[SPARK-40432][SS][PYTHON] Introduce GroupStateImpl and GroupStateTime…

…out in PySpark

### What changes were proposed in this pull request?

This PR introduces GroupStateImpl and GroupStateTimeout in PySpark, and updates Scala codebase to support convenient conversion between PySpark implementation and Scala implementation.

Co-authored with HyukjinKwon .

This is a breakdown PR of apache#37863.

### Why are the changes needed?

This change will be leveraged in SPARK-40434.

### Does this PR introduce _any_ user-facing change?

No.

### How was this patch tested?

N/A. We will make sure test suites are constructed via E2E manner under SPARK-40431.

Closes apache#37889 from HeartSaVioR/SPARK-40432.

Lead-authored-by: Jungtaek Lim <[email protected]>
Co-authored-by: Hyukjin Kwon <[email protected]>
Signed-off-by: Jungtaek Lim <[email protected]>

core/src/main/scala/org/apache/spark/util/Utils.scala

@@ -3051,7 +3051,7 @@ private[spark] object Utils extends Logging {
    * and return the trailing part after the last dollar sign in the middle
    */
   @scala.annotation.tailrec
-  private def stripDollars(s: String): String = {
+  def stripDollars(s: String): String = {
     val lastDollarIndex = s.lastIndexOf('$')
     if (lastDollarIndex < s.length - 1) {
       // The last char is not a dollar sign

