Java tutorial
/* * Copyright (C) 2010, Christian Halstrick <christian.halstrick@sap.com>, * Copyright (C) 2010-2012, Matthias Sohn <matthias.sohn@sap.com> * Copyright (C) 2012, Research In Motion Limited * 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 com.itemis.maven.plugins.unleash.scm.providers.merge; import static org.eclipse.jgit.lib.Constants.CHARACTER_ENCODING; import static org.eclipse.jgit.lib.Constants.OBJ_BLOB; import java.io.BufferedOutputStream; import java.io.ByteArrayOutputStream; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.util.ArrayList; import java.util.Arrays; import java.util.Collections; import java.util.HashMap; import java.util.Iterator; import java.util.LinkedList; import java.util.List; import java.util.Map; import org.eclipse.jgit.diff.DiffAlgorithm; import org.eclipse.jgit.diff.DiffAlgorithm.SupportedAlgorithm; import org.eclipse.jgit.diff.RawText; import org.eclipse.jgit.diff.Sequence; import org.eclipse.jgit.dircache.DirCache; import org.eclipse.jgit.dircache.DirCacheBuildIterator; import org.eclipse.jgit.dircache.DirCacheBuilder; import org.eclipse.jgit.dircache.DirCacheCheckout; import org.eclipse.jgit.dircache.DirCacheEntry; import org.eclipse.jgit.errors.CorruptObjectException; import org.eclipse.jgit.errors.IncorrectObjectTypeException; import org.eclipse.jgit.errors.IndexWriteException; import org.eclipse.jgit.errors.MissingObjectException; import org.eclipse.jgit.errors.NoWorkTreeException; import org.eclipse.jgit.lib.ConfigConstants; import org.eclipse.jgit.lib.FileMode; import org.eclipse.jgit.lib.ObjectId; import org.eclipse.jgit.lib.ObjectReader; import org.eclipse.jgit.lib.Repository; import org.eclipse.jgit.merge.MergeAlgorithm; import org.eclipse.jgit.merge.MergeChunk.ConflictState; import org.eclipse.jgit.merge.MergeFormatter; import org.eclipse.jgit.merge.MergeResult; import org.eclipse.jgit.merge.RecursiveMerger; import org.eclipse.jgit.merge.ResolveMerger; import org.eclipse.jgit.revwalk.RevTree; import org.eclipse.jgit.treewalk.AbstractTreeIterator; import org.eclipse.jgit.treewalk.CanonicalTreeParser; import org.eclipse.jgit.treewalk.NameConflictTreeWalk; import org.eclipse.jgit.treewalk.TreeWalk; import org.eclipse.jgit.treewalk.WorkingTreeIterator; import org.eclipse.jgit.treewalk.filter.TreeFilter; import org.eclipse.jgit.util.FS; import org.eclipse.jgit.util.TemporaryBuffer; import com.google.common.io.Closeables; import com.itemis.maven.plugins.unleash.scm.merge.MergeClient; import com.itemis.maven.plugins.unleash.scm.providers.ScmProviderGit; /** * This is a copy of the {@link ResolveMerger} class and is meant as a temporary solution until the * {@link ScmProviderGit} is fully implemented. After that the merger will be re-implemented to better match the * concepts we require. */ // TODO re-implement this merger or look at how to extend any existing merger implementation and modify required parts // only. public class UnleashGitMerger extends ResolveMerger { /** * The tree walk which we'll iterate over to merge entries. * * @since 3.4 */ protected NameConflictTreeWalk tw; /** * string versions of a list of commit SHA1s * * @since 3.0 */ protected String commitNames[]; /** * Index of the base tree within the {@link #tw tree walk}. * * @since 3.4 */ protected static final int T_BASE = 0; /** * Index of our tree in withthe {@link #tw tree walk}. * * @since 3.4 */ protected static final int T_OURS = 1; /** * Index of their tree within the {@link #tw tree walk}. * * @since 3.4 */ protected static final int T_THEIRS = 2; /** * Index of the index tree within the {@link #tw tree walk}. * * @since 3.4 */ protected static final int T_INDEX = 3; /** * Index of the working directory tree within the {@link #tw tree walk}. * * @since 3.4 */ protected static final int T_FILE = 4; /** * Builder to update the cache during this merge. * * @since 3.4 */ protected DirCacheBuilder builder; /** * merge result as tree * * @since 3.0 */ protected ObjectId resultTree; /** * Paths that could not be merged by this merger