Initial Commit for Graphite Metrics Reporter

Change-Id: If3fd168c0490dd530250309d3874e78fd2640ea4

BUCK

diff --git a/BUCK b/BUCK
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--- /dev/null
+++ b/BUCK
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+gerrit_plugin(
+  name = 'metrics-reporter-graphite',
+  srcs = glob(['src/main/java/**/*.java']),
+  resources = glob(['src/main/resources/**/*']),
+  deps = [
+    '//lib/dropwizard:dropwizard-core',
+    '//lib/dropwizard:metrics-graphite'
+  ],
+  manifest_entries = [
+    'Gerrit-PluginName: metrics-reporter-graphite',
+  ],
+)

src/main/java/com/googlesource/gerrit/plugins/metricsreporters/GerritGraphiteReporter.java

diff --git a/src/main/java/com/googlesource/gerrit/plugins/metricsreporters/GerritGraphiteReporter.java b/src/main/java/com/googlesource/gerrit/plugins/metricsreporters/GerritGraphiteReporter.java
new file mode 100644
index 0000000..ae3fa89
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+++ b/src/main/java/com/googlesource/gerrit/plugins/metricsreporters/GerritGraphiteReporter.java
@@ -0,0 +1,74 @@
+// Copyright (C) 2012 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.googlesource.gerrit.plugins.metricsreporters;
+
+import static com.codahale.metrics.MetricRegistry.name;
+
+import com.google.common.base.MoreObjects;
+import com.google.gerrit.extensions.annotations.Listen;
+import com.google.gerrit.extensions.annotations.PluginName;
+import com.google.gerrit.extensions.events.LifecycleListener;
+import com.google.gerrit.server.config.PluginConfigFactory;
+import com.google.inject.Inject;
+import com.google.inject.Singleton;
+
+import com.codahale.metrics.MetricFilter;
+import com.codahale.metrics.MetricRegistry;
+import com.codahale.metrics.graphite.Graphite;
+import com.codahale.metrics.graphite.GraphiteReporter;
+
+import org.eclipse.jgit.lib.Config;
+
+import java.net.InetAddress;
+import java.net.InetSocketAddress;
+import java.net.UnknownHostException;
+import java.util.concurrent.TimeUnit;
+
+@Listen
+@Singleton
+public class GerritGraphiteReporter
+    implements LifecycleListener {
+  private final GraphiteReporter graphiteReporter;
+
+  @Inject
+  public GerritGraphiteReporter(PluginConfigFactory configFactory,
+      @PluginName String pluginName, MetricRegistry registry) {
+    Config config = configFactory.getGlobalPluginConfig(pluginName);
+    String host =
+        MoreObjects.firstNonNull(config.getString("graphite", null, "host"), "localhost");
+    try {
+      Graphite graphite = new Graphite(
+          new InetSocketAddress(host, config.getInt("graphite", "port", 2003)));
+
+      graphiteReporter = GraphiteReporter.forRegistry(registry)
+          .convertRatesTo(TimeUnit.MINUTES)
+          .convertDurationsTo(TimeUnit.MILLISECONDS)
+          .prefixedWith(MoreObjects.firstNonNull(config.getString("graphite", null, "prefix"),
+              name("gerrit", InetAddress.getLocalHost().getHostName())))
+          .filter(MetricFilter.ALL).build(graphite);
+    } catch (UnknownHostException e) {
+      throw new RuntimeException(e);
+    }
+  }
+
+  @Override
+  public void start() {
+    graphiteReporter.start(1, TimeUnit.MINUTES);
+  }
+
+  @Override
+  public void stop() {
+    graphiteReporter.stop();
+  }
+}