Move Clock out of ServiceOptions, use it in RetryHelper

Author: mziccard

gcloud-java-core/src/main/java/com/google/cloud/Clock.java

@@ -0,0 +1,59 @@
+/*
+ * 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.cloud;
+
+import java.io.ObjectStreamException;
+import java.io.Serializable;
+
+/**
+ * A class providing access to the current time in milliseconds. This class is mainly used for
+ * testing and will be replaced by Java8's {@code java.time.Clock}.
+ *
+ * <p>Implementations should implement {@code Serializable} wherever possible and must document
+ * whether or not they do support serialization.
+ */
+public abstract class Clock {
+
+  private static final Clock DEFAULT_TIME_SOURCE = new DefaultClock();
+
+  /**
+   * Returns current time in milliseconds according to this clock.
+   */
+  public abstract long millis();
+
+  /**
+   * Returns the default clock. Default clock uses {@link System#currentTimeMillis()} to get time
+   * in milliseconds.
+   */
+  public static Clock defaultClock() {
+    return DEFAULT_TIME_SOURCE;
+  }
+
+  private static class DefaultClock extends Clock implements Serializable {
+
+    private static final long serialVersionUID = -5077300394286703864L;
+
+    @Override
+    public long millis() {
+      return System.currentTimeMillis();
+    }
+
+    private Object readResolve() throws ObjectStreamException {
+      return DEFAULT_TIME_SOURCE;
+    }
+  }
+}

gcloud-java-core/src/main/java/com/google/cloud/RetryHelper.java

@@ -21,12 +21,10 @@
 import static java.lang.StrictMath.min;
 import static java.lang.StrictMath.pow;
 import static java.lang.StrictMath.random;
-import static java.util.concurrent.TimeUnit.MILLISECONDS;
 
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.MoreObjects;
 import com.google.common.base.MoreObjects.ToStringHelper;
-import com.google.common.base.Stopwatch;
 
 import java.io.InterruptedIOException;
 import java.nio.channels.ClosedByInterruptException;
@@ -45,7 +43,7 @@ public class RetryHelper<V> {
 
   private static final Logger log = Logger.getLogger(RetryHelper.class.getName());
 
-  private final Stopwatch stopwatch;
+  private final Clock clock;
   private final Callable<V> callable;
   private final RetryParams params;
   private final ExceptionHandler exceptionHandler;
@@ -153,10 +151,10 @@ static Context getContext() {
 
   @VisibleForTesting
   RetryHelper(Callable<V> callable, RetryParams params, ExceptionHandler exceptionHandler,
-      Stopwatch stopwatch) {
+      Clock clock) {
     this.callable = checkNotNull(callable);
     this.params = checkNotNull(params);
-    this.stopwatch = checkNotNull(stopwatch);
+    this.clock = checkNotNull(clock);
     this.exceptionHandler = checkNotNull(exceptionHandler);
     exceptionHandler.verifyCaller(callable);
   }
@@ -165,15 +163,15 @@ static Context getContext() {
   public String toString() {
     ToStringHelper toStringHelper = MoreObjects.toStringHelper(this);
     toStringHelper.add("params", params);
-    toStringHelper.add("stopwatch", stopwatch);
+    toStringHelper.add("clock", clock);
     toStringHelper.add("attemptNumber", attemptNumber);
     toStringHelper.add("callable", callable);
     toStringHelper.add("exceptionHandler", exceptionHandler);
     return toStringHelper.toString();
   }
 
   private V doRetry() throws RetryHelperException {
-    stopwatch.start();
+    long start = clock.millis();
     while (true) {
       attemptNumber++;
       Exception exception;
@@ -196,7 +194,7 @@ private V doRetry() throws RetryHelperException {
       }
       if (attemptNumber >= params.retryMaxAttempts()
           || attemptNumber >= params.retryMinAttempts()
-          && stopwatch.elapsed(MILLISECONDS) >= params.totalRetryPeriodMillis()) {
+          && clock.millis() - start >= params.totalRetryPeriodMillis()) {
         throw new RetriesExhaustedException(this + ": Too many failures, giving up", exception);
       }
       long sleepDurationMillis = getSleepDuration(params, attemptNumber);
@@ -234,13 +232,13 @@ public static <V> V runWithRetries(Callable<V> callable) throws RetryHelperExcep
 
