Package elki.database.ids.integer

Class IntegerDBID

java.lang.Object

elki.database.ids.integer.IntegerDBID

All Implemented Interfaces:

ArrayDBIDs, DBID, DBIDRef, DBIDs, IntegerDBIDRef, SetDBIDs, java.lang.Comparable<DBIDRef>

final class IntegerDBID
extends java.lang.Object
implements DBID, IntegerDBIDRef

Database ID object. While this currently is just an Integer, it should be avoided to store the object IDs in regular integers to reduce problems if this API ever changes (for example if someone needs to support long, it should not require changes in too many places!) In particular, a developer should not make any assumption of these IDs being consistent across multiple results/databases.

Since:

0.4.0

Author:

Erich Schubert

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	IntegerDBID.DynamicSerializer	Dynamic sized serializer, using varint.
protected class	IntegerDBID.Itr	Pseudo iterator for DBIDs interface.
static class	IntegerDBID.StaticSerializer	Static sized serializer, using regular integers.

Field Summary

Fields

Modifier and Type	Field	Description
static ByteBufferSerializer<DBID>	DYNAMIC_SERIALIZER	The public instance to use for dynamic serialization.
protected int	id	The actual object ID.
static FixedSizeByteBufferSerializer<DBID>	STATIC_SERIALIZER	The public instance to use for static serialization.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	IntegerDBID(int id)	Constructor from integer id.
protected	IntegerDBID(java.lang.Integer id)	Constructor from integer id.

Method Summary

Modifier and Type	Method	Description
DBIDVar	assignVar(int index, DBIDVar var)	Assign a DBID variable the value of position index.
int	binarySearch(DBIDRef key)	Search for the position of the given key, assuming that the data set is sorted.
int	compareTo(DBIDRef o)	Compare two DBIDs for ordering.
boolean	contains(DBIDRef o)	Test whether an ID is contained.
boolean	equals(java.lang.Object obj)	Deprecated.
DBID	get(int i)	Get the i'th entry (starting at 0)
int	hashCode()	In contrast to DBIDRef, the DBID interface is supposed to have a stable hash code.
int	internalGetIndex()	Return the integer value of the object ID.
boolean	isEmpty()	Test for an empty DBID collection.
IntegerDBID.Itr	iter()	Iterable
int	size()	Size of the DBID "collection".
ArrayDBIDs	slice(int begin, int end)	Slice a subarray (as view, not copy!)
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Methods inherited from interface elki.database.ids.DBIDs

forEach

Field Detail

id

protected final int id

The actual object ID.

DYNAMIC_SERIALIZER

public static final ByteBufferSerializer<DBID> DYNAMIC_SERIALIZER

The public instance to use for dynamic serialization.

STATIC_SERIALIZER

public static final FixedSizeByteBufferSerializer<DBID> STATIC_SERIALIZER

The public instance to use for static serialization.

Constructor Detail

IntegerDBID

protected IntegerDBID(int id)

Constructor from integer id.

Parameters:

id - integer id.

IntegerDBID

protected IntegerDBID(java.lang.Integer id)

Constructor from integer id.

Parameters:

id - integer id.

Method Detail

internalGetIndex

public int internalGetIndex()

Return the integer value of the object ID.

Specified by:

internalGetIndex in interface DBIDRef

Specified by:

internalGetIndex in interface IntegerDBIDRef

Returns:

integer id

size

public int size()

Description copied from interface: ArrayDBIDs

Size of the DBID "collection".

Specified by:

size in interface ArrayDBIDs

Specified by:

size in interface DBIDs

Returns:

size

isEmpty

public boolean isEmpty()

Description copied from interface: DBIDs

Test for an empty DBID collection.

Specified by:

isEmpty in interface DBIDs

Returns:

true when empty.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

hashCode

public int hashCode()

Description copied from interface: DBID

In contrast to DBIDRef, the DBID interface is supposed to have a stable hash code. However, it is generally preferred to use optimized storage classes instead of Java collections!

Specified by:

hashCode in interface DBID

Specified by:

hashCode in interface DBIDRef

Overrides:

hashCode in class java.lang.Object

Returns:

hash code

equals

@Deprecated
public boolean equals(java.lang.Object obj)

Deprecated.

Description copied from interface: DBID

In contrast to DBIDRef, the DBID interface is supposed to have a stable equals for other DBIDs.

Yet, DBIDUtil.equal(elki.database.ids.DBIDRef, elki.database.ids.DBIDRef) is more type safe and explicit.

Specified by:

equals in interface DBID

Specified by:

equals in interface DBIDRef

Overrides:

equals in class java.lang.Object

Parameters:

obj - Other object

Returns:

true when the object is the same DBID.

compareTo

public int compareTo(DBIDRef o)

Description copied from interface: DBID

Compare two DBIDs for ordering.

Consider using DBIDUtil.compare(elki.database.ids.DBIDRef, elki.database.ids.DBIDRef), which is more explicit.

Specified by:

compareTo in interface java.lang.Comparable<DBIDRef>

Specified by:

compareTo in interface DBID

Parameters:

o - Other DBID object

Returns:

Comparison result

iter

public IntegerDBID.Itr iter()

Description copied from interface: ArrayDBIDs

Iterable

Specified by:

iter in interface ArrayDBIDs

Specified by:

iter in interface DBIDs

Returns:

Iterator

get

public DBID get(int i)

Description copied from interface: ArrayDBIDs

Get the i'th entry (starting at 0)

If possible, use an DBIDArrayIter via ArrayDBIDs.iter() instead, or an DBIDVar via ArrayDBIDs.assignVar(int, elki.database.ids.DBIDVar)

Specified by:

get in interface ArrayDBIDs

Parameters:

i - Index

Returns:

DBID of i'th entry.

assignVar

public DBIDVar assignVar(int index,
                         DBIDVar var)

Description copied from interface: ArrayDBIDs

Assign a DBID variable the value of position index.

Specified by:

assignVar in interface ArrayDBIDs

Parameters:

index - Position

var - Variable to assign the value to.

contains

public boolean contains(DBIDRef o)

Description copied from interface: DBIDs

Test whether an ID is contained.

Specified by:

contains in interface DBIDs

Parameters:

o - object to test

Returns:

true when contained

binarySearch

public int binarySearch(DBIDRef key)

Description copied from interface: ArrayDBIDs

Search for the position of the given key, assuming that the data set is sorted. For unsorted arrays, the result is undefined.

For keys not found, -(1+insertion position) is returned, as for Java Collections.binarySearch(java.util.List<? extends java.lang.Comparable<? super T>>, T)

Specified by:

binarySearch in interface ArrayDBIDs

Parameters:

key - Key to search for

Returns:

Offset of key

slice

public ArrayDBIDs slice(int begin,
                        int end)

Description copied from interface: ArrayDBIDs

Slice a subarray (as view, not copy!)

Specified by:

slice in interface ArrayDBIDs

Parameters:

begin - Begin (inclusive)

end - End (exclusive)

Returns:

Array slice.