Dissolve gerrit-server top-level directory

Change-Id: I538512dfe0f1bea774c01fdd45fa410a45634011

java/com/google/gerrit/server/ReviewerByEmailSet.java

@@ -0,0 +1,79 @@
+// Copyright (C) 2017 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;
+
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.ImmutableTable;
+import com.google.common.collect.Table;
+import com.google.gerrit.server.mail.Address;
+import com.google.gerrit.server.notedb.ReviewerStateInternal;
+import java.sql.Timestamp;
+
+/**
+ * Set of reviewers on a change that do not have a Gerrit account and were added by email instead.
+ *
+ * <p>A given account may appear in multiple states and at different timestamps. No reviewers with
+ * state {@link ReviewerStateInternal#REMOVED} are ever exposed by this interface.
+ */
+public class ReviewerByEmailSet {
+  private static final ReviewerByEmailSet EMPTY = new ReviewerByEmailSet(ImmutableTable.of());
+
+  public static ReviewerByEmailSet fromTable(
+      Table<ReviewerStateInternal, Address, Timestamp> table) {
+    return new ReviewerByEmailSet(table);
+  }
+
+  public static ReviewerByEmailSet empty() {
+    return EMPTY;
+  }
+
+  private final ImmutableTable<ReviewerStateInternal, Address, Timestamp> table;
+  private ImmutableSet<Address> users;
+
+  private ReviewerByEmailSet(Table<ReviewerStateInternal, Address, Timestamp> table) {
+    this.table = ImmutableTable.copyOf(table);
+  }
+
+  public ImmutableSet<Address> all() {
+    if (users == null) {
+      // Idempotent and immutable, don't bother locking.
+      users = ImmutableSet.copyOf(table.columnKeySet());
+    }
+    return users;
+  }
+
+  public ImmutableSet<Address> byState(ReviewerStateInternal state) {
+    return table.row(state).keySet();
+  }
+
+  public ImmutableTable<ReviewerStateInternal, Address, Timestamp> asTable() {
+    return table;
+  }
+
+  @Override
+  public boolean equals(Object o) {
+    return (o instanceof ReviewerByEmailSet) && table.equals(((ReviewerByEmailSet) o).table);
+  }
+
+  @Override
+  public int hashCode() {
+    return table.hashCode();
+  }
+
+  @Override
+  public String toString() {
+    return getClass().getSimpleName() + table;
+  }
+}