From b59ed06fa4b6f97bd0608780a441eaccd1c064b7 Mon Sep 17 00:00:00 2001
From: Dongjoon Hyun <dongjoon@apache.org>
Date: Thu, 6 Sep 2018 22:47:16 -0700
Subject: [PATCH] simplify

---
 .../execution/datasources/orc/OrcUtils.scala  | 35 ++++++-------------
 1 file changed, 10 insertions(+), 25 deletions(-)

diff --git a/sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/orc/OrcUtils.scala b/sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/orc/OrcUtils.scala
index 5e13c66bb4104..c76f1fe29391b 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/orc/OrcUtils.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/orc/OrcUtils.scala
@@ -17,8 +17,6 @@
 
 package org.apache.spark.sql.execution.datasources.orc
 
-import java.util.Locale
-
 import scala.collection.JavaConverters._
 
 import org.apache.hadoop.conf.Configuration
@@ -29,7 +27,7 @@ import org.apache.spark.SparkException
 import org.apache.spark.deploy.SparkHadoopUtil
 import org.apache.spark.internal.Logging
 import org.apache.spark.sql.SparkSession
-import org.apache.spark.sql.catalyst.analysis.caseSensitiveResolution
+import org.apache.spark.sql.catalyst.analysis.{caseInsensitiveResolution, caseSensitiveResolution}
 import org.apache.spark.sql.catalyst.parser.CatalystSqlParser
 import org.apache.spark.sql.types._
 
@@ -117,29 +115,16 @@ object OrcUtils extends Logging {
           }
         })
       } else {
-        if (isCaseSensitive) {
-          Some(requiredSchema.fieldNames.map { name =>
-            orcFieldNames.indexWhere(caseSensitiveResolution(_, name))
-          })
-        } else {
-          // Do case-insensitive resolution only if in case-insensitive mode
-          val caseInsensitiveOrcFieldMap =
-            orcFieldNames.zipWithIndex.groupBy(_._1.toLowerCase(Locale.ROOT))
-          Some(requiredSchema.fieldNames.map { requiredFieldName =>
-            caseInsensitiveOrcFieldMap
-              .get(requiredFieldName.toLowerCase(Locale.ROOT))
-              .map { matchedOrcFields =>
-                if (matchedOrcFields.size > 1) {
-                  // Need to fail if there is ambiguity, i.e. more than one field is matched.
-                  val matchedOrcFieldsString = matchedOrcFields.map(_._1).mkString("[", ", ", "]")
-                  throw new RuntimeException(s"""Found duplicate field(s) "$requiredFieldName": """
-                    + s"$matchedOrcFieldsString in case-insensitive mode")
-                } else {
-                  matchedOrcFields.head._2
-                }
-            }.getOrElse(-1)
-          })
+        val resolver = if (isCaseSensitive) caseSensitiveResolution else caseInsensitiveResolution
+        // Need to fail if there is ambiguity, i.e. more than one field is matched.
+        requiredSchema.fieldNames.foreach { requiredFieldName =>
+          val matchedOrcFields = orcFieldNames.filter(resolver(_, requiredFieldName))
+          if (matchedOrcFields.size > 1) {
+            throw new RuntimeException(s"""Found duplicate field(s) "$requiredFieldName": """ +
+              s"${matchedOrcFields.mkString("[", ", ", "]")} in case-insensitive mode")
+          }
         }
+        Some(requiredSchema.fieldNames.map { name => orcFieldNames.indexWhere(resolver(_, name)) })
       }
     }
   }