/*
* Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code 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
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*
*/
package sun.jvm.hotspot.utilities;
/** A BitMap implementing the BitMapInterface. */
public class BitMapSegmented implements BitMapInterface {
private static final int SegmentSizeBits = 30;
private static final int SegmentSize = 1 << (SegmentSizeBits - 1);
public BitMapSegmented(long sizeInBits) {
this.size = sizeInBits;
if (sizeInBits == 0) {
segmentBitMaps = new BitMap[0];
return;
}
int lastSegmentSize = (int)(sizeInBits % SegmentSize);
int segments = segmentIndex(sizeInBits - 1) + 1;
int completeSegments = segments - ((lastSegmentSize != 0) ? 1 : 0);
segmentBitMaps = new BitMap[segments];
for (int i = 0; i < completeSegments; i++) {
segmentBitMaps[i] = new BitMap(SegmentSize);
}
if (lastSegmentSize != 0) {
segmentBitMaps[completeSegments] = new BitMap(lastSegmentSize);
}
}
public long size() {
return size;
}
// Accessors
public boolean at(long offset) {
assert offset < size;
int segmentIndex = segmentIndex(offset);
int segmentOffset = segmentOffset(offset);
return segmentBitMaps[segmentIndex].at(segmentOffset);
}
public void atPut(long offset, boolean value) {
assert offset < size;
int segmentIndex = segmentIndex(offset);
int segmentOffset = segmentOffset(offset);
segmentBitMaps[segmentIndex].atPut(segmentOffset, value);
}
public void clear() {
for (BitMap map : segmentBitMaps) {
map.clear();
}
}
//----------------------------------------------------------------------
// Internals only below this point
//
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