ChangeSet: No longer be an AutoValue

Originally this class was designed as to be an AutoValue such that it
can be hashed and used for identification in the MergeQueue. The MergeQueue
is gone and we do not need to have the hashing in ChangeSet any more.

We rather want to carry the set of changes around, such that we do not
need to reconstruct the changes again and again. So this commit ought to
be a performance improvement.

Change-Id: I8b2a683d6f02e9cef1cd41b23e351f5384a4480d

gerrit-server/src/main/java/com/google/gerrit/server/change/GetRevisionActions.java

@@ -19,13 +19,12 @@ import com.google.common.hash.Hashing;
 import com.google.gerrit.extensions.common.ActionInfo;
 import com.google.gerrit.extensions.restapi.ETagView;
 import com.google.gerrit.extensions.restapi.Response;
-import com.google.gerrit.reviewdb.client.Change;
 import com.google.gerrit.reviewdb.server.ReviewDb;
 import com.google.gerrit.server.CurrentUser;
 import com.google.gerrit.server.config.GerritServerConfig;
 import com.google.gerrit.server.git.ChangeSet;
 import com.google.gerrit.server.git.MergeSuperSet;
-import com.google.gerrit.server.project.ProjectControl;
+import com.google.gerrit.server.query.change.ChangeData;
 import com.google.gwtorm.server.OrmException;
 import com.google.gwtorm.server.OrmRuntimeException;
 import com.google.inject.Inject;
@@ -69,11 +68,9 @@ public class GetRevisionActions implements ETagView<RevisionResource> {
       rsrc.getChangeResource().prepareETag(h, user);
       h.putBoolean(Submit.wholeTopicEnabled(config));
       ReviewDb db = dbProvider.get();
-      ChangeSet cs = mergeSuperSet.completeChangeSet(db,
+      ChangeSet cs = mergeSuperSet.completeChangeSet(db, rsrc.getChange());
-          ChangeSet.create(rsrc.getChange()));
+      for (ChangeData cd : cs.changes()) {
-      ProjectControl ctl = rsrc.getControl().getProjectControl();
+        new ChangeResource(cd.changeControl()).prepareETag(h, user);
-      for (Change c : cs.changes()) {
-        new ChangeResource(ctl.controlFor(c)).prepareETag(h, user);
       }
     } catch (IOException | OrmException e) {
       throw new OrmRuntimeException(e);

gerrit-server/src/main/java/com/google/gerrit/server/change/Submit.java

@@ -182,11 +182,9 @@ public class Submit implements RestModifyView<RevisionResource, SubmitInput>,
           rsrc.getPatchSet().getRevision().get()));
     }
 
-    ChangeSet submittedChanges = ChangeSet.create(change);
-
     try {
       ReviewDb db = dbProvider.get();
-      mergeOpProvider.get().merge(db, submittedChanges, caller, true);
+      mergeOpProvider.get().merge(db, change, caller, true);
       change = db.changes().get(change.getId());
     } catch (NoSuchChangeException e) {
       throw new OrmException("Submission failed", e);
@@ -306,8 +304,7 @@ public class Submit implements RestModifyView<RevisionResource, SubmitInput>,
 
     ChangeSet cs;
     try {
-      cs = mergeSuperSet.completeChangeSet(db,
+      cs = mergeSuperSet.completeChangeSet(db, cd.change());
-          ChangeSet.create(cd.change()));
     } catch (OrmException | IOException e) {
       throw new OrmRuntimeException("Could not determine complete set of " +
           "changes to be submitted", e);

gerrit-server/src/main/java/com/google/gerrit/server/change/SubmittedTogether.java

@@ -60,8 +60,8 @@ public class SubmittedTogether implements RestReadView<ChangeResource> {
       ResourceConflictException, Exception {
     try {
       ChangeSet cs = mergeSuperSet.completeChangeSet(dbProvider.get(),
-          ChangeSet.create(resource.getChange()));
+          resource.getChange());
-      if (cs.ids().size() > 1) {
+      if (cs.size() > 1) {
         return json.create(EnumSet.of(
             ListChangesOption.CURRENT_REVISION,
             ListChangesOption.CURRENT_COMMIT))

gerrit-server/src/main/java/com/google/gerrit/server/git/ChangeSet.java

@@ -14,70 +14,103 @@
 
 package com.google.gerrit.server.git;
 
