/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* 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,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.flink.runtime.state;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.util.Preconditions;
import java.io.Serializable;
import java.util.Arrays;
import java.util.Iterator;
/**
* This class combines a key-group range with offsets that correspond to the key-groups in the range.
*/
public class KeyGroupRangeOffsets implements Iterable<Tuple2<Integer, Long>> , Serializable {
private static final long serialVersionUID = 6595415219136429696L;
/** the range of key-groups */
private final KeyGroupRange keyGroupRange;
/** the aligned array of offsets for the key-groups */
private final long[] offsets;
/**
* Creates key-group range with offsets from the given key-group range. The order of given offsets must be aligned
* with respect to the key-groups in the range.
*
* @param keyGroupRange The range of key-groups.
* @param offsets The aligned array of offsets for the given key-groups.
*/
public KeyGroupRangeOffsets(KeyGroupRange keyGroupRange, long[] offsets) {
this.keyGroupRange = Preconditions.checkNotNull(keyGroupRange);
this.offsets = Preconditions.checkNotNull(offsets);
Preconditions.checkArgument(offsets.length == keyGroupRange.getNumberOfKeyGroups());
}
/**
* Creates key-group range with offsets from the given start key-group to end key-group. The order of given offsets
* must be aligned with respect to the key-groups in the range.
*
* @param rangeStart Start key-group of the range (inclusive)
* @param rangeEnd End key-group of the range (inclusive)
* @param offsets The aligned array of offsets for the given key-groups.
*/
public KeyGroupRangeOffsets(int rangeStart, int rangeEnd, long[] offsets) {
this(KeyGroupRange.of(rangeStart, rangeEnd), offsets);
}
/**
* Creates key-group range with offsets from the given start key-group to end key-group.
* All offsets are initially zero.
*
* @param rangeStart Start key-group of the range (inclusive)
* @param rangeEnd End key-group of the range (inclusive)
*/
public KeyGroupRangeOffsets(int rangeStart, int rangeEnd) {
this(KeyGroupRange.of(rangeStart, rangeEnd));
}
/**
* Creates key-group range with offsets for the given key-group range, where all offsets are initially zero.
*
* @param keyGroupRange The range of key-groups.
*/
public KeyGroupRangeOffsets(KeyGroupRange keyGroupRange) {
this(keyGroupRange, new long[keyGroupRange.getNumberOfKeyGroups()]);
}
/**
* Returns the offset for the given key-group. The key-group must be contained in the range.
*
* @param keyGroup Key-group for which we query the offset. Key-group must be contained in the range.
* @return The offset for the given key-group which must be contained in the range.
*/
public long getKeyGroupOffset(int keyGroup) {
return offsets[computeKeyGroupIndex(keyGroup)];
}
/**
* Sets the offset for the given key-group. The key-group must be contained in the range.
*
* @param keyGroup Key-group for which we set the offset. Must be contained in the range.
* @param offset Offset for the key-group.
*/
public void setKeyGroupOffset(int keyGroup, long offset) {
offsets[computeKeyGroupIndex(keyGroup)] = offset;
}
/**
* Returns a key-group range with offsets which is the intersection of the internal key-group range with the given
* key-group range.
*
* @param keyGroupRange Key-group range to intersect with the internal key-group range.
* @return The key-group range with offsets for the intersection of the internal key-group range with the given
* key-group range.
*/
public KeyGroupRangeOffsets getIntersection(KeyGroupRange keyGroupRange) {
Preconditions.checkNotNull(keyGroupRange);
KeyGroupRange intersection = this.keyGroupRange.getIntersection(keyGroupRange);
long[] subOffsets = new long[intersection.getNumberOfKeyGroups()];
if(subOffsets.length > 0) {
System.arraycopy(
offsets,
computeKeyGroupIndex(intersection.getStartKeyGroup()),
subOffsets,
0,
subOffsets.length);
}
return new KeyGroupRangeOffsets(intersection, subOffsets);
}
public KeyGroupRange getKeyGroupRange() {
return keyGroupRange;
}
@Override
public Iterator<Tuple2<Integer, Long>> iterator() {
return new KeyGroupOffsetsIterator();
}
private int computeKeyGroupIndex(int keyGroup) {
int idx = keyGroup - keyGroupRange.getStartKeyGroup();
if (idx < 0 || idx >= offsets.length) {
throw new IllegalArgumentException("Key group " + keyGroup + " is not in " + keyGroupRange + ".");
}
return idx;
}
/**
* Iterator for the Key-group/Offset pairs.
*/
private final class KeyGroupOffsetsIterator implements Iterator<Tuple2<Integer, Long>> {
public KeyGroupOffsetsIterator() {
this.keyGroupIterator = keyGroupRange.iterator();
}
private final Iterator<Integer> keyGroupIterator;
@Override
public boolean hasNext() {
return keyGroupIterator.hasNext();
}
@Override
public Tuple2<Integer, Long> next() {
Integer currentKeyGroup = keyGroupIterator.next();
Tuple2<Integer,Long> result = new Tuple2<>(
currentKeyGroup,
offsets[currentKeyGroup - keyGroupRange.getStartKeyGroup()]);
return result;
}
@Override
public void remove() {
throw new UnsupportedOperationException("Unsupported by this iterator!");
}
}
@Override
public boolean equals(Object o) {
if (this == o) {
return true;
}
if (!(o instanceof KeyGroupRangeOffsets)) {
return false;
}
KeyGroupRangeOffsets that = (KeyGroupRangeOffsets) o;
if (keyGroupRange != null ? !keyGroupRange.equals(that.keyGroupRange) : that.keyGroupRange != null) {
return false;
}
return Arrays.equals(offsets, that.offsets);
}
@Override
public int hashCode() {
int result = keyGroupRange != null ? keyGroupRange.hashCode() : 0;
result = 31 * result + Arrays.hashCode(offsets);
return result;
}
@Override
public String toString() {
return "KeyGroupRangeOffsets{" +
"keyGroupRange=" + keyGroupRange +
", offsets=" + Arrays.toString(offsets) +
'}';
}
}