org.terrier.structures

Class FilePosition

java.lang.Object

org.terrier.structures.FilePosition

All Implemented Interfaces:

BitFilePosition

public class FilePosition
extends Object
implements BitFilePosition

Models a position within a file as the offset in bytes and the offset in bits in that byte. For example, an instance of the class FilePosition that points to the 10th bit of a file should be constructed with a byte offset of 1 and a bit offset of 2.

Author:

Craig Macdonald, Vassilis Plachouras & John Kane

Field Summary

Fields

Modifier and Type	Field and Description
byte	Bits The offset in bits within the pointed byte.
long	Bytes The offset within a file in bytes.
protected static int	sizeInBytes The number of bytes a file position could be converted to - 8 for the byte's long, 1 for the bits

Constructor Summary

Constructors

Constructor and Description
FilePosition() Default constructor.
FilePosition(BitFilePosition in) Create a new FilePosition based on an existing one
FilePosition(byte[] in) Create an instance based on a byte buffer
FilePosition(long bytesPosition, byte bitsPosition) Creates an instance of the class from the given byte and bit offsets.

Method Summary

Modifier and Type	Method and Description
void	build(DataInput di) unseralize this object from the named dataoutput instance
boolean	equals(Object o) Is this FilePosition equal to another?
long	getOffset() Return the offset
byte	getOffsetBits() Return the offset bits
int	hashCode() Define a hashcode for this - objects which defined equals(Object) should define hashCode() also
void	setOffset(BitFilePosition pos) Set the offset
void	setOffset(long bytes, byte bits) Set the offset in bytes and bits
static int	sizeInBytes() How large is this object when serialized
void	toBytes(DataOutput dai) Seralize this object to the named dataoutput instance
String	toString() String representation of this object

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

sizeInBytes

protected static final int sizeInBytes

The number of bytes a file position could be converted to - 8 for the byte's long, 1 for the bits

See Also:

Constant Field Values

Bytes

public long Bytes

The offset within a file in bytes.

Bits

public byte Bits

The offset in bits within the pointed byte.

Constructor Detail

FilePosition

public FilePosition()

Default constructor. Create an uninitialiased FilePosition

FilePosition

public FilePosition(long bytesPosition,
                    byte bitsPosition)

Creates an instance of the class from the given byte and bit offsets.

Parameters:

bytesPosition - long the given byte offset.

bitsPosition - byte the given bit offset.

FilePosition

public FilePosition(byte[] in)

Create an instance based on a byte buffer

FilePosition

public FilePosition(BitFilePosition in)

Create a new FilePosition based on an existing one

Method Detail

getOffset

public long getOffset()

Return the offset

Specified by:

getOffset in interface BitFilePosition

getOffsetBits

public byte getOffsetBits()

Return the offset bits

Specified by:

getOffsetBits in interface BitFilePosition

setOffset

public void setOffset(long bytes,
                      byte bits)

Set the offset in bytes and bits

Specified by:

setOffset in interface BitFilePosition

setOffset

public void setOffset(BitFilePosition pos)

Set the offset

Specified by:

setOffset in interface BitFilePosition

sizeInBytes

public static int sizeInBytes()

How large is this object when serialized

toBytes

public void toBytes(DataOutput dai)

Seralize this object to the named dataoutput instance

build

public void build(DataInput di)

unseralize this object from the named dataoutput instance

equals

public boolean equals(Object o)

Is this FilePosition equal to another?

Overrides:

equals in class Object

hashCode

public int hashCode()

Define a hashcode for this - objects which defined equals(Object) should define hashCode() also

Overrides:

hashCode in class Object

toString

public String toString()

String representation of this object

Overrides:

toString in class Object