| /* |
| * Copyright (C) 2008, Google Inc. |
| * Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org> |
| * and other copyright owners as documented in the project's IP log. |
| * |
| * This program and the accompanying materials are made available |
| * under the terms of the Eclipse Distribution License v1.0 which |
| * accompanies this distribution, is reproduced below, and is |
| * available at http://www.eclipse.org/org/documents/edl-v10.php |
| * |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or |
| * without modification, are permitted provided that the following |
| * conditions are met: |
| * |
| * - Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * |
| * - Redistributions in binary form must reproduce the above |
| * copyright notice, this list of conditions and the following |
| * disclaimer in the documentation and/or other materials provided |
| * with the distribution. |
| * |
| * - Neither the name of the Eclipse Foundation, Inc. nor the |
| * names of its contributors may be used to endorse or promote |
| * products derived from this software without specific prior |
| * written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND |
| * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, |
| * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR |
| * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER |
| * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, |
| * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF |
| * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| package org.eclipse.jgit.dircache; |
| |
| import static org.eclipse.jgit.lib.FileMode.TYPE_TREE; |
| import static org.eclipse.jgit.util.Paths.compareSameName; |
| |
| import java.io.IOException; |
| |
| import org.eclipse.jgit.errors.DirCacheNameConflictException; |
| |
| /** |
| * Generic update/editing support for {@link DirCache}. |
| * <p> |
| * The different update strategies extend this class to provide their own unique |
| * services to applications. |
| */ |
| abstract class BaseDirCacheEditor { |
| /** The cache instance this editor updates during {@link #finish()}. */ |
| protected DirCache cache; |
| |
| /** |
| * Entry table this builder will eventually replace into {@link #cache}. |
| * <p> |
| * Use {@link #fastAdd(DirCacheEntry)} or {@link #fastKeep(int, int)} to |
| * make additions to this table. The table is automatically expanded if it |
| * is too small for a new addition. |
| * <p> |
| * Typically the entries in here are sorted by their path names, just like |
| * they are in the DirCache instance. |
| */ |
| protected DirCacheEntry[] entries; |
| |
| /** Total number of valid entries in {@link #entries}. */ |
| protected int entryCnt; |
| |
| /** |
| * Construct a new editor. |
| * |
| * @param dc |
| * the cache this editor will eventually update. |
| * @param ecnt |
| * estimated number of entries the editor will have upon |
| * completion. This sizes the initial entry table. |
| */ |
| protected BaseDirCacheEditor(final DirCache dc, final int ecnt) { |
| cache = dc; |
| entries = new DirCacheEntry[ecnt]; |
| } |
| |
| /** |
| * Get the {@code DirCache} |
| * |
| * @return the cache we will update on {@link #finish()}. |
| */ |
| public DirCache getDirCache() { |
| return cache; |
| } |
| |
| /** |
| * Append one entry into the resulting entry list. |
| * <p> |
| * The entry is placed at the end of the entry list. The caller is |
| * responsible for making sure the final table is correctly sorted. |
| * <p> |
| * The {@link #entries} table is automatically expanded if there is |
| * insufficient space for the new addition. |
| * |
| * @param newEntry |
| * the new entry to add. |
| */ |
| protected void fastAdd(final DirCacheEntry newEntry) { |
| if (entries.length == entryCnt) { |
| final DirCacheEntry[] n = new DirCacheEntry[(entryCnt + 16) * 3 / 2]; |
| System.arraycopy(entries, 0, n, 0, entryCnt); |
| entries = n; |
| } |
| entries[entryCnt++] = newEntry; |
| } |
| |
| /** |
| * Add a range of existing entries from the destination cache. |
| * <p> |
| * The entries are placed at the end of the entry list, preserving their |
| * current order. The caller is responsible for making sure the final table |
| * is correctly sorted. |
| * <p> |
| * This method copies from the destination cache, which has not yet been |
