolute offset is valid.
void	setState(int blockNumber, org.apache.hadoop.fs.impl.prefetch.BlockData.State blockState)	Sets the state of the given block to the given value.

Methods inherited from class java.lang.Object

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

Constructor Detail

BlockData

public BlockData(long fileSize,
                 int blockSize)

Constructs an instance of BlockData.

Parameters:

fileSize - the size of a file.

blockSize - the file is divided into blocks of this size.

Throws:

java.lang.IllegalArgumentException - if fileSize is negative.

java.lang.IllegalArgumentException - if blockSize is negative.

java.lang.IllegalArgumentException - if blockSize is zero or negative.

Method Detail

getBlockSize

public int getBlockSize()

Gets the size of each block.

Returns:

the size of each block.

getFileSize

public long getFileSize()

Gets the size of the associated file.

Returns:

the size of the associated file.

getNumBlocks

public int getNumBlocks()

Gets the number of blocks in the associated file.

Returns:

the number of blocks in the associated file.

isLastBlock

public boolean isLastBlock(int blockNumber)

Indicates whether the given block is the last block in the associated file.

Parameters:

blockNumber - the id of the desired block.

Returns:

true if the given block is the last block in the associated file, false otherwise.

Throws:

java.lang.IllegalArgumentException - if blockNumber is invalid.

getBlockNumber

public int getBlockNumber(long offset)

Gets the id of the block that contains the given absolute offset.

Parameters:

offset - the absolute offset to check.

Returns:

the id of the block that contains the given absolute offset.

Throws:

java.lang.IllegalArgumentException - if offset is invalid.

getSize

public int getSize(int blockNumber)

Gets the size of the given block.

Parameters:

blockNumber - the id of the desired block.

Returns:

the size of the given block.

isValidOffset

public boolean isValidOffset(long offset)

Indicates whether the given absolute offset is valid.

Parameters:

offset - absolute offset in the file..

Returns:

true if the given absolute offset is valid, false otherwise.

getStartOffset

public long getStartOffset(int blockNumber)

Gets the start offset of the given block.

Parameters:

blockNumber - the id of the given block.

Returns:

the start offset of the given block.

Throws:

java.lang.IllegalArgumentException - if blockNumber is invalid.

getRelativeOffset

public int getRelativeOffset(int blockNumber,
                             long offset)

Gets the relative offset corresponding to the given block and the absolute offset.

Parameters:

blockNumber - the id of the given block.

offset - absolute offset in the file.

Returns:

the relative offset corresponding to the given block and the absolute offset.

Throws:

java.lang.IllegalArgumentException - if either blockNumber or offset is invalid.

getState

public org.apache.hadoop.fs.impl.prefetch.BlockData.State getState(int blockNumber)

Gets the state of the given block.

Parameters:

blockNumber - the id of the given block.

Returns:

the state of the given block.

Throws:

java.lang.IllegalArgumentException - if blockNumber is invalid.

setState

public void setState(int blockNumber,
                     org.apache.hadoop.fs.impl.prefetch.BlockData.State blockState)

Sets the state of the given block to the given value.

Parameters:

blockNumber - the id of the given block.

blockState - the target state.

Throws:

java.lang.IllegalArgumentException - if blockNumber is invalid.

getStateString

public java.lang.String getStateString()