Add async/sync setting to logging handler (#1716)

* Add async/sync setting to logging handler

google-cloud-logging/src/main/java/com/google/cloud/logging/LoggingHandler.java

@@ -21,7 +21,6 @@
 import com.google.cloud.MonitoredResource;
 import com.google.cloud.logging.Logging.WriteOption;
 import com.google.common.collect.ImmutableList;
-
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.LinkedList;
@@ -83,6 +82,8 @@
  *     a {@link MonitoredResource} or {@link LogEntry} instance (defaults to empty list).
  * <li>{@code com.google.cloud.logging.LoggingHandler.resourceType} the type name to use when
  *     creating the default {@link MonitoredResource} (defaults to "global").
+ * <li>{@code com.google.cloud.logging.Synchronicity} the synchronicity of the write method to use
+ *     to write logs to the Stackdriver Logging service (defaults to {@link Synchronicity#ASYNC}).
  * </ul>
  *
  * <p>To add a {@code LoggingHandler} to an existing {@link Logger} and be sure to avoid infinite
@@ -106,6 +107,7 @@ public class LoggingHandler extends Handler {
   private volatile Logging logging;
   private Level flushLevel;
   private long flushSize;
+  private Synchronicity synchronicity;
   private final List<Enhancer> enhancers;
 
   /**
@@ -169,6 +171,8 @@ public LoggingHandler(String log, LoggingOptions options, MonitoredResource moni
       this.options = options != null ? options : LoggingOptions.getDefaultInstance();
       this.flushLevel = helper.getLevelProperty(className + ".flushLevel", LoggingLevel.ERROR);
       this.flushSize = helper.getLongProperty(className + ".flushSize", 1L);
+      this.synchronicity =
+          helper.getSynchronicityProperty(className + ".synchronicity", Synchronicity.ASYNC);
       setLevel(helper.getLevelProperty(className + ".level", Level.INFO));
       setFilter(helper.getFilterProperty(className + ".filter", null));
       setFormatter(helper.getFormatterProperty(className + ".formatter", new SimpleFormatter()));
@@ -296,6 +300,16 @@ List<Enhancer> getEnhancerProperty(String name) {
       }
       return Collections.emptyList();
     }
+
+    Synchronicity getSynchronicityProperty(String name, Synchronicity defaultValue) {
+      String synchronicity = manager.getProperty(name);
+      try {
+        return Synchronicity.valueOf(synchronicity);
+      } catch (Exception ex) {
+        // If we cannot create the Synchronicity we fall back to default value
+      }
+      return defaultValue;
+    }
   }
 
   /**
@@ -419,7 +433,15 @@ private static Severity severityFor(Level level) {
    * how entries should be written.
    */
   void write(List<LogEntry> entries, WriteOption... options) {
-    getLogging().writeAsync(entries, options);
+    switch (this.synchronicity) {
+      case SYNC:
+        getLogging().write(entries, options);
+        break;
+      case ASYNC:
+      default:
+        getLogging().writeAsync(entries, options);
+        break;
+    }
   }
 
   @Override
@@ -476,6 +498,11 @@ public synchronized Level setFlushLevel(Level flushLevel) {
     return flushLevel;
   }
 
+  /** Get the flush log level. */
+  public Level getFlushLevel() {
+    return this.flushLevel;
+  }
+
   /**
    * Sets the maximum size of the log buffer. Once the maximum size of the buffer is reached, logs
    * are transmitted to the Stackdriver Logging service. If not set, a log is sent to the service as
@@ -486,6 +513,28 @@ public synchronized long setFlushSize(long flushSize) {
     return flushSize;
   }
 
+  /** Get the maximum size of the log buffer. */
+  public long getFlushSize() {
+    return this.flushSize;
+  }
+
+  /**
+   * Sets the synchronicity of the write method used to write logs to the Stackdriver Logging
+   * service. Defaults to {@link Synchronicity#ASYNC}.
+   */
+  public synchronized Synchronicity setSynchronicity(Synchronicity synchronicity) {
+    this.synchronicity = synchronicity;
+    return synchronicity;
+  }
+
+  /**
+   * Get the synchronicity of the write method used to write logs to the Stackdriver Logging
+   * service.
+   */
+  public Synchronicity getSynchronicity() {
+    return this.synchronicity;
+  }
+
   /**
    * Adds the provided {@code LoggingHandler} to {@code logger}. Use this method to register Cloud
    * Logging handlers instead of {@link Logger#addHandler(Handler)} to avoid infinite recursion

google-cloud-logging/src/main/java/com/google/cloud/logging/Synchronicity.java

@@ -0,0 +1,27 @@
+/*
+ * Copyright 2017 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.logging;
+
+/**
+ * Used to specify the behavior of write calls to the Stackdriver Logging service. Specifying SYNC
+ * will make synchronous calls; specifying ASYNC will make asynchronous calls. The default behavior
+ * is ASYNC.
+ */
+public enum Synchronicity {
+  SYNC,
+  ASYNC,
+}

google-cloud-logging/src/test/java/com/google/cloud/logging/BaseSystemTest.java

@@ -40,17 +40,15 @@
 import com.google.common.collect.Sets;
 import com.google.protobuf.Any;
 import com.google.protobuf.StringValue;
-
-import org.junit.Rule;
-import org.junit.Test;
-import org.junit.rules.ExpectedException;
-import org.junit.rules.Timeout;
-
 import java.util.Iterator;
 import java.util.Set;
 import java.util.concurrent.ExecutionException;
 import java.util.logging.Level;
 import java.util.logging.Logger;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.junit.rules.Timeout;
 
 /**
  * A base class for system tests. This class can be extended to run system tests in different
@@ -497,15 +495,16 @@ public void testLoggingHandler() throws InterruptedException {
   }
 
   @Test
-  public void testAsyncLoggingHandler() throws InterruptedException {
-    String logName = formatForTest("test-async-logging-handler");
+  public void testSyncLoggingHandler() throws InterruptedException {
+    String logName = formatForTest("test-sync-logging-handler");
     LoggingOptions options = logging().getOptions();
     MonitoredResource resource = MonitoredResource.of("gce_instance",
         ImmutableMap.of("project_id", options.getProjectId(),
             "instance_id", "instance",
             "zone", "us-central1-a"));
-    LoggingHandler handler = new AsyncLoggingHandler(logName, options, resource);
+    LoggingHandler handler = new LoggingHandler(logName, options, resource);
     handler.setLevel(Level.WARNING);
+    handler.setSynchronicity(Synchronicity.SYNC);
     Logger logger = Logger.getLogger(getClass().getName());
     logger.addHandler(handler);
     logger.setLevel(Level.WARNING);