opendev/gerrit
Code Issues Proposed changes

Extract the PatchListLoader.automerge into the new AutoMerger class

Browse Source 
This is a preparation step for storing commits instead of just trees
under the refs/cache-automerge/. The main advantage now is that we
can inject additional dependencies into the AutoMerger.

Change-Id: Id0b7b14217de0260691f894d47f7909251df6ce1
This commit is contained in:
Saša Živkov
2016-04-01 16:54:11 +02:00
committed by Dave Borowitz
parent 2e7f2e9a7d
commit c28ebd8d72
3 changed files with 203 additions and 151 deletions
Download Patch File Download Diff File Expand all files Collapse all files

13
gerrit-server/src/main/java/com/google/gerrit/server/index/change/AllChangesIndexer.java
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@@ -39,7 +39,7 @@ import com.google.gerrit.server.git.MultiProgressMonitor.Task;
import com.google.gerrit.server.index.IndexExecutor;
import com.google.gerrit.server.index.SiteIndexer;
import com.google.gerrit.server.notedb.ChangeNotes;
import com.google.gerrit.server.patch.PatchListLoader;
import com.google.gerrit.server.patch.AutoMerger;
import com.google.gerrit.server.project.ProjectCache;
import com.google.gerrit.server.query.change.ChangeData;
import com.google.gwtorm.server.SchemaFactory;
@@ -90,6 +90,7 @@ public class AllChangesIndexer
private final ChangeNotes.Factory notesFactory;
private final ProjectCache projectCache;
private final ThreeWayMergeStrategy mergeStrategy;
private final AutoMerger autoMerger;
@Inject
AllChangesIndexer(SchemaFactory<ReviewDb> schemaFactory,
@@ -99,7 +100,8 @@ public class AllChangesIndexer
ChangeIndexer.Factory indexerFactory,
ChangeNotes.Factory notesFactory,
@GerritServerConfig Config config,
ProjectCache projectCache) {
ProjectCache projectCache,
AutoMerger autoMerger) {
this.schemaFactory = schemaFactory;
this.changeDataFactory = changeDataFactory;
this.repoManager = repoManager;
@@ -108,6 +110,7 @@ public class AllChangesIndexer
this.notesFactory = notesFactory;
this.projectCache = projectCache;
this.mergeStrategy = MergeUtil.getMergeStrategy(config);
this.autoMerger = autoMerger;
}
@Override
@@ -236,6 +239,7 @@ public class AllChangesIndexer
}
new ProjectIndexer(indexer,
mergeStrategy,
autoMerger,
byId,
repo,
done,
@@ -257,6 +261,7 @@ public class AllChangesIndexer
private static class ProjectIndexer implements Callable<Void> {
private final ChangeIndexer indexer;
private final ThreeWayMergeStrategy mergeStrategy;
private final AutoMerger autoMerger;
private final Multimap<ObjectId, ChangeData> byId;
private final ProgressMonitor done;
private final ProgressMonitor failed;
@@ -266,6 +271,7 @@ public class AllChangesIndexer
private ProjectIndexer(ChangeIndexer indexer,
ThreeWayMergeStrategy mergeStrategy,
AutoMerger autoMerger,
Multimap<ObjectId, ChangeData> changesByCommitId,
Repository repo,
ProgressMonitor done,
@@ -273,6 +279,7 @@ public class AllChangesIndexer
PrintWriter verboseWriter) {
this.indexer = indexer;
this.mergeStrategy = mergeStrategy;
this.autoMerger = autoMerger;
this.byId = changesByCommitId;
this.repo = repo;
this.done = done;
@@ -366,7 +373,7 @@ public class AllChangesIndexer
walk.parseBody(a);
return walk.parseTree(a.getTree());
case 2:
return PatchListLoader.automerge(repo, walk, b, mergeStrategy);
return autoMerger.merge(repo, walk, b, mergeStrategy);
default:
return null;
}

189
gerrit-server/src/main/java/com/google/gerrit/server/patch/AutoMerger.java Normal file
View File

