Revert "[SPARK-24882][SQL] improve data source v2 API"

This reverts commit e754887.

Author: cloud-fan

external/kafka-0-10-sql/src/main/scala/org/apache/spark/sql/kafka010/KafkaContinuousReadSupport.scala renamed to external/kafka-0-10-sql/src/main/scala/org/apache/spark/sql/kafka010/KafkaContinuousReader.scala

@@ -25,15 +25,16 @@ import org.apache.kafka.common.TopicPartition
 
 import org.apache.spark.TaskContext
 import org.apache.spark.internal.Logging
+import org.apache.spark.sql.SparkSession
 import org.apache.spark.sql.catalyst.InternalRow
 import org.apache.spark.sql.catalyst.expressions.UnsafeRow
 import org.apache.spark.sql.kafka010.KafkaSourceProvider.{INSTRUCTION_FOR_FAIL_ON_DATA_LOSS_FALSE, INSTRUCTION_FOR_FAIL_ON_DATA_LOSS_TRUE}
 import org.apache.spark.sql.sources.v2.reader._
-import org.apache.spark.sql.sources.v2.reader.streaming._
+import org.apache.spark.sql.sources.v2.reader.streaming.{ContinuousInputPartitionReader, ContinuousReader, Offset, PartitionOffset}
 import org.apache.spark.sql.types.StructType
 
 /**
- * A [[ContinuousReadSupport]] for data from kafka.
+ * A [[ContinuousReader]] for data from kafka.
  *
  * @param offsetReader  a reader used to get kafka offsets. Note that the actual data will be
  *                      read by per-task consumers generated later.
@@ -46,49 +47,70 @@ import org.apache.spark.sql.types.StructType
  *                       scenarios, where some offsets after the specified initial ones can't be
  *                       properly read.
  */
-class KafkaContinuousReadSupport(
+class KafkaContinuousReader(
     offsetReader: KafkaOffsetReader,
     kafkaParams: ju.Map[String, Object],
     sourceOptions: Map[String, String],
     metadataPath: String,
     initialOffsets: KafkaOffsetRangeLimit,
     failOnDataLoss: Boolean)
-  extends ContinuousReadSupport with Logging {
+  extends ContinuousReader with Logging {
+
+  private lazy val session = SparkSession.getActiveSession.get
+  private lazy val sc = session.sparkContext
 
   private val pollTimeoutMs = sourceOptions.getOrElse("kafkaConsumer.pollTimeoutMs", "512").toLong
 
-  override def initialOffset(): Offset = {
-    val offsets = initialOffsets match {
-      case EarliestOffsetRangeLimit => KafkaSourceOffset(offsetReader.fetchEarliestOffsets())
-      case LatestOffsetRangeLimit => KafkaSourceOffset(offsetReader.fetchLatestOffsets())
-      case SpecificOffsetRangeLimit(p) => offsetReader.fetchSpecificOffsets(p, reportDataLoss)
-    }
-    logInfo(s"Initial offsets: $offsets")
-    offsets
-  }
+  // Initialized when creating reader factories. If this diverges from the partitions at the latest
+  // offsets, we need to reconfigure.
+  // Exposed outside this object only for unit tests.
+  @volatile private[sql] var knownPartitions: Set[TopicPartition] = _
 
-  override def fullSchema(): StructType = KafkaOffsetReader.kafkaSchema
+  override def readSchema: StructType = KafkaOffsetReader.kafkaSchema
 
-  override def newScanConfigBuilder(start: Offset): ScanConfigBuilder = {
-    new KafkaContinuousScanConfigBuilder(fullSchema(), start, offsetReader, reportDataLoss)
+  private var offset: Offset = _
+  override def setStartOffset(start: ju.Optional[Offset]): Unit = {
+    offset = start.orElse {
+      val offsets = initialOffsets match {
+        case EarliestOffsetRangeLimit => KafkaSourceOffset(offsetReader.fetchEarliestOffsets())
+        case LatestOffsetRangeLimit => KafkaSourceOffset(offsetReader.fetchLatestOffsets())
+        case SpecificOffsetRangeLimit(p) => offsetReader.fetchSpecificOffsets(p, reportDataLoss)
+      }
+      logInfo(s"Initial offsets: $offsets")
+      offsets
+    }
   }
 
