MQFSM Usability WIP

code/common/message-queue/src/main/java/nu/marginalia/mqsm/StateFactory.java

@@ -3,8 +3,8 @@ package nu.marginalia.mqsm;
 import com.google.gson.Gson;
 import com.google.inject.Inject;
 import com.google.inject.Singleton;
+import nu.marginalia.mqsm.graph.ResumeBehavior;
 import nu.marginalia.mqsm.state.MachineState;
-import nu.marginalia.mqsm.state.ResumeBehavior;
 import nu.marginalia.mqsm.state.StateTransition;
 
 import java.util.function.Function;
@@ -74,4 +74,52 @@ public class StateFactory {
     public StateTransition transition(String state, Object message) {
         return StateTransition.to(state, gson.toJson(message));
     }
+
+    public static class ErrorState implements MachineState {
+        @Override
+        public String name() { return "ERROR"; }
+
+        @Override
+        public StateTransition next(String message) {
+            throw new UnsupportedOperationException();
+        }
+
+        @Override
+        public ResumeBehavior resumeBehavior() { return ResumeBehavior.RETRY; }
+
+        @Override
+        public boolean isFinal() { return true; }
+    }
+
+    public static class FinalState implements MachineState {
+        @Override
+        public String name() { return "END"; }
+
+        @Override
+        public StateTransition next(String message) {
+            throw new UnsupportedOperationException();
+        }
+
+        @Override
+        public ResumeBehavior resumeBehavior() { return ResumeBehavior.RETRY; }
+
+        @Override
+        public boolean isFinal() { return true; }
+    }
+
+    public static class ResumingState implements MachineState {
+        @Override
+        public String name() { return "RESUMING"; }
+
+        @Override
+        public StateTransition next(String message) {
+            throw new UnsupportedOperationException();
+        }
+
+        @Override
+        public ResumeBehavior resumeBehavior() { return ResumeBehavior.RETRY; }
+
+        @Override
+        public boolean isFinal() { return false; }
+    }
 }

code/common/message-queue/src/main/java/nu/marginalia/mqsm/StateMachine.java

@@ -7,7 +7,8 @@ import nu.marginalia.mq.inbox.MqInboxResponse;
 import nu.marginalia.mq.inbox.MqSubscription;
 import nu.marginalia.mq.outbox.MqOutbox;
 import nu.marginalia.mq.persistence.MqPersistence;
-import nu.marginalia.mqsm.graph.StateGraph;
+import nu.marginalia.mqsm.graph.ResumeBehavior;
+import nu.marginalia.mqsm.graph.AbstractStateGraph;
 import nu.marginalia.mqsm.state.*;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -30,13 +31,16 @@ public class StateMachine {
     private final String queueName;
     private MachineState state;
 
-    private final MachineState errorState = new ErrorState();
+    private final MachineState errorState = new StateFactory.ErrorState();
-    private final MachineState finalState = new FinalState();
+    private final MachineState finalState = new StateFactory.FinalState();
-    private final MachineState resumingState = new ResumingState();
+    private final MachineState resumingState = new StateFactory.ResumingState();
 
     private final Map<String, MachineState> allStates = new HashMap<>();
 
-    public StateMachine(MqPersistence persistence, String queueName, UUID instanceUUID) {
+    public StateMachine(MqPersistence persistence,
+                        String queueName,
+                        UUID instanceUUID,
+                        AbstractStateGraph stateGraph) {
         this.queueName = queueName;
 
         smInbox = new MqInbox(persistence, queueName, instanceUUID, Executors.newSingleThreadExecutor());
@@ -45,28 +49,24 @@ public class StateMachine {
         smInbox.subscribe(new StateEventSubscription());
 
         registerStates(List.of(errorState, finalState, resumingState));
+        registerStates(stateGraph);
+
+        for (var declaredState : stateGraph.declaredStates()) {
+            if (!allStates.containsKey(declaredState)) {
+                throw new IllegalArgumentException("State " + declaredState + " is not defined in the state graph");
+            }
+        }
     }
 
     /** Register the state graph */
-    public void registerStates(MachineState... states) {
+    void registerStates(List<MachineState> states) {
-        if (state != null) {
-            throw new IllegalStateException("Cannot register states after state machine has been initialized");
-        }
-
         for (var state : states) {
             allStates.put(state.name(), state);
         }
     }
 
     /** Register the state graph */
-    public void registerStates(List<MachineState> states) {
+    void registerStates(AbstractStateGraph states) {
-        for (var state : states) {
-            allStates.put(state.name(), state);
-        }
-    }
-
-    /** Register the state graph */
-    public void registerStates(StateGraph states) {
         registerStates(states.asStateList());
     }
 

code/common/message-queue/src/main/java/nu/marginalia/mqsm/graph/AbstractStateGraph.java

@@ -1,22 +1,20 @@
 package nu.marginalia.mqsm.graph;
 
-import nu.marginalia.mqsm.StateFactory;
 import nu.marginalia.mqsm.state.MachineState;
+import nu.marginalia.mqsm.StateFactory;
 import nu.marginalia.mqsm.state.StateTransition;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
-import java.util.ArrayList;
+import java.util.*;
-import java.util.Arrays;
-import java.util.List;
 
