/*
* 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 org.eclipse.jgit.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.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.RawTextComparator;
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.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;
/**
* A three-way merger performing a content-merge if necessary
*/
public class ResolveMerger extends ThreeWayMerger {
/**
* If the merge fails (means: not stopped because of unresolved conflicts)
* this enum is used to explain why it failed
*/
public enum MergeFailureReason {
/** the merge failed because of a dirty index */
DIRTY_INDEX,
/** the merge failed because of a dirty workingtree */
DIRTY_WORKTREE,
/** the merge failed because of a file could not be deleted */
COULD_NOT_DELETE
}
/**
* 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;
/**
* @param local
* @param inCore
*/
protected ResolveMerger(Repository local, boolean inCore) {
super(local);
SupportedAlgorithm diffAlg = local.getConfig().getEnum(
ConfigConstants.CONFIG_DIFF_SECTION, null,
ConfigConstants.CONFIG_KEY_ALGORITHM,
SupportedAlgorithm.HISTOGRAM);
mergeAlgorithm = new MergeAlgorithm(DiffAlgorithm.getAlgorithm(diffAlg));
commitNames = new String[] { "BASE", "OURS", "THEIRS" }; //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
this.inCore = inCore;
if (inCore) {
implicitDirCache = false;
dircache = DirCache.newInCore();
} else {
implicitDirCache = true;
}
}
/**
* @param local
*/
protected ResolveMerger(Repository local) {
this(local, false);
}
@Override
protected boolean mergeImpl() throws IOException {
if (implicitDirCache)
dircache = getRepository().lockDirCache();
try {
return mergeTrees(mergeBase(), sourceTrees[0], sourceTrees[1],
false);
} finally {
if (implicitDirCache)
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 = toBeDeleted.size() - 1; i >= 0; i--) {
String fileName = toBeDeleted.get(i);
File f = new File(db.getWorkTree(), fileName);
if (!f.delete())
if (!f.isDirectory())
failingPaths.put(fileName,
MergeFailureReason.COULD_NOT_DELETE);
modifiedFiles.add(fileName);
}
for (Map.Entry<String, DirCacheEntry> entry : toBeCheckedOut
.entrySet()) {
DirCacheCheckout.checkoutEntry(db, entry.getValue(), reader);
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
*/
protected void cleanUp() throws NoWorkTreeException,
CorruptObjectException,
IOException {
if (inCore) {
modifiedFiles.clear();
return;
}
DirCache dc = db.readDirCache();
Iterator<String> mpathsIt=modifiedFiles.iterator();
while(mpathsIt.hasNext()) {
String mpath=mpathsIt.next();
DirCacheEntry entry = dc.getEntry(mpath);
if (entry != null)
DirCacheCheckout.checkoutEntry(db, entry, 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);
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());
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 ResolveMerger#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
*/
protected boolean processEntry(CanonicalTreeParser base,
CanonicalTreeParser ours, CanonicalTreeParser theirs,
DirCacheBuildIterator index, WorkingTreeIterator work,
boolean ignoreConflicts)
throws MissingObjectException, IncorrectObjectTypeException,
CorruptObjectException, IOException {
enterSubtree = true;
final int modeO = tw.getRawMode(T_OURS);
final int modeT = tw.getRawMode(T_THEIRS);
final int modeB = 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(tw.getRawPath());
ourDce.setObjectId(tw.getObjectId(T_OURS));
ourDce.setFileMode(tw.getFileMode(T_OURS));
}
} else {
ourDce = index.getDirCacheEntry();
}
if (nonTree(modeO) && nonTree(modeT) && 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(tw.getRawPath(), theirs,
DirCacheEntry.STAGE_0, 0, 0);
toBeCheckedOut.put(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(tw.getRawPath(), base, DirCacheEntry.STAGE_1, 0, 0);
add(tw.getRawPath(), ours, DirCacheEntry.STAGE_2, 0, 0);
add(tw.getRawPath(), theirs, DirCacheEntry.STAGE_3, 0, 0);
unmergedPaths.add(tw.getPathString());
mergeResults.put(
tw.getPathString(),
new MergeResult<RawText>(Collections
.<RawText> emptyList()));
}
return true;
}
}
