Skips reading row group information when using task side metadata reading

Author: liancheng

sql/core/src/main/scala/org/apache/spark/sql/parquet/newParquet.scala

@@ -23,12 +23,11 @@ import scala.collection.JavaConversions._
 import scala.util.Try
 
 import com.google.common.base.Objects
-import org.apache.hadoop.fs.{FileStatus, FileSystem, Path}
+import org.apache.hadoop.fs.{FileStatus, Path}
 import org.apache.hadoop.io.Writable
 import org.apache.hadoop.mapreduce._
 import org.apache.hadoop.mapreduce.lib.input.FileInputFormat
 import parquet.filter2.predicate.FilterApi
-import parquet.format.converter.ParquetMetadataConverter
 import parquet.hadoop._
 import parquet.hadoop.metadata.CompressionCodecName
 import parquet.hadoop.util.ContextUtil
@@ -269,7 +268,7 @@ private[sql] class ParquetRelation2(
     val useMetadataCache = sqlContext.getConf(SQLConf.PARQUET_CACHE_METADATA, "true").toBoolean
     conf.set(SQLConf.PARQUET_CACHE_METADATA, useMetadataCache.toString)
 
-    val footers = inputFiles.map(metadataCache.footers)
+    val footers = inputFiles.map(f => metadataCache.footers(f.getPath))
 
     // TODO Stop using `FilteringParquetRowInputFormat` and overriding `getPartition`.
     // After upgrading to Parquet 1.6.0, we should be able to stop caching `FileStatus` objects and
@@ -330,7 +329,7 @@ private[sql] class ParquetRelation2(
     private var commonMetadataStatuses: Array[FileStatus] = _
 
     // Parquet footer cache.
-    var footers: Map[FileStatus, Footer] = _
+    var footers: Map[Path, Footer] = _
 
     // `FileStatus` objects of all data files (Parquet part-files).
     var dataStatuses: Array[FileStatus] = _
@@ -357,11 +356,19 @@ private[sql] class ParquetRelation2(
       commonMetadataStatuses =
         leaves.filter(_.getPath.getName == ParquetFileWriter.PARQUET_COMMON_METADATA_FILE)
 
-      footers = (dataStatuses ++ metadataStatuses ++ commonMetadataStatuses).par.map { f =>
-        val parquetMetadata = ParquetFileReader.readFooter(
-          SparkHadoopUtil.get.conf, f, ParquetMetadataConverter.NO_FILTER)
-        f -> new Footer(f.getPath, parquetMetadata)
-      }.seq.toMap
+      footers = {
+        val conf = SparkHadoopUtil.get.conf
+        val taskSideMetaData = conf.getBoolean(ParquetInputFormat.TASK_SIDE_METADATA, true)
+        val rawFooters = if (shouldMergeSchemas) {
+          ParquetFileReader.readAllFootersInParallel(
+            conf, seqAsJavaList(leaves), taskSideMetaData)
+        } else {
+          ParquetFileReader.readAllFootersInParallelUsingSummaryFiles(
+            conf, seqAsJavaList(leaves), taskSideMetaData)
+        }
+
+        rawFooters.map(footer => footer.getFile -> footer).toMap
+      }
 
       dataSchema = {
         val dataSchema0 =
@@ -428,7 +435,7 @@ private[sql] class ParquetRelation2(
         "No schema defined, " +
           s"and no Parquet data file or summary file found under ${paths.mkString(", ")}.")
 
-      ParquetRelation2.readSchema(filesToTouch.map(footers.apply), sqlContext)
+      ParquetRelation2.readSchema(filesToTouch.map(f => footers.apply(f.getPath)), sqlContext)
     }
   }
 }