Package it.unimi.di.law.bubing.frontier

Class VisitStateSet

java.lang.Object

it.unimi.di.law.bubing.frontier.VisitStateSet

All Implemented Interfaces:

Hash, java.io.Serializable

public class VisitStateSet
extends java.lang.Object
implements java.io.Serializable, Hash

A data structure representing the set of visit states created so far. It is a lightweight implementation of a map from scheme+authorities to visit states.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface it.unimi.dsi.fastutil.Hash

Hash.Strategy<K extends java.lang.Object>

Field Summary

Fields

Modifier and Type	Field	Description
protected int	mask	The mask for wrapping a position counter.
protected int	maxFill	The maximum number of entries that can be filled before rehashing.
protected int	n	The current table size.
protected int	size	Number of entries in the set.
protected VisitState[]	visitState	The array of keys.

Fields inherited from interface it.unimi.dsi.fastutil.Hash

DEFAULT_GROWTH_FACTOR, DEFAULT_INITIAL_SIZE, DEFAULT_LOAD_FACTOR, FAST_LOAD_FACTOR, FREE, OCCUPIED, PRIMES, REMOVED, VERY_FAST_LOAD_FACTOR

Constructor Summary

Constructors

Constructor	Description
VisitStateSet()	Creates an empty visit state set.

Method Summary

Modifier and Type	Method	Description
boolean	add(VisitState v)	Adds a visit state to the set, if necessary.
void	clear()	Removes all elements from this set.
void	ensureCapacity(int capacity)	Ensures that the set has a given capacity.
VisitState	get(byte[] array)	Returns the visit state associated to a given scheme+authority, or null.
VisitState	get(byte[] array, int offset, int length)	Returns the visit state associated to a given scheme+authority specified as a byte-array fragment, or null.
boolean	isEmpty()	Returns whether the set is empty.
protected void	rehash(int newN)	Rehashes the state set to a new size.
boolean	remove(VisitState k)	Removes a given visit state.
protected int	shiftKeys(int pos)	Shifts left entries with the specified hash code, starting at the specified position, and empties the resulting free entry.
int	size()	The number of visit states.
VisitState[]	visitStates()	Returns the array of visit states; the order is arbitrary.

Methods inherited from class java.lang.Object

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

Field Detail

visitState

protected transient VisitState[] visitState

The array of keys.

n

protected transient int n

The current table size.

mask

protected transient int mask

The mask for wrapping a position counter.

size

protected int size

Number of entries in the set.

maxFill

protected int maxFill

The maximum number of entries that can be filled before rehashing.

Constructor Detail

VisitStateSet

public VisitStateSet()

Creates an empty visit state set.

Method Detail

visitStates

public VisitState[] visitStates()

Returns the array of visit states; the order is arbitrary. The array may contain null elements.

Returns:

the array of visit states; it may contain null entries.

ensureCapacity

public void ensureCapacity(int capacity)

Ensures that the set has a given capacity.

Parameters:

capacity - the desired capacity.

add

public boolean add(VisitState v)

Adds a visit state to the set, if necessary.

Parameters:

v - the state to be added.

Returns:

true if the state set changed as a result of this operation.

shiftKeys

protected final int shiftKeys(int pos)

Shifts left entries with the specified hash code, starting at the specified position, and empties the resulting free entry.

Parameters:

pos - a starting position.

Returns:

the position cleared by the shifting process.

remove

public boolean remove(VisitState k)

Removes a given visit state.

Parameters:

k - the visit state to be removed.

Returns:

true if the state set changed as a result of this operation.

get

public VisitState get(byte[] array)

Returns the visit state associated to a given scheme+authority, or null.

Parameters:

array - a byte array.

Returns:

the visit state associated to a given scheme+authority, or null.

get

public VisitState get(byte[] array,
                      int offset,
                      int length)

Returns the visit state associated to a given scheme+authority specified as a byte-array fragment, or null.

Parameters:

array - a byte array.

offset - the first valid byte in array.

length - the number of valid elements in array.

Returns:

the visit state associated to a given scheme+authority, or null.

clear

public void clear()

Removes all elements from this set.

To increase object reuse, this method does not change the table size.

size

public int size()

The number of visit states.

Returns:

the number of visit states.

isEmpty

public boolean isEmpty()

Returns whether the set is empty.

Returns:

whether the set is empty.

rehash

protected void rehash(int newN)

Rehashes the state set to a new size.

Parameters:

newN - the new size.