-import com.google.auto.value.AutoValue;
+import com.google.common.collect.ArrayListMultimap;
+import com.google.common.collect.HashMultimap;
+import com.google.common.collect.ImmutableCollection;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
-import com.google.common.collect.ImmutableSetMultimap;
+import com.google.common.collect.ListMultimap;
+import com.google.common.collect.Multimap;
+import com.google.common.collect.SetMultimap;
 import com.google.gerrit.reviewdb.client.Branch;
 import com.google.gerrit.reviewdb.client.Change;
 import com.google.gerrit.reviewdb.client.PatchSet;
 import com.google.gerrit.reviewdb.client.Project;
+import com.google.gerrit.server.query.change.ChangeData;
+import com.google.gwtorm.server.OrmException;
 
-/** A set of changes grouped together to be submitted atomically.*/
+import java.util.HashSet;
-@AutoValue
+import java.util.Set;
-public abstract class ChangeSet {
-  public static ChangeSet create(Iterable<Change> changes) {
-    ImmutableSet.Builder<Project.NameKey> pb = ImmutableSet.builder();
-    ImmutableSet.Builder<Branch.NameKey> bb = ImmutableSet.builder();
-    ImmutableSet.Builder<Change.Id> ib = ImmutableSet.builder();
-    ImmutableSet.Builder<PatchSet.Id> psb = ImmutableSet.builder();
-    ImmutableSetMultimap.Builder<Project.NameKey, Branch.NameKey> pbb =
-        ImmutableSetMultimap.builder();
-    ImmutableSetMultimap.Builder<Project.NameKey, Change.Id> pcb =
-        ImmutableSetMultimap.builder();
-    ImmutableSetMultimap.Builder<Branch.NameKey, Change.Id> cbb =
-        ImmutableSetMultimap.builder();
-    ImmutableSet.Builder<Change> cb = ImmutableSet.builder();
 
-    for (Change c : changes) {
+/**
-      Branch.NameKey branch = c.getDest();
+ * A set of changes grouped together to be submitted atomically.
-      Project.NameKey project = branch.getParentKey();
+ * <p>
-      pb.add(project);
+ * This class is not thread safe.
-      bb.add(branch);
+ */
-      ib.add(c.getId());
+public class ChangeSet {
-      psb.add(c.currentPatchSetId());
+  private final ImmutableCollection<ChangeData> changeData;
-      pbb.put(project, branch);
+
-      pcb.put(project, c.getId());
+  public ChangeSet(Iterable<ChangeData> changes) {
-      cbb.put(branch, c.getId());
+    Set<Change.Id> ids = new HashSet<>();
-      cb.add(c);
+    ImmutableSet.Builder<ChangeData> cdb = ImmutableSet.builder();
+    for (ChangeData cd : changes) {
+      if (ids.add(cd.getId())) {
+        cdb.add(cd);
+      }
     }
-
+    changeData = cdb.build();
-    return new AutoValue_ChangeSet(pb.build(), bb.build(), ib.build(),
-        psb.build(), pbb.build(), pcb.build(), cbb.build(), cb.build());
   }
 
-  public static ChangeSet create(Change change) {
+  public ChangeSet(ChangeData change) {
-    return create(ImmutableList.of(change));
+    this(ImmutableList.of(change));
   }
 
-  public abstract ImmutableSet<Project.NameKey> projects();
+  public ImmutableSet<Change.Id> ids() {
-  public abstract ImmutableSet<Branch.NameKey> branches();
+    ImmutableSet.Builder<Change.Id> ret = ImmutableSet.builder();
-  public abstract ImmutableSet<Change.Id> ids();
+    for (ChangeData cd : changeData) {
-  public abstract ImmutableSet<PatchSet.Id> patchIds();
+      ret.add(cd.getId());
-  public abstract ImmutableSetMultimap<Project.NameKey, Branch.NameKey>
+    }
-      branchesByProject();
+    return ret.build();
-  public abstract ImmutableSetMultimap<Project.NameKey, Change.Id>
+  }
-      changesByProject();
-  public abstract ImmutableSetMultimap<Branch.NameKey, Change.Id>
-      changesByBranch();
-  public abstract ImmutableSet<Change> changes();
 