because of an unsolvable * conflict. * * @since 3.4 */ protected List<String> unmergedPaths = new ArrayList<String>(); /** * Files modified during this merge operation. * * @since 3.4 */ protected List<String> modifiedFiles = new LinkedList<String>(); /** * If the merger has nothing to do for a file but check it out at the end of * the operation, it can be added here. * * @since 3.4 */ protected Map<String, DirCacheEntry> toBeCheckedOut = new HashMap<String, DirCacheEntry>(); /** * Paths in this list will be deleted from the local copy at the end of the * operation. * * @since 3.4 */ protected List<String> toBeDeleted = new ArrayList<String>(); /** * Low-level textual merge results. Will be passed on to the callers in case * of conflicts. * * @since 3.4 */ protected Map<String, MergeResult<? extends Sequence>> mergeResults = new HashMap<String, MergeResult<? extends Sequence>>(); /** * Paths for which the merge failed altogether. * * @since 3.4 */ protected Map<String, MergeFailureReason> failingPaths = new HashMap<String, MergeFailureReason>(); /** * Updated as we merge entries of the tree walk. Tells us whether we should * recurse into the entry if it is a subtree. * * @since 3.4 */ protected boolean enterSubtree; /** * Set to true if this merge should work in-memory. The repos dircache and * workingtree are not touched by this method. Eventually needed files are * created as temporary files and a new empty, in-memory dircache will be * used instead the repo's one. Often used for bare repos where the repo * doesn't even have a workingtree and dircache. * * @since 3.0 */ protected boolean inCore; /** * Set to true if this merger should use the default dircache of the * repository and should handle locking and unlocking of the dircache. If * this merger should work in-core or if an explicit dircache was specified * during construction then this field is set to false. * * @since 3.0 */ protected boolean implicitDirCache; /** * Directory cache * * @since 3.0 */ protected DirCache dircache; /** * The iterator to access the working tree. If set to <code>null</code> this * merger will not touch the working tree. * * @since 3.0 */ protected WorkingTreeIterator workingTreeIterator; /** * our merge algorithm * * @since 3.0 */ protected MergeAlgorithm mergeAlgorithm; private MergeClient mergeClient; /** * @param local * @param inCore */ protected UnleashGitMerger(Repository local, boolean inCore, MergeClient mergeClient) { super(local); this.mergeClient = mergeClient; SupportedAlgorithm diffAlg = local.getConfig().getEnum(ConfigConstants.CONFIG_DIFF_SECTION, null, ConfigConstants.CONFIG_KEY_ALGORITHM, SupportedAlgorithm.HISTOGRAM); this.mergeAlgorithm = new MergeAlgorithm(DiffAlgorithm.getAlgorithm(diffAlg)); this.commitNames = new String[] { "BASE", "OURS", "THEIRS" }; //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ this.inCore = inCore; if (inCore) { this.implicitDirCache = false; this.dircache = DirCache.newInCore(); } else { this.implicitDirCache = true; } } /** * @param local */ protected UnleashGitMerger(Repository local, MergeClient mergeClient) { this(local, false, mergeClient); } @Override protected boolean mergeImpl() throws IOException { if (this.implicitDirCache) { this.dircache = getRepository().lockDirCache(); } try { return mergeTrees(mergeBase(), this.sourceTrees[0], this.sourceTrees[1], false); } finally { if (this.implicitDirCache) { this.dircache.unlock(); } } } private void checkout() throws NoWorkTreeException, IOException { // Iterate in reverse so that "folder/file" is deleted before // "folder". Otherwise this could result in a failing path because // of a non-empty directory, for which delete() would fail. for (int i = this.toBeDeleted.size() - 1; i >= 0; i--) { String fileName = this.toBeDeleted.get(i); File f = new File(this.db.getWorkTree(), fileName); if (!f.delete()) { if (!f.isDirectory()) { this.failingPaths.put(fileName, MergeFailureReason.COULD_NOT_DELETE); } } this.modifiedFiles.add(fileName); } for (Map.Entry<String, DirCacheEntry> entry : this.toBeCheckedOut.entrySet()) { DirCacheCheckout.checkoutEntry(this.db, entry.getValue(), this.reader); this.modifiedFiles.add(entry.getKey()); } } /** * Reverts the worktree after an unsuccessful merge. We know that for all * modified files the old content was in the old index and the index * contained only stage 0. In case if inCore operation just clear the * history of modified files. * * @throws IOException * @throws CorruptObjectException * @throws NoWorkTreeException * @since 3.4 */ @Override protected void cleanUp() throws NoWorkTreeException, CorruptObjectException, IOException { if (this.inCore) { this.modifiedFiles.clear(); return; } DirCache dc = this.db.readDirCache(); Iterator<String> mpathsIt = this.modifiedFiles.iterator(); while (mpathsIt.hasNext()) { String mpath = mpathsIt.next(); DirCacheEntry entry = dc.getEntry(mpath); if (entry != null) { DirCacheCheckout.checkoutEntry(this.db, entry, this.reader); } mpathsIt.remove(); } } /** * adds a new path with the specified stage to the index builder * * @param path * @param p * @param stage * @param lastMod * @param len * @return the entry which was added to the index */ private DirCacheEntry add(byte[] path, CanonicalTreeParser p, int stage, long lastMod, long len) { if (p != null && !p.getEntryFileMode().equals(FileMode.TREE)) { DirCacheEntry e = new DirCacheEntry(path, stage); e.setFileMode(p.getEntryFileMode()); e.setObjectId(p.getEntryObjectId()); e.setLastModified(lastMod); e.setLength(len); this.builder.add(e); return e; } return null; } /** * adds a entry to the index builder which is a copy of the specified * DirCacheEntry * * @param e * the entry which should be copied * * @return the entry which was added to the index */ private DirCacheEntry keep(DirCacheEntry e) { DirCacheEntry newEntry = new DirCacheEntry(e.getPathString(), e.getStage()); newEntry.setFileMode(e.getFileMode()); newEntry.setObjectId(e.getObjectId()); newEntry.setLastModified(e.getLastModified()); newEntry.setLength(e.getLength()); this.builder.add(newEntry); return newEntry; } /** * Processes one path and tries to merge. This method will do all do all * trivial (not content) merges and will also detect if a merge will fail. * The merge will fail when one of the following is true * <ul> * <li>the index entry does not match the entry in ours. When merging one * branch into the current HEAD, ours will point to HEAD and theirs will * point to the other branch. It is assumed that the index matches the HEAD * because it will only not match HEAD if it was populated before the merge * operation. But the merge commit should not accidentally contain * modifications done before the merge. Check the <a href= * "http://www.kernel.org/pub/software/scm/git/docs/git-read-tree.html#_3_way_merge" * >git read-tree</a> documentation for further explanations.</li> * <li>A conflict was detected and the working-tree file is dirty. When a * conflict is detected the content-merge algorithm will try to write a * merged version into the working-tree. If the file is dirty we would * override unsaved data.</li> * </ul> * * @param base * the common base for ours and theirs * @param ours * the ours side of the merge. When merging a branch into the * HEAD ours will point to HEAD * @param theirs * the theirs side of the merge. When merging a branch into the * current HEAD theirs will point to the branch which is merged * into HEAD. * @param index * the index entry * @param work * the file in the working tree * @param ignoreConflicts * see * {@link UnleashGitMerger#mergeTrees(AbstractTreeIterator, RevTree, RevTree, boolean)} * @return <code>false</code> if the merge will fail because the index entry * didn't match ours or the working-dir file was dirty and a * conflict occurred * @throws MissingObjectException * @throws IncorrectObjectTypeException * @throws CorruptObjectException * @throws IOException * @since 3.5 */ @Override protected boolean processEntry(CanonicalTreeParser base, CanonicalTreeParser ours, CanonicalTreeParser theirs, DirCacheBuildIterator