if (modeB == modeT && 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 && 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(tw.getRawPath(), theirs,
DirCacheEntry.STAGE_0, 0, 0);
if (e != null)
toBeCheckedOut.put(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 (tw.getTreeCount() > T_FILE && tw.getRawMode(T_FILE) == 0)
return true;
toBeDeleted.add(tw.getPathString());
return true;
}
}
if (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(tw.getRawPath(), base, DirCacheEntry.STAGE_1, 0, 0);
add(tw.getRawPath(), ours, DirCacheEntry.STAGE_2, 0, 0);
unmergedPaths.add(tw.getPathString());
enterSubtree = false;
return true;
}
if (nonTree(modeT) && !nonTree(modeO)) {
if (nonTree(modeB))
add(tw.getRawPath(), base, DirCacheEntry.STAGE_1, 0, 0);
add(tw.getRawPath(), theirs, DirCacheEntry.STAGE_3, 0, 0);
unmergedPaths.add(tw.getPathString());
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(tw.getRawPath(), base, DirCacheEntry.STAGE_1, 0, 0);
add(tw.getRawPath(), ours, DirCacheEntry.STAGE_2, 0, 0);
add(tw.getRawPath(), theirs, DirCacheEntry.STAGE_3, 0, 0);
unmergedPaths.add(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)
unmergedPaths.add(tw.getPathString());
modifiedFiles.add(tw.getPathString());
} else if (modeO != modeT) {
// OURS or THEIRS has been deleted
if (((modeO != 0 && !tw.idEqual(T_BASE, T_OURS)) || (modeT != 0 && !tw
.idEqual(T_BASE, T_THEIRS)))) {
add(tw.getRawPath(), base, DirCacheEntry.STAGE_1, 0, 0);
add(tw.getRawPath(), ours, DirCacheEntry.STAGE_2, 0, 0);
DirCacheEntry e = add(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)
toBeCheckedOut.put(tw.getPathString(), e);
}
}
unmergedPaths.add(tw.getPathString());
// generate a MergeResult for the deleted file
mergeResults.put(tw.getPathString(),
contentMerge(base, ours, theirs));
}
}
return true;
}
/**
* Does the content merge. The three texts base, ours and theirs are
* specified with {@link CanonicalTreeParser}. If any of the parsers is
* specified as <code>null</code> then an empty text will be used instead.
*
* @param base
* @param ours
* @param theirs
*
* @return the result of the content merge
* @throws IOException
*/
private MergeResult<RawText> contentMerge(CanonicalTreeParser base,
CanonicalTreeParser ours, CanonicalTreeParser theirs)
throws IOException {
RawText baseText = base == null ? RawText.EMPTY_TEXT : getRawText(
base.getEntryObjectId(), reader);
RawText ourText = ours == null ? RawText.EMPTY_TEXT : getRawText(
ours.getEntryObjectId(), reader);
RawText theirsText = theirs == null ? RawText.EMPTY_TEXT : getRawText(
theirs.getEntryObjectId(), reader);
return (mergeAlgorithm.merge(RawTextComparator.DEFAULT, baseText,
ourText, theirsText));
}
private boolean isIndexDirty() {
if (inCore)
return false;
final int modeI = tw.getRawMode(T_INDEX);
final int modeO = tw.getRawMode(T_OURS);
// Index entry has to match ours to be considered clean
final boolean isDirty = nonTree(modeI)
&& !(modeO == modeI && tw.idEqual(T_INDEX, T_OURS));
if (isDirty)
failingPaths
.put(tw.getPathString(), MergeFailureReason.DIRTY_INDEX);
return isDirty;
}
private boolean isWorktreeDirty(WorkingTreeIterator work,
DirCacheEntry ourDce) throws IOException {
if (work == null)
return false;
final int modeF = tw.getRawMode(T_FILE);
final int modeO = tw.getRawMode(T_OURS);
// Worktree entry has to match ours to be considered clean
boolean isDirty;
if (ourDce != null)
isDirty = work.isModified(ourDce, true, reader);
else {
isDirty = work.isModeDifferent(modeO);
if (!isDirty && nonTree(modeF))
isDirty = !tw.idEqual(T_FILE, T_OURS);
}
// Ignore existing empty directories
if (isDirty && modeF == FileMode.TYPE_TREE
&& modeO == FileMode.TYPE_MISSING)
isDirty = false;
if (isDirty)
failingPaths.put(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 = !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(tw.getRawPath(), base, DirCacheEntry.STAGE_1, 0, 0);
add(tw.getRawPath(), ours, DirCacheEntry.STAGE_2, 0, 0);
add(tw.getRawPath(), theirs, DirCacheEntry.STAGE_3, 0, 0);
mergeResults.put(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(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(
