[SPARK-41970][SQL][FOLLOWUP] Revert SparkPath changes to FileIndex an…

…d FileRelation

### What changes were proposed in this pull request?
This PR reverts the `SparkPath`changes to `FileIndex` and `FileRelation` because they provided little benefit to Open Source Spark, but are widely used extension points for other open source projects. For the 3.4.0 release we want to preserve this type of binary compatibility.

That said, we reserve the right to make this change for Spark 4.0.

### Why are the changes needed?
Revert `inputFiles: Array[SparkPath]` back to `inputFiles: Array[String]`, with an explicit comment that the strings are expected to be url-encoded.

### Does this PR introduce _any_ user-facing change?
This is to revert an internal interface change.

### How was this patch tested?
Existing unit tests.

Closes #39808 from databricks-david-lewis/SPARK_PATH_FOLLOWUP.

Authored-by: David Lewis <david.lewis@databricks.com>
Signed-off-by: Hyukjin Kwon <gurwls223@apache.org>
(cherry picked from commit 3887e71)
Signed-off-by: Hyukjin Kwon <gurwls223@apache.org>

connector/avro/src/test/scala/org/apache/spark/sql/avro/AvroRowReaderSuite.scala

@@ -18,11 +18,13 @@
 package org.apache.spark.sql.avro
 
 import java.io._
+import java.net.URI
 
 import org.apache.avro.file.DataFileReader
 import org.apache.avro.generic.{GenericDatumReader, GenericRecord}
 import org.apache.avro.mapred.FsInput
 import org.apache.hadoop.conf.Configuration
+import org.apache.hadoop.fs.Path
 
 import org.apache.spark.SparkConf
 import org.apache.spark.sql._
@@ -60,8 +62,10 @@ class AvroRowReaderSuite
         case BatchScanExec(_, f: AvroScan, _, _, _, _, _) => f
       }
       val filePath = fileScan.get.fileIndex.inputFiles(0)
-      val fileSize = new File(filePath.toUri).length
-      val in = new FsInput(filePath.toPath, new Configuration())
+      val fileSize = new File(new URI(filePath)).length
+      // scalastyle:off pathfromuri
+      val in = new FsInput(new Path(new URI(filePath)), new Configuration())
+      // scalastyle:on pathfromuri
       val reader = DataFileReader.openReader(in, new GenericDatumReader[GenericRecord]())
 
       val it = new Iterator[InternalRow] with AvroUtils.RowReader {

sql/core/src/main/scala/org/apache/spark/sql/Dataset.scala

@@ -34,7 +34,6 @@ import org.apache.spark.api.java.function._
 import org.apache.spark.api.python.{PythonRDD, SerDeUtil}
 import org.apache.spark.api.r.RRDD
 import org.apache.spark.broadcast.Broadcast
-import org.apache.spark.paths.SparkPath
 import org.apache.spark.rdd.RDD
 import org.apache.spark.sql.catalyst.{CatalystTypeConverters, InternalRow, QueryPlanningTracker, ScalaReflection, TableIdentifier}
 import org.apache.spark.sql.catalyst.analysis._
@@ -3925,18 +3924,18 @@ class Dataset[T] private[sql](
    * @since 2.0.0
    */
   def inputFiles: Array[String] = {
-    val files: Seq[SparkPath] = queryExecution.optimizedPlan.collect {
+    val files: Seq[String] = queryExecution.optimizedPlan.collect {
       case LogicalRelation(fsBasedRelation: FileRelation, _, _, _) =>
         fsBasedRelation.inputFiles
       case fr: FileRelation =>
         fr.inputFiles
       case r: HiveTableRelation =>
-        r.tableMeta.storage.locationUri.map(SparkPath.fromUri).toArray
+        r.tableMeta.storage.locationUri.map(_.toString).toArray
       case DataSourceV2ScanRelation(DataSourceV2Relation(table: FileTable, _, _, _, _),
           _, _, _, _) =>
         table.fileIndex.inputFiles
     }.flatten
-    files.iterator.map(_.urlEncoded).toSet.toArray
+    files.toSet.toArray
   }
 
   /**

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

@@ -17,14 +17,15 @@
 
 package org.apache.spark.sql.execution
 
-import org.apache.spark.paths.SparkPath
-
 /**
  * An interface for relations that are backed by files.  When a class implements this interface,
  * the list of paths that it returns will be returned to a user who calls `inputPaths` on any
  * DataFrame that queries this relation.
  */
 trait FileRelation {
-  /** Returns the list of files that will be read when scanning this relation. */
-  def inputFiles: Array[SparkPath]
+  /**
+   * Returns the list of files that will be read when scanning this relation.
+   * The strings returned are expected to be url-encoded paths.
+   */
+  def inputFiles: Array[String]
 }

sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/CatalogFileIndex.scala

@@ -22,7 +22,6 @@ import java.net.URI
 import org.apache.hadoop.conf.Configuration
 import org.apache.hadoop.fs.Path
 
-import org.apache.spark.paths.SparkPath
 import org.apache.spark.sql.SparkSession
 import org.apache.spark.sql.catalyst.catalog.{CatalogTable, ExternalCatalogUtils}
 import org.apache.spark.sql.catalyst.expressions._
@@ -95,7 +94,7 @@ class CatalogFileIndex(
     }
   }
 
-  override def inputFiles: Array[SparkPath] = filterPartitions(Nil).inputFiles
+  override def inputFiles: Array[String] = filterPartitions(Nil).inputFiles
 
   // `CatalogFileIndex` may be a member of `HadoopFsRelation`, `HadoopFsRelation` may be a member
   // of `LogicalRelation`, and `LogicalRelation` may be used as the cache key. So we need to

sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/FileIndex.scala

@@ -19,7 +19,6 @@ package org.apache.spark.sql.execution.datasources
 
 import org.apache.hadoop.fs._
 
-import org.apache.spark.paths.SparkPath
 import org.apache.spark.sql.catalyst.InternalRow
 import org.apache.spark.sql.catalyst.expressions._
 import org.apache.spark.sql.types.StructType
@@ -62,8 +61,9 @@ trait FileIndex {
   /**
    * Returns the list of files that will be read when scanning this relation. This call may be
    * very expensive for large tables.
+   * The strings returned are expected to be url-encoded paths.
    */
-  def inputFiles: Array[SparkPath]
+  def inputFiles: Array[String]
 
   /** Refresh any cached file listings */
   def refresh(): Unit

sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/HadoopFsRelation.scala

@@ -17,7 +17,6 @@
 
 package org.apache.spark.sql.execution.datasources
 
-import org.apache.spark.paths.SparkPath
 import org.apache.spark.sql.{SparkSession, SQLContext}
 import org.apache.spark.sql.catalyst.catalog.BucketSpec
 import org.apache.spark.sql.execution.FileRelation
@@ -71,5 +70,5 @@ case class HadoopFsRelation(
   }
 
 
-  override def inputFiles: Array[SparkPath] = location.inputFiles
+  override def inputFiles: Array[String] = location.inputFiles
 }

sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/PartitioningAwareFileIndex.scala

@@ -137,8 +137,8 @@ abstract class PartitioningAwareFileIndex(
   }
 
   /** Returns the list of files that will be read when scanning this relation. */
-  override def inputFiles: Array[SparkPath] =
-    allFiles().map(SparkPath.fromFileStatus).toArray
+  override def inputFiles: Array[String] =
+    allFiles().map(fs => SparkPath.fromFileStatus(fs).urlEncoded).toArray
 
   override def sizeInBytes: Long = allFiles().map(_.getLen).sum