   public static <V> V runWithRetries(Callable<V> callable, RetryParams params,
       ExceptionHandler exceptionHandler) throws RetryHelperException {
-    return runWithRetries(callable, params, exceptionHandler, Stopwatch.createUnstarted());
+    return runWithRetries(callable, params, exceptionHandler, Clock.defaultClock());
   }
 
   @VisibleForTesting
   static <V> V runWithRetries(Callable<V> callable, RetryParams params,
-      ExceptionHandler exceptionHandler, Stopwatch stopwatch) throws RetryHelperException {
-    RetryHelper<V> retryHelper = new RetryHelper<>(callable, params, exceptionHandler, stopwatch);
+      ExceptionHandler exceptionHandler, Clock clock) throws RetryHelperException {
+    RetryHelper<V> retryHelper = new RetryHelper<>(callable, params, exceptionHandler, clock);
     Context previousContext = getContext();
     setContext(new Context(retryHelper));
     try {

gcloud-java-core/src/main/java/com/google/cloud/ServiceOptions.java

@@ -43,7 +43,6 @@
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.ObjectInputStream;
-import java.io.ObjectStreamException;
 import java.io.Serializable;
 import java.lang.reflect.Method;
 import java.net.HttpURLConnection;
@@ -125,45 +124,6 @@ public HttpTransport create() {
     }
   }
 
-  /**
-   * A class providing access to the current time in milliseconds. This class is mainly used for
-   * testing and will be replaced by Java8's {@code java.time.Clock}.
-   *
-   * <p>Implementations should implement {@code Serializable} wherever possible and must document
-   * whether or not they do support serialization.
-   */
-  public abstract static class Clock {
-
-    private static final ServiceOptions.Clock DEFAULT_TIME_SOURCE = new DefaultClock();
-
-    /**
-     * Returns current time in milliseconds according to this clock.
-     */
-    public abstract long millis();
-
-    /**
-     * Returns the default clock. Default clock uses {@link System#currentTimeMillis()} to get time
-     * in milliseconds.
-     */
-    public static ServiceOptions.Clock defaultClock() {
-      return DEFAULT_TIME_SOURCE;
-    }
-
-    private static class DefaultClock extends ServiceOptions.Clock implements Serializable {
-
-      private static final long serialVersionUID = -5077300394286703864L;
-
-      @Override
-      public long millis() {
-        return System.currentTimeMillis();
-      }
-
-      private Object readResolve() throws ObjectStreamException {
-        return DEFAULT_TIME_SOURCE;
-      }
-    }
-  }
-
   /**
    * Builder for {@code ServiceOptions}.
    *

gcloud-java-core/src/test/java/com/google/cloud/RetryHelperTest.java

@@ -24,8 +24,6 @@
 
 import com.google.cloud.RetryHelper.NonRetriableException;
 import com.google.cloud.RetryHelper.RetriesExhaustedException;
-import com.google.common.base.Stopwatch;
-import com.google.common.base.Ticker;
 
 import org.junit.Test;
 
@@ -157,24 +155,24 @@ public void testTriesNoMoreThanMaxTimes() {
     }
   }
 
-  private static class FakeTicker extends Ticker {
-    private final AtomicLong nanos = new AtomicLong();
+  private static class FakeClock extends Clock {
 
-    // Advances the ticker value by {@code time} in {@code timeUnit}.
+    private final AtomicLong millis = new AtomicLong();
+
+    // Advances the clock value by {@code time} in {@code timeUnit}.
     void advance(long time, TimeUnit timeUnit) {
-      nanos.addAndGet(timeUnit.toNanos(time));
+      millis.addAndGet(timeUnit.toMillis(time));
     }
 
     @Override
-    public long read() {
-      return nanos.get();
+    public long millis() {
+      return millis.get();
     }
   }
 