+  override def getStartOffset(): Offset = offset
+
   override def deserializeOffset(json: String): Offset = {
     KafkaSourceOffset(JsonUtils.partitionOffsets(json))
   }
 
-  override def planInputPartitions(config: ScanConfig): Array[InputPartition] = {
-    val startOffsets = config.asInstanceOf[KafkaContinuousScanConfig].startOffsets
+  override def planInputPartitions(): ju.List[InputPartition[InternalRow]] = {
+    import scala.collection.JavaConverters._
+
+    val oldStartPartitionOffsets = KafkaSourceOffset.getPartitionOffsets(offset)
+
+    val currentPartitionSet = offsetReader.fetchEarliestOffsets().keySet
+    val newPartitions = currentPartitionSet.diff(oldStartPartitionOffsets.keySet)
+    val newPartitionOffsets = offsetReader.fetchEarliestOffsets(newPartitions.toSeq)
+
+    val deletedPartitions = oldStartPartitionOffsets.keySet.diff(currentPartitionSet)
+    if (deletedPartitions.nonEmpty) {
+      reportDataLoss(s"Some partitions were deleted: $deletedPartitions")
+    }
+
+    val startOffsets = newPartitionOffsets ++
+      oldStartPartitionOffsets.filterKeys(!deletedPartitions.contains(_))
+    knownPartitions = startOffsets.keySet
+
     startOffsets.toSeq.map {
       case (topicPartition, start) =>
         KafkaContinuousInputPartition(
-          topicPartition, start, kafkaParams, pollTimeoutMs, failOnDataLoss)
-    }.toArray
-  }
-
-  override def createContinuousReaderFactory(
-      config: ScanConfig): ContinuousPartitionReaderFactory = {
-    KafkaContinuousReaderFactory
+          topicPartition, start, kafkaParams, pollTimeoutMs, failOnDataLoss
+        ): InputPartition[InternalRow]
+    }.asJava
   }
 
   /** Stop this source and free any resources it has allocated. */
@@ -105,9 +127,8 @@ class KafkaContinuousReadSupport(
     KafkaSourceOffset(mergedMap)
   }
 
-  override def needsReconfiguration(config: ScanConfig): Boolean = {
-    val knownPartitions = config.asInstanceOf[KafkaContinuousScanConfig].knownPartitions
-    offsetReader.fetchLatestOffsets().keySet != knownPartitions
+  override def needsReconfiguration(): Boolean = {
+    knownPartitions != null && offsetReader.fetchLatestOffsets().keySet != knownPartitions
   }
 
   override def toString(): String = s"KafkaSource[$offsetReader]"
@@ -141,51 +162,23 @@ case class KafkaContinuousInputPartition(
     startOffset: Long,
     kafkaParams: ju.Map[String, Object],
     pollTimeoutMs: Long,
-    failOnDataLoss: Boolean) extends InputPartition
-
-object KafkaContinuousReaderFactory extends ContinuousPartitionReaderFactory {
-  override def createReader(partition: InputPartition): ContinuousPartitionReader[InternalRow] = {
-    val p = partition.asInstanceOf[KafkaContinuousInputPartition]
-    new KafkaContinuousPartitionReader(
-      p.topicPartition, p.startOffset, p.kafkaParams, p.pollTimeoutMs, p.failOnDataLoss)
+    failOnDataLoss: Boolean) extends ContinuousInputPartition[InternalRow] {
+
+  override def createContinuousReader(
+      offset: PartitionOffset): InputPartitionReader[InternalRow] = {
+    val kafkaOffset = offset.asInstanceOf[KafkaSourcePartitionOffset]
+    require(kafkaOffset.topicPartition == topicPartition,
+      s"Expected topicPartition: $topicPartition, but got: ${kafkaOffset.topicPartition}")
+    new KafkaContinuousInputPartitionReader(
+      topicPartition, kafkaOffset.partitionOffset, kafkaParams, pollTimeoutMs, failOnDataLoss)
   }
-}
-
-class KafkaContinuousScanConfigBuilder(
-    schema: StructType,
-    startOffset: Offset,
-    offsetReader: KafkaOffsetReader,
-    reportDataLoss: String => Unit)
-  extends ScanConfigBuilder {
-
-  override def build(): ScanConfig = {
-    val oldStartPartitionOffsets = KafkaSourceOffset.getPartitionOffsets(startOffset)
-
-    val currentPartitionSet = offsetReader.fetchEarliestOffsets().keySet
-    val newPartitions = currentPartitionSet.diff(oldStartPartitionOffsets.keySet)
-    val newPartitionOffsets = offsetReader.fetchEarliestOffsets(newPartitions.toSeq)
 
