Add option to omit duplicate comments.

Change-Id: I6afc938ad72afbcfd5cb653b88f7e65431d2018c

Documentation/rest-api-changes.txt

@@ -4491,7 +4491,7 @@ label names to the voting values.
 |`comments`               |optional|
 The comments that should be added as a map that maps a file path to a
 list of link:#comment-input[CommentInput] entities.
-|`strict_labels`|`true` if not set|
+|`strict_labels`          |`true` if not set|
 Whether all labels are required to be within the user's permitted ranges
 based on access controls. +
 If `true`, attempting to use a label not granted to the user will fail
@@ -4511,7 +4511,9 @@ Notify handling that defines to whom email notifications should be sent
 after the review is stored. +
 Allowed values are `NONE`, `OWNER`, `OWNER_REVIEWERS` and `ALL`. +
 If not set, the default is `ALL`.
-|`on_behalf_of`|optional|
+|`omit_duplicate_comments`|optional|
+If `true`, comments with the same content at the same place will be omitted.
+|`on_behalf_of`           |optional|
 link:rest-api-accounts.html#account-id[\{account-id\}] the review
 should be posted on behalf of. To use this option the caller must
 have been granted `labelAs-NAME` permission for all keys of labels.

gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/server/change/CommentsIT.java

@@ -188,12 +188,35 @@ public class CommentsIT extends AbstractDaemonTest {
     }
   }
 
+  @Test
+  public void addDuplicateComments() throws Exception {
+    PushOneCommit.Result r1 = createChange();
+    String changeId = r1.getChangeId();
+    String revId = r1.getCommit().getName();
+    addComment(r1, "nit: trailing whitespace");
+    addComment(r1, "nit: trailing whitespace");
+    Map<String, List<CommentInfo>> result = getPublishedComments(changeId, revId);
+    assertThat(result.get(FILE_NAME)).hasSize(2);
+    addComment(r1, "nit: trailing whitespace", true);
+    result = getPublishedComments(changeId, revId);
+    assertThat(result.get(FILE_NAME)).hasSize(2);
+
+    PushOneCommit.Result r2 = pushFactory.create(
+          db, admin.getIdent(), testRepo, SUBJECT, FILE_NAME, "content")
+        .to("refs/for/master");
+    changeId = r2.getChangeId();
+    revId = r2.getCommit().getName();
+    addComment(r2, "nit: trailing whitespace", true);
+    result = getPublishedComments(changeId, revId);
+    assertThat(result.get(FILE_NAME)).hasSize(1);
+  }
+
   @Test
   public void listChangeDrafts() throws Exception {
     PushOneCommit.Result r1 = createChange();
 
     PushOneCommit.Result r2 = pushFactory.create(
-          db, admin.getIdent(), testRepo, SUBJECT, FILE_NAME, "new cntent",
+          db, admin.getIdent(), testRepo, SUBJECT, FILE_NAME, "new content",
           r1.getChangeId())
         .to("refs/for/master");
 
@@ -363,9 +386,13 @@ public class CommentsIT extends AbstractDaemonTest {
         + "-- \n");
   }
 
-
   private void addComment(PushOneCommit.Result r, String message)
       throws Exception {
+    addComment(r, message, false);
+  }
+
+  private void addComment(PushOneCommit.Result r, String message,
+      boolean omitDuplicateComments) throws Exception {
     CommentInput c = new CommentInput();
     c.line = 1;
     c.message = message;
@@ -373,6 +400,7 @@ public class CommentsIT extends AbstractDaemonTest {
     ReviewInput in = new ReviewInput();
     in.comments = ImmutableMap.<String, List<CommentInput>> of(
         FILE_NAME, ImmutableList.of(c));
+    in.omitDuplicateComments = omitDuplicateComments;
     gApi.changes()
         .id(r.getChangeId())
         .revision(r.getCommit().name())

gerrit-extension-api/src/main/java/com/google/gerrit/extensions/api/changes/ReviewInput.java

@@ -48,6 +48,12 @@ public class ReviewInput {
   /** Who to send email notifications to after review is stored. */
   public NotifyHandling notify = NotifyHandling.ALL;
 
+  /**
+   * If true check to make sure that the comments being posted aren't already
+   * present.
+   */
+  public boolean omitDuplicateComments;
+
   /**
    * Account ID, name, email address or username of another user. The review
    * will be posted/updated on behalf of this named user instead of the

gerrit-extension-api/src/main/java/com/google/gerrit/extensions/client/Side.java

@@ -15,5 +15,16 @@
 package com.google.gerrit.extensions.client;
 
 public enum Side {
-  PARENT, REVISION
+  PARENT,
+  REVISION;
+
+  public static Side fromShort(short s) {
+    switch (s) {
+      case 0:
+        return PARENT;
+      case 1:
+        return REVISION;
+    }
+    return null;
+  }
 }

gerrit-reviewdb/src/main/java/com/google/gerrit/reviewdb/client/PatchLineComment.java