-  @Override
+  public Set<PatchSet.Id> patchIds() throws OrmException {
-  public int hashCode() {
+    Set<PatchSet.Id> ret = new HashSet<>();
-    return ids().hashCode();
+    for (ChangeData cd : changeData) {
+      ret.add(cd.change().currentPatchSetId());
+    }
+    return ret;
+  }
+
+  public SetMultimap<Project.NameKey, Branch.NameKey> branchesByProject()
+      throws OrmException {
+    SetMultimap<Project.NameKey, Branch.NameKey> ret =
+        HashMultimap.create();
+    for (ChangeData cd : changeData) {
+      ret.put(cd.change().getProject(), cd.change().getDest());
+    }
+    return ret;
+  }
+
+  public Multimap<Project.NameKey, Change.Id> changesByProject()
+      throws OrmException {
+    ListMultimap<Project.NameKey, Change.Id> ret =
+        ArrayListMultimap.create();
+    for (ChangeData cd : changeData) {
+      ret.put(cd.change().getProject(), cd.getId());
+    }
+    return ret;
+  }
+
+  public Multimap<Branch.NameKey, Change.Id> changesByBranch()
+      throws OrmException {
+    ListMultimap<Branch.NameKey, Change.Id> ret =
+        ArrayListMultimap.create();
+    for (ChangeData cd : changeData) {
+      ret.put(cd.change().getDest(), cd.getId());
+    }
+    return ret;
+  }
+
+  public ImmutableCollection<ChangeData> changes() {
+    return changeData;
   }
 
   public int size() {
-    return ids().size();
+    return changeData.size();
+  }
+
+  @Override
+  public String toString() {
+    return getClass().getSimpleName() + ids();
   }
 }

gerrit-server/src/main/java/com/google/gerrit/server/git/MergeOp.java

@@ -25,6 +25,7 @@ import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Iterables;
 import com.google.common.collect.ListMultimap;
 import com.google.common.collect.Maps;
+import com.google.common.collect.Multimap;
 import com.google.common.collect.Table;
 import com.google.gerrit.common.ChangeHooks;
 import com.google.gerrit.common.TimeUtil;
@@ -331,14 +332,14 @@ public class MergeOp {
     }
   }
 
-  public void merge(ReviewDb db, ChangeSet changes, IdentifiedUser caller,
+  public void merge(ReviewDb db, Change change, IdentifiedUser caller,
       boolean checkSubmitRules) throws NoSuchChangeException,
       OrmException, ResourceConflictException {
-    logPrefix = String.format("[%s]: ", String.valueOf(changes.hashCode()));
+    logPrefix = String.format("[%s]: ", String.valueOf(change.hashCode()));
     this.db = db;
-    logDebug("Beginning merge of {}", changes);
+    logDebug("Beginning integration of {}", change);
     try {
-      ChangeSet cs = mergeSuperSet.completeChangeSet(db, changes);
+      ChangeSet cs = mergeSuperSet.completeChangeSet(db, change);
       logDebug("Calculated to merge {}", cs);
       if (checkSubmitRules) {
         logDebug("Checking submit rules and state");
@@ -361,15 +362,17 @@ public class MergeOp {
     logDebug("Beginning merge attempt on {}", cs);
     Map<Branch.NameKey, ListMultimap<SubmitType, ChangeData>> toSubmit =
         new HashMap<>();
+    logDebug("Perform the merges");
     try {
-      logDebug("Perform the merges");
+      Multimap<Project.NameKey, Branch.NameKey> br = cs.branchesByProject();
-      for (Project.NameKey project : cs.projects()) {
+      Multimap<Branch.NameKey, Change.Id> cbb = cs.changesByBranch();
+      for (Project.NameKey project : br.keySet()) {
         openRepository(project);
-        for (Branch.NameKey branch : cs.branchesByProject().get(project)) {
+        for (Branch.NameKey branch : br.get(project)) {
           setDestProject(branch);
 