-    val deletedPartitions = oldStartPartitionOffsets.keySet.diff(currentPartitionSet)
-    if (deletedPartitions.nonEmpty) {
-      reportDataLoss(s"Some partitions were deleted: $deletedPartitions")
-    }
-
-    val startOffsets = newPartitionOffsets ++
-      oldStartPartitionOffsets.filterKeys(!deletedPartitions.contains(_))
-    KafkaContinuousScanConfig(schema, startOffsets)
+  override def createPartitionReader(): KafkaContinuousInputPartitionReader = {
+    new KafkaContinuousInputPartitionReader(
+      topicPartition, startOffset, kafkaParams, pollTimeoutMs, failOnDataLoss)
   }
 }
 
-case class KafkaContinuousScanConfig(
-    readSchema: StructType,
-    startOffsets: Map[TopicPartition, Long])
-  extends ScanConfig {
-
-  // Created when building the scan config builder. If this diverges from the partitions at the
-  // latest offsets, we need to reconfigure the kafka read support.
-  def knownPartitions: Set[TopicPartition] = startOffsets.keySet
-}
-
 /**
  * A per-task data reader for continuous Kafka processing.
  *
@@ -196,12 +189,12 @@ case class KafkaContinuousScanConfig(
  * @param failOnDataLoss Flag indicating whether data reader should fail if some offsets
  *                       are skipped.
  */
-class KafkaContinuousPartitionReader(
+class KafkaContinuousInputPartitionReader(
     topicPartition: TopicPartition,
     startOffset: Long,
     kafkaParams: ju.Map[String, Object],
     pollTimeoutMs: Long,
-    failOnDataLoss: Boolean) extends ContinuousPartitionReader[InternalRow] {
+    failOnDataLoss: Boolean) extends ContinuousInputPartitionReader[InternalRow] {
   private val consumer = KafkaDataConsumer.acquire(topicPartition, kafkaParams, useCache = false)
   private val converter = new KafkaRecordToUnsafeRowConverter
 

external/kafka-0-10-sql/src/main/scala/org/apache/spark/sql/kafka010/KafkaMicroBatchReadSupport.scala renamed to external/kafka-0-10-sql/src/main/scala/org/apache/spark/sql/kafka010/KafkaMicroBatchReader.scala

@@ -21,6 +21,8 @@ import java.{util => ju}
 import java.io._
 import java.nio.charset.StandardCharsets
 
+import scala.collection.JavaConverters._
+
 import org.apache.commons.io.IOUtils
 
 import org.apache.spark.SparkEnv
@@ -29,17 +31,16 @@ import org.apache.spark.scheduler.ExecutorCacheTaskLocation
 import org.apache.spark.sql.SparkSession
 import org.apache.spark.sql.catalyst.InternalRow
 import org.apache.spark.sql.catalyst.expressions.UnsafeRow
-import org.apache.spark.sql.execution.streaming.{HDFSMetadataLog, SerializedOffset, SimpleStreamingScanConfig, SimpleStreamingScanConfigBuilder}
-import org.apache.spark.sql.execution.streaming.sources.RateControlMicroBatchReadSupport
+import org.apache.spark.sql.execution.streaming.{HDFSMetadataLog, SerializedOffset}
 import org.apache.spark.sql.kafka010.KafkaSourceProvider.{INSTRUCTION_FOR_FAIL_ON_DATA_LOSS_FALSE, INSTRUCTION_FOR_FAIL_ON_DATA_LOSS_TRUE}
 import org.apache.spark.sql.sources.v2.DataSourceOptions
-import org.apache.spark.sql.sources.v2.reader._
-import org.apache.spark.sql.sources.v2.reader.streaming.{MicroBatchReadSupport, Offset}
+import org.apache.spark.sql.sources.v2.reader.{InputPartition, InputPartitionReader}
+import org.apache.spark.sql.sources.v2.reader.streaming.{MicroBatchReader, Offset}
 import org.apache.spark.sql.types.StructType
 import org.apache.spark.util.UninterruptibleThread
 
