1 files changed, 157 insertions, 0 deletions
diff --git a/java/com/google/gerrit/server/submit/SubmitDryRun.java b/java/com/google/gerrit/server/submit/SubmitDryRun.java
new file mode 100644
index 0000000000..e273652d9d
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+++ b/java/com/google/gerrit/server/submit/SubmitDryRun.java
@@ -0,0 +1,157 @@
+// Copyright (C) 2015 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.submit;
+
+import static java.util.stream.Collectors.toSet;
+
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Streams;
+import com.google.common.flogger.FluentLogger;
+import com.google.gerrit.extensions.client.SubmitType;
+import com.google.gerrit.reviewdb.client.Branch;
+import com.google.gerrit.server.git.CodeReviewCommit;
+import com.google.gerrit.server.git.CodeReviewCommit.CodeReviewRevWalk;
+import com.google.gerrit.server.git.MergeUtil;
+import com.google.gerrit.server.project.NoSuchProjectException;
+import com.google.gerrit.server.project.ProjectCache;
+import com.google.gerrit.server.project.ProjectState;
+import com.google.gerrit.server.query.change.InternalChangeQuery;
+import com.google.inject.Inject;
+import com.google.inject.Provider;
+import java.io.IOException;
+import java.util.Collection;
+import java.util.HashSet;
+import java.util.Objects;
+import java.util.Set;
+import org.eclipse.jgit.lib.Constants;
+import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.lib.Ref;
+import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.revwalk.RevCommit;
+import org.eclipse.jgit.revwalk.RevFlag;
+import org.eclipse.jgit.revwalk.RevObject;
+import org.eclipse.jgit.revwalk.RevTag;
+import org.eclipse.jgit.revwalk.RevWalk;
+
+/** Dry run of a submit strategy. */
+public class SubmitDryRun {
+  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
+
+  static class Arguments {
+    final Repository repo;
+    final CodeReviewRevWalk rw;
+    final MergeUtil mergeUtil;
+    final MergeSorter mergeSorter;
+
+    Arguments(Repository repo, CodeReviewRevWalk rw, MergeUtil mergeUtil, MergeSorter mergeSorter) {
+      this.repo = repo;
+      this.rw = rw;
+      this.mergeUtil = mergeUtil;
+      this.mergeSorter = mergeSorter;
+    }
+  }
+
+  public static Set<ObjectId> getAlreadyAccepted(Repository repo) throws IOException {
+    return Streams.concat(
+            repo.getRefDatabase().getRefsByPrefix(Constants.R_HEADS).stream(),
+            repo.getRefDatabase().getRefsByPrefix(Constants.R_TAGS).stream())
+        .map(Ref::getObjectId)
+        .filter(Objects::nonNull)
+        .collect(toSet());
+  }
+
+  public static Set<RevCommit> getAlreadyAccepted(Repository repo, RevWalk rw) throws IOException {
+    Set<RevCommit> accepted = new HashSet<>();
+    addCommits(getAlreadyAccepted(repo), rw, accepted);
+    return accepted;
+  }
+
+  public static void addCommits(Iterable<ObjectId> ids, RevWalk rw, Collection<RevCommit> out)
+      throws IOException {
+    for (ObjectId id : ids) {
+      RevObject obj = rw.parseAny(id);
+      if (obj instanceof RevTag) {
+        obj = rw.peel(obj);
+      }
+      if (obj instanceof RevCommit) {
+        out.add((RevCommit) obj);
+      }
+    }
+  }
+
+  private final ProjectCache projectCache;
+  private final MergeUtil.Factory mergeUtilFactory;
+  private final Provider<InternalChangeQuery> queryProvider;
+
+  @Inject
+  SubmitDryRun(
+      ProjectCache projectCache,
+      MergeUtil.Factory mergeUtilFactory,
+      Provider<InternalChangeQuery> queryProvider) {
+    this.projectCache = projectCache;
+    this.mergeUtilFactory = mergeUtilFactory;
+    this.queryProvider = queryProvider;
+  }
+
+  public boolean run(
+      SubmitType submitType,
+      Repository repo,
+      CodeReviewRevWalk rw,
+      Branch.NameKey destBranch,
+      ObjectId tip,
+      ObjectId toMerge,
+      Set<RevCommit> alreadyAccepted)
+      throws IntegrationException, NoSuchProjectException, IOException {
+    CodeReviewCommit tipCommit = rw.parseCommit(tip);
+    CodeReviewCommit toMergeCommit = rw.parseCommit(toMerge);
+    RevFlag canMerge = rw.newFlag("CAN_MERGE");
+    toMergeCommit.add(canMerge);
+    Arguments args =
+        new Arguments(
+            repo,
+            rw,
+            mergeUtilFactory.create(getProject(destBranch)),
+            new MergeSorter(
+                rw, alreadyAccepted, canMerge, queryProvider, ImmutableSet.of(toMergeCommit)));
+
+    switch (submitType) {
+      case CHERRY_PICK:
+        return CherryPick.dryRun(args, tipCommit, toMergeCommit);
+      case FAST_FORWARD_ONLY:
+        return FastForwardOnly.dryRun(args, tipCommit, toMergeCommit);
+      case MERGE_ALWAYS:
+        return MergeAlways.dryRun(args, tipCommit, toMergeCommit);
+      case MERGE_IF_NECESSARY:
+        return MergeIfNecessary.dryRun(args, tipCommit, toMergeCommit);
+      case REBASE_IF_NECESSARY:
+        return RebaseIfNecessary.dryRun(args, repo, tipCommit, toMergeCommit);
+      case REBASE_ALWAYS:
+        return RebaseAlways.dryRun(args, repo, tipCommit, toMergeCommit);
+      case INHERIT:
+      default:
+        String errorMsg = "No submit strategy for: " + submitType;
+        logger.atSevere().log(errorMsg);
+        throw new IntegrationException(errorMsg);
+    }
+  }
+
+  private ProjectState getProject(Branch.NameKey branch) throws NoSuchProjectException {
+    ProjectState p = projectCache.get(branch.getParentKey());
+    if (p == null) {
+      throw new NoSuchProjectException(branch.getParentKey());
+    }
+    return p;
+  }
+}