Gadgetbridge/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/util/RangeMap.java

88 lines
2.4 KiB
Java

/* Copyright (C) 2023-2024 José Rebelo
This file is part of Gadgetbridge.
Gadgetbridge is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as published
by the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
Gadgetbridge 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 Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>. */
package nodomain.freeyourgadget.gadgetbridge.util;
import android.util.Pair;
import androidx.annotation.Nullable;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
/**
* A map of bounds for ranges. Returns the value closest to the key, in upper or lower bound mode.
*/
public class RangeMap<K extends Comparable<K>, V> {
private final List<Pair<K, V>> list = new ArrayList<>();
private boolean isSorted = false;
private final Comparator<K> comparator;
public RangeMap() {
this(Mode.LOWER_BOUND);
}
public RangeMap(final Mode mode) {
switch (mode) {
case LOWER_BOUND:
comparator = (k1, k2) -> k1.compareTo(k2);
break;
case UPPER_BOUND:
comparator = (k1, k2) -> k2.compareTo(k1);
break;
default:
throw new IllegalArgumentException("Unknown mode " + mode);
}
}
public void put(final K key, final V value) {
list.add(Pair.create(key, value));
isSorted = false;
}
@Nullable
public V get(final K key) {
if (!isSorted) {
Collections.sort(list, (a, b) -> comparator.compare(a.first, b.first));
isSorted = true;
}
for (int i = list.size() - 1; i >= 0; i--) {
if (comparator.compare(key, list.get(i).first) >= 0) {
return list.get(i).second;
}
}
return null;
}
public boolean isEmpty() {
return list.isEmpty();
}
public int size() {
return list.size();
}
public enum Mode {
LOWER_BOUND,
UPPER_BOUND,
;
}
}