 /**
- * A [[MicroBatchReadSupport]] that reads data from Kafka.
+ * A [[MicroBatchReader]] that reads data from Kafka.
  *
  * The [[KafkaSourceOffset]] is the custom [[Offset]] defined for this source that contains
  * a map of TopicPartition -> offset. Note that this offset is 1 + (available offset). For
@@ -54,13 +55,17 @@ import org.apache.spark.util.UninterruptibleThread
  * To avoid this issue, you should make sure stopping the query before stopping the Kafka brokers
  * and not use wrong broker addresses.
  */
-private[kafka010] class KafkaMicroBatchReadSupport(
+private[kafka010] class KafkaMicroBatchReader(
     kafkaOffsetReader: KafkaOffsetReader,
     executorKafkaParams: ju.Map[String, Object],
     options: DataSourceOptions,
     metadataPath: String,
     startingOffsets: KafkaOffsetRangeLimit,
-    failOnDataLoss: Boolean) extends RateControlMicroBatchReadSupport with Logging {
+    failOnDataLoss: Boolean)
+  extends MicroBatchReader with Logging {
+
+  private var startPartitionOffsets: PartitionOffsetMap = _
+  private var endPartitionOffsets: PartitionOffsetMap = _
 
   private val pollTimeoutMs = options.getLong(
     "kafkaConsumer.pollTimeoutMs",
@@ -70,40 +75,34 @@ private[kafka010] class KafkaMicroBatchReadSupport(
     Option(options.get("maxOffsetsPerTrigger").orElse(null)).map(_.toLong)
 
   private val rangeCalculator = KafkaOffsetRangeCalculator(options)
-
-  private var endPartitionOffsets: KafkaSourceOffset = _
-
   /**
    * Lazily initialize `initialPartitionOffsets` to make sure that `KafkaConsumer.poll` is only
    * called in StreamExecutionThread. Otherwise, interrupting a thread while running
    * `KafkaConsumer.poll` may hang forever (KAFKA-1894).
    */
-  override def initialOffset(): Offset = {
-    KafkaSourceOffset(getOrCreateInitialPartitionOffsets())
-  }
-
-  override def latestOffset(start: Offset): Offset = {
-    val startPartitionOffsets = start.asInstanceOf[KafkaSourceOffset].partitionToOffsets
-    val latestPartitionOffsets = kafkaOffsetReader.fetchLatestOffsets()
-    endPartitionOffsets = KafkaSourceOffset(maxOffsetsPerTrigger.map { maxOffsets =>
-      rateLimit(maxOffsets, startPartitionOffsets, latestPartitionOffsets)
-    }.getOrElse {
-      latestPartitionOffsets
-    })
-    endPartitionOffsets
-  }
-
-  override def fullSchema(): StructType = KafkaOffsetReader.kafkaSchema
-
-  override def newScanConfigBuilder(start: Offset, end: Offset): ScanConfigBuilder = {
-    new SimpleStreamingScanConfigBuilder(fullSchema(), start, Some(end))
+  private lazy val initialPartitionOffsets = getOrCreateInitialPartitionOffsets()
+
+  override def setOffsetRange(start: ju.Optional[Offset], end: ju.Optional[Offset]): Unit = {
+    // Make sure initialPartitionOffsets is initialized
+    initialPartitionOffsets
+
+    startPartitionOffsets = Option(start.orElse(null))
+        .map(_.asInstanceOf[KafkaSourceOffset].partitionToOffsets)
+        .getOrElse(initialPartitionOffsets)
+
+    endPartitionOffsets = Option(end.orElse(null))
+        .map(_.asInstanceOf[KafkaSourceOffset].partitionToOffsets)
+        .getOrElse {
+          val latestPartitionOffsets = kafkaOffsetReader.fetchLatestOffsets()
+          maxOffsetsPerTrigger.map { maxOffsets =>
+            rateLimit(maxOffsets, startPartitionOffsets, latestPartitionOffsets)
+          }.getOrElse {
+            latestPartitionOffsets
+          }
+        }
   }
 
