Create an injectable LockHandler

We create an injectable LockHandler that just calls the static
Lock.executeWithLocks function.

I'm not sure what's the correct place to put the LockHandler. I think
model/server is only appropriate for the actual datastore lock. This is a "per request" lock, so maybe request/lock?

-----------------------------

This is the initial step in adding the "lock implicitly released on request death" feature, but it's also useful on its own - easier to test Actions when we can use a fake lock.

To keep this CL simple, we keep using the old Lock as is in most places. We just choose a single example to convert to LockHandler to showcase it. Converting all other uses will be in a subsequent CL.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=167357564

java/google/registry/export/sheet/BUILD

@@ -12,6 +12,7 @@ java_library(
         "//java/google/registry/model",
         "//java/google/registry/request",
         "//java/google/registry/request/auth",
+        "//java/google/registry/request/lock",
         "//java/google/registry/util",
         "//third_party/java/objectify:objectify-v4_1",
         "@com_google_api_client",

java/google/registry/export/sheet/SyncRegistrarsSheetAction.java

@@ -30,11 +30,11 @@ import com.google.appengine.api.taskqueue.TaskOptions.Method;
 import com.google.common.base.Optional;
 import com.google.gdata.util.ServiceException;
 import google.registry.config.RegistryConfig.Config;
-import google.registry.model.server.Lock;
 import google.registry.request.Action;
 import google.registry.request.Parameter;
 import google.registry.request.Response;
 import google.registry.request.auth.Auth;
+import google.registry.request.lock.LockHandler;
 import google.registry.util.FormattingLogger;
 import google.registry.util.NonFinalForTesting;
 import java.io.IOException;
@@ -117,6 +117,7 @@ public class SyncRegistrarsSheetAction implements Runnable {
   @Inject @Config("sheetLockTimeout") Duration timeout;
   @Inject @Config("sheetRegistrarId") Optional<String> idConfig;
   @Inject @Parameter("id") Optional<String> idParam;
+  @Inject LockHandler lockHandler;
   @Inject SyncRegistrarsSheetAction() {}
 
   @Override
@@ -146,7 +147,7 @@ public class SyncRegistrarsSheetAction implements Runnable {
         return null;
       }
     };
-    if (!Lock.executeWithLocks(runner, null, timeout, sheetLockName)) {
+    if (!lockHandler.executeWithLocks(runner, null, timeout, sheetLockName)) {
       // If we fail to acquire the lock, it probably means lots of updates are happening at once, in
       // which case it should be safe to not bother. The task queue definition should *not* specify
       // max-concurrent-requests for this very reason.

java/google/registry/request/BUILD

@@ -12,7 +12,7 @@ java_library(
     ),
     deps = [
         "//java/google/registry/request/auth",
-        "//java/google/registry/security",
+        "//java/google/registry/request/lock",
         "//java/google/registry/util",
         "@com_google_appengine_api_1_0_sdk",
         "@com_google_auto_value",

java/google/registry/request/RequestModule.java

@@ -27,6 +27,8 @@ import dagger.Provides;
 import google.registry.request.HttpException.BadRequestException;
 import google.registry.request.HttpException.UnsupportedMediaTypeException;
 import google.registry.request.auth.AuthResult;
+import google.registry.request.lock.LockHandler;
+import google.registry.request.lock.LockHandlerPassthrough;
 import java.io.IOException;
 import java.util.Map;
 import javax.servlet.http.HttpServletRequest;
@@ -122,6 +124,11 @@ public final class RequestModule {
     }
   }
 
