1 files changed, 167 insertions, 0 deletions
diff --git a/core/src/main/scala/org/apache/spark/internal/Logging.scala b/core/src/main/scala/org/apache/spark/internal/Logging.scala
new file mode 100644
index 0000000000..66a0cfec62
--- /dev/null
+++ b/core/src/main/scala/org/apache/spark/internal/Logging.scala
@@ -0,0 +1,167 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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 org.apache.spark.internal
+
+import org.apache.log4j.{Level, LogManager, PropertyConfigurator}
+import org.slf4j.{Logger, LoggerFactory}
+import org.slf4j.impl.StaticLoggerBinder
+
+import org.apache.spark.util.Utils
+
+/**
+ * Utility trait for classes that want to log data. Creates a SLF4J logger for the class and allows
+ * logging messages at different levels using methods that only evaluate parameters lazily if the
+ * log level is enabled.
+ */
+private[spark] trait Logging {
+
+  // Make the log field transient so that objects with Logging can
+  // be serialized and used on another machine
+  @transient private var log_ : Logger = null
+
+  // Method to get the logger name for this object
+  protected def logName = {
+    // Ignore trailing $'s in the class names for Scala objects
+    this.getClass.getName.stripSuffix("$")
+  }
+
+  // Method to get or create the logger for this object
+  protected def log: Logger = {
+    if (log_ == null) {
+      initializeLogIfNecessary(false)
+      log_ = LoggerFactory.getLogger(logName)
+    }
+    log_
+  }
+
+  // Log methods that take only a String
+  protected def logInfo(msg: => String) {
+    if (log.isInfoEnabled) log.info(msg)
+  }
+
+  protected def logDebug(msg: => String) {
+    if (log.isDebugEnabled) log.debug(msg)
+  }
+
+  protected def logTrace(msg: => String) {
+    if (log.isTraceEnabled) log.trace(msg)
+  }
+
+  protected def logWarning(msg: => String) {
+    if (log.isWarnEnabled) log.warn(msg)
+  }
+
+  protected def logError(msg: => String) {
+    if (log.isErrorEnabled) log.error(msg)
+  }
+
+  // Log methods that take Throwables (Exceptions/Errors) too
+  protected def logInfo(msg: => String, throwable: Throwable) {
+    if (log.isInfoEnabled) log.info(msg, throwable)
+  }
+
+  protected def logDebug(msg: => String, throwable: Throwable) {
+    if (log.isDebugEnabled) log.debug(msg, throwable)
+  }
+
+  protected def logTrace(msg: => String, throwable: Throwable) {
+    if (log.isTraceEnabled) log.trace(msg, throwable)
+  }
+
+  protected def logWarning(msg: => String, throwable: Throwable) {
+    if (log.isWarnEnabled) log.warn(msg, throwable)
+  }
+
+  protected def logError(msg: => String, throwable: Throwable) {
+    if (log.isErrorEnabled) log.error(msg, throwable)
+  }
+
+  protected def isTraceEnabled(): Boolean = {
+    log.isTraceEnabled
+  }
+
+  protected def initializeLogIfNecessary(isInterpreter: Boolean): Unit = {
+    if (!Logging.initialized) {
+      Logging.initLock.synchronized {
+        if (!Logging.initialized) {
+          initializeLogging(isInterpreter)
+        }
+      }
+    }
+  }
+
+  private def initializeLogging(isInterpreter: Boolean): Unit = {
+    // Don't use a logger in here, as this is itself occurring during initialization of a logger
+    // If Log4j 1.2 is being used, but is not initialized, load a default properties file
+    val binderClass = StaticLoggerBinder.getSingleton.getLoggerFactoryClassStr
+    // This distinguishes the log4j 1.2 binding, currently
+    // org.slf4j.impl.Log4jLoggerFactory, from the log4j 2.0 binding, currently
+    // org.apache.logging.slf4j.Log4jLoggerFactory
+    val usingLog4j12 = "org.slf4j.impl.Log4jLoggerFactory".equals(binderClass)
+    if (usingLog4j12) {
+      val log4j12Initialized = LogManager.getRootLogger.getAllAppenders.hasMoreElements
+      // scalastyle:off println
+      if (!log4j12Initialized) {
+        val defaultLogProps = "org/apache/spark/log4j-defaults.properties"
+        Option(Utils.getSparkClassLoader.getResource(defaultLogProps)) match {
+          case Some(url) =>
+            PropertyConfigurator.configure(url)
+            System.err.println(s"Using Spark's default log4j profile: $defaultLogProps")
+          case None =>
+            System.err.println(s"Spark was unable to load $defaultLogProps")
+        }
+      }
+
+      if (isInterpreter) {
+        // Use the repl's main class to define the default log level when running the shell,
+        // overriding the root logger's config if they're different.
+        val rootLogger = LogManager.getRootLogger()
+        val replLogger = LogManager.getLogger(logName)
+        val replLevel = Option(replLogger.getLevel()).getOrElse(Level.WARN)
+        if (replLevel != rootLogger.getEffectiveLevel()) {
+          System.err.printf("Setting default log level to \"%s\".\n", replLevel)
+          System.err.println("To adjust logging level use sc.setLogLevel(newLevel).")
+          rootLogger.setLevel(replLevel)
+        }
+      }
+      // scalastyle:on println
+    }
+    Logging.initialized = true
+
+    // Force a call into slf4j to initialize it. Avoids this happening from multiple threads
+    // and triggering this: http://mailman.qos.ch/pipermail/slf4j-dev/2010-April/002956.html
+    log
+  }
+}
+
+private object Logging {
+  @volatile private var initialized = false
+  val initLock = new Object()
+  try {
+    // We use reflection here to handle the case where users remove the
+    // slf4j-to-jul bridge order to route their logs to JUL.
+    val bridgeClass = Utils.classForName("org.slf4j.bridge.SLF4JBridgeHandler")
+    bridgeClass.getMethod("removeHandlersForRootLogger").invoke(null)
+    val installed = bridgeClass.getMethod("isInstalled").invoke(null).asInstanceOf[Boolean]
+    if (!installed) {
+      bridgeClass.getMethod("install").invoke(null)
+    }
+  } catch {
+    case e: ClassNotFoundException => // can't log anything yet so just fail silently
+  }
+}