   @Test
   public void testTriesNoMoreLongerThanTotalRetryPeriod() {
-    final FakeTicker ticker = new FakeTicker();
-    Stopwatch stopwatch = Stopwatch.createUnstarted(ticker);
+    final FakeClock fakeClock = new FakeClock();
     // The 8th attempt (after min and before max) will trigger a 1 second (virtual) delay exceeding
     // total retry period which is set just under 1 second. Test occurs faster than realtime.
     RetryParams params = RetryParams.builder().initialRetryDelayMillis(0)
@@ -190,11 +188,11 @@ public void testTriesNoMoreLongerThanTotalRetryPeriod() {
         @Override public void run() {
           timesCalled.incrementAndGet();
           if (timesCalled.get() == sleepOnAttempt) {
-            ticker.advance(1000, TimeUnit.MILLISECONDS);
+            fakeClock.advance(1000, TimeUnit.MILLISECONDS);
           }
           throw new RuntimeException();
         }
-      }), params, handler, stopwatch);
+      }), params, handler, fakeClock);
       fail();
     } catch (RetriesExhaustedException expected) {
       // verify timesCalled

gcloud-java-core/src/test/java/com/google/cloud/ServiceOptionsTest.java

@@ -22,7 +22,6 @@
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
-import com.google.cloud.ServiceOptions.Clock;
 import com.google.cloud.ServiceOptions.DefaultHttpTransportFactory;
 import com.google.cloud.ServiceOptions.HttpTransportFactory;
 import com.google.cloud.spi.ServiceRpcFactory;

gcloud-java-dns/src/test/java/com/google/cloud/dns/DnsImplTest.java

@@ -22,9 +22,9 @@
 import com.google.api.services.dns.model.Change;
 import com.google.api.services.dns.model.ManagedZone;
 import com.google.api.services.dns.model.ResourceRecordSet;
+import com.google.cloud.Clock;
 import com.google.cloud.Page;
 import com.google.cloud.RetryParams;
-import com.google.cloud.ServiceOptions;
 import com.google.cloud.dns.spi.DnsRpc;
 import com.google.cloud.dns.spi.DnsRpcFactory;
 import com.google.common.collect.ImmutableList;
@@ -100,7 +100,7 @@ public class DnsImplTest {
 
   // Other
   private static final Map<DnsRpc.Option, ?> EMPTY_RPC_OPTIONS = ImmutableMap.of();
-  private static final ServiceOptions.Clock TIME_SOURCE = new ServiceOptions.Clock() {
+  private static final Clock TIME_SOURCE = new Clock() {
     @Override
     public long millis() {
       return 42000L;

gcloud-java-storage/src/test/java/com/google/cloud/storage/StorageImplTest.java

@@ -26,10 +26,10 @@
 
 import com.google.api.services.storage.model.StorageObject;
 import com.google.cloud.AuthCredentials.ServiceAccountAuthCredentials;
+import com.google.cloud.Clock;
 import com.google.cloud.Page;
 import com.google.cloud.ReadChannel;
 import com.google.cloud.RetryParams;
-import com.google.cloud.ServiceOptions;
 import com.google.cloud.WriteChannel;
 import com.google.cloud.storage.Storage.CopyRequest;
 import com.google.cloud.storage.spi.StorageRpc;
@@ -225,7 +225,7 @@ public class StorageImplTest {
           + "EkPPhszldvQTY486uPxyD/D7HdfnGW/Nbw5JUhfvecAdudDEhNAQ3PNabyDMI+TpiHy4NTWOrgdcWrzj6VXcdc"
           + "+uuABnPwRCdcyJ1xl2kOrPksRnp1auNGMLOe4IpEBjGY7baX9UG8+A45MbG0aHmkR59Op/aR9XowIDAQAB";
 
-  private static final ServiceOptions.Clock TIME_SOURCE = new ServiceOptions.Clock() {
+  private static final Clock TIME_SOURCE = new Clock() {
     @Override
     public long millis() {
       return 42000L;