cn.nukkit.level.util.PaddedBitArray Maven / Gradle / Ivy
package cn.nukkit.level.util;
import cn.nukkit.math.MathHelper;
import com.google.common.base.Preconditions;
import java.util.Arrays;
public class PaddedBitArray implements BitArray {
/**
* Array used to store data
*/
private final int[] words;
/**
* Palette version information
*/
private final BitArrayVersion version;
/**
* Number of entries in this palette (not the length of the words array that internally backs this palette)
*/
private final int size;
PaddedBitArray(BitArrayVersion version, int size, int[] words) {
this.size = size;
this.version = version;
this.words = words;
int expectedWordsLength = MathHelper.ceil((float) size / version.entriesPerWord);
if (words.length != expectedWordsLength) {
throw new IllegalArgumentException("Invalid length given for storage, got: " + words.length +
" but expected: " + expectedWordsLength);
}
}
@Override
public void set(int index, int value) {
Preconditions.checkElementIndex(index, this.size);
Preconditions.checkArgument(value >= 0 && value <= this.version.maxEntryValue,
"Max value: %s. Received value", this.version.maxEntryValue, value);
int arrayIndex = index / this.version.entriesPerWord;
int offset = (index % this.version.entriesPerWord) * this.version.bits;
this.words[arrayIndex] = this.words[arrayIndex] & ~(this.version.maxEntryValue << offset) | (value & this.version.maxEntryValue) << offset;
}
@Override
public int get(int index) {
Preconditions.checkElementIndex(index, this.size);
int arrayIndex = index / this.version.entriesPerWord;
int offset = (index % this.version.entriesPerWord) * this.version.bits;
return (this.words[arrayIndex] >>> offset) & this.version.maxEntryValue;
}
@Override
public int size() {
return this.size;
}
@Override
public int[] getWords() {
return this.words;
}
@Override
public BitArrayVersion getVersion() {
return this.version;
}
@Override
public BitArray copy() {
return new PaddedBitArray(this.version, this.size, Arrays.copyOf(this.words, this.words.length));
}
}
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