python/pyspark/sql/streaming/state.py

@@ -0,0 +1,192 @@
+#
+# 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.
+#
+import datetime
+import json
+from typing import Tuple, Optional
+
+from pyspark.sql.types import DateType, Row, StructType
+
+__all__ = ["GroupStateImpl", "GroupStateTimeout"]
+
+
+class GroupStateTimeout:
+    NoTimeout: str = "NoTimeout"
+    ProcessingTimeTimeout: str = "ProcessingTimeTimeout"
+    EventTimeTimeout: str = "EventTimeTimeout"
+
+
+class GroupStateImpl:
+    NO_TIMESTAMP: int = -1
+
+    def __init__(
+        self,
+        # JVM Constructor
+        optionalValue: Row,
+        batchProcessingTimeMs: int,
+        eventTimeWatermarkMs: int,
+        timeoutConf: str,
+        hasTimedOut: bool,
+        watermarkPresent: bool,
+        # JVM internal state.
+        defined: bool,
+        updated: bool,
+        removed: bool,
+        timeoutTimestamp: int,
+        # Python internal state.
+        keyAsUnsafe: bytes,
+        valueSchema: StructType,
+    ) -> None:
+        self._keyAsUnsafe = keyAsUnsafe
+        self._value = optionalValue
+        self._batch_processing_time_ms = batchProcessingTimeMs
+        self._event_time_watermark_ms = eventTimeWatermarkMs
+
+        assert timeoutConf in [
+            GroupStateTimeout.NoTimeout,
+            GroupStateTimeout.ProcessingTimeTimeout,
+            GroupStateTimeout.EventTimeTimeout,
+        ]
+        self._timeout_conf = timeoutConf
+
+        self._has_timed_out = hasTimedOut
+        self._watermark_present = watermarkPresent
+
+        self._defined = defined
+        self._updated = updated
+        self._removed = removed
+        self._timeout_timestamp = timeoutTimestamp
+        # Python internal state.
+        self._old_timeout_timestamp = timeoutTimestamp
+
+        self._value_schema = valueSchema
+
+    @property
+    def exists(self) -> bool:
+        return self._defined
+
+    @property
+    def get(self) -> Tuple:
+        if self.exists:
+            return tuple(self._value)
+        else:
+            raise ValueError("State is either not defined or has already been removed")
+
+    @property
+    def getOption(self) -> Optional[Tuple]:
+        if self.exists:
+            return tuple(self._value)
+        else:
+            return None
+
+    @property
+    def hasTimedOut(self) -> bool:
+        return self._has_timed_out
+
+    # NOTE: this function is only available to PySpark implementation due to underlying
+    # implementation, do not port to Scala implementation!
+    @property
+    def oldTimeoutTimestamp(self) -> int:
+        return self._old_timeout_timestamp
+
+    def update(self, newValue: Tuple) -> None:
+        if newValue is None:
+            raise ValueError("'None' is not a valid state value")
+
+        self._value = Row(*newValue)
+        self._defined = True
+        self._updated = True
+        self._removed = False
+
+    def remove(self) -> None:
+        self._defined = False
+        self._updated = False
+        self._removed = True
+
+    def setTimeoutDuration(self, durationMs: int) -> None:
+        if isinstance(durationMs, str):
+            # TODO(SPARK-40437): Support string representation of durationMs.
+            raise ValueError("durationMs should be int but get :%s" % type(durationMs))
+
+        if self._timeout_conf != GroupStateTimeout.ProcessingTimeTimeout:
+            raise RuntimeError(
+                "Cannot set timeout duration without enabling processing time timeout in "
+                "applyInPandasWithState"
+            )
+
+        if durationMs <= 0:
+            raise ValueError("Timeout duration must be positive")
+        self._timeout_timestamp = durationMs + self._batch_processing_time_ms
+
+    # TODO(SPARK-40438): Implement additionalDuration parameter.
+    def setTimeoutTimestamp(self, timestampMs: int) -> None:
+        if self._timeout_conf != GroupStateTimeout.EventTimeTimeout:
+            raise RuntimeError(
+                "Cannot set timeout duration without enabling processing time timeout in "
+                "applyInPandasWithState"
+            )
+
+        if isinstance(timestampMs, datetime.datetime):
+            timestampMs = DateType().toInternal(timestampMs)
+
+        if timestampMs <= 0:
+            raise ValueError("Timeout timestamp must be positive")
+
+        if (
+            self._event_time_watermark_ms != GroupStateImpl.NO_TIMESTAMP
+            and timestampMs < self._event_time_watermark_ms
+        ):
+            raise ValueError(
+                "Timeout timestamp (%s) cannot be earlier than the "
+                "current watermark (%s)" % (timestampMs, self._event_time_watermark_ms)
+            )
+
+        self._timeout_timestamp = timestampMs
+
+    def getCurrentWatermarkMs(self) -> int:
+        if not self._watermark_present:
+            raise RuntimeError(
+                "Cannot get event time watermark timestamp without setting watermark before "
+                "applyInPandasWithState"
+            )
+        return self._event_time_watermark_ms
+
+    def getCurrentProcessingTimeMs(self) -> int:
+        return self._batch_processing_time_ms
+
+    def __str__(self) -> str:
+        if self.exists:
+            return "GroupState(%s)" % (self.get,)
+        else:
+            return "GroupState(<undefined>)"
+
+    def json(self) -> str:
+        return json.dumps(
+            {
+                # Constructor
+                "optionalValue": None,  # Note that optionalValue will be manually serialized.
+                "batchProcessingTimeMs": self._batch_processing_time_ms,
+                "eventTimeWatermarkMs": self._event_time_watermark_ms,
+                "timeoutConf": self._timeout_conf,
+                "hasTimedOut": self._has_timed_out,
+                "watermarkPresent": self._watermark_present,
+                # JVM internal state.
+                "defined": self._defined,
+                "updated": self._updated,
+                "removed": self._removed,
+                "timeoutTimestamp": self._timeout_timestamp,
+            }
+        )

sql/catalyst/src/main/java/org/apache/spark/sql/streaming/GroupStateTimeout.java

@@ -32,6 +32,10 @@
 @Experimental
 @Evolving
 public class GroupStateTimeout {
+  // NOTE: if you're adding new type of timeout, you should also fix the places below:
+  // - Scala:
+  //     org.apache.spark.sql.execution.streaming.GroupStateImpl.getGroupStateTimeoutFromString
+  // - Python: pyspark.sql.streaming.state.GroupStateTimeout
 
   /**
    * Timeout based on processing time.