-  override def planInputPartitions(config: ScanConfig): Array[InputPartition] = {
-    val sc = config.asInstanceOf[SimpleStreamingScanConfig]
-    val startPartitionOffsets = sc.start.asInstanceOf[KafkaSourceOffset].partitionToOffsets
-    val endPartitionOffsets = sc.end.get.asInstanceOf[KafkaSourceOffset].partitionToOffsets
-
+  override def planInputPartitions(): ju.List[InputPartition[InternalRow]] = {
     // Find the new partitions, and get their earliest offsets
     val newPartitions = endPartitionOffsets.keySet.diff(startPartitionOffsets.keySet)
     val newPartitionInitialOffsets = kafkaOffsetReader.fetchEarliestOffsets(newPartitions.toSeq)
@@ -145,19 +144,26 @@ private[kafka010] class KafkaMicroBatchReadSupport(
 
     // Generate factories based on the offset ranges
     offsetRanges.map { range =>
-      KafkaMicroBatchInputPartition(
-        range, executorKafkaParams, pollTimeoutMs, failOnDataLoss, reuseKafkaConsumer)
-    }.toArray
+      new KafkaMicroBatchInputPartition(
+        range, executorKafkaParams, pollTimeoutMs, failOnDataLoss, reuseKafkaConsumer
+      ): InputPartition[InternalRow]
+    }.asJava
+  }
+
+  override def getStartOffset: Offset = {
+    KafkaSourceOffset(startPartitionOffsets)
   }
 
-  override def createReaderFactory(config: ScanConfig): PartitionReaderFactory = {
-    KafkaMicroBatchReaderFactory
+  override def getEndOffset: Offset = {
+    KafkaSourceOffset(endPartitionOffsets)
   }
 
   override def deserializeOffset(json: String): Offset = {
     KafkaSourceOffset(JsonUtils.partitionOffsets(json))
   }
 
+  override def readSchema(): StructType = KafkaOffsetReader.kafkaSchema
+
   override def commit(end: Offset): Unit = {}
 
   override def stop(): Unit = {
@@ -300,23 +306,22 @@ private[kafka010] case class KafkaMicroBatchInputPartition(
     executorKafkaParams: ju.Map[String, Object],
     pollTimeoutMs: Long,
     failOnDataLoss: Boolean,
-    reuseKafkaConsumer: Boolean) extends InputPartition
+    reuseKafkaConsumer: Boolean) extends InputPartition[InternalRow] {
 
-private[kafka010] object KafkaMicroBatchReaderFactory extends PartitionReaderFactory {
-  override def createReader(partition: InputPartition): PartitionReader[InternalRow] = {
-    val p = partition.asInstanceOf[KafkaMicroBatchInputPartition]
-    KafkaMicroBatchPartitionReader(p.offsetRange, p.executorKafkaParams, p.pollTimeoutMs,
-      p.failOnDataLoss, p.reuseKafkaConsumer)
-  }
+  override def preferredLocations(): Array[String] = offsetRange.preferredLoc.toArray
+
+  override def createPartitionReader(): InputPartitionReader[InternalRow] =
+    new KafkaMicroBatchInputPartitionReader(offsetRange, executorKafkaParams, pollTimeoutMs,
+      failOnDataLoss, reuseKafkaConsumer)
 }
 
-/** A [[PartitionReader]] for reading Kafka data in a micro-batch streaming query. */
-private[kafka010] case class KafkaMicroBatchPartitionReader(
+/** A [[InputPartitionReader]] for reading Kafka data in a micro-batch streaming query. */
+private[kafka010] case class KafkaMicroBatchInputPartitionReader(
     offsetRange: KafkaOffsetRange,
     executorKafkaParams: ju.Map[String, Object],
     pollTimeoutMs: Long,
     failOnDataLoss: Boolean,
-    reuseKafkaConsumer: Boolean) extends PartitionReader[InternalRow] with Logging {
+    reuseKafkaConsumer: Boolean) extends InputPartitionReader[InternalRow] with Logging {
 
   private val consumer = KafkaDataConsumer.acquire(
     offsetRange.topicPartition, executorKafkaParams, reuseKafkaConsumer)