index, WorkingTreeIterator work, boolean ignoreConflicts) throws MissingObjectException, IncorrectObjectTypeException, CorruptObjectException, IOException { this.enterSubtree = true; final int modeO = this.tw.getRawMode(T_OURS); final int modeT = this.tw.getRawMode(T_THEIRS); final int modeB = this.tw.getRawMode(T_BASE); if (modeO == 0 && modeT == 0 && modeB == 0) { // File is either untracked or new, staged but uncommitted return true; } if (isIndexDirty()) { return false; } DirCacheEntry ourDce = null; if (index == null || index.getDirCacheEntry() == null) { // create a fake DCE, but only if ours is valid. ours is kept only // in case it is valid, so a null ourDce is ok in all other cases. if (nonTree(modeO)) { ourDce = new DirCacheEntry(this.tw.getRawPath()); ourDce.setObjectId(this.tw.getObjectId(T_OURS)); ourDce.setFileMode(this.tw.getFileMode(T_OURS)); } } else { ourDce = index.getDirCacheEntry(); } if (nonTree(modeO) && nonTree(modeT) && this.tw.idEqual(T_OURS, T_THEIRS)) { // OURS and THEIRS have equal content. Check the file mode if (modeO == modeT) { // content and mode of OURS and THEIRS are equal: it doesn't // matter which one we choose. OURS is chosen. Since the index // is clean (the index matches already OURS) we can keep the existing one keep(ourDce); // no checkout needed! return true; } else { // same content but different mode on OURS and THEIRS. // Try to merge the mode and report an error if this is // not possible. int newMode = mergeFileModes(modeB, modeO, modeT); if (newMode != FileMode.MISSING.getBits()) { if (newMode == modeO) { // ours version is preferred keep(ourDce); } else { // the preferred version THEIRS has a different mode // than ours. Check it out! if (isWorktreeDirty(work, ourDce)) { return false; } // we know about length and lastMod only after we have written the new content. // This will happen later. Set these values to 0 for know. DirCacheEntry e = add(this.tw.getRawPath(), theirs, DirCacheEntry.STAGE_0, 0, 0); this.toBeCheckedOut.put(this.tw.getPathString(), e); } return true; } else { // FileModes are not mergeable. We found a conflict on modes. // For conflicting entries we don't know lastModified and length. add(this.tw.getRawPath(), base, DirCacheEntry.STAGE_1, 0, 0); add(this.tw.getRawPath(), ours, DirCacheEntry.STAGE_2, 0, 0); add(this.tw.getRawPath(), theirs, DirCacheEntry.STAGE_3, 0, 0); this.unmergedPaths.add(this.tw.getPathString()); this.mergeResults.put(this.tw.getPathString(), new MergeResult<RawText>(Collections.<RawText>emptyList())); } return true; } } if (modeB == modeT && this.tw.idEqual(T_BASE, T_THEIRS)) { // THEIRS was not changed compared to BASE. All changes must be in // OURS. OURS is chosen. We can keep the existing entry. if (ourDce != null) { keep(ourDce); } // no checkout needed! return true; } if (modeB == modeO && this.tw.idEqual(T_BASE, T_OURS)) { // OURS was not changed compared to BASE. All changes must be in // THEIRS. THEIRS is chosen. // Check worktree before checking out THEIRS if (isWorktreeDirty(work, ourDce)) { return false; } if (nonTree(modeT)) { // we know about length and lastMod only after we have written // the new content. // This will happen later. Set these values to 0 for know. DirCacheEntry e = add(this.tw.getRawPath(), theirs, DirCacheEntry.STAGE_0, 0, 0); if (e != null) { this.toBeCheckedOut.put(this.tw.getPathString(), e); } return true; } else { // we want THEIRS ... but THEIRS contains a folder or the // deletion of the path. Delete what's in the workingtree (the // workingtree is clean) but do not complain if the file is // already deleted locally. This complements the test in // isWorktreeDirty() for the same case. if (this.tw.getTreeCount() > T_FILE && this.tw.getRawMode(T_FILE) == 0) { return true; } this.toBeDeleted.add(this.tw.getPathString()); return true; } } if (this.tw.isSubtree()) { // file/folder conflicts: here I want to detect only file/folder // conflict between ours and theirs. file/folder conflicts between // base/index/workingTree and something