1 files changed, 123 insertions, 0 deletions
diff --git a/java/com/google/gerrit/server/logging/LoggingContext.java b/java/com/google/gerrit/server/logging/LoggingContext.java
new file mode 100644
index 0000000000..1e81c29bd6
--- /dev/null
+++ b/java/com/google/gerrit/server/logging/LoggingContext.java
@@ -0,0 +1,123 @@
+// Copyright (C) 2018 The Android Open Source Project
+//
+// 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.gerrit.server.logging;
+
+import com.google.common.collect.ImmutableSetMultimap;
+import com.google.common.flogger.backend.Tags;
+import java.util.concurrent.Callable;
+import java.util.logging.Level;
+
+/**
+ * Logging context for Flogger.
+ *
+ * <p>To configure this logging context for Flogger set the following system property (also see
+ * {@link com.google.common.flogger.backend.system.DefaultPlatform}):
+ *
+ * <ul>
+ *   <li>{@code
+ *       flogger.logging_context=com.google.gerrit.server.logging.LoggingContext#getInstance}.
+ * </ul>
+ */
+public class LoggingContext extends com.google.common.flogger.backend.system.LoggingContext {
+  private static final LoggingContext INSTANCE = new LoggingContext();
+
+  private static final ThreadLocal<MutableTags> tags = new ThreadLocal<>();
+  private static final ThreadLocal<Boolean> forceLogging = new ThreadLocal<>();
+
+  private LoggingContext() {}
+
+  /** This method is expected to be called via reflection (and might otherwise be unused). */
+  public static LoggingContext getInstance() {
+    return INSTANCE;
+  }
+
+  public static Runnable copy(Runnable runnable) {
+    if (runnable instanceof LoggingContextAwareRunnable) {
+      return runnable;
+    }
+    return new LoggingContextAwareRunnable(runnable);
+  }
+
+  public static <T> Callable<T> copy(Callable<T> callable) {
+    if (callable instanceof LoggingContextAwareCallable) {
+      return callable;
+    }
+    return new LoggingContextAwareCallable<>(callable);
+  }
+
+  @Override
+  public boolean shouldForceLogging(String loggerName, Level level, boolean isEnabled) {
+    return isLoggingForced();
+  }
+
+  @Override
+  public Tags getTags() {
+    MutableTags mutableTags = tags.get();
+    return mutableTags != null ? mutableTags.getTags() : Tags.empty();
+  }
+
+  public ImmutableSetMultimap<String, String> getTagsAsMap() {
+    MutableTags mutableTags = tags.get();
+    return mutableTags != null ? mutableTags.asMap() : ImmutableSetMultimap.of();
+  }
+
+  boolean addTag(String name, String value) {
+    return getMutableTags().add(name, value);
+  }
+
+  void removeTag(String name, String value) {
+    MutableTags mutableTags = getMutableTags();
+    mutableTags.remove(name, value);
+    if (mutableTags.isEmpty()) {
+      tags.remove();
+    }
+  }
+
+  void setTags(ImmutableSetMultimap<String, String> newTags) {
+    if (newTags.isEmpty()) {
+      tags.remove();
+      return;
+    }
+    getMutableTags().set(newTags);
+  }
+
+  void clearTags() {
+    tags.remove();
+  }
+
+  private MutableTags getMutableTags() {
+    MutableTags mutableTags = tags.get();
+    if (mutableTags == null) {
+      mutableTags = new MutableTags();
+      tags.set(mutableTags);
+    }
+    return mutableTags;
+  }
+
+  boolean isLoggingForced() {
+    Boolean force = forceLogging.get();
+    return force != null ? force : false;
+  }
+
+  boolean forceLogging(boolean force) {
+    Boolean oldValue = forceLogging.get();
+    if (force) {
+      forceLogging.set(true);
+    } else {
+      forceLogging.remove();
+    }
+    return oldValue != null ? oldValue : false;
+  }
+}