Add deterministic GUID generation (#176)

Author: kaibocai

CHANGELOG.md

@@ -1,5 +1,6 @@
 ## placeholder
 * Fix exception type issue when using `RetriableTask` in fan in/out pattern ([#174](https://github.com/microsoft/durabletask-java/pull/174))
+* Add implementation to generate name-based deterministic UUID ([#175](https://github.com/microsoft/durabletask-java/pull/175))
 
 
 ## v1.4.0

client/src/main/java/com/microsoft/durabletask/TaskOrchestrationContext.java

@@ -8,6 +8,7 @@
 import java.time.ZonedDateTime;
 import java.util.Arrays;
 import java.util.List;
+import java.util.UUID;
 
 /**
  * Used by orchestrators to perform actions such as scheduling tasks, durable timers, waiting for external events,
@@ -301,6 +302,20 @@ default void continueAsNew(Object input){
         this.continueAsNew(input, true);
     }
 
+    /**
+     * Create a new UUID that is safe for replay within an orchestration or operation.
+     * <p>
+     * The default implementation of this method creates a name-based UUID
+     * using the algorithm from RFC 4122 §4.3. The name input used to generate
+     * this value is a combination of the orchestration instance ID and an
+     * internally managed sequence number.
+     *</p>
+     * @return a deterministic UUID
+     */
+    default UUID newUUID() {
+        throw new RuntimeException("No implementation found.");
+    }
+
     /**
      * Restarts the orchestration with a new input and clears its history.
      * <p>

client/src/main/java/com/microsoft/durabletask/TaskOrchestrationExecutor.java

@@ -8,6 +8,7 @@
 import com.microsoft.durabletask.interruption.OrchestratorBlockedException;
 import com.microsoft.durabletask.implementation.protobuf.OrchestratorService.*;
 import com.microsoft.durabletask.implementation.protobuf.OrchestratorService.ScheduleTaskAction.Builder;
+import com.microsoft.durabletask.util.UUIDGenerator;
 
 import javax.annotation.Nullable;
 import java.time.Duration;
@@ -80,6 +81,7 @@ private class ContextImplTask implements TaskOrchestrationContext {
         private boolean isComplete;
         private boolean isSuspended;
         private boolean isReplaying = true;
+        private int newUUIDCounter;
 
         // LinkedHashMap to maintain insertion order when returning the list of pending actions
         private final LinkedHashMap<Integer, OrchestratorAction> pendingActions = new LinkedHashMap<>();
@@ -294,6 +296,7 @@ public <V> Task<V> callActivity(
             return this.createAppropriateTask(taskFactory, options);
         }
 
+        @Override
         public void continueAsNew(Object input, boolean preserveUnprocessedEvents) {
             Helpers.throwIfOrchestratorComplete(this.isComplete);
 
@@ -309,6 +312,20 @@ public void continueAsNew(Object input, boolean preserveUnprocessedEvents) {
                     "The orchestrator invoked continueAsNew. This Throwable should never be caught by user code.");
         }
 
+        @Override
+        public UUID newUUID() {
+            final int version = 5;
+            final String hashV5 = "SHA-1";
+            final String dnsNameSpace = "9e952958-5e33-4daf-827f-2fa12937b875";
+            final String name = new StringBuilder(this.instanceId)
+                    .append("-")
+                    .append(this.currentInstant)
+                    .append("-")
+                    .append(this.newUUIDCounter).toString();
+            this.newUUIDCounter++;
+            return UUIDGenerator.generate(version, hashV5, UUID.fromString(dnsNameSpace), name);
+        }
+
         @Override
         public void sendEvent(String instanceId, String eventName, Object eventData) {
             Helpers.throwIfOrchestratorComplete(this.isComplete);
@@ -358,11 +375,8 @@ public <V> Task<V> callSubOrchestrator(
                 createSubOrchestrationActionBuilder.setInput(StringValue.of(serializedInput));
             }
 
