Merge "Rewrite remote oracle wrapper to reduce requests"

gerrit-gwtui/src/main/java/com/google/gerrit/client/admin/AccountGroupInfoScreen.java

@@ -21,7 +21,7 @@ import com.google.gerrit.client.groups.GroupInfo;
 import com.google.gerrit.client.rpc.GerritCallback;
 import com.google.gerrit.client.ui.AccountGroupSuggestOracle;
 import com.google.gerrit.client.ui.OnEditEnabler;
-import com.google.gerrit.client.ui.RPCSuggestOracle;
+import com.google.gerrit.client.ui.RemoteSuggestOracle;
 import com.google.gerrit.client.ui.SmallHeading;
 import com.google.gerrit.reviewdb.client.AccountGroup;
 import com.google.gwt.event.dom.client.ClickEvent;
@@ -120,7 +120,7 @@ public class AccountGroupInfoScreen extends AccountGroupScreen {
     ownerTxtBox = new NpTextBox();
     ownerTxtBox.setVisibleLength(60);
     final AccountGroupSuggestOracle accountGroupOracle = new AccountGroupSuggestOracle();
-    ownerTxt = new SuggestBox(new RPCSuggestOracle(
+    ownerTxt = new SuggestBox(new RemoteSuggestOracle(
         accountGroupOracle), ownerTxtBox);
     ownerTxt.setStyleName(Gerrit.RESOURCES.css().groupOwnerTextBox());
     ownerPanel.add(ownerTxt);

gerrit-gwtui/src/main/java/com/google/gerrit/client/admin/GroupReferenceBox.java

@@ -15,7 +15,7 @@
 package com.google.gerrit.client.admin;
 
 import com.google.gerrit.client.ui.AccountGroupSuggestOracle;
-import com.google.gerrit.client.ui.RPCSuggestOracle;
+import com.google.gerrit.client.ui.RemoteSuggestOracle;
 import com.google.gerrit.common.data.GroupReference;
 import com.google.gerrit.reviewdb.client.Project;
 import com.google.gwt.editor.client.LeafValueEditor;
@@ -53,7 +53,7 @@ public class GroupReferenceBox extends Composite implements
     textBox = new NpTextBox();
     oracle = new AccountGroupSuggestOracle();
     suggestBox = new SuggestBox( //
-        new RPCSuggestOracle(oracle), //
+        new RemoteSuggestOracle(oracle), //
         textBox, //
         suggestions);
     initWidget(suggestBox);

gerrit-gwtui/src/main/java/com/google/gerrit/client/change/ReviewerSuggestOracle.java

@@ -25,9 +25,9 @@ import com.google.gerrit.client.ui.SuggestAfterTypingNCharsOracle;
 import com.google.gerrit.reviewdb.client.Change;
 import com.google.gwt.core.client.JavaScriptObject;
 import com.google.gwt.core.client.JsArray;
-import com.google.gwt.user.client.ui.SuggestOracle;
 
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 
 /** REST API based suggestion Oracle for reviewers. */
@@ -35,17 +35,22 @@ public class ReviewerSuggestOracle extends SuggestAfterTypingNCharsOracle {
   private Change.Id changeId;
 
   @Override
-  protected void _onRequestSuggestions(final Request req, final Callback callback) {
+  protected void _onRequestSuggestions(final Request req, final Callback cb) {
-    ChangeApi.suggestReviewers(changeId.get(), req.getQuery(),
+    ChangeApi.suggestReviewers(changeId.get(), req.getQuery(), req.getLimit())
-        req.getLimit()).get(new GerritCallback<JsArray<SuggestReviewerInfo>>() {
+        .get(new GerritCallback<JsArray<SuggestReviewerInfo>>() {
           @Override
           public void onSuccess(JsArray<SuggestReviewerInfo> result) {
-            final List<RestReviewerSuggestion> r =
+            List<RestReviewerSuggestion> r = new ArrayList<>(result.length());
-                new ArrayList<>(result.length());
+            for (SuggestReviewerInfo reviewer : Natives.asList(result)) {
-            for (final SuggestReviewerInfo reviewer : Natives.asList(result)) {
               r.add(new RestReviewerSuggestion(reviewer));
             }
-            callback.onSuggestionsReady(req, new Response(r));
+            cb.onSuggestionsReady(req, new Response(r));
+          }
+
+          @Override
+          public void onFailure(Throwable err) {
+            List<Suggestion> r = Collections.emptyList();
+            cb.onSuggestionsReady(req, new Response(r));
           }
         });
   }
@@ -54,7 +59,7 @@ public class ReviewerSuggestOracle extends SuggestAfterTypingNCharsOracle {
     this.changeId = changeId;
   }
 
-  private static class RestReviewerSuggestion implements SuggestOracle.Suggestion {
+  private static class RestReviewerSuggestion implements Suggestion {
     private final SuggestReviewerInfo reviewer;
 
