| /* |
| * Copyright (C) 2009, Google Inc. |
| * Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org> and others |
| * |
| * This program and the accompanying materials are made available under the |
| * terms of the Eclipse Distribution License v. 1.0 which is available at |
| * https://www.eclipse.org/org/documents/edl-v10.php. |
| * |
| * SPDX-License-Identifier: BSD-3-Clause |
| */ |
| |
| package org.eclipse.jgit.util; |
| |
| import org.eclipse.jgit.internal.JGitText; |
| import org.eclipse.jgit.lib.Constants; |
| |
| /** |
| * Searches text using only substring search. |
| * <p> |
| * Instances are thread-safe. Multiple concurrent threads may perform matches on |
| * different character sequences at the same time. |
| */ |
| public class RawSubStringPattern { |
| private final String needleString; |
| |
| private final byte[] needle; |
| |
| /** |
| * Construct a new substring pattern. |
| * |
| * @param patternText |
| * text to locate. This should be a literal string, as no |
| * meta-characters are supported by this implementation. The |
| * string may not be the empty string. |
| */ |
| public RawSubStringPattern(String patternText) { |
| if (patternText.length() == 0) |
| throw new IllegalArgumentException(JGitText.get().cannotMatchOnEmptyString); |
| needleString = patternText; |
| |
| final byte[] b = Constants.encode(patternText); |
| needle = new byte[b.length]; |
| for (int i = 0; i < b.length; i++) |
| needle[i] = lc(b[i]); |
| } |
| |
| /** |
| * Match a character sequence against this pattern. |
| * |
| * @param rcs |
| * the sequence to match. Must not be null but the length of the |
| * sequence is permitted to be 0. |
| * @return offset within <code>rcs</code> of the first occurrence of this |
| * pattern; -1 if this pattern does not appear at any position of |
| * <code>rcs</code>. |
| */ |
| public int match(RawCharSequence rcs) { |
| final int needleLen = needle.length; |
| final byte first = needle[0]; |
| |
| final byte[] text = rcs.buffer; |
| int matchPos = rcs.startPtr; |
| final int maxPos = rcs.endPtr - needleLen; |
| |
| OUTER: for (; matchPos <= maxPos; matchPos++) { |
| if (neq(first, text[matchPos])) { |
| while (++matchPos <= maxPos && neq(first, text[matchPos])) { |
| /* skip */ |
| } |
| if (matchPos > maxPos) |
| return -1; |
| } |
| |
| int si = matchPos + 1; |
| for (int j = 1; j < needleLen; j++, si++) { |
| if (neq(needle[j], text[si])) |
| continue OUTER; |
| } |
| return matchPos; |
| } |
| return -1; |
| } |
| |
| private static final boolean neq(byte a, byte b) { |
| return a != b && a != lc(b); |
| } |
| |
| private static final byte lc(byte q) { |
| return (byte) StringUtils.toLowerCase((char) (q & 0xff)); |
| } |
| |
| /** |
| * Get the literal pattern string this instance searches for. |
| * |
| * @return the pattern string given to our constructor. |
| */ |
| public String pattern() { |
| return needleString; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public String toString() { |
| return pattern(); |
| } |
| } |