com.bigdata.btree.raba
Class EmptyRaba

java.lang.Object
  com.bigdata.btree.raba.EmptyRaba

All Implemented Interfaces:

IRaba, Externalizable, Serializable, Iterable<byte[]>

Direct Known Subclasses:

EmptyRaba.EmptyKeysRaba, EmptyRaba.EmptyValuesRaba

public abstract class EmptyRaba
extends Object
implements IRaba, Externalizable

An immutable, empty IRaba.

Version:

$Id: EmptyRaba.java 2265 2009-10-26 12:51:06Z thompsonbry $

Author:

Bryan Thompson

See Also:

Serialized Form

Nested Class Summary

static class	EmptyRaba.EmptyKeysRaba An empty, immutable B+Tree keys IRaba.
static class	EmptyRaba.EmptyValuesRaba An empty, immutable B+Tree values IRaba.

Field Summary

static IRaba	KEYS An empty, immutable B+Tree keys IRaba instance.
static IRaba	VALUES An empty, immutable B+Tree values IRaba instance.

Constructor Summary

EmptyRaba()
De-serialization ctor.

Method Summary

int	add(byte[] a) Append a byte[] value to the end of the logical byte[][] (optional operation).
int	add(byte[] value, int off, int len) Append a byte[] value to the end of the logical byte[][] (optional operation).
int	add(DataInput in, int len) Append a byte[] value to the end of the logical byte[][] (optional operation).
int	capacity() The capacity of the logical byte[][].
int	copy(int index, OutputStream os) Copy the value at the specified index onto the output stream.
byte[]	get(int index) Return the byte[] at the specified index.
boolean	isEmpty() True iff the logical byte[][] is empty.
boolean	isFull() True iff the logical byte[][] is full.
boolean	isNull(int index) Return true iff the byte[] at that index is null.
boolean	isReadOnly() Return true if this implementation is read-only.
Iterator<byte[]>	iterator() Iterator visits the byte[] elements in the view order.
int	length(int index) The length of the byte[] at that index.
void	readExternal(ObjectInput in)
int	search(byte[] searchKey) Search for the given searchKey in the key buffer (optional operation).
void	set(int index, byte[] a) Set the byte[] value at the specified index (optional operation).
int	size() The #of entries in the logical byte[][].
void	writeExternal(ObjectOutput out)

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.bigdata.btree.raba.IRaba

isKeys

Field Detail

KEYS

public static transient IRaba KEYS

An empty, immutable B+Tree keys IRaba instance.

VALUES

public static transient IRaba VALUES

An empty, immutable B+Tree values IRaba instance.

Constructor Detail

EmptyRaba

public EmptyRaba()

De-serialization ctor.

Method Detail

capacity

public final int capacity()

Description copied from interface: IRaba

The capacity of the logical byte[][].

Specified by:

capacity in interface IRaba

isEmpty

public final boolean isEmpty()

Description copied from interface: IRaba

True iff the logical byte[][] is empty.

Specified by:

isEmpty in interface IRaba

isFull

public final boolean isFull()

Description copied from interface: IRaba

True iff the logical byte[][] is full.

Specified by:

isFull in interface IRaba

size

public final int size()

Description copied from interface: IRaba

The #of entries in the logical byte[][].

Specified by:

size in interface IRaba

isReadOnly

public final boolean isReadOnly()

Description copied from interface: IRaba

Return true if this implementation is read-only.

Specified by:

isReadOnly in interface IRaba

isNull

public final boolean isNull(int index)

Description copied from interface: IRaba

Return true iff the byte[] at that index is null. If IRaba.isKeys() would return true then this method MUST return false since nulls are not permitted for B+Tree keys.

Specified by:

isNull in interface IRaba

Parameters:

index - The index in [0:IRaba.size()-1].

length

public final int length(int index)

Description copied from interface: IRaba

The length of the byte[] at that index.

Specified by:

length in interface IRaba

Parameters:

index - The index in [0:IRaba.size()-1].

Returns:

The length of the byte[] at that index.

get

public final byte[] get(int index)

Description copied from interface: IRaba

Return the byte[] at the specified index. For greater efficiency, implementations MAY return a reference to an internal the byte[].

Specified by:

get in interface IRaba

Parameters:

index - The index in [0:IRaba.size()-1].

Returns:

The byte[] value at that index and null if a null value was stored at that index.

copy

public final int copy(int index,
                      OutputStream os)

Description copied from interface: IRaba

Copy the value at the specified index onto the output stream. This is often used with an ByteArrayBuffer so that the same backing byte[] can be overwritten by each visited key.

Specified by:

copy in interface IRaba

Parameters:

index - The index in [0:IRaba.size()-1].

Returns:

The #of bytes copied.

iterator

public final Iterator<byte[]> iterator()

Description copied from interface: IRaba

Iterator visits the byte[] elements in the view order. If an element is null, then the iterator will report a null for that element.

Specified by:

iterator in interface IRaba

Specified by:

iterator in interface Iterable<byte[]>

search

public final int search(byte[] searchKey)

Description copied from interface: IRaba

Search for the given searchKey in the key buffer (optional operation). Whether or not search is supported depends on whether the logical byte[][] is ordered. However, the efficiency of search, where supported, depends on the implementation. Some implementations support binary search of the coded byte[] values. Others may require a mixture of binary and linear search, etc.

 entryIndex = -entryIndex - 1
 

or just

 entryIndex = -entryIndex
 

if you are looking for the first key after the searchKey.

Specified by:

search in interface IRaba

Parameters:

searchKey - The search key.

Returns:

index of the search key, if it is found; otherwise, (-(insertion point) - 1). The insertion point is defined as the point at which the key would be inserted. Note that this guarantees that the return value will be >= 0 if and only if the key is found.

set

public final void set(int index,
                      byte[] a)

Description copied from interface: IRaba

Set the byte[] value at the specified index (optional operation).

Specified by:

set in interface IRaba

Parameters:

index - The index in [0:IRaba.size()-1].

a - The byte[] value.

add

public final int add(byte[] a)

Description copied from interface: IRaba

Append a byte[] value to the end of the logical byte[][] (optional operation).

Specified by:

add in interface IRaba

Parameters:

a - A value.

Returns:

The #of values in the logical byte[][] (postcondition).

add

public final int add(byte[] value,
                     int off,
                     int len)

Description copied from interface: IRaba

Append a byte[] value to the end of the logical byte[][] (optional operation).

Specified by:

add in interface IRaba

Parameters:

value - A value

off - The offset of the first byte to be copied.

len - The #of bytes to be copied.

Returns:

The #of values in the logical byte[][] (postcondition).

add

public final int add(DataInput in,
                     int len)
              throws IOException

Description copied from interface: IRaba

Append a byte[] value to the end of the logical byte[][] (optional operation).

Specified by:

add in interface IRaba

Parameters:

in - The input stream from which the byte[] will be read.

len - The #of bytes to be read.

Returns:

The #of values in the logical byte[][] (postcondition).

Throws:

IOException

readExternal

public void readExternal(ObjectInput in)
                  throws IOException,
                         ClassNotFoundException

Specified by:

readExternal in interface Externalizable

Throws:

IOException

ClassNotFoundException

writeExternal

public void writeExternal(ObjectOutput out)
                   throws IOException

Specified by:

writeExternal in interface Externalizable

Throws:

IOException