-            // TODO:replace this with a deterministic GUID generation so that it's safe for replay,
-            //  please find potential bug here https://github.com/microsoft/durabletask-dotnet/issues/9
-
             if (instanceId == null) {
-                instanceId = UUID.randomUUID().toString();
+                instanceId = this.newUUID().toString();
             }
             createSubOrchestrationActionBuilder.setInstanceId(instanceId);
 

client/src/main/java/com/microsoft/durabletask/util/UUIDGenerator.java

@@ -0,0 +1,37 @@
+package com.microsoft.durabletask.util;
+
+import java.nio.ByteBuffer;
+import java.nio.charset.StandardCharsets;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.util.UUID;
+
+public class UUIDGenerator {
+    public static UUID generate(int version, String algorithm, UUID namespace, String name) {
+
+        MessageDigest hasher = hasher(algorithm);
+
+        if (namespace != null) {
+            ByteBuffer ns = ByteBuffer.allocate(16);
+            ns.putLong(namespace.getMostSignificantBits());
+            ns.putLong(namespace.getLeastSignificantBits());
+            hasher.update(ns.array());
+        }
+
+        hasher.update(name.getBytes(StandardCharsets.UTF_8));
+        ByteBuffer hash = ByteBuffer.wrap(hasher.digest());
+
+        final long msb = (hash.getLong() & 0xffffffffffff0fffL) | (version & 0x0f) << 12;
+        final long lsb = (hash.getLong() & 0x3fffffffffffffffL) | 0x8000000000000000L;
+
+        return new UUID(msb, lsb);
+    }
+
+    private static MessageDigest hasher(String algorithm) {
+        try {
+            return MessageDigest.getInstance(algorithm);
+        } catch (NoSuchAlgorithmException e) {
+            throw new RuntimeException(String.format("%s not supported.", algorithm));
+        }
+    }
+}

client/src/test/java/com/microsoft/durabletask/IntegrationTests.java

@@ -1484,4 +1484,50 @@ void activityAnyOf() throws IOException, TimeoutException {
             assertTrue(Integer.parseInt(output) >= 0 && Integer.parseInt(output) < activityCount);
         }
     }
+
+    @Test
+    public void newUUIDTest() {
+        String orchestratorName = "test-new-uuid";
+        String echoActivityName = "Echo";
+        DurableTaskGrpcWorker worker = this.createWorkerBuilder()
+                .addOrchestrator(orchestratorName, ctx -> {
+                    // Test 1: Ensure two consequiteively created GUIDs are not unique
+                    UUID currentUUID0 = ctx.newUUID();
+                    UUID currentUUID1 = ctx.newUUID();
+                    if (currentUUID0.equals(currentUUID1)) {
+                        ctx.complete(false);
+                    }
+
+                    // Test 2: Ensure that the same GUID values are created on each replay
+                    UUID originalUUID1 = ctx.callActivity(echoActivityName, currentUUID1, UUID.class).await();
+                    if (!currentUUID1.equals(originalUUID1)) {
+                        ctx.complete(false);
+                    }
+
+                    // Test 3: Ensure that the same UUID values are created on each replay even after an await
+                    UUID currentUUID2 = ctx.newUUID();
+                    UUID originalUUID2 = ctx.callActivity(echoActivityName, currentUUID2, UUID.class).await();
+                    if (!currentUUID2.equals(originalUUID2)) {
+                        ctx.complete(false);
+                    }
+
+                    // Test 4: Finish confirming that every generated UUID is unique
+                    if (currentUUID1.equals(currentUUID2)) ctx.complete(false);
+                    else ctx.complete(true);
+                })
+                .addActivity(echoActivityName, ctx -> ctx.getInput(UUID.class))
+                .buildAndStart();
+        DurableTaskClient client = new DurableTaskGrpcClientBuilder().build();
+
+        try(worker; client) {
+            String instanceId = client.scheduleNewOrchestrationInstance(orchestratorName);
+            OrchestrationMetadata instance = client.waitForInstanceCompletion(instanceId, defaultTimeout, true);
+            assertNotNull(instance);
+            assertEquals(OrchestrationRuntimeStatus.COMPLETED, instance.getRuntimeStatus());
+            assertTrue(instance.readOutputAs(boolean.class));
+        } catch (TimeoutException e) {
+            throw new RuntimeException(e);
+        }
+
+    }
 }