+  @Provides
+  static LockHandler provideLockHandler(LockHandlerPassthrough lockHandler) {
+    return lockHandler;
+  }
+
   @Provides
   @JsonPayload
   @SuppressWarnings("unchecked")

javatests/google/registry/export/sheet/SyncRegistrarsSheetActionTest.java

@@ -24,12 +24,12 @@ import static org.mockito.Mockito.verifyZeroInteractions;
 import static org.mockito.Mockito.when;
 
 import com.google.common.base.Optional;
-import google.registry.model.server.Lock;
 import google.registry.testing.AppEngineRule;
+import google.registry.testing.FakeLockHandler;
 import google.registry.testing.FakeResponse;
-import java.util.concurrent.Callable;
 import javax.annotation.Nullable;
 import org.joda.time.Duration;
+import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -48,16 +48,23 @@ public class SyncRegistrarsSheetActionTest {
   private final FakeResponse response = new FakeResponse();
   private final SyncRegistrarsSheet syncRegistrarsSheet = mock(SyncRegistrarsSheet.class);
 
+  private SyncRegistrarsSheetAction action;
+
   private void runAction(@Nullable String idConfig, @Nullable String idParam) {
-    SyncRegistrarsSheetAction action = new SyncRegistrarsSheetAction();
-    action.response = response;
-    action.syncRegistrarsSheet = syncRegistrarsSheet;
     action.idConfig = Optional.fromNullable(idConfig);
     action.idParam = Optional.fromNullable(idParam);
-    action.timeout = Duration.standardHours(1);
     action.run();
   }
 
+  @Before
+  public void setUp() {
+    action = new SyncRegistrarsSheetAction();
+    action.response = response;
+    action.syncRegistrarsSheet = syncRegistrarsSheet;
+    action.timeout = Duration.standardHours(1);
+    action.lockHandler = new FakeLockHandler(true);
+  }
+
   @Test
   public void testPost_withoutParamsOrSystemProperty_dropsTask() throws Exception {
     runAction(null, null);
@@ -96,14 +103,8 @@ public class SyncRegistrarsSheetActionTest {
 
   @Test
   public void testPost_failToAquireLock_servletDoesNothingAndReturns() throws Exception {
-    String lockName = "Synchronize registrars sheet: foobar";
-    Lock.executeWithLocks(new Callable<Void>() {
-      @Override
-      public Void call() throws Exception {
+    action.lockHandler = new FakeLockHandler(false);
     runAction(null, "foobar");
-        return null;
-      }
-    }, null, Duration.standardHours(1), lockName);
     assertThat(response.getPayload()).startsWith("LOCKED");
     verifyZeroInteractions(syncRegistrarsSheet);
   }

javatests/google/registry/testing/BUILD

@@ -29,6 +29,7 @@ java_library(
         "//java/google/registry/monitoring/whitebox",
         "//java/google/registry/pricing",
         "//java/google/registry/request",
+        "//java/google/registry/request/lock",
         "//java/google/registry/tmch",
         "//java/google/registry/util",
         "//java/google/registry/xml",

javatests/google/registry/testing/FakeLockHandler.java

@@ -0,0 +1,57 @@
+// Copyright 2017 The Nomulus Authors. 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 google.registry.testing;
+
+import static com.google.common.base.Throwables.throwIfUnchecked;
+
+import google.registry.request.lock.LockHandler;
+import java.util.concurrent.Callable;
+import javax.annotation.Nullable;
+import org.joda.time.Duration;
+
+/** A fake {@link LockHandler} where user can control if lock acquisition succeeds. */
+public class FakeLockHandler implements LockHandler {
+
+  private static final long serialVersionUID = 6437880915118738492L;
+
+  boolean lockSucceeds = true;
+
+  /**
+   * @param lockSucceeds if true - the lock acquisition will succeed and the callable will be
+   * called. If false, lock acquisition will fail and the caller isn't called.
+   */
+  public FakeLockHandler(boolean lockSucceeds) {
+    this.lockSucceeds = lockSucceeds;
+  }
+
+  @Override
+  public boolean executeWithLocks(
+      final Callable<Void> callable,
+      @Nullable String tld,
+      Duration leaseLength,
+      String... lockNames) {
+    if (!lockSucceeds) {
+      return false;
+    }
+
+    try {
+      callable.call();
+    } catch (Exception e) {
+      throwIfUnchecked(e);
+      throw new RuntimeException(e);
+    }
+    return true;
+  }
+}