| * updated with this editor's new table. So all offsets into the destination |
| * cache are not affected by any updates that may be currently taking place |
| * in this editor. |
| * <p> |
| * The {@link #entries} table is automatically expanded if there is |
| * insufficient space for the new additions. |
| * |
| * @param pos |
| * first entry to copy from the destination cache. |
| * @param cnt |
| * number of entries to copy. |
| */ |
| protected void fastKeep(final int pos, int cnt) { |
| if (entryCnt + cnt > entries.length) { |
| final int m1 = (entryCnt + 16) * 3 / 2; |
| final int m2 = entryCnt + cnt; |
| final DirCacheEntry[] n = new DirCacheEntry[Math.max(m1, m2)]; |
| System.arraycopy(entries, 0, n, 0, entryCnt); |
| entries = n; |
| } |
| |
| cache.toArray(pos, entries, entryCnt, cnt); |
| entryCnt += cnt; |
| } |
| |
| /** |
| * Finish this builder and update the destination |
| * {@link org.eclipse.jgit.dircache.DirCache}. |
| * <p> |
| * When this method completes this builder instance is no longer usable by |
| * the calling application. A new builder must be created to make additional |
| * changes to the index entries. |
| * <p> |
| * After completion the DirCache returned by {@link #getDirCache()} will |
| * contain all modifications. |
| * <p> |
| * <i>Note to implementors:</i> Make sure {@link #entries} is fully sorted |
| * then invoke {@link #replace()} to update the DirCache with the new table. |
| */ |
| public abstract void finish(); |
| |
| /** |
| * Update the DirCache with the contents of {@link #entries}. |
| * <p> |
| * This method should be invoked only during an implementation of |
| * {@link #finish()}, and only after {@link #entries} is sorted. |
| */ |
| protected void replace() { |
| checkNameConflicts(); |
| if (entryCnt < entries.length / 2) { |
| final DirCacheEntry[] n = new DirCacheEntry[entryCnt]; |
| System.arraycopy(entries, 0, n, 0, entryCnt); |
| entries = n; |
| } |
| cache.replace(entries, entryCnt); |
| } |
| |
| private void checkNameConflicts() { |
| int end = entryCnt - 1; |
| for (int eIdx = 0; eIdx < end; eIdx++) { |
| DirCacheEntry e = entries[eIdx]; |
| if (e.getStage() != 0) { |
| continue; |
| } |
| |
| byte[] ePath = e.path; |
| int prefixLen = lastSlash(ePath) + 1; |
| |
| for (int nIdx = eIdx + 1; nIdx < entryCnt; nIdx++) { |
| DirCacheEntry n = entries[nIdx]; |
| if (n.getStage() != 0) { |
| continue; |
| } |
| |
| byte[] nPath = n.path; |
| if (!startsWith(ePath, nPath, prefixLen)) { |
| // Different prefix; this entry is in another directory. |
| break; |
| } |
| |
| int s = nextSlash(nPath, prefixLen); |
| int m = s < nPath.length ? TYPE_TREE : n.getRawMode(); |
| int cmp = compareSameName( |
| ePath, prefixLen, ePath.length, |
| nPath, prefixLen, s, m); |
| if (cmp < 0) { |
| break; |
| } else if (cmp == 0) { |
| throw new DirCacheNameConflictException( |
| e.getPathString(), |
| n.getPathString()); |
| } |
| } |
| } |
| } |
| |
| private static int lastSlash(byte[] path) { |
| for (int i = path.length - 1; i >= 0; i--) { |
| if (path[i] == '/') { |
| return i; |
| } |
| } |
| return -1; |
| } |
| |
| private static int nextSlash(byte[] b, int p) { |
| final int n = b.length; |
| for (; p < n; p++) { |
| if (b[p] == '/') { |
| return p; |
| } |
| } |
| return n; |
| } |
| |
| private static boolean startsWith(byte[] a, byte[] b, int n) { |
| if (b.length < n) { |
| return false; |
| } |
| for (n--; n >= 0; n--) { |
| if (a[n] != b[n]) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| /** |
| * Finish, write, commit this change, and release the index lock. |
| * <p> |
| * If this method fails (returns false) the lock is still released. |
| * <p> |
| * This is a utility method for applications as the finish-write-commit |
| * pattern is very common after using a builder to update entries. |
| * |
| * @return true if the commit was successful and the file contains the new |
| * data; false if the commit failed and the file remains with the |
| * old data. |
| * @throws java.lang.IllegalStateException |
| * the lock is not held. |
| * @throws java.io.IOException |
| * the output file could not be created. The caller no longer |
| * holds the lock. |
| */ |
| public boolean commit() throws IOException { |
| finish(); |
| cache.write(); |
| return cache.commit(); |
| } |
| } |