1 files changed, 177 insertions, 0 deletions
diff --git a/java/com/google/gerrit/server/extensions/webui/UiActions.java b/java/com/google/gerrit/server/extensions/webui/UiActions.java
new file mode 100644
index 0000000000..3ca2bdb93d
--- /dev/null
+++ b/java/com/google/gerrit/server/extensions/webui/UiActions.java
@@ -0,0 +1,177 @@
+// Copyright (C) 2013 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.extensions.webui;
+
+import static com.google.gerrit.extensions.conditions.BooleanCondition.and;
+import static com.google.gerrit.extensions.conditions.BooleanCondition.or;
+import static java.util.stream.Collectors.toList;
+
+import com.google.common.annotations.VisibleForTesting;
+import com.google.common.base.Predicate;
+import com.google.common.collect.Streams;
+import com.google.common.flogger.FluentLogger;
+import com.google.gerrit.common.Nullable;
+import com.google.gerrit.extensions.api.access.GlobalOrPluginPermission;
+import com.google.gerrit.extensions.conditions.BooleanCondition;
+import com.google.gerrit.extensions.registration.DynamicMap;
+import com.google.gerrit.extensions.registration.Extension;
+import com.google.gerrit.extensions.registration.PluginName;
+import com.google.gerrit.extensions.restapi.RestCollection;
+import com.google.gerrit.extensions.restapi.RestResource;
+import com.google.gerrit.extensions.restapi.RestView;
+import com.google.gerrit.extensions.webui.PrivateInternals_UiActionDescription;
+import com.google.gerrit.extensions.webui.UiAction;
+import com.google.gerrit.extensions.webui.UiAction.Description;
+import com.google.gerrit.metrics.Description.Units;
+import com.google.gerrit.metrics.Field;
+import com.google.gerrit.metrics.MetricMaker;
+import com.google.gerrit.metrics.Timer1;
+import com.google.gerrit.server.permissions.GlobalPermission;
+import com.google.gerrit.server.permissions.PermissionBackend;
+import com.google.gerrit.server.permissions.PermissionBackendCondition;
+import com.google.gerrit.server.permissions.PermissionBackendException;
+import com.google.inject.Inject;
+import com.google.inject.Singleton;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Set;
+
+@Singleton
+public class UiActions {
+  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
+
+  public static Predicate<UiAction.Description> enabled() {
+    return UiAction.Description::isEnabled;
+  }
+
+  private final PermissionBackend permissionBackend;
+  private final Timer1<String> uiActionLatency;
+
+  @Inject
+  UiActions(PermissionBackend permissionBackend, MetricMaker metricMaker) {
+    this.permissionBackend = permissionBackend;
+    this.uiActionLatency =
+        metricMaker.newTimer(
+            "http/server/rest_api/ui_actions/latency",
+            new com.google.gerrit.metrics.Description("Latency for RestView#getDescription calls")
+                .setCumulative()
+                .setUnit(Units.MILLISECONDS),
+            Field.ofString("view"));
+  }
+
+  public <R extends RestResource> Iterable<UiAction.Description> from(
+      RestCollection<?, R> collection, R resource) {
+    return from(collection.views(), resource);
+  }
+
+  public <R extends RestResource> Iterable<UiAction.Description> from(
+      DynamicMap<RestView<R>> views, R resource) {
+    List<UiAction.Description> descs =
+        Streams.stream(views)
+            .map(e -> describe(e, resource))
+            .filter(Objects::nonNull)
+            .collect(toList());
+
+    List<PermissionBackendCondition> conds =
+        Streams.concat(
+                descs.stream().flatMap(u -> Streams.stream(visibleCondition(u))),
+                descs.stream().flatMap(u -> Streams.stream(enabledCondition(u))))
+            .collect(toList());
+
+    evaluatePermissionBackendConditions(permissionBackend, conds);
+
+    return descs.stream().filter(Description::isVisible).collect(toList());
+  }
+
+  @VisibleForTesting
+  static void evaluatePermissionBackendConditions(
+      PermissionBackend perm, List<PermissionBackendCondition> conds) {
+    Map<PermissionBackendCondition, PermissionBackendCondition> dedupedConds =
+        new HashMap<>(conds.size());
+    for (PermissionBackendCondition cond : conds) {
+      dedupedConds.put(cond, cond);
+    }
+    perm.bulkEvaluateTest(dedupedConds.keySet());
+    for (PermissionBackendCondition cond : conds) {
+      cond.set(dedupedConds.get(cond).value());
+    }
+  }
+
+  private static Iterable<PermissionBackendCondition> visibleCondition(Description u) {
+    return u.getVisibleCondition().reduce().children(PermissionBackendCondition.class);
+  }
+
+  private static Iterable<PermissionBackendCondition> enabledCondition(Description u) {
+    return u.getEnabledCondition().reduce().children(PermissionBackendCondition.class);
+  }
+
+  @Nullable
+  private <R extends RestResource> UiAction.Description describe(
+      Extension<RestView<R>> e, R resource) {
+    int d = e.getExportName().indexOf('.');
+    if (d < 0) {
+      return null;
+    }
+
+    RestView<R> view;
+    try {
+      view = e.getProvider().get();
+    } catch (RuntimeException err) {
+      logger.atSevere().withCause(err).log(
+          "error creating view %s.%s", e.getPluginName(), e.getExportName());
+      return null;
+    }
+
+    if (!(view instanceof UiAction)) {
+      return null;
+    }
+
+    String name = e.getExportName().substring(d + 1);
+    UiAction.Description dsc;
+    try (Timer1.Context ignored = uiActionLatency.start(name)) {
+      dsc = ((UiAction<R>) view).getDescription(resource);
+    }
+
+    if (dsc == null) {
+      return null;
+    }
+
+    Set<GlobalOrPluginPermission> globalRequired;
+    try {
+      globalRequired = GlobalPermission.fromAnnotation(e.getPluginName(), view.getClass());
+    } catch (PermissionBackendException err) {
+      logger.atSevere().withCause(err).log(
+          "exception testing view %s.%s", e.getPluginName(), e.getExportName());
+      return null;
+    }
+    if (!globalRequired.isEmpty()) {
+      PermissionBackend.WithUser withUser = permissionBackend.currentUser();
+      Iterator<GlobalOrPluginPermission> i = globalRequired.iterator();
+      BooleanCondition p = withUser.testCond(i.next());
+      while (i.hasNext()) {
+        p = or(p, withUser.testCond(i.next()));
+      }
+      dsc.setVisible(and(p, dsc.getVisibleCondition()));
+    }
+
+    PrivateInternals_UiActionDescription.setMethod(dsc, e.getExportName().substring(0, d));
+    PrivateInternals_UiActionDescription.setId(
+        dsc, PluginName.GERRIT.equals(e.getPluginName()) ? name : e.getPluginName() + '~' + name);
+    return dsc;
+  }
+}