[Spark][Version Checksum] Clean up stale checksum files during cleanup (delta-io#4509)

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- [X] Spark
- [ ] Standalone
- [ ] Flink
- [ ] Kernel
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## Description

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Fixes Metadata Cleanup so that checksum files are also considered for
removal. Resolves delta-io#4475

## How was this patch tested?

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Updated DeltaRetentionSuite

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Author: dhruvarya-db

spark/src/main/scala/org/apache/spark/sql/delta/MetadataCleanup.scala

@@ -149,8 +149,8 @@ trait MetadataCleanup extends DeltaLogging {
   }
 
   /** Helper function for getting the version of a checkpoint or a commit. */
-  def getDeltaFileOrCheckpointVersion(filePath: Path): Long = {
-    require(isCheckpointFile(filePath) || isDeltaFile(filePath))
+  def getDeltaFileChecksumOrCheckpointVersion(filePath: Path): Long = {
+    require(isCheckpointFile(filePath) || isDeltaFile(filePath) || isChecksumFile(filePath))
     getFileVersion(filePath)
   }
 
@@ -165,10 +165,10 @@ trait MetadataCleanup extends DeltaLogging {
     if (latestCheckpoint.isEmpty) return Iterator.empty
     val threshold = latestCheckpoint.get.version - 1L
     val files = store.listFrom(listingPrefix(logPath, 0), newDeltaHadoopConf())
-      .filter(f => isCheckpointFile(f) || isDeltaFile(f))
+      .filter(f => isCheckpointFile(f) || isDeltaFile(f) || isChecksumFile(f))
 
     new BufferingLogDeletionIterator(
-      files, fileCutOffTime, threshold, getDeltaFileOrCheckpointVersion)
+      files, fileCutOffTime, threshold, getDeltaFileChecksumOrCheckpointVersion)
   }
 
   protected def checkpointExistsAtCleanupBoundary(deltaLog: DeltaLog, version: Long): Boolean = {

spark/src/test/scala/org/apache/spark/sql/delta/DeltaRetentionSuite.scala

@@ -44,7 +44,8 @@ class DeltaRetentionSuite extends QueryTest
   protected override def sparkConf: SparkConf = super.sparkConf
 
   override protected def getLogFiles(dir: File): Seq[File] =
-    getDeltaFiles(dir) ++ getUnbackfilledDeltaFiles(dir) ++ getCheckpointFiles(dir)
+    getDeltaFiles(dir) ++ getUnbackfilledDeltaFiles(dir) ++ getCheckpointFiles(dir)++
+      getCrcFiles(dir)
 
   test("delete expired logs") {
     withTempDir { tempDir =>
@@ -80,7 +81,7 @@ class DeltaRetentionSuite extends QueryTest
 
       log.checkpoint()
 
-      val expectedFiles = Seq("04.json", "04.checkpoint.parquet")
+      val expectedFiles = Seq("04.json", "04.checkpoint.parquet", "04.crc")
       // after checkpointing, the files should be cleared
       log.cleanUpExpiredLogs(log.snapshot)
       val afterCleanup = getLogFiles(logPath)
@@ -262,7 +263,7 @@ class DeltaRetentionSuite extends QueryTest
     }
   }
 
-  test("the checkpoint file for version 0 should be cleaned") {
+  test("the checkpoint and checksum for version 0 should be cleaned") {
     withTempDir { tempDir =>
       val clock = new ManualClock(getStartTimeForRetentionTest)
       val log = DeltaLog.forTable(spark, new Path(tempDir.getCanonicalPath), clock)
@@ -289,6 +290,9 @@ class DeltaRetentionSuite extends QueryTest
       initialFiles.foreach { file =>
         assert(!afterCleanup.contains(file))
       }
+      compareVersions(getCrcVersions(logPath), "checksum", Set(1))
+      compareVersions(getFileVersions(getDeltaFiles(logPath)), "commit", Set(1))
+      compareVersions(getFileVersions(getCheckpointFiles(logPath)), "checkpoint", Set(1))
     }
   }
 

spark/src/test/scala/org/apache/spark/sql/delta/DeltaRetentionSuiteBase.scala

@@ -89,6 +89,16 @@ trait DeltaRetentionSuiteBase extends QueryTest
     files.map(f => f.getName()).map(s => s.substring(0, s.indexOf(".")).toLong).toSet
   }
 
+  protected def getCrcFiles(dir: File): Seq[File] =
+    dir.listFiles().filter(f => FileNames.isChecksumFile(new Path(f.getCanonicalPath)))
+
+  protected def getCrcVersions(dir: File): Set[Long] =
+    getFileVersions(getCrcFiles(dir))
+
+  protected def getDeltaAndCrcFiles(dir: File): Seq[File] =
+    getDeltaFiles(dir) ++ getCrcFiles(dir)
+
+
   protected def getDeltaVersions(dir: File): Set[Long] = {
     val backfilledDeltaVersions = getFileVersions(getDeltaFiles(dir))
     val unbackfilledDeltaVersions = getUnbackfilledDeltaVersions(dir)