com.datastrato.gravitino.utils.Bytes Maven / Gradle / Ivy
/*
* 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 com.datastrato.gravitino.utils;
import java.io.Serializable;
import java.util.Arrays;
import java.util.Comparator;
// Referred from Apache Kafka's Bytes implementation
// clients/src/main/java/org/apache/kafka/common/utils/Bytes.java
public class Bytes implements Comparable {
public static final byte[] EMPTY = new byte[0];
private static final char[] HEX_CHARS_UPPER = {
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'
};
private final byte[] bytes;
// cache the hash code for the string, default to 0
private int hashCode;
public static Bytes wrap(byte[] bytes) {
if (bytes == null) return null;
return new Bytes(bytes);
}
/**
* Create a Bytes using the byte array.
*
* @param bytes This array becomes the backing storage for the object.
*/
public Bytes(byte[] bytes) {
this.bytes = bytes;
// initialize hash code to 0
hashCode = 0;
}
/**
* Get the data from the Bytes.
*
* @return The underlying byte array
*/
public byte[] get() {
return this.bytes;
}
/**
* Concatenates multiple byte arrays into a single byte array.
*
* @param values An array of byte arrays to be concatenated.
* @return A new byte array containing the concatenated data.
*/
public static byte[] concat(byte[]... values) {
int totalLen = 0;
for (byte[] b : values) {
totalLen += b.length;
}
byte[] res = new byte[totalLen];
int currentPos = 0;
for (int i = 0; i < values.length; i++) {
System.arraycopy(values[i], 0, res, currentPos, values[i].length);
currentPos += values[i].length;
}
return res;
}
/**
* The hashcode is cached except for the case where it is computed as 0, in which case we compute
* the hashcode on every call.
*
* @return the hashcode
*/
@Override
public int hashCode() {
if (hashCode == 0) {
hashCode = Arrays.hashCode(bytes);
}
return hashCode;
}
@Override
public boolean equals(Object other) {
if (this == other) return true;
if (other == null) return false;
// we intentionally use the function to compute hashcode here
if (this.hashCode() != other.hashCode()) return false;
if (other instanceof Bytes) return Arrays.equals(this.bytes, ((Bytes) other).get());
return false;
}
@Override
public int compareTo(byte[] o) {
return BYTES_LEXICO_COMPARATOR.compare(this.bytes, o);
}
@Override
public String toString() {
return Bytes.toString(bytes, 0, bytes.length);
}
/**
* Write a printable representation of a byte array. Non-printable characters are hex escaped in
* the format \\x%02X, eg: \x00 \x05 etc.
*
* This function is brought from org.apache.hadoop.hbase.util.Bytes
*
* @param b array to write out
* @param off offset to start at
* @param len length to write
* @return string output
*/
private static String toString(final byte[] b, int off, int len) {
StringBuilder result = new StringBuilder();
if (b == null) return result.toString();
// just in case we are passed a 'len' that is > buffer length...
if (off >= b.length) return result.toString();
if (off + len > b.length) len = b.length - off;
for (int i = off; i < off + len; ++i) {
int ch = b[i] & 0xFF;
if (ch >= ' ' && ch <= '~' && ch != '\\') {
result.append((char) ch);
} else {
result.append("\\x");
result.append(HEX_CHARS_UPPER[ch / 0x10]);
result.append(HEX_CHARS_UPPER[ch % 0x10]);
}
}
return result.toString();
}
/**
* Increment the underlying byte array by adding 1. Throws an IndexOutOfBoundsException if
* incrementing would cause the underlying input byte array to overflow.
*
* @param input - The byte array to increment
* @return A new copy of the incremented byte array.
*/
public static Bytes increment(Bytes input) throws IndexOutOfBoundsException {
byte[] inputArr = input.get();
if (inputArr.length == 0) {
throw new IndexOutOfBoundsException("The length of Key should be greater than 0");
}
byte[] ret = new byte[inputArr.length];
int carry = 1;
for (int i = inputArr.length - 1; i >= 0; i--) {
if (inputArr[i] == (byte) 0xFF && carry == 1) {
ret[i] = (byte) 0x00;
} else {
ret[i] = (byte) (inputArr[i] + carry);
carry = 0;
}
}
if (carry == 0) {
return wrap(ret);
} else {
throw new IndexOutOfBoundsException();
}
}
/** A byte array comparator based on lexicograpic ordering. */
public static final ByteArrayComparator BYTES_LEXICO_COMPARATOR =
new LexicographicByteArrayComparator();
public interface ByteArrayComparator extends Comparator, Serializable {
int compare(
final byte[] buffer1,
int offset1,
int length1,
final byte[] buffer2,
int offset2,
int length2);
}
private static class LexicographicByteArrayComparator implements ByteArrayComparator {
@Override
public int compare(byte[] buffer1, byte[] buffer2) {
return compare(buffer1, 0, buffer1.length, buffer2, 0, buffer2.length);
}
public int compare(
final byte[] buffer1,
int offset1,
int length1,
final byte[] buffer2,
int offset2,
int length2) {
// short circuit equal case
if (buffer1 == buffer2 && offset1 == offset2 && length1 == length2) {
return 0;
}
// similar to Arrays.compare() but considers offset and length
int end1 = offset1 + length1;
int end2 = offset2 + length2;
for (int i = offset1, j = offset2; i < end1 && j < end2; i++, j++) {
int a = buffer1[i] & 0xff;
int b = buffer2[j] & 0xff;
if (a != b) {
return a - b;
}
}
return length1 - length2;
}
}
}