Package it.unimi.dsi.webgraph.labelling

Class FixedWidthIntLabel

java.lang.Object

it.unimi.dsi.webgraph.labelling.AbstractLabel

it.unimi.dsi.webgraph.labelling.AbstractIntLabel

it.unimi.dsi.webgraph.labelling.FixedWidthIntLabel

All Implemented Interfaces:

FlyweightPrototype<Label>, Label

public class FixedWidthIntLabel
extends AbstractIntLabel

An integer represented in fixed width. The provided width must be smaller than 32.

Field Summary

Fields

Modifier and Type	Field	Description
protected int	width	The bit width used to represent the value of this label.

Fields inherited from class it.unimi.dsi.webgraph.labelling.AbstractIntLabel

key, value

Fields inherited from interface it.unimi.dsi.webgraph.labelling.Label

EMPTY_LABEL_ARRAY

Constructor Summary

Constructors

Constructor	Description
FixedWidthIntLabel(String... arg)	Creates a new fixed-width integer label using the given key and width with value 0.
FixedWidthIntLabel(String key, int width)	Creates a new fixed-width int label of value 0.
FixedWidthIntLabel(String key, int width, int value)	Creates a new fixed-width int label.

Method Summary

Modifier and Type	Method	Description
Label	copy()	Returns a copy of this label.
int	fixedWidth()	Returns the width of this label (as provided at construction time).
int	fromBitStream(InputBitStream inputBitStream, int sourceUnused)	Fills this label with data from the given input bit stream, knowing the source node of the arc.
int	toBitStream(OutputBitStream outputBitStream, int sourceUnused)	Writes out this label to the given input bit stream, in self-delimiting form, knowing the source node of the arc.
String	toSpec()	Returns a string representing the specification of this label.
String	toString()

Methods inherited from class it.unimi.dsi.webgraph.labelling.AbstractIntLabel

attributeKeys, attributeTypes, equals, get, get, getDouble, getDouble, getFloat, getFloat, getInt, getInt, getLong, getLong, hashCode, wellKnownAttributeKey

Methods inherited from class it.unimi.dsi.webgraph.labelling.AbstractLabel

getBoolean, getBoolean, getByte, getByte, getChar, getChar, getShort, getShort

Methods inherited from class java.lang.Object

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

Methods inherited from interface it.unimi.dsi.webgraph.labelling.Label

getBoolean, getBoolean, getByte, getByte, getChar, getChar, getShort, getShort

Field Details

width

protected final int width

The bit width used to represent the value of this label.

Constructor Details

FixedWidthIntLabel

public FixedWidthIntLabel(String key,
int width,
int value)

Creates a new fixed-width int label.

Parameters:

key - the (only) key of this label.

width - the label width (in bits).

value - the value of this label.

FixedWidthIntLabel

public FixedWidthIntLabel(String key,
int width)

Creates a new fixed-width int label of value 0.

Parameters:

key - the (only) key of this label.

width - the label width (in bits).

FixedWidthIntLabel

public FixedWidthIntLabel(String... arg)

Creates a new fixed-width integer label using the given key and width with value 0.

Parameters:

arg - two strings containing the key and the width of this label.

Method Details

copy

public Label copy()

Description copied from interface: Label

Returns a copy of this label.

Returns:

a new label that copies this one.

fromBitStream

public int fromBitStream(InputBitStream inputBitStream,
int sourceUnused)
                  throws IOException

Description copied from interface: Label

Fills this label with data from the given input bit stream, knowing the source node of the arc. If Label.fixedWidth() is not negative, the value returned must coincide with Label.fixedWidth(). This method is optional.

Parameters:

inputBitStream - an input bit stream offering a label.

sourceUnused - the source node.

Returns:

the number of bits read to fill this label.

Throws:

IOException

toBitStream

public int toBitStream(OutputBitStream outputBitStream,
int sourceUnused)
                throws IOException

Description copied from interface: Label

Writes out this label to the given input bit stream, in self-delimiting form, knowing the source node of the arc. If Label.fixedWidth() is not negative, the value returned must coincide with Label.fixedWidth(). This method is optional.

Parameters:

outputBitStream - an output bit stream where the label will be written.

sourceUnused - the source node.

Returns:

the number of bits written.

Throws:

IOException

fixedWidth

public int fixedWidth()

Returns the width of this label (as provided at construction time).

Returns:

the width of this label.

toString

public String toString()

Overrides:

toString in class AbstractIntLabel

toSpec

public String toSpec()

Description copied from interface: Label

Returns a string representing the specification of this label.

Each label class can be instantiated in several ways (e.g., FixedWidthIntLabel requires a name for the well-known attribute and a number of bits). This method must return a representation that can be used by ObjectParser to instantiate the class, and consequently there must exist a matching constructor whose arguments are strings.

There is an equation that must be always satisfied:

 ObjectParser.fromSpec(x.toSpec()).toSpec().equals(x.toSpec())
 

Returns:

a string representing the specification of this label.

See Also:

ObjectParser.fromSpec(String, Class)