Add async/sync setting to logging handler

Author: michaelbausor

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

@@ -19,9 +19,7 @@
 import static com.google.common.base.MoreObjects.firstNonNull;
 
 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;
@@ -35,6 +33,7 @@
 import java.util.logging.LogRecord;
 import java.util.logging.Logger;
 import java.util.logging.SimpleFormatter;
+import com.google.cloud.logging.Logging.WriteOption;
 
 /**
  * A logging handler that synchronously outputs logs generated with {@link java.util.logging.Logger}
@@ -54,40 +53,44 @@
  * <tr><td>FINEST</td><td>DEBUG</td></tr>
  * </table>
  *
- * <p>Original Java logging levels are added as labels (with {@code levelName} and
- * {@code levelValue} keys, respectively) to the corresponding Stackdriver Logging {@link LogEntry}.
- * You can read entry labels using {@link LogEntry#getLabels()}. To use logging levels that
- * correspond to Stackdriver Logging severities you can use {@link LoggingLevel}.
+ * <p>Original Java logging levels are added as labels (with {@code levelName} and {@code
+ * levelValue} keys, respectively) to the corresponding Stackdriver Logging {@link LogEntry}. You
+ * can read entry labels using {@link LogEntry#getLabels()}. To use logging levels that correspond
+ * to Stackdriver Logging severities you can use {@link LoggingLevel}.
  *
  * <p><b>Configuration</b>: By default each {@code LoggingHandler} is initialized using the
- * following {@code LogManager} configuration properties (that you can set in the
- * {@code logging.properties} file). If properties are not defined (or have invalid values) then the
+ * following {@code LogManager} configuration properties (that you can set in the {@code
+ * logging.properties} file). If properties are not defined (or have invalid values) then the
  * specified default values are used.
+ *
  * <ul>
- * <li>{@code com.google.cloud.logging.LoggingHandler.log} the log name (defaults to
- *     {@code java.log}).
- * <li>{@code com.google.cloud.logging.LoggingHandler.level} specifies the default level for the
- *     handler (defaults to {@code Level.INFO}).
- * <li>{@code com.google.cloud.logging.LoggingHandler.filter} specifies the name of a {@link Filter}
- *     class to use (defaults to no filter).
- * <li>{@code com.google.cloud.logging.LoggingHandler.formatter} specifies the name of a
- *     {@link Formatter} class to use (defaults to {@link SimpleFormatter}).
- * <li>{@code com.google.cloud.logging.LoggingHandler.flushSize} specifies the maximum size of the
- *     log buffer. Once reached, logs are transmitted to the Stackdriver Logging service (defaults
- *     to 1).
- * <li>{@code com.google.cloud.logging.LoggingHandler.flushLevel} specifies the flush log level.
- *     When a log with this level is published, logs are transmitted to the Stackdriver Logging
- *     service (defaults to {@link LoggingLevel#ERROR}).
- * <li>{@code com.google.cloud.logging.LoggingHandler.enhancers} specifies a comma separated list
- *     of {@link Enhancer} classes. This handler will call each enhancer list whenever it builds
- *     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.LoggingHandler.log} the log name (defaults to {@code
+ *       java.log}).
+ *   <li>{@code com.google.cloud.logging.LoggingHandler.level} specifies the default level for the
+ *       handler (defaults to {@code Level.INFO}).
+ *   <li>{@code com.google.cloud.logging.LoggingHandler.filter} specifies the name of a {@link
+ *       Filter} class to use (defaults to no filter).
+ *   <li>{@code com.google.cloud.logging.LoggingHandler.formatter} specifies the name of a {@link
+ *       Formatter} class to use (defaults to {@link SimpleFormatter}).
+ *   <li>{@code com.google.cloud.logging.LoggingHandler.flushSize} specifies the maximum size of the
+ *       log buffer. Once reached, logs are transmitted to the Stackdriver Logging service (defaults
+ *       to 1).
+ *   <li>{@code com.google.cloud.logging.LoggingHandler.flushLevel} specifies the flush log level.
+ *       When a log with this level is published, logs are transmitted to the Stackdriver Logging
+ *       service (defaults to {@link LoggingLevel#ERROR}).
+ *   <li>{@code com.google.cloud.logging.LoggingHandler.enhancers} specifies a comma separated list
+ *       of {@link Enhancer} classes. This handler will call each enhancer list whenever it builds 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.WriteLogMethod} the type of write method to use to write
+ *       logs to the Stackdriver Logging service (defaults to {@link WriteLogMethod#ASYNC}).
  * </ul>
  *
  * <p>To add a {@code LoggingHandler} to an existing {@link Logger} and be sure to avoid infinite
  * recursion when logging, use the {@link #addHandler(Logger, LoggingHandler)} method. Alternatively
  * you can add the handler via {@code logging.properties}. For example using the following line:
+ *
  * <pre>
  * {@code com.example.mypackage.handlers=com.google.cloud.logging.LoggingHandler}
  * </pre>
@@ -106,6 +109,7 @@ public class LoggingHandler extends Handler {
   private volatile Logging logging;
   private Level flushLevel;
   private long flushSize;
+  private WriteLogMethod writeLogMethod;
   private final List<Enhancer> enhancers;
 
   /**
@@ -169,6 +173,8 @@ 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.writeLogMethod =
+          helper.getWriteLogMethodProperty(className + ".writeLogMethod", WriteLogMethod.ASYNC);
       setLevel(helper.getLevelProperty(className + ".level", Level.INFO));
       setFilter(helper.getFilterProperty(className + ".filter", null));
       setFormatter(helper.getFormatterProperty(className + ".formatter", new SimpleFormatter()));
@@ -296,6 +302,16 @@ List<Enhancer> getEnhancerProperty(String name) {
       }
       return Collections.emptyList();
     }
+    
+    WriteLogMethod getWriteLogMethodProperty(String name, WriteLogMethod defaultValue) {
+      String writeLogMethod = manager.getProperty(name);
+      try {
+        return WriteLogMethod.valueOf(writeLogMethod);
+      } catch (Exception ex) {
+        // If we cannot create the WriteLogMethod we fall back to default value
+      }
+      return defaultValue;
+    }
   }
 
   /**
@@ -419,7 +435,15 @@ private static Severity severityFor(Level level) {
    * how entries should be written.
    */
   void write(List<LogEntry> entries, WriteOption... options) {
-    getLogging().writeAsync(entries, options);
+    switch (this.writeLogMethod) {
+      case SYNC:
+        getLogging().write(entries, options);
+        break;
+      case ASYNC:
+      default:
+        getLogging().writeAsync(entries, options);
+        break;
+    }
   }
 
   @Override

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

@@ -0,0 +1,22 @@
+/*
+ * 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;
+
+public enum WriteLogMethod {
+  SYNC,
+  ASYNC,
+}

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

@@ -41,6 +41,8 @@
 import com.google.protobuf.Any;
 import com.google.protobuf.StringValue;
 
+import java.io.ByteArrayInputStream;
+import java.util.logging.LogManager;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
@@ -497,14 +499,21 @@ 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");
+    try {
+      LogManager.getLogManager().readConfiguration(
+          new ByteArrayInputStream(
+              "com.google.cloud.logging.LoggingHandler.writeLogMethod=SYNC".getBytes()));
+    } catch (Exception e) {
+      throw new RuntimeException(e);
+    }
     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);
     Logger logger = Logger.getLogger(getClass().getName());
     logger.addHandler(handler);