[ID Refactor] Shorten the length of JobID to 4 bytes (#5110)

* WIP

* Fix

* Add jobid test

* Fix

* Add python part

* Fix

* Fix tes

* Remove TODOs

* Fix C++ tests

* Lint

* Fix

* Fix exporting functions in multiple ray.init

* Fix java test

* Fix lint

* Fix linting

* Address comments.

* FIx

* Address and fix linting

* Refine and fix

* Fix

* address

* Address comments.

* Fix linting

* Fix

* Address

* Address comments.

* Address

* Address

* Fix

* Fix

* Fix

* Fix lint

* Fix

* Fix linting

* Address comments.

* Fix linting

* Address comments.

* Fix linting

* address comments.

* Fix

java/test/src/main/java/org/ray/api/test/GcsClientTest.java

@@ -4,6 +4,7 @@ import com.google.common.base.Preconditions;
 import java.util.List;
 import org.ray.api.Ray;
 import org.ray.api.TestUtils;
+import org.ray.api.id.JobId;
 import org.ray.api.runtimecontext.NodeInfo;
 import org.ray.runtime.AbstractRayRuntime;
 import org.ray.runtime.config.RayConfig;
@@ -39,4 +40,17 @@ public class GcsClientTest extends BaseTest {
     Assert.assertEquals(allNodeInfo.get(0).resources.get("A"), 8.0);
   }
 
+  @Test
+  public void testNextJob() {
+    TestUtils.skipTestUnderSingleProcess();
+    RayConfig config = ((AbstractRayRuntime)Ray.internal()).getRayConfig();
+    // The value of job id of this driver in cluster should be `1L`.
+    Assert.assertEquals(config.getJobId(), JobId.fromInt(1));
+
+    GcsClient gcsClient = ((AbstractRayRuntime)Ray.internal()).getGcsClient();
+    for (int i  = 2; i < 100; ++i) {
+      Assert.assertEquals(gcsClient.nextJobId(), JobId.fromInt(i));
+    }
+
+  }
 }

java/test/src/main/java/org/ray/api/test/RuntimeContextTest.java

@@ -3,6 +3,7 @@ package org.ray.api.test;
 import org.ray.api.Ray;
 import org.ray.api.RayActor;
 import org.ray.api.annotation.RayRemote;
+import org.ray.api.id.JobId;
 import org.ray.api.id.UniqueId;
 import org.testng.Assert;
 import org.testng.annotations.AfterClass;
@@ -11,8 +12,7 @@ import org.testng.annotations.Test;
 
 public class RuntimeContextTest extends BaseTest {
 
-  private static UniqueId JOB_ID =
-      UniqueId.fromHexString("0011223344556677889900112233445566778899");
+  private static JobId JOB_ID = JobId.fromHexString("00112233");
   private static String RAYLET_SOCKET_NAME = "/tmp/ray/test/raylet_socket";
   private static String OBJECT_STORE_SOCKET_NAME = "/tmp/ray/test/object_store_socket";