org.neo4j.collection.primitive.hopscotch

Class PowerOfTwoQuantizedTable<VALUE>

java.lang.Object

org.neo4j.collection.primitive.hopscotch.PowerOfTwoQuantizedTable<VALUE>

All Implemented Interfaces:

AutoCloseable, Table<VALUE>

Direct Known Subclasses:

IntArrayBasedKeyTable, UnsafeTable

public abstract class PowerOfTwoQuantizedTable<VALUE>
extends Object
implements Table<VALUE>

Contains the basic table capacity- and size calculations. Always keeps the capacity a power of 2 for an efficient table mask.

Method Summary

Modifier and Type	Method and Description
static int	baseCapacity(int h)
int	capacity()
void	clear() Removes all entries from this table.
void	close() Free any resources
Table<VALUE>	grow() Grows the table to double that of the current size.
int	h()
boolean	isEmpty()
int	mask()
long	nullKey()
int	size()
String	toString()
int	version()
int	version(int index)

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.neo4j.collection.primitive.hopscotch.Table

hopBits, key, move, moveHopBit, put, putHopBit, putValue, remove, removeHopBit, value

Method Detail

baseCapacity

public static int baseCapacity(int h)

h

public int h()

Specified by:

h in interface Table<VALUE>

Returns:

H as defined by the hop-scotch algorithm, i.e. how many entries can share the same table index, i.e. how many conflicts there can be at most for any given table index.

mask

public int mask()

Specified by:

mask in interface Table<VALUE>

Returns:

a bit mask for doing table length modulo, for example when incrementing or decrementing a table index, so that it wraps around the edges.

capacity

public int capacity()

Specified by:

capacity in interface Table<VALUE>

Returns:

number of entries this table can hold at most.

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface Table<VALUE>

Returns:

true if there are no entries in this table, otherwise false.

size

public int size()

Specified by:

size in interface Table<VALUE>

Returns:

number of entries this table holds at the moment.

clear

public void clear()

Description copied from interface: Table

Removes all entries from this table.

Specified by:

clear in interface Table<VALUE>

version

public int version()

Specified by:

version in interface Table<VALUE>

Returns:

the version of the table, i.e. the version of the newest entry in the table.

version

public int version(int index)

Specified by:

version in interface Table<VALUE>

Parameters:

index - the index of the entry to get.

Returns:

the version of the entry by the given index in this table.

nullKey

public long nullKey()

Specified by:

nullKey in interface Table<VALUE>

Returns:

key representing an index that has not been assigned. Why is this a method? Since an implementation could based this value on Table.h() for example, which although is final per table instance, changes from table to table.

grow

public Table<VALUE> grow()

Description copied from interface: Table

Grows the table to double that of the current size. This method should not populate the table, it's just responsible for growing the structure holding the entries. All entries should have Table.nullKey() after this method has been called. The Table.size() should be reset here as well since after it has grown then it will be re-populated immediately with the existing data.

Specified by:

grow in interface Table<VALUE>

Returns:

the new table.

toString

public String toString()

Overrides:

toString in class Object

close

public void close()

Description copied from interface: Table

Free any resources

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Table<VALUE>