     RestReviewerSuggestion(final SuggestReviewerInfo reviewer) {

gerrit-gwtui/src/main/java/com/google/gerrit/client/change/Reviewers.java

@@ -28,6 +28,7 @@ import com.google.gerrit.client.rpc.NativeMap;
 import com.google.gerrit.client.rpc.NativeString;
 import com.google.gerrit.client.rpc.Natives;
 import com.google.gerrit.client.ui.HintTextBox;
+import com.google.gerrit.client.ui.RemoteSuggestOracle;
 import com.google.gerrit.reviewdb.client.Change;
 import com.google.gwt.core.client.GWT;
 import com.google.gwt.core.client.JavaScriptObject;
@@ -82,7 +83,9 @@ public class Reviewers extends Composite {
   Reviewers() {
     reviewerSuggestOracle = new ReviewerSuggestOracle();
     nameTxtBox = new HintTextBox();
-    suggestBox = new SuggestBox(reviewerSuggestOracle, nameTxtBox);
+    suggestBox = new SuggestBox(
+        new RemoteSuggestOracle(reviewerSuggestOracle),
+        nameTxtBox);
     initWidget(uiBinder.createAndBindUi(this));
 
     nameTxtBox.setVisibleLength(55);

gerrit-gwtui/src/main/java/com/google/gerrit/client/ui/AddMemberBox.java

@@ -42,7 +42,7 @@ public class AddMemberBox extends Composite {
     addPanel = new FlowPanel();
     addMember = new Button(buttonLabel);
     nameTxtBox = new HintTextBox();
-    nameTxt = new SuggestBox(new RPCSuggestOracle(
+    nameTxt = new SuggestBox(new RemoteSuggestOracle(
         suggestOracle), nameTxtBox);
     nameTxt.setStyleName(Gerrit.RESOURCES.css().addMemberTextBox());
 

gerrit-gwtui/src/main/java/com/google/gerrit/client/ui/RPCSuggestOracle.java

@@ -1,59 +0,0 @@
-// Copyright (C) 2010 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.client.ui;
-
-import com.google.gwt.user.client.ui.SuggestOracle;
-
-/** This class will proxy SuggestOracle requests to another SuggestOracle
- *  while keeping track of the latest request.  Any repsonse that belongs
- *  to a request which is not the latest request will be dropped to prevent
- *  invalid deliveries.
- */
-
-public class RPCSuggestOracle extends SuggestOracle {
-
-  private SuggestOracle oracle;
-  private SuggestOracle.Request request;
-  private SuggestOracle.Callback callback;
-  private SuggestOracle.Callback myCallback = new SuggestOracle.Callback() {
-      @Override
-      public void onSuggestionsReady(SuggestOracle.Request req,
-            SuggestOracle.Response response) {
-          if (request == req) {
-            callback.onSuggestionsReady(req, response);
-            request = null;
-            callback = null;
-          }
-        }
-      };
-
-
-  public RPCSuggestOracle(SuggestOracle ora) {
-    oracle = ora;
-  }
-
-  @Override
-  public void requestSuggestions(SuggestOracle.Request req,
-      SuggestOracle.Callback cb) {
-    request = req;
-    callback = cb;
-    oracle.requestSuggestions(req, myCallback);
-  }
-
-  @Override
-  public boolean isDisplayStringHTML() {
-    return oracle.isDisplayStringHTML();
-  }
-}

gerrit-gwtui/src/main/java/com/google/gerrit/client/ui/RemoteSuggestOracle.java

@@ -0,0 +1,79 @@
+// Copyright (C) 2010 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.client.ui;
+
+import com.google.gwt.user.client.ui.SuggestOracle;
+
+/**
+ * Delegates to a slow SuggestOracle, such as a remote server API.
+ * <p>
+ * A response is only supplied to the UI if no requests were made after the
+ * oracle begin that request.
+ * <p>
+ * When a request is made while the delegate is still processing a prior request
+ * all intermediate requests are discarded and the most recent request is
+ * queued. The pending request's response is discarded and the most recent
+ * request is started.
+ */
+public class RemoteSuggestOracle extends SuggestOracle {
+  private final SuggestOracle oracle;
+  private Query query;
+
+  public RemoteSuggestOracle(SuggestOracle src) {
+    oracle = src;
+  }
+
+  @Override
+  public void requestSuggestions(Request req, Callback cb) {
+    Query q = new Query(req, cb);
+    if (query == null) {
+      q.start();
+    }
+    query = q;
+  }
+
+  @Override
+  public boolean isDisplayStringHTML() {
+    return oracle.isDisplayStringHTML();
+  }
+
+  private class Query implements Callback {
+    final Request request;
+    final Callback callback;
+
+    Query(Request req, Callback cb) {
+      request = req;
+      callback = cb;
+    }
+
+    void start() {
+      oracle.requestSuggestions(request, this);
+    }
+
+    @Override
+    public void onSuggestionsReady(Request req, Response res) {
+      if (query == this) {
+        // No new request was started while this query was running.
+        // Propose this request's response as the suggestions.
+        query = null;
+        callback.onSuggestionsReady(req, res);
+      } else {
+        // Another query came in while this one was running. Skip
+        // this response and start the most recent query.
+        query.start();
+      }
+    }
+  }
+}