org.mapdb

Class BTreeKeySerializer.Tuple2KeySerializer<A,B>

java.lang.Object

org.mapdb.BTreeKeySerializer<Fun.Tuple2<A,B>>

org.mapdb.BTreeKeySerializer.Tuple2KeySerializer<A,B>

Type Parameters:

A - first tuple value

B - second tuple value

All Implemented Interfaces:

Serializable

Enclosing class:

BTreeKeySerializer<K>

public static final class BTreeKeySerializer.Tuple2KeySerializer<A,B>
extends BTreeKeySerializer<Fun.Tuple2<A,B>>
implements Serializable

Applies delta compression on array of tuple. First tuple value may be shared between consequentive tuples, so only first occurrence is serialized. An example:

     Value            Serialized as
     -------------------------
     Tuple(1, 1)       1, 1
     Tuple(1, 2)          2
     Tuple(1, 3)          3
     Tuple(1, 4)          4
 

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class org.mapdb.BTreeKeySerializer

BTreeKeySerializer.BasicKeySerializer, BTreeKeySerializer.Tuple2KeySerializer<A,B>, BTreeKeySerializer.Tuple3KeySerializer<A,B,C>, BTreeKeySerializer.Tuple4KeySerializer<A,B,C,D>, BTreeKeySerializer.Tuple5KeySerializer<A,B,C,D,E>, BTreeKeySerializer.Tuple6KeySerializer<A,B,C,D,E,F>

Field Summary

Fields

Modifier and Type	Field and Description
protected Comparator<A>	aComparator
protected Serializer<A>	aSerializer
protected Serializer<B>	bSerializer

Fields inherited from class org.mapdb.BTreeKeySerializer

BASIC, STRING, TUPLE2, TUPLE3, TUPLE4, ZERO_OR_POSITIVE_INT, ZERO_OR_POSITIVE_LONG

Constructor Summary

Constructors

Constructor and Description
Tuple2KeySerializer(Comparator<A> aComparator, Serializer<A> aSerializer, Serializer<B> bSerializer) Construct new Tuple2 Key Serializer.

Method Summary

Modifier and Type	Method and Description
Object[]	deserialize(DataInput in, int start, int end, int size) Deserializes keys for single BTree Node.
boolean	equals(Object o)
Comparator<Fun.Tuple2<A,B>>	getComparator() Some key serializers may only work with they own comparators.
int	hashCode()
void	serialize(DataOutput out, int start, int end, Object[] keys) Serialize keys from single BTree Node.

Methods inherited from class org.mapdb.BTreeKeySerializer

leadingValuePackRead, leadingValuePackWrite

Methods inherited from class java.lang.Object

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

Field Detail

aComparator

protected final Comparator<A> aComparator

aSerializer

protected final Serializer<A> aSerializer

bSerializer

protected final Serializer<B> bSerializer

Constructor Detail

Tuple2KeySerializer

public Tuple2KeySerializer(Comparator<A> aComparator,
                           Serializer<A> aSerializer,
                           Serializer<B> bSerializer)

Construct new Tuple2 Key Serializer. You may pass null for some value, In that case 'default' value will be used, Comparable comparator and Default Serializer from DB.

Parameters:

aComparator - comparator used for first tuple value

aSerializer - serializer used for first tuple value

bSerializer - serializer used for second tuple value

Method Detail

serialize

public void serialize(DataOutput out,
                      int start,
                      int end,
                      Object[] keys)
               throws IOException

Description copied from class: BTreeKeySerializer

Serialize keys from single BTree Node.

Specified by:

serialize in class BTreeKeySerializer<Fun.Tuple2<A,B>>

Parameters:

out - output stream where to put ata

start - where data start in array. Before this index all keys are null

end - where data ends in array (exclusive). From this index all keys are null

keys - array of keys for single BTree Node

Throws:

IOException

deserialize

public Object[] deserialize(DataInput in,
                            int start,
                            int end,
                            int size)
                     throws IOException

Description copied from class: BTreeKeySerializer

Deserializes keys for single BTree Node. To

Specified by:

deserialize in class BTreeKeySerializer<Fun.Tuple2<A,B>>

Parameters:

in - input stream to read data from

start - where data start in array. Before this index all keys are null

end - where data ends in array (exclusive). From this index all keys are null

size - size of array which should be returned

Returns:

array of keys for single BTree Node

Throws:

IOException

getComparator

public Comparator<Fun.Tuple2<A,B>> getComparator()

Description copied from class: BTreeKeySerializer

Some key serializers may only work with they own comparators. For example delta-packing stores increments between numbers and requires ascending order. So Key Serializer may provide its own comparator.

Specified by:

getComparator in class BTreeKeySerializer<Fun.Tuple2<A,B>>

Returns:

comparator which must be used with this method. `null` if comparator is not strictly required.

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object