Introduce ValueKind to Java and add to WindowedValue

sdks/java/core/src/main/java/org/apache/beam/sdk/values/OutputBuilder.java

@@ -53,5 +53,7 @@ public interface OutputBuilder<T> extends WindowedValue<T> {
 
   OutputBuilder<T> setOpenTelemetryContext(@Nullable Context openTelemetryContext);
 
+  OutputBuilder<T> setValueKind(ValueKind valueKind);
+
   void output();
 }

sdks/java/core/src/main/java/org/apache/beam/sdk/values/ValueInSingleWindow.java

@@ -71,6 +71,8 @@ public T getValue() {
 
   public abstract @Nullable Context getOpenTelemetryContext();
 
+  public abstract ValueKind getValueKind();
+
   // todo #33176 specify additional metadata in the future
   public static <T> ValueInSingleWindow<T> of(
       T value,
@@ -81,6 +83,28 @@ public static <T> ValueInSingleWindow<T> of(
       @Nullable Long currentRecordOffset,
       CausedByDrain causedByDrain,
       @Nullable Context openTelemetryContext) {
+    return of(
+        value,
+        timestamp,
+        window,
+        paneInfo,
+        currentRecordId,
+        currentRecordOffset,
+        causedByDrain,
+        openTelemetryContext,
+        ValueKind.INSERT);
+  }
+
+  public static <T> ValueInSingleWindow<T> of(
+      T value,
+      Instant timestamp,
+      BoundedWindow window,
+      PaneInfo paneInfo,
+      @Nullable String currentRecordId,
+      @Nullable Long currentRecordOffset,
+      CausedByDrain causedByDrain,
+      @Nullable Context openTelemetryContext,
+      ValueKind valueKind) {
     return new AutoValue_ValueInSingleWindow<>(
         value,
         timestamp,
@@ -89,12 +113,22 @@ public static <T> ValueInSingleWindow<T> of(
         currentRecordId,
         currentRecordOffset,
         causedByDrain,
-        openTelemetryContext);
+        openTelemetryContext,
+        valueKind);
   }
 
   public static <T> ValueInSingleWindow<T> of(
       T value, Instant timestamp, BoundedWindow window, PaneInfo paneInfo) {
-    return of(value, timestamp, window, paneInfo, null, null, CausedByDrain.NORMAL, null);
+    return of(
+        value,
+        timestamp,
+        window,
+        paneInfo,
+        null,
+        null,
+        CausedByDrain.NORMAL,
+        null,
+        ValueKind.INSERT);
   }
 
   /** A coder for {@link ValueInSingleWindow}. */
@@ -142,9 +176,9 @@ public void encode(
         io.opentelemetry.context.Context openTelemetryContext =
             windowedElem.getOpenTelemetryContext();
         if (openTelemetryContext != null) {
-
           OpenTelemetryContextPropagator.set(openTelemetryContext, builder);
         }
+        builder.setValueKind(ValueKindUtil.toProto(windowedElem.getValueKind()));
         BeamFnApi.Elements.ElementMetadata metadata = builder.build();
         ByteArrayCoder.of().encode(metadata.toByteArray(), outStream);
       }
@@ -166,6 +200,7 @@ public ValueInSingleWindow<T> decode(InputStream inStream, Coder.Context context
       PaneInfo paneInfo = PaneInfo.PaneInfoCoder.INSTANCE.decode(inStream);
       CausedByDrain causedByDrain = CausedByDrain.NORMAL;
       io.opentelemetry.context.@Nullable Context openTelemetryContext = null;
+      ValueKind valueKind = ValueKind.INSERT;
       if (WindowedValues.WindowedValueCoder.isMetadataSupported() && paneInfo.isElementMetadata()) {
         BeamFnApi.Elements.ElementMetadata elementMetadata =
             BeamFnApi.Elements.ElementMetadata.parseFrom(ByteArrayCoder.of().decode(inStream));
@@ -174,12 +209,21 @@ public ValueInSingleWindow<T> decode(InputStream inStream, Coder.Context context
                 ? CausedByDrain.CAUSED_BY_DRAIN
                 : CausedByDrain.NORMAL;
         openTelemetryContext = OpenTelemetryContextPropagator.read(elementMetadata);
+        valueKind = ValueKindUtil.fromProto(elementMetadata.getValueKind());
       }
 
       T value = valueCoder.decode(inStream, context);
       // todo #33176 specify additional metadata in the future
       return new AutoValue_ValueInSingleWindow<>(
-          value, timestamp, window, paneInfo, null, null, causedByDrain, openTelemetryContext);
+          value,
+          timestamp,
+          window,
+          paneInfo,
+          null,
+          null,
+          causedByDrain,
+          openTelemetryContext,
+          valueKind);
     }
 
     @Override

sdks/java/core/src/main/java/org/apache/beam/sdk/values/ValueKind.java

@@ -0,0 +1,40 @@
+/*
+ * 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.beam.sdk.values;
+
+/** The type of change operation represented by a Change Data Capture (CDC) record. */
+public enum ValueKind {
+  /** Indicates a new record was created in the source system. */
+  INSERT,
+
+  /**
+   * Indicates the state of a record immediately <b>before</b> an update occurred. This is typically
+   * used to identify the previous values of modified columns or to locate the record via its
+   * primary key.
+   */
+  UPDATE_BEFORE,
+
+  /**
+   * Indicates the state of a record immediately <b>after</b> an update occurred. Represents the
+   * current, valid state of the record following the change.
+   */
+  UPDATE_AFTER,
+
+  /** Indicates that an existing record was removed from the source system. */
+  DELETE
+}

sdks/java/core/src/main/java/org/apache/beam/sdk/values/ValueKindUtil.java

@@ -0,0 +1,54 @@
+/*
+ * 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.beam.sdk.values;
+
+import org.apache.beam.model.fnexecution.v1.BeamFnApi.Elements;
+
+/** Utility class for converting between {@link ValueKind} and {@link Elements.ValueKind.Enum}. */
+public class ValueKindUtil {
+  public static Elements.ValueKind.Enum toProto(ValueKind valueKind) {
+    switch (valueKind) {
+      case INSERT:
+        return Elements.ValueKind.Enum.INSERT;
+      case UPDATE_BEFORE:
+        return Elements.ValueKind.Enum.UPDATE_BEFORE;
+      case UPDATE_AFTER:
+        return Elements.ValueKind.Enum.UPDATE_AFTER;
+      case DELETE:
+        return Elements.ValueKind.Enum.DELETE;
+      default:
+        throw new IllegalArgumentException("Unknown ValueKind: " + valueKind);
+    }
+  }
+
+  public static ValueKind fromProto(Elements.ValueKind.Enum proto) {
+    switch (proto) {
+      case VALUE_KIND_UNSPECIFIED:
+      case INSERT:
+        return ValueKind.INSERT;
+      case UPDATE_BEFORE:
+        return ValueKind.UPDATE_BEFORE;
+      case UPDATE_AFTER:
+        return ValueKind.UPDATE_AFTER;
+      case DELETE:
+        return ValueKind.DELETE;
+      default:
+        throw new IllegalArgumentException("Unknown ValueKind: " + proto);
+    }
+  }
+}

sdks/java/core/src/main/java/org/apache/beam/sdk/values/WindowedValue.java

@@ -58,6 +58,10 @@ public interface WindowedValue<T> {
 
   CausedByDrain causedByDrain();
 
+  /** Returns the {@link ValueKind} associated with this WindowedValue. */
+  @Pure
+  ValueKind getValueKind();
+
   /**
    * A representation of each of the actual values represented by this compressed {@link
    * WindowedValue}, one per window.