else are not relevant or // detected later if (nonTree(modeO) && !nonTree(modeT)) { if (nonTree(modeB)) { add(this.tw.getRawPath(), base, DirCacheEntry.STAGE_1, 0, 0); } add(this.tw.getRawPath(), ours, DirCacheEntry.STAGE_2, 0, 0); this.unmergedPaths.add(this.tw.getPathString()); this.enterSubtree = false; return true; } if (nonTree(modeT) && !nonTree(modeO)) { if (nonTree(modeB)) { add(this.tw.getRawPath(), base, DirCacheEntry.STAGE_1, 0, 0); } add(this.tw.getRawPath(), theirs, DirCacheEntry.STAGE_3, 0, 0); this.unmergedPaths.add(this.tw.getPathString()); this.enterSubtree = false; return true; } // ours and theirs are both folders or both files (and treewalk // tells us we are in a subtree because of index or working-dir). // If they are both folders no content-merge is required - we can // return here. if (!nonTree(modeO)) { return true; } // ours and theirs are both files, just fall out of the if block // and do the content merge } if (nonTree(modeO) && nonTree(modeT)) { // Check worktree before modifying files if (isWorktreeDirty(work, ourDce)) { return false; } // Don't attempt to resolve submodule link conflicts if (isGitLink(modeO) || isGitLink(modeT)) { add(this.tw.getRawPath(), base, DirCacheEntry.STAGE_1, 0, 0); add(this.tw.getRawPath(), ours, DirCacheEntry.STAGE_2, 0, 0); add(this.tw.getRawPath(), theirs, DirCacheEntry.STAGE_3, 0, 0); this.unmergedPaths.add(this.tw.getPathString()); return true; } MergeResult<RawText> result = contentMerge(base, ours, theirs); // if (ignoreConflicts) { // result.setContainsConflicts(false); // } updateIndex(base, ours, theirs, result); if (result.containsConflicts() && !ignoreConflicts) { this.unmergedPaths.add(this.tw.getPathString()); } this.modifiedFiles.add(this.tw.getPathString()); } else if (modeO != modeT) { // OURS or THEIRS has been deleted if (modeO != 0 && !this.tw.idEqual(T_BASE, T_OURS) || modeT != 0 && !this.tw.idEqual(T_BASE, T_THEIRS)) { add(this.tw.getRawPath(), base, DirCacheEntry.STAGE_1, 0, 0); add(this.tw.getRawPath(), ours, DirCacheEntry.STAGE_2, 0, 0); DirCacheEntry e = add(this.tw.getRawPath(), theirs, DirCacheEntry.STAGE_3, 0, 0); // OURS was deleted checkout THEIRS if (modeO == 0) { // Check worktree before checking out THEIRS if (isWorktreeDirty(work, ourDce)) { return false; } if (nonTree(modeT)) { if (e != null) { this.toBeCheckedOut.put(this.tw.getPathString(), e); } } } this.unmergedPaths.add(this.tw.getPathString()); // generate a MergeResult for the deleted file this.mergeResults.put(this.tw.getPathString(), contentMerge(base, ours, theirs)); } } return true; } // TODO this is the main adaption of this class -> merge delegation to the mergeclient private MergeResult<RawText> contentMerge(CanonicalTreeParser base, CanonicalTreeParser ours, CanonicalTreeParser theirs) throws IOException { InputStream localIn = getInputStream(ours.getEntryObjectId()); InputStream remoteIn = getInputStream(theirs.getEntryObjectId()); InputStream baseIn = getInputStream(base.getEntryObjectId()); ByteArrayOutputStream resultOut = new ByteArrayOutputStream(); this.mergeClient.merge(localIn, remoteIn, baseIn, resultOut); RawText resultText = new RawText(resultOut.toByteArray()); List<RawText> sequences = new ArrayList<RawText>(1); sequences.add(resultText); MergeResult<RawText> result = new MergeResult<RawText>(sequences); result.add(0, 0, resultText.size(), ConflictState.NO_CONFLICT); return result; } private InputStream getInputStream(ObjectId id) throws IOException { if (id.equals(ObjectId.zeroId())) { return null; } return this.reader.open(id, OBJ_BLOB).openStream(); } private boolean isIndexDirty() { if (this.inCore) { return false; } final int modeI = this.tw.getRawMode(T_INDEX); final int modeO = this.tw.getRawMode(T_OURS); // Index entry has to match ours to be considered clean final boolean isDirty = nonTree(modeI) && !