Mercurial > jhg
view src/org/tmatesoft/hg/repo/HgIgnore.java @ 366:189dc6dc1c3e
Use exceptions to expose errors reading mercurial data
author | Artem Tikhomirov <tikhomirov.artem@gmail.com> |
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date | Fri, 16 Dec 2011 04:43:18 +0100 |
parents | 58016b1b8554 |
children | e732521a9eb4 |
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/* * Copyright (c) 2010-2011 TMate Software Ltd * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; version 2 of the License. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * For information on how to redistribute this software under * the terms of a license other than GNU General Public License * contact TMate Software at support@hg4j.com */ package org.tmatesoft.hg.repo; import java.io.BufferedReader; import java.io.File; import java.io.FileReader; import java.io.IOException; import java.util.ArrayList; import java.util.Collections; import java.util.List; import java.util.regex.Pattern; import java.util.regex.PatternSyntaxException; import org.tmatesoft.hg.util.Path; /** * Handling of ignored paths according to .hgignore configuration * * @author Artem Tikhomirov * @author TMate Software Ltd. */ public class HgIgnore implements Path.Matcher { private List<Pattern> entries; HgIgnore() { entries = Collections.emptyList(); } /* package-local */List<String> read(File hgignoreFile) throws IOException { if (!hgignoreFile.exists()) { return null; } BufferedReader fr = new BufferedReader(new FileReader(hgignoreFile)); try { return read(fr); } finally { fr.close(); } } /* package-local */List<String> read(BufferedReader content) throws IOException { ArrayList<String> errors = new ArrayList<String>(); ArrayList<Pattern> result = new ArrayList<Pattern>(entries); // start with existing String syntax = "regexp"; // or "glob" String line; while ((line = content.readLine()) != null) { line = line.trim(); if (line.startsWith("syntax:")) { syntax = line.substring("syntax:".length()).trim(); if (!"regexp".equals(syntax) && !"glob".equals(syntax)) { errors.add(line); continue; //throw new IllegalStateException(line); } } else if (line.length() > 0) { // shall I account for local paths in the file (i.e. // back-slashed on windows)? int x, s = 0; while ((x = line.indexOf('#', s)) >= 0) { if (x > 0 && line.charAt(x-1) == '\\') { // remove escape char line = line.substring(0, x-1).concat(line.substring(x)); s = x; // with exclusion of char at [x], s now points to what used to be at [x+1] } else { line = line.substring(0, x).trim(); } } if (line.length() == 0) { continue; } if ("glob".equals(syntax)) { // hgignore(5) // (http://www.selenic.com/mercurial/hgignore.5.html) says slashes '\' are escape characters, // hence no special treatment of Windows path // however, own attempts make me think '\' on Windows are not treated as escapes line = glob2regex(line); } else { assert "regexp".equals(syntax); // regular expression patterns need not match start of the line unless demanded explicitly line = line.charAt(0) == '^' ? line : ".*" + line; } try { result.add(Pattern.compile(line)); // case-sensitive } catch (PatternSyntaxException ex) { errors.add(line + "@" + ex.getMessage()); } } } result.trimToSize(); entries = result; return errors.isEmpty() ? null : errors; } // note, #isIgnored(), even if queried for directories and returned positive reply, may still get // a file from that ignored folder to get examined. Thus, patterns like "bin" shall match not only a folder, // but any file under that folder as well // Alternatively, file walker may memorize folder is ignored and uses this information for all nested files. However, // this approach would require walker (a) return directories (b) provide nesting information. This may become // troublesome when one walks not over io.File, but Eclipse's IResource or any other custom VFS. // // // might be interesting, although looks like of no direct use in my case // @see http://stackoverflow.com/questions/1247772/is-there-an-equivalent-of-java-util-regex-for-glob-type-patterns // // TODO consider refactoring to reuse in PathGlobMatcher#glob2regexp private static String glob2regex(String line) { assert line.length() > 0; StringBuilder sb = new StringBuilder(line.length() + 10); int start = 0, end = line.length() - 1; sb.append("(?:|.*/)"); // glob patterns shall match file in any directory int inCurly = 0; for (int i = start; i <= end; i++) { char ch = line.charAt(i); if (ch == '.' || ch == '\\') { sb.append('\\'); } else if (ch == '?') { // simple '.' substitution might work out, however, more formally // a char class seems more appropriate to avoid accidentally // matching a subdirectory with ? char (i.e. /a/b?d against /a/bad, /a/bed and /a/b/d) // @see http://pubs.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_13_03 // quote: "The slash character in a pathname shall be explicitly matched by using one or more slashes in the pattern; // it shall neither be matched by the asterisk or question-mark special characters nor by a bracket expression" sb.append("[^/]"); continue; } else if (ch == '*') { sb.append("[^/]*?"); continue; } else if (ch == '{') { // XXX in fact, need to respect if last char was escaping ('\\'), then don't need to treat this as special // see link at javadoc above for reasonable example inCurly++; sb.append('('); continue; } else if (ch == '}') { if (inCurly > 0) { inCurly--; sb.append(')'); continue; } } else if (ch == ',' && inCurly > 0) { sb.append('|'); continue; } sb.append(ch); } sb.append("(?:/|$)"); return sb.toString(); } /** * @param path file or directory name in question * @return <code>true</code> if matches repository configuration of ignored files. */ public boolean isIgnored(Path path) { String ps = path.toString(); for (Pattern p : entries) { int x = ps.indexOf('/'); // reset for each pattern if (p.matcher(ps).find()) { return true; } while (x != -1 && x+1 != ps.length() /*skip very last segment not to check complete string twice*/) { String fragment = ps.substring(0, x); if (p.matcher(fragment).matches()) { return true; } x = ps.indexOf('/', x+1); } } return false; } /** * A handy wrap of {@link #isIgnored(Path)} into {@link Path.Matcher}. Yields same result as {@link #isIgnored(Path)}. * @return <code>true</code> if file is deemed ignored. */ public boolean accept(Path path) { return isIgnored(path); } }