@@ -0,0 +1,189 @@
// Copyright (C) 2016 The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package com.google.gerrit.server.patch;
import static java.nio.charset.StandardCharsets.UTF_8;
import com.google.gerrit.reviewdb.client.RefNames;
import com.google.inject.Inject;
import org.eclipse.jgit.diff.Sequence;
import org.eclipse.jgit.dircache.DirCache;
import org.eclipse.jgit.dircache.DirCacheBuilder;
import org.eclipse.jgit.dircache.DirCacheEntry;
import org.eclipse.jgit.lib.Constants;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.lib.ObjectInserter;
import org.eclipse.jgit.lib.Ref;
import org.eclipse.jgit.lib.RefUpdate;
import org.eclipse.jgit.lib.Repository;
import org.eclipse.jgit.merge.MergeFormatter;
import org.eclipse.jgit.merge.MergeResult;
import org.eclipse.jgit.merge.ResolveMerger;
import org.eclipse.jgit.merge.ThreeWayMergeStrategy;
import org.eclipse.jgit.revwalk.RevCommit;
import org.eclipse.jgit.revwalk.RevTree;
import org.eclipse.jgit.revwalk.RevWalk;
import org.eclipse.jgit.util.TemporaryBuffer;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.Map;
public class AutoMerger {
private static final Logger log = LoggerFactory.getLogger(AutoMerger.class);
@Inject
AutoMerger() {
}
public RevTree merge(Repository repo, RevWalk rw, RevCommit merge,
ThreeWayMergeStrategy mergeStrategy) throws IOException {
rw.parseHeaders(merge);
String hash = merge.name();
String refName = RefNames.REFS_CACHE_AUTOMERGE
+ hash.substring(0, 2)
+ "/"
+ hash.substring(2);
Ref ref = repo.getRefDatabase().exactRef(refName);
if (ref != null && ref.getObjectId() != null) {
return rw.parseTree(ref.getObjectId());
}
ResolveMerger m = (ResolveMerger) mergeStrategy.newMerger(repo, true);
try (ObjectInserter ins = repo.newObjectInserter()) {
DirCache dc = DirCache.newInCore();
m.setDirCache(dc);
m.setObjectInserter(new ObjectInserter.Filter() {
@Override
protected ObjectInserter delegate() {
return ins;
}
@Override
public void flush() {
}
@Override
public void close() {
}
});
boolean couldMerge;
try {
couldMerge = m.merge(merge.getParents());
} catch (IOException e) {
// It is not safe to continue further down in this method as throwing
// an exception most likely means that the merge tree was not created
// and m.getMergeResults() is empty. This would mean that all paths are
// unmerged and Gerrit UI would show all paths in the patch list.
log.warn("Error attempting automerge " + refName, e);
return null;
}
ObjectId treeId;
if (couldMerge) {
treeId = m.getResultTreeId();
} else {
RevCommit ours = merge.getParent(0);
RevCommit theirs = merge.getParent(1);
rw.parseBody(ours);
rw.parseBody(theirs);
String oursMsg = ours.getShortMessage();
String theirsMsg = theirs.getShortMessage();
String oursName = String.format("HEAD (%s %s)",
ours.abbreviate(6).name(),
oursMsg.substring(0, Math.min(oursMsg.length(), 60)));
String theirsName = String.format("BRANCH (%s %s)",
theirs.abbreviate(6).name(),
theirsMsg.substring(0, Math.min(theirsMsg.length(), 60)));
MergeFormatter fmt = new MergeFormatter();
Map<String, MergeResult<? extends Sequence>> r = m.getMergeResults();
Map<String, ObjectId> resolved = new HashMap<>();
for (Map.Entry<String, MergeResult<? extends Sequence>> entry : r.entrySet()) {
MergeResult<? extends Sequence> p = entry.getValue();
try (TemporaryBuffer buf =
new TemporaryBuffer.LocalFile(null, 10 * 1024 * 1024)) {
fmt.formatMerge(buf, p, "BASE", oursName, theirsName, UTF_8.name());
buf.close();
try (InputStream in = buf.openInputStream()) {
resolved.put(entry.getKey(), ins.insert(Constants.OBJ_BLOB, buf.length(), in));
}
}
}
DirCacheBuilder builder = dc.builder();
int cnt = dc.getEntryCount();
for (int i = 0; i < cnt;) {
DirCacheEntry entry = dc.getEntry(i);
if (entry.getStage() == 0) {
builder.add(entry);
i++;
continue;
}
int next = dc.nextEntry(i);
String path = entry.getPathString();
DirCacheEntry res = new DirCacheEntry(path);
if (resolved.containsKey(path)) {
// For a file with content merge conflict that we produced a result
// above on, collapse the file down to a single stage 0 with just
// the blob content, and a randomly selected mode (the lowest stage,
// which should be the merge base, or ours).
res.setFileMode(entry.getFileMode());
res.setObjectId(resolved.get(path));
} else if (next == i + 1) {
// If there is exactly one stage present, shouldn't be a conflict...
res.setFileMode(entry.getFileMode());
res.setObjectId(entry.getObjectId());
} else if (next == i + 2) {
// Two stages suggests a delete/modify conflict. Pick the higher
// stage as the automatic result.
entry = dc.getEntry(i + 1);
res.setFileMode(entry.getFileMode());
res.setObjectId(entry.getObjectId());
} else {
// 3 stage conflict, no resolve above
// Punt on the 3-stage conflict and show the base, for now.
res.setFileMode(entry.getFileMode());
res.setObjectId(entry.getObjectId());
}
builder.add(res);
i = next;
}
builder.finish();
treeId = dc.writeTree(ins);
}
ins.flush();
RefUpdate update = repo.updateRef(refName);
update.setNewObjectId(treeId);
update.disableRefLog();
update.forceUpdate();
return rw.lookupTree(treeId);
}
}
}

