2 * Copyright (c) 2013 Cisco Systems, Inc. and others. All rights reserved.
4 * This program and the accompanying materials are made available under the
5 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
6 * and is available at http://www.eclipse.org/legal/epl-v10.html
8 package org.opendaylight.protocol.util;
10 import com.google.common.base.Preconditions;
11 import io.netty.buffer.ByteBuf;
13 import java.io.FileInputStream;
14 import java.io.IOException;
15 import java.nio.ByteBuffer;
16 import java.nio.charset.CharacterCodingException;
17 import java.nio.charset.StandardCharsets;
18 import java.util.Arrays;
19 import java.util.BitSet;
20 import org.slf4j.Logger;
21 import org.slf4j.LoggerFactory;
24 * Util class for methods working with byte array.
26 public final class ByteArray {
28 private static final Logger LOG = LoggerFactory.getLogger(ByteArray.class);
31 throw new UnsupportedOperationException();
35 * Helper method missing from netty ByteBuf methods. Directly returns byte array part of the given buffer, starting
36 * at reader index, with given length. Increases reader index of the buffer by 'length'.
38 * @param buffer ByteBuf from which the bytes are going to be taken
39 * @param length length of the returned byte array
42 public static byte[] readBytes(final ByteBuf buffer, final int length) {
43 Preconditions.checkArgument(buffer != null && buffer.readableBytes() >= length,
44 "Buffer cannot be read for %s bytes.", length);
45 final byte[] result = new byte[length];
46 buffer.readBytes(result);
51 * Helper method missing from netty ByteBuf methods. Directly returns all readable bytes from buffer as byte array.
52 * Adjusts reader index of the buffer by length of readable bytes in the buffer.
54 * @param buffer byteBuf from which the bytes are going to be taken
57 public static byte[] readAllBytes(final ByteBuf buffer) {
58 return readBytes(buffer, buffer.readableBytes());
62 * Helper method missing from netty ByteBuf methods. Directly returns byte array part of the given buffer, starting
63 * at reader index, with given length. Does not modify reader or writer index of the buffer.
65 * @param buffer ByteBuf from which the bytes are going to be taken
66 * @param length length of the returned byte array
69 public static byte[] getBytes(final ByteBuf buffer, final int length) {
70 Preconditions.checkArgument(buffer != null && buffer.readableBytes() >= length,
71 "Buffer cannot be read for %s bytes.", length);
72 final byte[] result = new byte[length];
73 buffer.getBytes(buffer.readerIndex(), result);
78 * Helper method missing from netty ByteBuf methods. Directly returns all readable bytes from buffer as byte array.
79 * Does not modify writer or reader index of the buffer.
81 * @param buffer byteBuf from which the bytes are going to be taken
84 public static byte[] getAllBytes(final ByteBuf buffer) {
85 return getBytes(buffer, buffer.readableBytes());
89 * Returns a new byte array from given byte array, starting at start index with the size of the length parameter.
90 * Byte array given as parameter stays untouched.
92 * @param bytes original byte array
93 * @param startIndex beginning index, inclusive
94 * @param length how many bytes should be in the sub-array
95 * @return a new byte array that is a sub-array of the original
97 public static byte[] subByte(final byte[] bytes, final int startIndex, final int length) {
98 Preconditions.checkArgument(checkLength(bytes, length) && checkStartIndex(bytes, startIndex, length), "Cannot create subByte, invalid arguments: Length: %s startIndex: %s", length, startIndex);
99 final byte[] res = new byte[length];
100 System.arraycopy(bytes, startIndex, res, 0, length);
104 private static boolean checkLength(final byte[] bytes, final int length) {
105 return length > 0 && bytes.length > 0 && length <= bytes.length;
108 private static boolean checkStartIndex(final byte[] bytes, final int startIndex, final int length) {
109 return startIndex >= 0 && startIndex < bytes.length && (startIndex + length <= bytes.length);
113 * Converts byte array to Integer. If there are less bytes in the array as required (4), the method will push
114 * adequate number of zero bytes prepending given byte array.
116 * @param bytes array to be converted to int
119 public static int bytesToInt(final byte[] bytes) {
120 Preconditions.checkArgument(bytes.length <= Integer.SIZE / Byte.SIZE, "Cannot convert bytes to integer. Byte array too big.");
121 byte[] res = new byte[Integer.SIZE / Byte.SIZE];
122 if (bytes.length != Integer.SIZE / Byte.SIZE) {
123 System.arraycopy(bytes, 0, res, Integer.SIZE / Byte.SIZE - bytes.length, bytes.length);
127 final ByteBuffer buff = ByteBuffer.wrap(res);
128 return buff.getInt();
132 * Converts byte array to long. If there are less bytes in the array as required (Long.Size), the method will push
133 * adequate number of zero bytes prepending given byte array.
