[37/50] [abbrv] kafka git commit: MINOR: Avoid compiler warnings when registering metrics in KafkaServer

[gwenshap]

MINOR: Avoid compiler warnings when registering metrics in KafkaServer

Author: Liquan Pei <liquan...@gmail.com>

Reviewers: Ismael Juma <ism...@juma.me.uk>

Closes #1280 from Ishiihara/minor-warning-fix


Project: http://git-wip-us.apache.org/repos/asf/kafka/repo
Commit: http://git-wip-us.apache.org/repos/asf/kafka/commit/346df727
Tree: http://git-wip-us.apache.org/repos/asf/kafka/tree/346df727
Diff: http://git-wip-us.apache.org/repos/asf/kafka/diff/346df727

Branch: refs/heads/0.10.0
Commit: 346df72736d03acb4a6f5681e705ce3e330900a8
Parents: fdded2d
Author: Liquan Pei <liquan...@gmail.com>
Authored: Thu Apr 28 14:46:47 2016 -0700
Committer: Ismael Juma <ism...@juma.me.uk>
Committed: Thu Apr 28 14:46:47 2016 -0700

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 .../scala/kafka/controller/KafkaController.scala | 19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)
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http://git-wip-us.apache.org/repos/asf/kafka/blob/346df727/core/src/main/scala/kafka/controller/KafkaController.scala
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diff --git a/core/src/main/scala/kafka/controller/KafkaController.scala 
b/core/src/main/scala/kafka/controller/KafkaController.scala
index 103f6cf..6c503a5 100755
--- a/core/src/main/scala/kafka/controller/KafkaController.scala
+++ b/core/src/main/scala/kafka/controller/KafkaController.scala
@@ -23,15 +23,16 @@ import org.apache.kafka.common.protocol.ApiKeys
 import org.apache.kafka.common.requests.{AbstractRequest, 
AbstractRequestResponse}
 
 import scala.collection._
-import com.yammer.metrics.core.Gauge
+import com.yammer.metrics.core.{Gauge, Meter}
 import java.util.concurrent.TimeUnit
+
 import kafka.admin.AdminUtils
 import kafka.admin.PreferredReplicaLeaderElectionCommand
 import kafka.api._
 import kafka.cluster.Broker
 import kafka.common._
 import kafka.log.LogConfig
-import kafka.metrics.{KafkaTimer, KafkaMetricsGroup}
+import kafka.metrics.{KafkaMetricsGroup, KafkaTimer}
 import kafka.utils.ZkUtils._
 import kafka.utils._
 import kafka.utils.CoreUtils._
@@ -39,8 +40,9 @@ import org.apache.zookeeper.Watcher.Event.KeeperState
 import org.apache.kafka.common.metrics.Metrics
 import org.apache.kafka.common.utils.Time
 import org.I0Itec.zkclient.{IZkChildListener, IZkDataListener, 
IZkStateListener, ZkClient, ZkConnection}
-import org.I0Itec.zkclient.exception.{ZkNodeExistsException, ZkNoNodeException}
+import org.I0Itec.zkclient.exception.{ZkNoNodeException, ZkNodeExistsException}
 import java.util.concurrent.locks.ReentrantLock
+
 import kafka.server._
 import kafka.common.TopicAndPartition
 
@@ -1468,6 +1470,13 @@ case class LeaderIsrAndControllerEpoch(leaderAndIsr: 
LeaderAndIsr, controllerEpo
 }
 
 object ControllerStats extends KafkaMetricsGroup {
-  val uncleanLeaderElectionRate = newMeter("UncleanLeaderElectionsPerSec", 
"elections", TimeUnit.SECONDS)
-  val leaderElectionTimer = new 
KafkaTimer(newTimer("LeaderElectionRateAndTimeMs", TimeUnit.MILLISECONDS, 
TimeUnit.SECONDS))
+
+  private val _uncleanLeaderElectionRate = 
newMeter("UncleanLeaderElectionsPerSec", "elections", TimeUnit.SECONDS)
+  private val _leaderElectionTimer = new 
KafkaTimer(newTimer("LeaderElectionRateAndTimeMs", TimeUnit.MILLISECONDS, 
TimeUnit.SECONDS))
+
+  // KafkaServer needs to initialize controller metrics during startup. We 
perform initialization
+  // through method calls to avoid Scala compiler warnings.
+  def uncleanLeaderElectionRate: Meter = _uncleanLeaderElectionRate
+
+  def leaderElectionTimer: KafkaTimer = _leaderElectionTimer
 }