152
gerrit-server/src/main/java/com/google/gerrit/server/patch/PatchListLoader.java
View File

@@ -24,7 +24,6 @@ import com.google.common.collect.FluentIterable;
import com.google.gerrit.extensions.client.DiffPreferencesInfo.Whitespace;
import com.google.gerrit.reviewdb.client.Patch;
import com.google.gerrit.reviewdb.client.Project;
import com.google.gerrit.reviewdb.client.RefNames;
import com.google.gerrit.server.config.ConfigUtil;
import com.google.gerrit.server.config.GerritServerConfig;
import com.google.gerrit.server.git.GitRepositoryManager;
@@ -39,22 +38,13 @@ import org.eclipse.jgit.diff.EditList;
import org.eclipse.jgit.diff.HistogramDiff;
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.DirCacheBuilder;
import org.eclipse.jgit.dircache.DirCacheEntry;
import org.eclipse.jgit.lib.Config;
import org.eclipse.jgit.lib.Constants;
import org.eclipse.jgit.lib.FileMode;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.lib.ObjectInserter;
import org.eclipse.jgit.lib.ObjectReader;
import org.eclipse.jgit.lib.Ref;
import org.eclipse.jgit.lib.RefUpdate;
import org.eclipse.jgit.lib.Repository;
import org.eclipse.jgit.merge.MergeFormatter;
import org.eclipse.jgit.merge.MergeResult;
import org.eclipse.jgit.merge.ResolveMerger;
import org.eclipse.jgit.merge.ThreeWayMergeStrategy;
import org.eclipse.jgit.patch.FileHeader;
import org.eclipse.jgit.patch.FileHeader.PatchType;
@@ -63,18 +53,14 @@ import org.eclipse.jgit.revwalk.RevObject;
import org.eclipse.jgit.revwalk.RevTree;
import org.eclipse.jgit.revwalk.RevWalk;
import org.eclipse.jgit.treewalk.TreeWalk;
import org.eclipse.jgit.util.TemporaryBuffer;
import org.eclipse.jgit.util.io.DisabledOutputStream;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
@@ -94,6 +80,7 @@ public class PatchListLoader implements Callable<PatchList> {
private final PatchListCache patchListCache;
private final ThreeWayMergeStrategy mergeStrategy;
private final ExecutorService diffExecutor;
private final AutoMerger autoMerger;
private final PatchListKey key;
private final Project.NameKey project;
private final long timeoutMillis;
@@ -104,12 +91,14 @@ public class PatchListLoader implements Callable<PatchList> {
PatchListCache plc,
@GerritServerConfig Config cfg,
@DiffExecutor ExecutorService de,
AutoMerger am,
@Assisted PatchListKey k,
@Assisted Project.NameKey p) {
repoManager = mgr;
patchListCache = plc;
mergeStrategy = MergeUtil.getMergeStrategy(cfg);
diffExecutor = de;
autoMerger = am;
key = k;
project = p;
lock = new Object();
@@ -344,146 +333,13 @@ public class PatchListLoader implements Callable<PatchList> {
return r;
}
case 2:
return automerge(repo, rw, b, mergeStrategy);
return autoMerger.merge(repo, rw, b, mergeStrategy);
default:
// TODO(sop) handle an octopus merge.
return null;
}
}
public static RevTree automerge(Repository repo, RevWalk rw, RevCommit b,
ThreeWayMergeStrategy mergeStrategy) throws IOException {
String hash = b.name();
String refName = RefNames.REFS_CACHE_AUTOMERGE
+ hash.substring(0, 2)
+ "/"
+ hash.substring(2);
Ref ref = repo.getRefDatabase().exactRef(refName);
if (ref != null && ref.getObjectId() != null) {
return rw.parseTree(ref.getObjectId());
}
ResolveMerger m = (ResolveMerger) mergeStrategy.newMerger(repo, true);
try (ObjectInserter ins = repo.newObjectInserter()) {
DirCache dc = DirCache.newInCore();
m.setDirCache(dc);
m.setObjectInserter(new ObjectInserter.Filter() {
