1 /**
2 * Copyright (c) 2004-2011 QOS.ch
3 * All rights reserved.
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining
6 * a copy of this software and associated documentation files (the
7 * "Software"), to deal in the Software without restriction, including
8 * without limitation the rights to use, copy, modify, merge, publish,
9 * distribute, sublicense, and/or sell copies of the Software, and to
10 * permit persons to whom the Software is furnished to do so, subject to
11 * the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be
14 * included in all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
17 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
18 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
19 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
20 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
21 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
22 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
23 *
24 */
25 package org.slf4j.migrator.helper;
26
27 public class Abbreviator {
28 static final String FILLER = "...";
29
30 final char folderSeparator;
31 final int invariantPrefixLength;
32 final int desiredLength;
33
34 public Abbreviator(int invariantPrefixLength, int desiredLength,
35 char folderSeparator) {
36 this.invariantPrefixLength = invariantPrefixLength;
37 this.desiredLength = desiredLength;
38 this.folderSeparator = folderSeparator;
39 }
40
41 public String abbreviate(String filename) {
42 if (filename.length() <= desiredLength) {
43 return filename;
44 } else {
45
46 int firstIndex = filename.indexOf(folderSeparator, invariantPrefixLength);
47 if (firstIndex == -1) {
48 // we cant't process this string
49 return filename;
50 }
51 StringBuffer buf = new StringBuffer(desiredLength);
52 buf.append(filename.substring(0, firstIndex + 1));
53 buf.append(FILLER);
54 int nextIndex = computeNextIndex(filename, firstIndex);
55 if (nextIndex != -1) {
56 buf.append(filename.substring(nextIndex));
57 } else {
58 // better long than wrong
59 return filename;
60 }
61
62 if (buf.length() < filename.length()) {
63 return buf.toString();
64 } else {
65 // we tried our best but we are still could not shorten the input
66 return filename;
67 }
68 }
69 }
70
71 int computeNextIndex(String filename, int firstIndex) {
72 int nextIndex = firstIndex + 1;
73 int hitCount = 0;
74 int minToRemove = filename.length() - desiredLength + FILLER.length();
75 while (nextIndex < firstIndex + minToRemove) {
76 int tmpIndex = filename.indexOf(folderSeparator, nextIndex + 1);
77 if (tmpIndex == -1) {
78 if (hitCount == 0) {
79 return -1;
80 } else {
81 return nextIndex;
82 }
83 } else {
84 hitCount++;
85 nextIndex = tmpIndex;
86 }
87 }
88 return nextIndex;
89 }
90 }