Streaming state (#7348)

streaming/java/streaming-api/pom.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-        <!-- This file is auto-generated by Bazel from pom_template.xml, do not modify it. -->
+    <!-- This file is auto-generated by Bazel from pom_template.xml, do not modify it. -->
 <project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
          xmlns="http://maven.apache.org/POM/4.0.0"
          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
@@ -23,6 +23,11 @@
             <version>${project.version}</version>
         </dependency>
         <dependency>
+            <groupId>org.ray</groupId>
+            <artifactId>streaming-state</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+        <dependency>
   <groupId>com.google.guava</groupId>
   <artifactId>guava</artifactId>
   <version>27.0.1-jre</version>

streaming/java/streaming-api/pom_template.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-        {auto_gen_header}
+    {auto_gen_header}
 <project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
          xmlns="http://maven.apache.org/POM/4.0.0"
          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
@@ -22,6 +22,11 @@
             <artifactId>ray-api</artifactId>
             <version>${project.version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.ray</groupId>
+            <artifactId>streaming-state</artifactId>
+            <version>${project.version}</version>
+        </dependency>
         {generated_bzl_deps}
     </dependencies>
 </project>

streaming/java/streaming-api/src/main/java/io/ray/streaming/api/context/RuntimeContext.java

@@ -1,5 +1,14 @@
 package io.ray.streaming.api.context;
 
+import io.ray.streaming.state.backend.KeyStateBackend;
+import io.ray.streaming.state.keystate.desc.ListStateDescriptor;
+import io.ray.streaming.state.keystate.desc.MapStateDescriptor;
+import io.ray.streaming.state.keystate.desc.ValueStateDescriptor;
+import io.ray.streaming.state.keystate.state.ListState;
+import io.ray.streaming.state.keystate.state.MapState;
+import io.ray.streaming.state.keystate.state.ValueState;
+import java.util.Map;
+
 /**
  * Encapsulate the runtime information of a streaming task.
  */
@@ -11,8 +20,23 @@ public interface RuntimeContext {
 
   int getParallelism();
 
-  Long getBatchId();
+  Long getCheckpointId();
+
+  void setCheckpointId(long checkpointId);
 
   Long getMaxBatch();
 
+  Map<String, String> getConfig();
+
+  void setCurrentKey(Object key);
+
+  KeyStateBackend getKeyStateBackend();
+
+  void setKeyStateBackend(KeyStateBackend keyStateBackend);
+
+  <T> ValueState<T> getValueState(ValueStateDescriptor<T> stateDescriptor);
+
+  <T> ListState<T> getListState(ListStateDescriptor<T> stateDescriptor);
+
+  <S, T> MapState<S, T> getMapState(MapStateDescriptor<S, T> stateDescriptor);
 }

streaming/java/streaming-api/src/main/java/io/ray/streaming/operator/impl/SourceOperator.java

@@ -10,7 +10,6 @@ import io.ray.streaming.operator.StreamOperator;
 import java.util.List;
 
 public class SourceOperator<T> extends StreamOperator<SourceFunction<T>> {
-
   private SourceContextImpl sourceContext;
 
   public SourceOperator(SourceFunction<T> function) {
@@ -38,6 +37,7 @@ public class SourceOperator<T> extends StreamOperator<SourceFunction<T>> {
   }
 
   class SourceContextImpl implements SourceContext<T> {
+
     private List<Collector> collectors;
 
     public SourceContextImpl(List<Collector> collectors) {