(modeO == modeI && this.tw.idEqual(T_INDEX, T_OURS)); if (isDirty) { this.failingPaths.put(this.tw.getPathString(), MergeFailureReason.DIRTY_INDEX); } return isDirty; } private boolean isWorktreeDirty(WorkingTreeIterator work, DirCacheEntry ourDce) throws IOException { if (work == null) { return false; } final int modeF = this.tw.getRawMode(T_FILE); final int modeO = this.tw.getRawMode(T_OURS); // Worktree entry has to match ours to be considered clean boolean isDirty; if (ourDce != null) { isDirty = work.isModified(ourDce, true, this.reader); } else { isDirty = work.isModeDifferent(modeO); if (!isDirty && nonTree(modeF)) { isDirty = !this.tw.idEqual(T_FILE, T_OURS); } } // Ignore existing empty directories if (isDirty && modeF == FileMode.TYPE_TREE && modeO == FileMode.TYPE_MISSING) { isDirty = false; } if (isDirty) { this.failingPaths.put(this.tw.getPathString(), MergeFailureReason.DIRTY_WORKTREE); } return isDirty; } /** * Updates the index after a content merge has happened. If no conflict has * occurred this includes persisting the merged content to the object * database. In case of conflicts this method takes care to write the * correct stages to the index. * * @param base * @param ours * @param theirs * @param result * @throws FileNotFoundException * @throws IOException */ private void updateIndex(CanonicalTreeParser base, CanonicalTreeParser ours, CanonicalTreeParser theirs, MergeResult<RawText> result) throws FileNotFoundException, IOException { File mergedFile = !this.inCore ? writeMergedFile(result) : null; if (result.containsConflicts()) { // A conflict occurred, the file will contain conflict markers // the index will be populated with the three stages and the // workdir (if used) contains the halfway merged content. add(this.tw.getRawPath(), base, DirCacheEntry.STAGE_1, 0, 0); add(this.tw.getRawPath(), ours, DirCacheEntry.STAGE_2, 0, 0); add(this.tw.getRawPath(), theirs, DirCacheEntry.STAGE_3, 0, 0); this.mergeResults.put(this.tw.getPathString(), result); return; } // No conflict occurred, the file will contain fully merged content. // The index will be populated with the new merged version. DirCacheEntry dce = new DirCacheEntry(this.tw.getPathString()); // Set the mode for the new content. Fall back to REGULAR_FILE if // we can't merge modes of OURS and THEIRS. int newMode = mergeFileModes(this.tw.getRawMode(0), this.tw.getRawMode(1), this.tw.getRawMode(2)); dce.setFileMode(newMode == FileMode.MISSING.getBits() ? FileMode.REGULAR_FILE : FileMode.fromBits(newMode)); if (mergedFile != null) { long len = mergedFile.length(); dce.setLastModified(mergedFile.lastModified()); dce.setLength((int) len); InputStream is = new FileInputStream(mergedFile); try { dce.setObjectId(getObjectInserter().insert(OBJ_BLOB, len, is)); } finally { is.close(); } } else { dce.setObjectId(insertMergeResult(result)); } this.builder.add(dce); } /** * Writes merged file content to the working tree. * * @param result * the result of the content merge * @return the working tree file to which the merged content was written. * @throws FileNotFoundException * @throws IOException */ private File writeMergedFile(MergeResult<RawText> result) throws FileNotFoundException, IOException { File workTree = this.db.getWorkTree(); FS fs = this.db.getFS(); File of = new File(workTree, this.tw.getPathString()); File parentFolder = of.getParentFile(); if (!fs.exists(parentFolder)) { parentFolder.mkdirs(); } OutputStream os = null; try { os = new BufferedOutputStream(new FileOutputStream(of)); new MergeFormatter().formatMerge(os, result, Arrays.asList(this.commitNames), CHARACTER_ENCODING); } finally { Closeables.close(os, true); } return of; } private ObjectId insertMergeResult(MergeResult<RawText> result) throws IOException { TemporaryBuffer.LocalFile buf = new TemporaryBuffer.LocalFile(this.db.getDirectory(), 10 << 20); try { new MergeFormatter().formatMerge(buf, result, Arrays.asList(this.commitNames), CHARACTER_ENCODING); buf.close(); InputStream in = null; try { in = buf.openInputStream(); return getObjectInserter().insert(OBJ_BLOB, buf.length(), in); } finally { Closeables.closeQuietly(in); } } finally { buf.destroy(); } } /** * Try to merge filemodes. If only ours or theirs