@Override
protected ObjectInserter delegate() {
return ins;
}
@Override
public void flush() {
}
@Override
public void close() {
}
});
boolean couldMerge;
try {
couldMerge = m.merge(b.getParents());
} catch (IOException e) {
// It is not safe to continue further down in this method as throwing
// an exception most likely means that the merge tree was not created
// and m.getMergeResults() is empty. This would mean that all paths are
// unmerged and Gerrit UI would show all paths in the patch list.
log.warn("Error attempting automerge " + refName, e);
return null;
}
ObjectId treeId;
if (couldMerge) {
treeId = m.getResultTreeId();
} else {
RevCommit ours = b.getParent(0);
RevCommit theirs = b.getParent(1);
rw.parseBody(ours);
rw.parseBody(theirs);
String oursMsg = ours.getShortMessage();
String theirsMsg = theirs.getShortMessage();
String oursName = String.format("HEAD (%s %s)",
ours.abbreviate(6).name(),
oursMsg.substring(0, Math.min(oursMsg.length(), 60)));
String theirsName = String.format("BRANCH (%s %s)",
theirs.abbreviate(6).name(),
theirsMsg.substring(0, Math.min(theirsMsg.length(), 60)));
MergeFormatter fmt = new MergeFormatter();
Map<String, MergeResult<? extends Sequence>> r = m.getMergeResults();
Map<String, ObjectId> resolved = new HashMap<>();
for (Map.Entry<String, MergeResult<? extends Sequence>> entry : r.entrySet()) {
MergeResult<? extends Sequence> p = entry.getValue();
try (TemporaryBuffer buf =
new TemporaryBuffer.LocalFile(null, 10 * 1024 * 1024)) {
fmt.formatMerge(buf, p, "BASE", oursName, theirsName, UTF_8.name());
buf.close();
try (InputStream in = buf.openInputStream()) {
resolved.put(entry.getKey(), ins.insert(Constants.OBJ_BLOB, buf.length(), in));
}
}
}
DirCacheBuilder builder = dc.builder();
int cnt = dc.getEntryCount();
for (int i = 0; i < cnt;) {
DirCacheEntry entry = dc.getEntry(i);
if (entry.getStage() == 0) {
builder.add(entry);
i++;
continue;
}
int next = dc.nextEntry(i);
String path = entry.getPathString();
DirCacheEntry res = new DirCacheEntry(path);
if (resolved.containsKey(path)) {
// For a file with content merge conflict that we produced a result
// above on, collapse the file down to a single stage 0 with just
// the blob content, and a randomly selected mode (the lowest stage,
// which should be the merge base, or ours).
res.setFileMode(entry.getFileMode());
res.setObjectId(resolved.get(path));
} else if (next == i + 1) {
// If there is exactly one stage present, shouldn't be a conflict...
res.setFileMode(entry.getFileMode());
res.setObjectId(entry.getObjectId());
} else if (next == i + 2) {
// Two stages suggests a delete/modify conflict. Pick the higher
// stage as the automatic result.
entry = dc.getEntry(i + 1);
res.setFileMode(entry.getFileMode());
res.setObjectId(entry.getObjectId());
} else { // 3 stage conflict, no resolve above
// Punt on the 3-stage conflict and show the base, for now.
res.setFileMode(entry.getFileMode());
res.setObjectId(entry.getObjectId());
}
builder.add(res);
i = next;
}
builder.finish();
treeId = dc.writeTree(ins);
}
ins.flush();
RefUpdate update = repo.updateRef(refName);
update.setNewObjectId(treeId);
update.disableRefLog();
update.forceUpdate();
return rw.lookupTree(treeId);
}
}
private static ObjectId emptyTree(final Repository repo) throws IOException {
try (ObjectInserter oi = repo.newObjectInserter()) {
ObjectId id = oi.insert(Constants.OBJ_TREE, new byte[] {});