com.bigdata.btree.raba
Class AbstractRaba

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

All Implemented Interfaces:

IRaba, Iterable<byte[]>

Direct Known Subclasses:

MutableKeysRaba, MutableValuesRaba, ReadOnlyKeysRaba, ReadOnlyValuesRaba

public abstract class AbstractRaba
extends Object
implements IRaba

Abstract base class implements mutation operators and search. A concrete subclass need only indicate if it is mutable, searchable, or allows nulls by overriding the appropriate methods.

Version:

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

Author:

Bryan Thompson

Field Summary

protected byte[][]	a The backing array.
protected int	capacity The maximum #of elements in the view of the backing array.
protected int	fromIndex The inclusive lower bound of the view.
protected int	toIndex The exclusive upper bound of the view.

Constructor Summary

AbstractRaba(byte[][] a)
Create a view of a byte[][].

AbstractRaba(int fromIndex, int toIndex, int capacity, byte[][] a)
Create a view from a slice of a byte[][].

Method Summary

int	add(byte[] key) Append a byte[] value to the end of the logical byte[][] (optional operation).
int	add(byte[] key, 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).
protected void	assertNotFull()
protected void	assertNotReadOnly()
protected void	assertNullAllowed(byte[] a)
int	capacity() The capacity of the logical byte[][].
int	copy(int index, OutputStream out) 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.
Iterator<byte[]>	iterator() Iterator visits the byte[] elements in the view order.
int	length(int index) The length of the byte[] at that index.
protected boolean	rangeCheck(int index)
AbstractRaba	resize(int n) Resize the buffer, copying up to n references to the existing data into a new view backed by a new byte[][].
int	search(byte[] searchKey) Search for the given searchKey in the key buffer (optional operation).
void	set(int index, byte[] key) Set the byte[] value at the specified index (optional operation).
int	size() The #of entries in the logical byte[][].
String	toString()
static String	toString(IRaba raba) If IRaba.isKeys() is true then represents the elements as unsigned byte[]s.

Methods inherited from class java.lang.Object

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

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

isKeys, isReadOnly

Field Detail

fromIndex

protected final int fromIndex

The inclusive lower bound of the view.

toIndex

protected int toIndex

The exclusive upper bound of the view.

Note: This field is NOT final since it is modified by a subclass which permits mutation.

capacity

protected final int capacity

The maximum #of elements in the view of the backing array.

a

protected final byte[][] a

The backing array.

Constructor Detail

AbstractRaba

public AbstractRaba(byte[][] a)

Create a view of a byte[][]. All elements in the array are visible in the view.

Parameters:

a - The backing byte[][].

AbstractRaba

public AbstractRaba(int fromIndex,
                    int toIndex,
                    int capacity,
                    byte[][] a)

Create a view from a slice of a byte[][].

Parameters:

fromIndex - The index of the first element in the byte[][] which is visible in the view (inclusive lower bound).

toIndex - The index of the first element in the byte[][] beyond the view (exclusive upper bound).

capacity - The #of elements which may be used in the view.

a - The backing byte[][].

Method Detail

size

public final int size()

Description copied from interface: IRaba

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

Specified by:

size 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

capacity

public final int capacity()

Description copied from interface: IRaba

The capacity of the logical byte[][].

Specified by:

capacity in interface IRaba

rangeCheck

protected final boolean rangeCheck(int index)
                            throws IndexOutOfBoundsException

Throws:

IndexOutOfBoundsException

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.

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.

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].

copy

public final int copy(int index,
                      OutputStream out)

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[]>

assertNotReadOnly

protected void assertNotReadOnly()

Throws:

UnsupportedOperationException - if the view is read-only.

assertNotFull

protected void assertNotFull()

Throws:

IllegalStateException - unless there is room to store another value.

assertNullAllowed

protected void assertNullAllowed(byte[] a)

Parameters:

a - A byte[] to be inserted or set on the IRaba.

Throws:

IllegalArgumentException - if the byte[] is null and the implementation does not permit nulls to be stored.

set

public void set(int index,
                byte[] key)

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].

key - The byte[] value.

add

public int add(byte[] key)

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:

key - A value.

Returns:

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

add

public int add(byte[] key,
               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:

key - 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 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

search

public 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.

toString

public String toString()

Overrides:

toString in class Object

toString

public static String toString(IRaba raba)

If IRaba.isKeys() is true then represents the elements as unsigned byte[]s. Otherwise represents the elements as signed byte[]s.

resize

public AbstractRaba resize(int n)

Resize the buffer, copying up to n references to the existing data into a new view backed by a new byte[][]. fromIndex will be zero in the new view.

This method requires a public constructor with the following signature:

 ctor(byte[][])
 

Parameters:

n - The size of the new buffer.

Returns:

The new view, backed by a new byte[][].

Throws:

IllegalArgumentException - if n is negative.

RuntimeException - if the AbstractRaba instance does not declare an appropriate ctor.

TODO:

redefine as slice() (view onto the same data) and copy(int n)?