have changed the mode * (compared to base) we choose that one. If ours and theirs have equal * modes return that one. If also that is not the case the modes are not * mergeable. Return {@link FileMode#MISSING} int that case. * * @param modeB * filemode found in BASE * @param modeO * filemode found in OURS * @param modeT * filemode found in THEIRS * * @return the merged filemode or {@link FileMode#MISSING} in case of a * conflict */ private int mergeFileModes(int modeB, int modeO, int modeT) { if (modeO == modeT) { return modeO; } if (modeB == modeO) { // Base equal to Ours -> chooses Theirs if that is not missing return modeT == FileMode.MISSING.getBits() ? modeO : modeT; } if (modeB == modeT) { // Base equal to Theirs -> chooses Ours if that is not missing return modeO == FileMode.MISSING.getBits() ? modeT : modeO; } return FileMode.MISSING.getBits(); } private static RawText getRawText(ObjectId id, ObjectReader reader) throws IOException { if (id.equals(ObjectId.zeroId())) { return new RawText(new byte[] {}); } return new RawText(reader.open(id, OBJ_BLOB).getCachedBytes()); } private static boolean nonTree(final int mode) { return mode != 0 && !FileMode.TREE.equals(mode); } private static boolean isGitLink(final int mode) { return FileMode.GITLINK.equals(mode); } @Override public ObjectId getResultTreeId() { return this.resultTree == null ? null : this.resultTree.toObjectId(); } /** * @param commitNames * the names of the commits as they would appear in conflict * markers */ @Override public void setCommitNames(String[] commitNames) { this.commitNames = commitNames; } /** * @return the names of the commits as they would appear in conflict * markers. */ @Override public String[] getCommitNames() { return this.commitNames; } /** * @return the paths with conflicts. This is a subset of the files listed * by {@link #getModifiedFiles()} */ @Override public List<String> getUnmergedPaths() { return this.unmergedPaths; } /** * @return the paths of files which have been modified by this merge. A * file will be modified if a content-merge works on this path or if * the merge algorithm decides to take the theirs-version. This is a * superset of the files listed by {@link #getUnmergedPaths()}. */ @Override public List<String> getModifiedFiles() { return this.modifiedFiles; } /** * @return a map which maps the paths of files which have to be checked out * because the merge created new fully-merged content for this file * into the index. This means: the merge wrote a new stage 0 entry * for this path. */ @Override public Map<String, DirCacheEntry> getToBeCheckedOut() { return this.toBeCheckedOut; } /** * @return the mergeResults */ @Override public Map<String, MergeResult<? extends Sequence>> getMergeResults() { return this.mergeResults; } /** * @return lists paths causing this merge to fail (not stopped because of a * conflict). <code>null</code> is returned if this merge didn't * fail. */ @Override public Map<String, MergeFailureReason> getFailingPaths() { return this.failingPaths.size() == 0 ? null : this.failingPaths; } /** * Returns whether this merge failed (i.e. not stopped because of a * conflict) * * @return <code>true</code> if a failure occurred, <code>false</code> * otherwise */ @Override public boolean failed() { return this.failingPaths.size() > 0; } /** * Sets the DirCache which shall be used by this merger. If the DirCache is * not set explicitly and if this merger doesn't work in-core, this merger * will implicitly get and lock a default DirCache. If the DirCache is * explicitly set the caller is responsible to lock it in advance. Finally * the merger will call {@link DirCache#commit()} which requires that the * DirCache is locked. If the {@link #mergeImpl()} returns without throwing * an exception the lock will be released. In case of exceptions the caller * is responsible to release the lock. * * @param dc * the DirCache to set */ @Override public void setDirCache(DirCache dc) { this.dircache = dc; this.implicitDirCache = false; } /** * Sets the WorkingTreeIterator