com.bigdata.btree.raba.ReadOnlyKeysRaba Maven / Gradle / Ivy
/*
Copyright (C) SYSTAP, LLC DBA Blazegraph 2006-2016. All rights reserved.
Contact:
SYSTAP, LLC DBA Blazegraph
2501 Calvert ST NW #106
Washington, DC 20008
[email protected]
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
* Created on Aug 7, 2009
*/
package com.bigdata.btree.raba;
import com.bigdata.btree.proc.IKeyArrayIndexProcedure;
import com.bigdata.util.BytesUtil;
/**
* Immutable implementation does not allow nulls but supports
* search.
*
* @author Bryan Thompson
* @version $Id$
*/
public class ReadOnlyKeysRaba extends AbstractRaba {
/**
* A read-only empty keys raba.
*/
public static final transient ReadOnlyKeysRaba EMPTY = new ReadOnlyKeysRaba(
BytesUtil.EMPTY2);
/**
* This view is read-only.
*/
final public boolean isReadOnly() {
return true;
}
/**
* For B+Tree keys (does not allow nulls, is searchable).
*/
final public boolean isKeys() {
return true;
}
/**
* Create a view of a byte[][]. All elements in the array are visible in the
* view.
*
* @param a
* The backing byte[][].
*/
public ReadOnlyKeysRaba(final byte[][] a) {
this(0/* fromIndex */, a.length/* toIndex */, a.length/* capacity */, a);
}
/**
* Create a view of a byte[][]. All elements in the array are visible in the
* view. The elements in the array from index ZERO (0) through index
* size-1 are assumed to have valid data.
*
* @param size
* The #of elements with valid data.
* @param a
* The backing byte[][].
*/
public ReadOnlyKeysRaba(final int size, final byte[][] a) {
this(0/* fromIndex */, size/* toIndex */, a.length/* capacity */, a);
}
/**
* Create a view of a byte[][] slice. The slice will include
* only those elements between the fromIndex and the toIndex. The capacity
* will be the #of elements. {@link #isFull()} will report true
* .
*
* Note: This constructor is used when we split an
* {@link IKeyArrayIndexProcedure} based on a key-range partitioned index.
*
* @param fromIndex
* The index of the first visible in the view (inclusive lower
* bound).
* @param toIndex
* The index of the first element beyond the view (exclusive
* upper bound). If toIndex == fromIndex then the view is empty.
* @param a
* The backing byte[][].
*/
public ReadOnlyKeysRaba(final int fromIndex, final int toIndex,
final byte[][] a) {
this(fromIndex, toIndex, a.length - fromIndex, a);
}
/**
* Create a view from a slice of a byte[][].
*
* @param fromIndex
* The index of the first element in the byte[][] which is
* visible in the view (inclusive lower bound).
* @param toIndex
* The index of the first element in the byte[][] which lies
* beyond the view (exclusive upper bound).
* @param capacity
* The #of elements which may be used in the view.
* @param a
* The backing byte[][].
*/
public ReadOnlyKeysRaba(final int fromIndex, final int toIndex,
final int capacity, final byte[][] a) {
super(fromIndex, toIndex, capacity, a);
// FIXME This is too much overhead for normal runtime.
// assert assertTotalOrder(fromIndex, toIndex, a);
}
/**
* Asserts that the unsigned byte[]s in the logical byte[][]
* are in a total order.
*
* @param fromIndex
* The first index in the view (inclusive lower bound).
* @param toIndex
* The first index outside the view (exclusive upper bound).
* @param a
* The backing byte[][].
*
* @return true if the total ordering constraint is respected by the data.
*/
protected boolean assertTotalOrder(final int fromIndex, final int toIndex,
final byte[][] a) {
for (int i = fromIndex; i < toIndex; i++) {
if (i > fromIndex) {
final int ret = BytesUtil.compareBytes(a[i - 1], a[i]);
assert ret < 0 : "unsigned byte[]s are out of order at index="
+ i +", ret="+ret //
+ "\na[" + (i - 1) + "]=" + BytesUtil.toString(a[i-1]) //
+ "\na[" + (i) + "]=" + BytesUtil.toString(a[i]);
}
}
return true;
}
}