135 * @param bytes array to be converted to long
138 public static long bytesToLong(final byte[] bytes) {
139 Preconditions.checkArgument(bytes.length <= Long.SIZE / Byte.SIZE, "Cannot convert bytes to long.Byte array too big.");
140 byte[] res = new byte[Long.SIZE / Byte.SIZE];
141 if (bytes.length != Long.SIZE / Byte.SIZE) {
142 System.arraycopy(bytes, 0, res, Long.SIZE / Byte.SIZE - bytes.length, bytes.length);
146 final ByteBuffer buff = ByteBuffer.wrap(res);
147 return buff.getLong();
151 * Cuts 'count' number of bytes from the beginning of given byte array.
153 * @param bytes array to be cut, cannot be null
154 * @param count how many bytes needed to be cut, needs to be greater than 0
155 * @return bytes array without first 'count' bytes
157 public static byte[] cutBytes(final byte[] bytes, final int count) {
158 Preconditions.checkArgument(bytes.length != 0 && count <= bytes.length && count > 0, "Cannot cut bytes, invalid arguments: Count: %s bytes.length: %s", count, bytes.length);
159 return Arrays.copyOfRange(bytes, count, bytes.length);
163 * Parse byte to bits, from the leftmost bit.
165 * @param b byte to be parsed
166 * @return array of booleans with size of 8
169 public static boolean[] parseBits(final byte b) {
170 final boolean[] bits = new boolean[Byte.SIZE];
172 for (int i = Byte.SIZE - 1; i >= 0; i--) {
173 bits[j] = ((b & (1 << i)) != 0);
180 * Parses array of bytes to BitSet, from left most bit.
182 * @param bytes array of bytes to be parsed
183 * @return BitSet with length = bytes.length * Byte.SIZE
186 public static BitSet bytesToBitSet(final byte[] bytes) {
187 final BitSet bitSet = new BitSet(bytes.length * Byte.SIZE);
188 for (int bytesIter = 0; bytesIter < bytes.length; bytesIter++) {
189 final int offset = bytesIter * Byte.SIZE;
190 for (int byteIter = Byte.SIZE - 1; byteIter >= 0; byteIter--) {
191 bitSet.set(offset + (Byte.SIZE - byteIter - 1), (bytes[bytesIter] & 1 << (byteIter)) != 0);
198 * Parses BitSet to bytes, from most left bit.
200 * @param bitSet BitSet to be parsed
201 * @param returnedLength Length of returned array. Overlapping flags are truncated.
202 * @return parsed array of bytes with length of bitSet.length / Byte.SIZE
205 public static byte[] bitSetToBytes(final BitSet bitSet, final int returnedLength) {
206 final byte[] bytes = new byte[returnedLength];
208 for (int bytesIter = 0; bytesIter < bytes.length; bytesIter++) {
209 final int offset = bytesIter * Byte.SIZE;
211 for (int byteIter = Byte.SIZE - 1; byteIter >= 0; byteIter--) {
212 bytes[bytesIter] |= (bitSet.get(offset + (Byte.SIZE - byteIter - 1)) ? 1 << byteIter : 0);
219 * Parses file to array of bytes
221 * @param name path to file to by parsed
222 * @return parsed array of bytes
224 public static byte[] fileToBytes(final String name) throws IOException {
225 final File file = new File(name);
229 if (file.length() > Integer.MAX_VALUE) {
230 throw new IOException("Too large file to load in byte array.");
232 final byte[] byteArray = new byte[(int) file.length()];
233 try (final FileInputStream fin = new FileInputStream(file)) {
234 while (offset < byteArray.length) {
235 numRead = fin.read(byteArray, offset, byteArray.length - offset);
246 * Copies range of bits from passed byte and align to right.<br>
248 * @param src source byte to copy from
249 * @param fromBit bit from which will copy (inclusive) - numbered from 0
250 * @param length of bits to by copied, valid values are 1 through 8
251 * @return copied value aligned to right
253 public static byte copyBitsRange(final byte src, final int fromBit, final int length) {
254 Preconditions.checkArgument(fromBit >= 0 && fromBit <= Byte.SIZE - 1 && length >= 1 && length <= Byte.SIZE, "fromBit or toBit is out of range.");
255 Preconditions.checkArgument(fromBit + length <= Byte.SIZE, "Out of range.");
260 for (int i = fromBit + length - 1; i >= fromBit; i--) {
262 if ((src & 1 << (Byte.SIZE - i - 1)) != 0) {
263 retByte |= 1 << retI;
273 * Decodes bytes to human readable UTF-8 string. If bytes are not valid UTF-8, they are represented as raw binary.
275 * @param bytes bytes to be decoded to string
276 * @return String representation of passed bytes
278 public static String bytesToHRString(final byte[] bytes) {
280 return StandardCharsets.UTF_8.newDecoder().decode(ByteBuffer.wrap(bytes)).toString();
281 } catch (final CharacterCodingException e) {
282 LOG.debug("Could not apply UTF-8 encoding.", e);
283 return Arrays.toString(bytes);