/* * Copyright 2017, 2018 IBM Corp. All Rights Reserved. * * Licensed 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.ibm.etcd.client; import com.google.protobuf.ByteString; import com.google.protobuf.UnsafeByteOperations; /** * Helper methods for manipulating ByteString keys */ public class KeyUtils { private KeyUtils() {} // static only public static final ByteString ZERO_BYTE = singleByte(0); public static ByteString plusOne(ByteString key) { int max = key.size() - 1; if (max < 0) { return singleByte(1); } int lastPlusOne = key.byteAt(max) + 1; ByteString excludeLast = key.substring(0, max); return lastPlusOne == 0 ? plusOne(excludeLast) : excludeLast.concat(singleByte(lastPlusOne)); } public static ByteString singleByte(int b) { return UnsafeByteOperations.unsafeWrap(new byte[] { (byte) b }); } public static int compareByteStrings(ByteString bs1, ByteString bs2) { int s1 = bs1.size(), s2 = bs2.size(), n = Math.min(s1, s2); for (int i = 0; i < n; i++) { int cmp = (bs1.byteAt(i) & 0xff) - (bs2.byteAt(i) & 0xff); if (cmp != 0) { return cmp; } } return s1 - s2; } public static ByteString bs(String str) { return str != null ? ByteString.copyFromUtf8(str) : null; } private static final String HEX_CHARS_STR = "0123456789abcdef"; private static final char[] HEX_CHARS = HEX_CHARS_STR.toCharArray(); public static String toHexString(ByteString bs) { int len = bs.size(); if (len == 0) { return ""; } StringBuilder sb = new StringBuilder(len << 1); for (int i = 0; i < len; i++) { int b = bs.byteAt(i); sb.append(HEX_CHARS[(b >> 4) & 0xf]).append(HEX_CHARS[b & 0xf]); } return sb.toString(); } public static ByteString fromHexString(CharSequence seq) { int len = seq.length(); if (len == 0) { return ByteString.EMPTY; } if (len % 2 != 0) { throw new IllegalArgumentException("must be even number of chars"); } int blen = len >> 1; byte[] bytes = new byte[blen]; for (int i = 0, j = 0; i < blen; i ++, j += 2) { bytes[i] = (byte) ((digitFor(seq.charAt(j)) << 4) | digitFor(seq.charAt(j + 1))); } return UnsafeByteOperations.unsafeWrap(bytes); } private static int digitFor(char c) { int d = HEX_CHARS_STR.indexOf(Character.toLowerCase(c)); if (d == -1) { throw new IllegalArgumentException("invalid char: " + c); } return d; } //TODO other stuff for namespaces etc }