Import code from internal repository to git

java/com/google/domain/registry/model/registry/Registries.java

@@ -0,0 +1,112 @@
+// Copyright 2016 Google Inc. All Rights Reserved.
+//
+// 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.domain.registry.model.registry;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
+import static com.google.common.base.Predicates.equalTo;
+import static com.google.common.base.Strings.emptyToNull;
+import static com.google.common.collect.Maps.filterValues;
+import static com.google.domain.registry.model.common.EntityGroupRoot.getCrossTldKey;
+import static com.google.domain.registry.model.ofy.ObjectifyService.ofy;
+import static com.google.domain.registry.util.CacheUtils.memoizeWithShortExpiration;
+
+import com.google.common.base.Optional;
+import com.google.common.base.Supplier;
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.net.InternetDomainName;
+import com.google.domain.registry.model.registry.Registry.TldType;
+
+import com.googlecode.objectify.Work;
+
+/** Utilities for finding and listing {@link Registry} entities. */
+public final class Registries {
+
+  private Registries() {}
+
+  /** Supplier of a cached registries map. */
+  private static Supplier<ImmutableMap<String, TldType>> cache = createFreshCache();
+
+  /**
+   * Returns a newly-created Supplier of a registries to types map.
+   *
+   * <p>The supplier's get() method enters a transactionless context briefly to avoid enrolling the
+   * query inside an unrelated client-affecting transaction.
+   */
+  private static Supplier<ImmutableMap<String, TldType>> createFreshCache() {
+    return memoizeWithShortExpiration(new Supplier<ImmutableMap<String, TldType>>() {
+      @Override
+      public ImmutableMap<String, TldType> get() {
+        return ofy().doTransactionless(new Work<ImmutableMap<String, TldType>>() {
+          @Override
+          public ImmutableMap<String, TldType> run() {
+            ImmutableMap.Builder<String, TldType> builder = new ImmutableMap.Builder<>();
+            for (Registry registry : ofy().load().type(Registry.class).ancestor(getCrossTldKey())) {
+              builder.put(registry.getTldStr(), registry.getTldType());
+            }
+            return builder.build();
+          }});
+      }});
+  }
+
+  /** Manually reset the static cache backing the methods on this class. */
+  // TODO(b/24903801): offer explicit cached and uncached paths instead.
+  public static void resetCache() {
+    cache = createFreshCache();
+  }
+
+  public static ImmutableSet<String> getTlds() {
+    return cache.get().keySet();
+  }
+
+  public static ImmutableSet<String> getTldsOfType(TldType type) {
+    return ImmutableSet.copyOf(filterValues(cache.get(), equalTo(type)).keySet());
+  }
+
+  /** Shortcut to check whether a tld exists or else throw. If it exists, it is returned back. */
+  public static String assertTldExists(String tld) {
+    checkArgument(
+        getTlds().contains(checkNotNull(emptyToNull(tld), "Null or empty TLD specified")),
+        "TLD %s does not exist",
+        tld);
+    return tld;
+  }
+
+  /**
+   * Returns the TLD which the domain name or hostname falls under, no matter how many levels of
+   * subdomains there are.
+   */
+  public static Optional<InternetDomainName> findTldForName(InternetDomainName domainName) {
+    ImmutableSet<String> tlds = getTlds();
+    while (domainName.hasParent()) {
+      domainName = domainName.parent();
+      if (tlds.contains(domainName.toString())) {
+        return Optional.of(domainName);
+      }
+    }
+    return Optional.absent();
+  }
+
+  /**
+   * Returns the registered TLD which this domain name falls under, or throws an exception if no
+   * match exists.
+   */
+  public static InternetDomainName findTldForNameOrThrow(InternetDomainName domainName) {
+    return checkNotNull(
+        findTldForName(domainName).orNull(),
+        "Domain name is not under a recognized TLD: %s", domainName.toString());
+  }
+}