use pattern match to dump file scan metadata

Author: LantaoJin

sql/core/src/main/scala/org/apache/spark/sql/execution/SparkPlan.scala

@@ -73,11 +73,6 @@ abstract class SparkPlan extends QueryPlan[SparkPlan] with Logging with Serializ
     super.makeCopy(newArgs)
   }
 
-  /**
-   * @return Metadata that describes more details of this SparkPlan.
-   */
-  def metadata: Map[String, String] = Map.empty
-
   /**
    * @return All metrics containing metrics of this SparkPlan.
    */

sql/core/src/main/scala/org/apache/spark/sql/execution/SparkPlanInfo.scala

@@ -17,8 +17,6 @@
 
 package org.apache.spark.sql.execution
 
-import com.fasterxml.jackson.annotation.JsonIgnoreProperties
-
 import org.apache.spark.annotation.DeveloperApi
 import org.apache.spark.sql.execution.exchange.ReusedExchangeExec
 import org.apache.spark.sql.execution.metric.SQLMetricInfo
@@ -59,7 +57,12 @@ private[execution] object SparkPlanInfo {
       new SQLMetricInfo(metric.name.getOrElse(key), metric.id, metric.metricType)
     }
 
+    // dump the file scan metadata (e.g file path) to event log
+    val metadata = plan match {
+      case fileScan: FileSourceScanExec => fileScan.metadata
+      case _ => Map[String, String]()
+    }
     new SparkPlanInfo(plan.nodeName, plan.simpleString, children.map(fromSparkPlan),
-      plan.metadata, metrics)
+      metadata, metrics)
   }
 }