1 /*
2 * Copyright (C) 2010, Google Inc. and others
3 *
4 * This program and the accompanying materials are made available under the
5 * terms of the Eclipse Distribution License v. 1.0 which is available at
6 * https://www.eclipse.org/org/documents/edl-v10.php.
7 *
8 * SPDX-License-Identifier: BSD-3-Clause
9 */
10
11 package org.eclipse.jgit.util;
12
13 /**
14 * Utility class for character functions on raw bytes
15 * <p>
16 * Characters are assumed to be 8-bit US-ASCII.
17 */
18 public class RawCharUtil {
19 private static final boolean[] WHITESPACE = new boolean[256];
20
21 static {
22 WHITESPACE['\r'] = true;
23 WHITESPACE['\n'] = true;
24 WHITESPACE['\t'] = true;
25 WHITESPACE[' '] = true;
26 }
27
28 /**
29 * Determine if an 8-bit US-ASCII encoded character is represents whitespace
30 *
31 * @param c
32 * the 8-bit US-ASCII encoded character
33 * @return true if c represents a whitespace character in 8-bit US-ASCII
34 */
35 public static boolean isWhitespace(byte c) {
36 return WHITESPACE[c & 0xff];
37 }
38
39 /**
40 * Returns the new end point for the byte array passed in after trimming any
41 * trailing whitespace characters, as determined by the isWhitespace()
42 * function. start and end are assumed to be within the bounds of raw.
43 *
44 * @param raw
45 * the byte array containing the portion to trim whitespace for
46 * @param start
47 * the start of the section of bytes
48 * @param end
49 * the end of the section of bytes
50 * @return the new end point
51 */
52 public static int trimTrailingWhitespace(byte[] raw, int start, int end) {
53 int ptr = end - 1;
54 while (start <= ptr && isWhitespace(raw[ptr]))
55 ptr--;
56
57 return ptr + 1;
58 }
59
60 /**
61 * Returns the new start point for the byte array passed in after trimming
62 * any leading whitespace characters, as determined by the isWhitespace()
63 * function. start and end are assumed to be within the bounds of raw.
64 *
65 * @param raw
66 * the byte array containing the portion to trim whitespace for
67 * @param start
68 * the start of the section of bytes
69 * @param end
70 * the end of the section of bytes
71 * @return the new start point
72 */
73 public static int trimLeadingWhitespace(byte[] raw, int start, int end) {
74 while (start < end && isWhitespace(raw[start]))
75 start++;
76
77 return start;
78 }
79
80 private RawCharUtil() {
81 // This will never be called
82 }
83 }