creating new file

sql/core/src/main/scala/org/apache/spark/sql/execution/streaming/StateVariableInfo.scala

@@ -0,0 +1,71 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.spark.sql.execution.streaming
+
+import org.json4s.{DefaultFormats, Formats, JValue}
+import org.json4s.JsonAST.{JBool, JString}
+import org.json4s.JsonDSL._
+
+// Enum to store the types of state variables we support
+sealed trait StateVariableType
+
+case object ValueState extends StateVariableType
+case object ListState extends StateVariableType
+case object MapState extends StateVariableType
+
+// This object is used to convert the state type from string to the corresponding enum
+object StateVariableType {
+  def withName(name: String): StateVariableType = name match {
+    case "ValueState" => ValueState
+    case "ListState" => ListState
+    case "MapState" => MapState
+    case _ => throw new IllegalArgumentException(s"Unknown state type: $name")
+  }
+}
+
+// This class is used to store the information about a state variable.
+// It is stored in operatorProperties for the TransformWithStateExec operator
+// to be able to validate that the State Variables are the same across restarts.
+class StateVariableInfo(
+   val stateName: String,
+   val stateType: StateVariableType,
+   val isTtlEnabled: Boolean
+ ) {
+  def jsonValue: JValue = {
+    ("stateName" -> JString(stateName)) ~
+      ("stateType" -> JString(stateType.toString)) ~
+      ("isTtlEnabled" -> JBool(isTtlEnabled))
+  }
+}
+
+// This object is used to convert the state variable information
+// from JSON to a list of StateVariableInfo
+object StateVariableInfo {
+  implicit val formats: Formats = DefaultFormats
+  def fromJson(json: Any): List[StateVariableInfo] = {
+    assert(json.isInstanceOf[List[_]], s"Expected List but got ${json.getClass}")
+    val stateVariables = json.asInstanceOf[List[Map[String, Any]]]
+    // Extract each JValue to StateVariableInfo
+    stateVariables.map { stateVariable =>
+      new StateVariableInfo(
+        stateVariable("stateName").asInstanceOf[String],
+        StateVariableType.withName(stateVariable("stateType").asInstanceOf[String]),
+        stateVariable("isTtlEnabled").asInstanceOf[Boolean]
+      )
+    }
+  }
+}

sql/core/src/main/scala/org/apache/spark/sql/execution/streaming/StatefulProcessorHandleImpl.scala

@@ -21,10 +21,6 @@ import java.util.UUID
 
 import scala.collection.mutable
 
-import org.json4s.{DefaultFormats, Formats, JValue}
-import org.json4s.JsonAST.{JBool, JString}
-import org.json4s.JsonDSL._
-
 import org.apache.spark.TaskContext
 import org.apache.spark.internal.Logging
 import org.apache.spark.sql.Encoder
@@ -73,52 +69,6 @@ class QueryInfoImpl(
   }
 }
 
-sealed trait StateVariableType
-
-case object ValueState extends StateVariableType
-case object ListState extends StateVariableType
-case object MapState extends StateVariableType
-
-object StateVariableType {
-  def withName(name: String): StateVariableType = name match {
-    case "ValueState" => ValueState
-    case "ListState" => ListState
-    case "MapState" => MapState
-    case _ => throw new IllegalArgumentException(s"Unknown state type: $name")
-  }
-}
-class StateVariableInfo(
-    val stateName: String,
-    val stateType: StateVariableType,
-    val isTtlEnabled: Boolean
-) {
-  override def toString: String = {
-    s"StateVariableInfo(stateName=$stateName, stateType=$stateType, isTtlEnabled=$isTtlEnabled)"
-  }
-
-  def jsonValue: JValue = {
-    ("stateName" -> JString(stateName)) ~
-      ("stateType" -> JString(stateType.toString)) ~
-      ("isTtlEnabled" -> JBool(isTtlEnabled))
-
-  }
-}
-
-object StateVariableInfo {
-  implicit val formats: Formats = DefaultFormats
-  def fromJson(json: Any): List[StateVariableInfo] = {
-    val stateVariables = json.asInstanceOf[List[Map[String, Any]]]
-    // Extract each JValue to StateVariableInfo
-    stateVariables.map { stateVariable =>
-      new StateVariableInfo(
-        stateVariable("stateName").asInstanceOf[String],
-        StateVariableType.withName(stateVariable("stateType").asInstanceOf[String]),
-        stateVariable("isTtlEnabled").asInstanceOf[Boolean]
-      )
-    }
-  }
-}
-
 /**
  * Class that provides a concrete implementation of a StatefulProcessorHandle. Note that we keep
  * track of valid transitions as various functions are invoked to track object lifecycle.