Mercurial > hg4j
view src/org/tmatesoft/hg/internal/PathPool.java @ 709:497e697636fc
Report merged lines as changed block if possible, not as a sequence of added/deleted blocks. To facilitate access to merge parent lines AddBlock got mergeLineAt() method that reports index of the line in the second parent (if any), while insertedAt() has been changed to report index in the first parent always
author | Artem Tikhomirov <tikhomirov.artem@gmail.com> |
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date | Wed, 21 Aug 2013 16:23:27 +0200 |
parents | 12f668401613 |
children |
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/* * Copyright (c) 2011-2012 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.internal; import java.lang.ref.SoftReference; import java.util.WeakHashMap; import org.tmatesoft.hg.util.Convertor; import org.tmatesoft.hg.util.Path; import org.tmatesoft.hg.util.PathRewrite; /** * Produces path from strings and caches (weakly) result for reuse * * @author Artem Tikhomirov * @author TMate Software Ltd. */ public class PathPool implements Path.Source, Convertor<Path> { private final WeakHashMap<CharSequence, SoftReference<Path>> cache; private final PathRewrite pathRewrite; public PathPool(PathRewrite rewrite) { pathRewrite = rewrite; cache = new WeakHashMap<CharSequence, SoftReference<Path>>(); } /* * (non-Javadoc) * @see org.tmatesoft.hg.util.Path.Source#path(java.lang.CharSequence) */ public Path path(CharSequence p) { if (p instanceof Path) { return asPath((Path) p); } p = pathRewrite.rewrite(p); return get(p, true); } /* * (non-Javadoc) * @see org.tmatesoft.hg.util.Convertor#mangle(java.lang.Object) */ public Path mangle(Path p) { return asPath(p); } // pipes path object through cache to reuse instance, if possible // TODO unify with Pool<Path> private Path asPath(Path p) { CharSequence s = pathRewrite.rewrite(p.toString()); // rewrite string, not path to avoid use of Path object as key // in case pathRewrite does nothing and returns supplied instance // Path cached = get(s, false); if (cached == null) { cache.put(s, new SoftReference<Path>(cached = p)); } return cached; } // XXX what would be parent of an empty path? // Path shall have similar functionality public Path parent(Path path) { if (path.length() == 0) { throw new IllegalArgumentException(); } for (int i = path.length() - 2 /*if path represents a dir, trailing char is slash, skip*/; i >= 0; i--) { if (path.charAt(i) == '/') { return get(path.subSequence(0, i+1).toString(), true); } } return get("", true); } // invoke when path pool is no longer in use, to ease gc work public void clear() { cache.clear(); } private Path get(CharSequence p, boolean create) { SoftReference<Path> sr = cache.get(p); Path path = sr == null ? null : sr.get(); if (path == null) { if (create) { path = Path.create(p); cache.put(p, new SoftReference<Path>(path)); } else if (sr != null) { // cached path no longer used, clear cache entry - do not wait for RefQueue to step in cache.remove(p); } } return path; } }