org.bluedb.api.keys

Class HashGroupedKey<T extends java.lang.Comparable<T>>

java.lang.Object

org.bluedb.api.keys.ValueKey

org.bluedb.api.keys.HashGroupedKey<T>

Type Parameters:

T - The type of the id of this key. Existing types include UUID and String.

All Implemented Interfaces:

java.io.Serializable, java.lang.Comparable<BlueKey>, BlueKey

Direct Known Subclasses:

StringKey, UUIDKey

public abstract class HashGroupedKey<T extends java.lang.Comparable<T>>
extends ValueKey

A key that can be mapped to a value in a BlueCollection or BlueIndex. The hashcode of these keys is used to determine the location of the corresponding values on disk. Collections with this type of key will be unordered and if the hash is good then they will be spread fairly evenly across the collection segments. This means that there will be few collisions and high i-node usage.

Known implementations include UUIDKey and StringKey

See Also:

Serialized Form

Field Summary

Fields inherited from interface org.bluedb.api.keys.BlueKey

nullSafeClassComparator

Constructor Summary

Constructors

Constructor and Description
HashGroupedKey()

Method Summary

Modifier and Type	Method and Description
boolean	equals(java.lang.Object obj)
long	getGroupingNumber() Returns the grouping number which helps to determine the order and location of the key/value pairs on disk
abstract T	getId()
int	hashCode()
int	postGroupingNumberCompareTo(BlueKey other) This is used to order the key/value pairs on disk.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.bluedb.api.keys.BlueKey

compareCanonicalClassNames, compareCanonicalClassNames, compareTo, compareWithNullsLast, getIntegerIdIfPresent, getLongIdIfPresent, isInRange, unsafeCompareCanonicalClassNames

Constructor Detail

HashGroupedKey

public HashGroupedKey()

Method Detail

getId

public abstract T getId()

Returns:

the id of this key

hashCode

public final int hashCode()

Specified by:

hashCode in interface BlueKey

Overrides:

hashCode in class java.lang.Object

toString

public final java.lang.String toString()

Overrides:

toString in class java.lang.Object

postGroupingNumberCompareTo

public final int postGroupingNumberCompareTo(BlueKey other)

Description copied from interface: BlueKey

This is used to order the key/value pairs on disk. If this is being called then other is not null and the grouping numbers matched.

getGroupingNumber

public final long getGroupingNumber()

Description copied from interface: BlueKey

Returns the grouping number which helps to determine the order and location of the key/value pairs on disk

Returns:

grouping number

equals

public final boolean equals(java.lang.Object obj)

Specified by:

equals in interface BlueKey

Overrides:

equals in class java.lang.Object