           List<ChangeData> cds = new ArrayList<>();
-          for (Change.Id id : cs.changesByBranch().get(branch)) {
+          for (Change.Id id : cbb.get(branch)) {
             cds.add(changeDataFactory.create(db, id));
           }
           ListMultimap<SubmitType, ChangeData> submitting =
@@ -393,9 +396,9 @@ public class MergeOp {
       }
       logDebug("Write out the new branch tips");
       SubmoduleOp subOp = subOpProvider.get();
-      for (Project.NameKey project : cs.projects()) {
+      for (Project.NameKey project : br.keySet()) {
         openRepository(project);
-        for (Branch.NameKey branch : cs.branchesByProject().get(project)) {
+        for (Branch.NameKey branch : br.get(project)) {
 
           RefUpdate update = updateBranch(branch);
           pendingRefUpdates.remove(branch);
@@ -413,7 +416,8 @@ public class MergeOp {
         }
         closeRepository();
       }
-      updateSuperProjects(subOp, cs.branches());
+
+      updateSuperProjects(subOp, br.values());
       checkState(pendingRefUpdates.isEmpty(), "programmer error: "
           + "pending ref update list not emptied");
     } catch (NoSuchProjectException noProject) {
@@ -906,7 +910,7 @@ public class MergeOp {
   }
 
   private void updateSuperProjects(SubmoduleOp subOp,
-      Set<Branch.NameKey> branches) {
+      Collection<Branch.NameKey> branches) {
     logDebug("Updating superprojects");
     try {
       subOp.updateSuperProjects(db, branches);

gerrit-server/src/main/java/com/google/gerrit/server/git/MergeSuperSet.java

@@ -15,6 +15,7 @@
 package com.google.gerrit.server.git;
 
 import com.google.common.base.Strings;
+import com.google.common.collect.Multimap;
 import com.google.gerrit.common.data.SubmitTypeRecord;
 import com.google.gerrit.extensions.client.SubmitType;
 import com.google.gerrit.reviewdb.client.Branch;
@@ -80,25 +81,27 @@ public class MergeSuperSet {
     this.repoManager = repoManager;
   }
 
-  public ChangeSet completeChangeSet(ReviewDb db, ChangeSet changes)
+  public ChangeSet completeChangeSet(ReviewDb db, Change change)
       throws MissingObjectException, IncorrectObjectTypeException, IOException,
       OrmException {
+    ChangeData cd = changeDataFactory.create(db, change.getId());
     if (Submit.wholeTopicEnabled(cfg)) {
-      return completeChangeSetIncludingTopics(db, changes);
+      return completeChangeSetIncludingTopics(db, new ChangeSet(cd));
     } else {
-      return completeChangeSetWithoutTopic(db, changes);
+      return completeChangeSetWithoutTopic(db, new ChangeSet(cd));
     }
   }
 
   private ChangeSet completeChangeSetWithoutTopic(ReviewDb db, ChangeSet changes)
       throws MissingObjectException, IncorrectObjectTypeException, IOException,
       OrmException {
-    List<Change> ret = new ArrayList<>();
+    List<ChangeData> ret = new ArrayList<>();
 
-    for (Project.NameKey project : changes.projects()) {
+    Multimap<Project.NameKey, Change.Id> pc = changes.changesByProject();
+    for (Project.NameKey project : pc.keySet()) {
       try (Repository repo = repoManager.openRepository(project);
            RevWalk rw = CodeReviewCommit.newRevWalk(repo)) {
-        for (Change.Id cId : changes.changesByProject().get(project)) {
+        for (Change.Id cId : pc.get(project)) {
           ChangeData cd = changeDataFactory.create(db, cId);
 
           SubmitTypeRecord r = new SubmitRuleEvaluator(cd).getSubmitType();
@@ -106,7 +109,7 @@ public class MergeSuperSet {
             logErrorAndThrow("Failed to get submit type for " + cd.getId());
           }
           if (r.type == SubmitType.CHERRY_PICK) {
-            ret.add(cd.change());
+            ret.add(cd);
             continue;
           }
 