to be used by this merger. If no * WorkingTreeIterator is set this merger will ignore the working tree and * fail if a content merge is necessary. * <p> * TODO: enhance WorkingTreeIterator to support write operations. Then this * merger will be able to merge with a different working tree abstraction. * * @param workingTreeIterator * the workingTreeIt to set */ @Override public void setWorkingTreeIterator(WorkingTreeIterator workingTreeIterator) { this.workingTreeIterator = workingTreeIterator; } /** * The resolve conflict way of three way merging * * @param baseTree * @param headTree * @param mergeTree * @param ignoreConflicts * Controls what to do in case a content-merge is done and a * conflict is detected. The default setting for this should be * <code>false</code>. In this case the working tree file is * filled with new content (containing conflict markers) and the * index is filled with multiple stages containing BASE, OURS and * THEIRS content. Having such non-0 stages is the sign to git * tools that there are still conflicts for that path. * <p> * If <code>true</code> is specified the behavior is different. * In case a conflict is detected the working tree file is again * filled with new content (containing conflict markers). But * also stage 0 of the index is filled with that content. No * other stages are filled. Means: there is no conflict on that * path but the new content (including conflict markers) is * stored as successful merge result. This is needed in the * context of {@link RecursiveMerger} where when determining * merge bases we don't want to deal with content-merge * conflicts. * @return whether the trees merged cleanly * @throws IOException * @since 3.5 */ @Override protected boolean mergeTrees(AbstractTreeIterator baseTree, RevTree headTree, RevTree mergeTree, boolean ignoreConflicts) throws IOException { this.builder = this.dircache.builder(); DirCacheBuildIterator buildIt = new DirCacheBuildIterator(this.builder); this.tw = new NameConflictTreeWalk(this.reader); this.tw.addTree(baseTree); this.tw.addTree(headTree); this.tw.addTree(mergeTree); this.tw.addTree(buildIt); if (this.workingTreeIterator != null) { this.tw.addTree(this.workingTreeIterator); } else { this.tw.setFilter(TreeFilter.ANY_DIFF); } if (!mergeTreeWalk(this.tw, ignoreConflicts)) { return false; } if (!this.inCore) { // No problem found. The only thing left to be done is to // checkout all files from "theirs" which have been selected to // go into the new index. checkout(); // All content-merges are successfully done. If we can now write the // new index we are on quite safe ground. Even if the checkout of // files coming from "theirs" fails the user can work around such // failures by checking out the index again. if (!this.builder.commit()) { cleanUp(); throw new IndexWriteException(); } this.builder = null; } else { this.builder.finish(); this.builder = null; } if (getUnmergedPaths().isEmpty() && !failed()) { this.resultTree = this.dircache.writeTree(getObjectInserter()); return true; } else { this.resultTree = null; return false; } } /** * Process the given TreeWalk's entries. * * @param treeWalk * The walk to iterate over. * @param ignoreConflicts * see * {@link UnleashGitMerger#mergeTrees(AbstractTreeIterator, RevTree, RevTree, boolean)} * @return Whether the trees merged cleanly. * @throws IOException * @since 3.5 */ @Override protected boolean mergeTreeWalk(TreeWalk treeWalk, boolean ignoreConflicts) throws IOException { boolean hasWorkingTreeIterator = this.tw.getTreeCount() > T_FILE; while (treeWalk.next()) { if (!processEntry(treeWalk.getTree(T_BASE, CanonicalTreeParser.class), treeWalk.getTree(T_OURS, CanonicalTreeParser.class), treeWalk.getTree(T_THEIRS, CanonicalTreeParser.class), treeWalk.getTree(T_INDEX, DirCacheBuildIterator.class), hasWorkingTreeIterator ? treeWalk.getTree(T_FILE, WorkingTreeIterator.class) : null, ignoreConflicts)) { cleanUp(); return false; } if (treeWalk.isSubtree() && this.enterSubtree) { treeWalk.enterSubtree(); } } return true; } }