@@ -52,7 +52,7 @@ public final class PatchLineComment {
     }
 
     @Override
-    protected void set(String newValue) {
+    public void set(String newValue) {
       uuid = newValue;
     }
 

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

@@ -17,12 +17,17 @@ package com.google.gerrit.server.change;
 import static com.google.common.base.MoreObjects.firstNonNull;
 import static com.google.common.base.Preconditions.checkNotNull;
 import static com.google.gerrit.server.PatchLineCommentsUtil.setCommentRevId;
+import static java.nio.charset.StandardCharsets.UTF_8;
 
+import com.google.auto.value.AutoValue;
 import com.google.common.base.Strings;
 import com.google.common.collect.Lists;
 import com.google.common.collect.Maps;
 import com.google.common.collect.Sets;
+import com.google.common.hash.HashCode;
+import com.google.common.hash.Hashing;
 import com.google.gerrit.common.ChangeHooks;
+import com.google.gerrit.common.Nullable;
 import com.google.gerrit.common.TimeUtil;
 import com.google.gerrit.common.data.LabelType;
 import com.google.gerrit.common.data.LabelTypes;
@@ -75,9 +80,11 @@ import java.sql.Timestamp;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import java.util.Set;
 
 @Singleton
@@ -299,6 +306,32 @@ public class PostReview implements RestModifyView<RevisionResource, ReviewInput>
     }
   }
 
+  /**
+   * Used to compare PatchLineComments with CommentInput comments.
+   */
+  @AutoValue
+  abstract static class CommentSetEntry {
+    private static CommentSetEntry create(Patch.Key key,
+        Integer line, Side side, HashCode message, CommentRange range) {
+      return new AutoValue_PostReview_CommentSetEntry(key, line, side, message,
+          range);
+    }
+
+    public static CommentSetEntry create(PatchLineComment comment) {
+      return create(comment.getKey().getParentKey(),
+          comment.getLine(),
+          Side.fromShort(comment.getSide()),
+          Hashing.sha1().hashString(comment.getMessage(), UTF_8),
+          comment.getRange());
+    }
+
+    abstract Patch.Key key();
+    @Nullable abstract Integer line();
+    abstract Side side();
+    abstract HashCode message();
+    @Nullable abstract CommentRange range();
+  }
+
   private class Op extends BatchUpdate.Op {
     private final PatchSet.Id psId;
     private final ReviewInput in;
@@ -374,6 +407,10 @@ public class PostReview implements RestModifyView<RevisionResource, ReviewInput>
       List<PatchLineComment> del = Lists.newArrayList();
       List<PatchLineComment> ups = Lists.newArrayList();
 
+      Set<CommentSetEntry> existingIds = in.omitDuplicateComments
+          ? readExistingComments(ctx)
+          : Collections.<CommentSetEntry>emptySet();
+
       for (Map.Entry<String, List<CommentInput>> ent : map.entrySet()) {
         String path = ent.getKey();
         for (CommentInput c : ent.getValue()) {
@@ -381,9 +418,7 @@ public class PostReview implements RestModifyView<RevisionResource, ReviewInput>
           PatchLineComment e = drafts.remove(Url.decode(c.id));
           if (e == null) {
             e = new PatchLineComment(
-                new PatchLineComment.Key(
+                new PatchLineComment.Key(new Patch.Key(psId, path), null),
-                    new Patch.Key(psId, path),
-                    ChangeUtil.messageUUID(ctx.getDb())),
                 c.line != null ? c.line : 0,
                 user.getAccountId(),
                 parent, ctx.getWhen());
@@ -403,6 +438,12 @@ public class PostReview implements RestModifyView<RevisionResource, ReviewInput>
                 c.range.endCharacter));
             e.setLine(c.range.endLine);
           }
+          if (existingIds.contains(CommentSetEntry.create(e))) {
+            continue;
+          }
+          if (e.getKey().get() == null) {
+            e.getKey().set(ChangeUtil.messageUUID(ctx.getDb()));
+          }
           ups.add(e);
         }
       }
@@ -430,6 +471,16 @@ public class PostReview implements RestModifyView<RevisionResource, ReviewInput>
       return !del.isEmpty() || !ups.isEmpty();
     }
 
+    private Set<CommentSetEntry> readExistingComments(ChangeContext ctx)
+        throws OrmException {
+      Set<CommentSetEntry> r = new HashSet<>();
+      for (PatchLineComment c : plcUtil.publishedByChange(ctx.getDb(),
+            ctx.getChangeNotes())) {
+        r.add(CommentSetEntry.create(c));
+      }
+      return r;
+    }
+
     private Map<String, PatchLineComment> changeDrafts(ChangeContext ctx)
         throws OrmException {
       Map<String, PatchLineComment> drafts = Maps.newHashMap();