@@ -137,17 +140,15 @@ public class MergeSuperSet {
             // Merged changes are ok to exclude
             Iterable<ChangeData> destChanges = queryProvider.get()
                 .byCommitsOnBranchNotMerged(cd.change().getDest(), hashes);
-
             for (ChangeData chd : destChanges) {
-              Change chg = chd.change();
+              ret.add(chd);
-              ret.add(chg);
             }
           }
         }
       }
     }
 
-    return ChangeSet.create(ret);
+    return new ChangeSet(ret);
   }
 
   private ChangeSet completeChangeSetIncludingTopics(
@@ -157,24 +158,18 @@ public class MergeSuperSet {
     boolean done = false;
     ChangeSet newCs = completeChangeSetWithoutTopic(db, changes);
     while (!done) {
-      List<Change> chgs = new ArrayList<>();
+      List<ChangeData> chgs = new ArrayList<>();
       done = true;
-      for (Change.Id cId : newCs.ids()) {
+      for (ChangeData cd : newCs.changes()) {
-        // TODO(sbeller): Cache the change data here and in completeChangeSet
+        chgs.add(cd);
-        // There is no need to reread it a few times.
-        ChangeData cd = changeDataFactory.create(db, cId);
-        chgs.add(cd.change());
-
         String topic = cd.change().getTopic();
         if (!Strings.isNullOrEmpty(topic) && !topicsTraversed.contains(topic)) {
-          for (ChangeData addCd : queryProvider.get().byTopicOpen(topic)) {
+          chgs.addAll(queryProvider.get().byTopicOpen(topic));
-            chgs.add(addCd.change());
-          }
           done = false;
           topicsTraversed.add(topic);
         }
       }
-      changes = ChangeSet.create(chgs);
+      changes = new ChangeSet(chgs);
       newCs = completeChangeSetWithoutTopic(db, changes);
     }
     return newCs;

gerrit-server/src/main/java/com/google/gerrit/server/git/ReceiveCommits.java

@@ -1787,31 +1787,28 @@ public class ReceiveCommits {
       throws OrmException, ResourceConflictException {
     Submit submit = submitProvider.get();
     RevisionResource rsrc = new RevisionResource(changes.parse(changeCtl), ps);
-    List<Change> changes = Lists.newArrayList(rsrc.getChange());
     try {
-      mergeOpProvider.get().merge(db, ChangeSet.create(changes),
+      mergeOpProvider.get().merge(db, rsrc.getChange(),
           (IdentifiedUser) changeCtl.getCurrentUser(), false);
     } catch (NoSuchChangeException e) {
       throw new OrmException(e);
     }
     addMessage("");
-    for (Change c : changes) {
+    Change c = db.changes().get(rsrc.getChange().getId());
-      c = db.changes().get(c.getId());
+    switch (c.getStatus()) {
-      switch (c.getStatus()) {
+      case MERGED:
-        case MERGED:
+        addMessage("Change " + c.getChangeId() + " merged.");
-          addMessage("Change " + c.getChangeId() + " merged.");
+        break;
+      case NEW:
+        ChangeMessage msg = submit.getConflictMessage(rsrc);
+        if (msg != null) {
+          addMessage("Change " + c.getChangeId() + ": " + msg.getMessage());
           break;
-        case NEW:
+        }
-          ChangeMessage msg = submit.getConflictMessage(rsrc);
+        //$FALL-THROUGH$
-          if (msg != null) {
+      default:
-            addMessage("Change " + c.getChangeId() + ": " + msg.getMessage());
+        addMessage("change " + c.getChangeId() + " is "
-            break;
+            + c.getStatus().name().toLowerCase());
-          }
-          //$FALL-THROUGH$
-        default:
-          addMessage("change " + c.getChangeId() + " is "
-              + c.getStatus().name().toLowerCase());
-      }
     }
   }
 

gerrit-server/src/main/java/com/google/gerrit/server/git/SubmoduleOp.java

@@ -180,7 +180,7 @@ public class SubmoduleOp {
   }
 
   protected void updateSuperProjects(ReviewDb db,
-      Set<Branch.NameKey> updatedBranches) throws SubmoduleException {
+      Collection<Branch.NameKey> updatedBranches) throws SubmoduleException {
     try {
       // These (repo/branch) will be updated later with all the given
       // individual submodule subscriptions