tw.getRawMode(0),
tw.getRawMode(1),
tw.getRawMode(2));
dce.setFileMode(newMode == FileMode.MISSING.getBits()
? FileMode.REGULAR_FILE
: FileMode.fromBits(newMode));
if (mergedFile != null) {
long len = mergedFile.length();
dce.setLastModified(FS.DETECTED.lastModified(mergedFile));
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));
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 = db.getWorkTree();
FS fs = db.getFS();
File of = new File(workTree, tw.getPathString());
File parentFolder = of.getParentFile();
if (!fs.exists(parentFolder))
parentFolder.mkdirs();
try (OutputStream os = new BufferedOutputStream(
new FileOutputStream(of))) {
new MergeFormatter().formatMerge(os, result,
Arrays.asList(commitNames), CHARACTER_ENCODING);
}
return of;
}
private ObjectId insertMergeResult(MergeResult<RawText> result)
throws IOException {
TemporaryBuffer.LocalFile buf = new TemporaryBuffer.LocalFile(
db.getDirectory(), 10 << 20);
try {
new MergeFormatter().formatMerge(buf, result,
Arrays.asList(commitNames), CHARACTER_ENCODING);
buf.close();
try (InputStream in = buf.openInputStream()) {
return getObjectInserter().insert(OBJ_BLOB, buf.length(), 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 (resultTree == null) ? null : resultTree.toObjectId();
}
/**
* @param commitNames
* the names of the commits as they would appear in conflict
* markers
*/
public void setCommitNames(String[] commitNames) {
this.commitNames = commitNames;
}
/**
* @return the names of the commits as they would appear in conflict
* markers.
*/
public String[] getCommitNames() {
return commitNames;
}
/**
* @return the paths with conflicts. This is a subset of the files listed
* by {@link #getModifiedFiles()}
*/
public List<String> getUnmergedPaths() {
return 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()}.
*/
public List<String> getModifiedFiles() {
return 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.
*/
public Map<String, DirCacheEntry> getToBeCheckedOut() {
return toBeCheckedOut;
}
/**
* @return the mergeResults
*/
public Map<String, MergeResult<? extends Sequence>> getMergeResults() {
return 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.
*/
public Map<String, MergeFailureReason> getFailingPaths() {
return (failingPaths.size() == 0) ? null : 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
*/
public boolean failed() {
return 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
*/
public void setDirCache(DirCache dc) {
this.dircache = dc;
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
*/
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
*/
protected boolean mergeTrees(AbstractTreeIterator baseTree,
RevTree headTree, RevTree mergeTree, boolean ignoreConflicts)
throws IOException {
builder = dircache.builder();
DirCacheBuildIterator buildIt = new DirCacheBuildIterator(builder);
tw = new NameConflictTreeWalk(db, reader);
tw.addTree(baseTree);
tw.addTree(headTree);
tw.addTree(mergeTree);
int dciPos = tw.addTree(buildIt);
if (workingTreeIterator != null) {
tw.addTree(workingTreeIterator);
workingTreeIterator.setDirCacheIterator(tw, dciPos);
} else {
tw.setFilter(TreeFilter.ANY_DIFF);
}
if (!mergeTreeWalk(tw, ignoreConflicts)) {
return false;
}
if (!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 (!builder.commit()) {
cleanUp();
throw new IndexWriteException();
}
builder = null;
} else {
builder.finish();
builder = null;
}
if (getUnmergedPaths().isEmpty() && !failed()) {
resultTree = dircache.writeTree(getObjectInserter());
return true;
} else {
resultTree = null;
return false;
}
}
/**
* Process the given TreeWalk's entries.
*
* @param treeWalk
* The walk to iterate over.
* @param ignoreConflicts
* see
* {@link ResolveMerger#mergeTrees(AbstractTreeIterator, RevTree, RevTree, boolean)}
* @return Whether the trees merged cleanly.
* @throws IOException
* @since 3.5
*/
protected boolean mergeTreeWalk(TreeWalk treeWalk, boolean ignoreConflicts)
throws IOException {
boolean hasWorkingTreeIterator = 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() && enterSubtree)
treeWalk.enterSubtree();
}
return true;
}
}