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

@@ -20,13 +20,17 @@ package org.apache.spark.sql.execution.streaming
 import java.sql.Date
 import java.util.concurrent.TimeUnit
 
+import org.json4s._
+import org.json4s.jackson.JsonMethods._
+
 import org.apache.spark.api.java.Optional
 import org.apache.spark.sql.catalyst.plans.logical.{EventTimeTimeout, NoTimeout, ProcessingTimeTimeout}
 import org.apache.spark.sql.catalyst.util.IntervalUtils
 import org.apache.spark.sql.errors.QueryExecutionErrors
 import org.apache.spark.sql.execution.streaming.GroupStateImpl._
 import org.apache.spark.sql.streaming.{GroupStateTimeout, TestGroupState}
 import org.apache.spark.unsafe.types.UTF8String
+import org.apache.spark.util.Utils
 
 /**
  * Internal implementation of the [[TestGroupState]] interface. Methods are not thread-safe.
@@ -46,6 +50,9 @@ private[sql] class GroupStateImpl[S] private(
     timeoutConf: GroupStateTimeout,
     override val hasTimedOut: Boolean,
     watermarkPresent: Boolean) extends TestGroupState[S] {
+  // NOTE: if you're adding new properties here, fix:
+  // - `json` and `fromJson` methods of this class in Scala
+  // - pyspark.sql.streaming.state.GroupStateImpl in Python
 
   private var value: S = optionalValue.getOrElse(null.asInstanceOf[S])
   private var defined: Boolean = optionalValue.isDefined
@@ -173,6 +180,22 @@ private[sql] class GroupStateImpl[S] private(
       throw QueryExecutionErrors.cannotSetTimeoutTimestampError()
     }
   }
+
+  private[sql] def json(): String = compact(render(new JObject(
+    // Constructor
+    "optionalValue" -> JNull :: // Note that optionalValue will be manually serialized.
+    "batchProcessingTimeMs" -> JLong(batchProcessingTimeMs) ::
+    "eventTimeWatermarkMs" -> JLong(eventTimeWatermarkMs) ::
+    "timeoutConf" -> JString(Utils.stripDollars(Utils.getSimpleName(timeoutConf.getClass))) ::
+    "hasTimedOut" -> JBool(hasTimedOut) ::
+    "watermarkPresent" -> JBool(watermarkPresent) ::
+
+    // Internal state
+    "defined" -> JBool(defined) ::
+    "updated" -> JBool(updated) ::
+    "removed" -> JBool(removed) ::
+    "timeoutTimestamp" -> JLong(timeoutTimestamp) :: Nil
+  )))
 }
 
 
@@ -214,4 +237,35 @@ private[sql] object GroupStateImpl {
       hasTimedOut = false,
       watermarkPresent)
   }
+
+  def groupStateTimeoutFromString(clazz: String): GroupStateTimeout = clazz match {
+    case "ProcessingTimeTimeout" => GroupStateTimeout.ProcessingTimeTimeout
+    case "EventTimeTimeout" => GroupStateTimeout.EventTimeTimeout
+    case "NoTimeout" => GroupStateTimeout.NoTimeout
+    case _ => throw new IllegalStateException("Invalid string for GroupStateTimeout: " + clazz)
+  }
+
+  def fromJson[S](value: Option[S], json: JValue): GroupStateImpl[S] = {
+    implicit val formats = org.json4s.DefaultFormats
+
+    val hmap = json.extract[Map[String, Any]]
+
+    // Constructor
+    val newGroupState = new GroupStateImpl[S](
+      value,
+      hmap("batchProcessingTimeMs").asInstanceOf[Number].longValue(),
+      hmap("eventTimeWatermarkMs").asInstanceOf[Number].longValue(),
+      groupStateTimeoutFromString(hmap("timeoutConf").asInstanceOf[String]),
+      hmap("hasTimedOut").asInstanceOf[Boolean],
+      hmap("watermarkPresent").asInstanceOf[Boolean])
+
+    // Internal state
+    newGroupState.defined = hmap("defined").asInstanceOf[Boolean]
+    newGroupState.updated = hmap("updated").asInstanceOf[Boolean]
+    newGroupState.removed = hmap("removed").asInstanceOf[Boolean]
+    newGroupState.timeoutTimestamp =
+      hmap("timeoutTimestamp").asInstanceOf[Number].longValue()
+
+    newGroupState
+  }
 }