org.apache.flink.runtime.operators.util.BitSet Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
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* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
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* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.flink.runtime.operators.util;
import org.apache.flink.core.memory.MemorySegment;
import org.apache.flink.util.Preconditions;
public class BitSet {
private MemorySegment memorySegment;
// MemorySegment byte array offset.
private int offset;
// The BitSet byte size.
private int byteLength;
// The BitSet bit size.
private int bitLength;
private final int BYTE_POSITION_MASK = 0xfffffff8;
private final int BYTE_INDEX_MASK = 0x00000007;
public BitSet(int byteSize) {
Preconditions.checkArgument(byteSize > 0, "bits size should be greater than 0.");
this.byteLength = byteSize;
this.bitLength = byteSize << 3;
}
public void setMemorySegment(MemorySegment memorySegment, int offset) {
Preconditions.checkArgument(memorySegment != null, "MemorySegment can not be null.");
Preconditions.checkArgument(offset >= 0, "Offset should be positive integer.");
Preconditions.checkArgument(offset + byteLength <= memorySegment.size(),
"Could not set MemorySegment, the remain buffers is not enough.");
this.memorySegment = memorySegment;
this.offset = offset;
}
/**
* Sets the bit at specified index.
*
* @param index - position
*/
public void set(int index) {
Preconditions.checkArgument(index < bitLength && index >= 0);
int byteIndex = (index & BYTE_POSITION_MASK) >>> 3;
byte current = memorySegment.get(offset + byteIndex);
current |= (1 << (index & BYTE_INDEX_MASK));
memorySegment.put(offset + byteIndex, current);
}
/**
* Returns true if the bit is set in the specified index.
*
* @param index - position
* @return - value at the bit position
*/
public boolean get(int index) {
Preconditions.checkArgument(index < bitLength && index >= 0);
int byteIndex = (index & BYTE_POSITION_MASK) >>> 3;
byte current = memorySegment.get(offset + byteIndex);
return (current & (1 << (index & BYTE_INDEX_MASK))) != 0;
}
/**
* Number of bits
*/
public int bitSize() {
return bitLength;
}
/**
* Clear the bit set.
*/
public void clear() {
for (int i = 0; i < byteLength; i++) {
memorySegment.put(offset + i, (byte) 0);
}
}
@Override
public String toString() {
StringBuilder output = new StringBuilder();
output.append("BitSet:\n");
output.append("\tMemorySegment:").append(memorySegment.size()).append("\n");
output.append("\tOffset:").append(offset).append("\n");
output.append("\tLength:").append(byteLength).append("\n");
return output.toString();
}
}