-public abstract class StateGraph {
+public abstract class AbstractStateGraph {
     private final StateFactory stateFactory;
-    private static final Logger logger = LoggerFactory.getLogger(StateGraph.class);
+    private static final Logger logger = LoggerFactory.getLogger(AbstractStateGraph.class);
 
-    public StateGraph(StateFactory stateFactory) {
+    public AbstractStateGraph(StateFactory stateFactory) {
         this.stateFactory = stateFactory;
     }
 
@@ -38,6 +36,19 @@ public abstract class StateGraph {
         throw new ControlFlowException("ERROR", ex.getClass().getSimpleName() + ":" + ex.getMessage());
     }
 
+    public Set<String> declaredStates() {
+        Set<String> ret = new HashSet<>();
+
+        for (var method : getClass().getMethods()) {
+            var gs = method.getAnnotation(GraphState.class);
+            if (gs != null) {
+                ret.add(gs.name());
+                ret.add(gs.next());
+            }
+        }
+
+        return ret;
+    }
     public List<MachineState> asStateList() {
         List<MachineState> ret = new ArrayList<>();
 

code/common/message-queue/src/main/java/nu/marginalia/mqsm/graph/GraphState.java

@@ -1,8 +1,6 @@
 package nu.marginalia.mqsm.graph;
 
 
-import nu.marginalia.mqsm.state.ResumeBehavior;
-
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 

code/common/message-queue/src/main/java/nu/marginalia/mqsm/graph/ResumeBehavior.java

@@ -0,0 +1,8 @@
+package nu.marginalia.mqsm.graph;
+
+public enum ResumeBehavior {
+    /** Retry the state on resume */
+    RETRY,
+    /** Jump to ERROR on resume if the message has been acknowledged */
+    ERROR
+}

code/common/message-queue/src/main/java/nu/marginalia/mqsm/state/ErrorState.java

@@ -1,17 +0,0 @@
-package nu.marginalia.mqsm.state;
-
-public class ErrorState implements MachineState {
-    @Override
-    public String name() { return "ERROR"; }
-
-    @Override
-    public StateTransition next(String message) {
-        throw new UnsupportedOperationException();
-    }
-
-    @Override
-    public ResumeBehavior resumeBehavior() { return ResumeBehavior.RETRY; }
-
-    @Override
-    public boolean isFinal() { return true; }
-}

code/common/message-queue/src/main/java/nu/marginalia/mqsm/state/FinalState.java

@@ -1,17 +0,0 @@
-package nu.marginalia.mqsm.state;
-
-public class FinalState implements MachineState {
-    @Override
-    public String name() { return "END"; }
-
-    @Override
-    public StateTransition next(String message) {
-        throw new UnsupportedOperationException();
-    }
-
-    @Override
-    public ResumeBehavior resumeBehavior() { return ResumeBehavior.RETRY; }
-
-    @Override
-    public boolean isFinal() { return true; }
-}

code/common/message-queue/src/main/java/nu/marginalia/mqsm/state/MachineState.java

@@ -1,9 +1,13 @@
 package nu.marginalia.mqsm.state;
 
+import nu.marginalia.mqsm.graph.ResumeBehavior;
+
 public interface MachineState {
     String name();
+
     StateTransition next(String message);
 
     ResumeBehavior resumeBehavior();
+
     boolean isFinal();
 }

code/common/message-queue/src/main/java/nu/marginalia/mqsm/state/ResumeBehavior.java

@@ -1,6 +0,0 @@
-package nu.marginalia.mqsm.state;
-
-public enum ResumeBehavior {
-    RETRY,
-    ERROR
-}

code/common/message-queue/src/main/java/nu/marginalia/mqsm/state/ResumingState.java

@@ -1,17 +0,0 @@
-package nu.marginalia.mqsm.state;
-
-public class ResumingState implements MachineState {
-    @Override
-    public String name() { return "RESUMING"; }
-
-    @Override
-    public StateTransition next(String message) {
-        throw new UnsupportedOperationException();
-    }
-
-    @Override
-    public ResumeBehavior resumeBehavior() { return ResumeBehavior.RETRY; }
-
-    @Override
-    public boolean isFinal() { return false; }
-}

code/common/message-queue/src/test/java/nu/marginalia/mqsm/StateMachineErrorTest.java

@@ -4,12 +4,11 @@ import com.google.gson.GsonBuilder;
 import com.zaxxer.hikari.HikariConfig;
 import com.zaxxer.hikari.HikariDataSource;
 import nu.marginalia.mq.MqMessageRow;
-import nu.marginalia.mq.MqMessageState;
 import nu.marginalia.mq.MqTestUtil;
 import nu.marginalia.mq.persistence.MqPersistence;
 import nu.marginalia.mqsm.graph.GraphState;
-import nu.marginalia.mqsm.graph.StateGraph;
+import nu.marginalia.mqsm.graph.AbstractStateGraph;
-import nu.marginalia.mqsm.state.ResumeBehavior;
+import nu.marginalia.mqsm.graph.ResumeBehavior;
 import org.junit.jupiter.api.*;
 import org.testcontainers.containers.MariaDBContainer;
 import org.testcontainers.junit.jupiter.Container;
@@ -55,7 +54,7 @@ public class StateMachineErrorTest {
         dataSource.close();
     }
 
-    public static class ErrorHurdles extends StateGraph {
+    public static class ErrorHurdles extends AbstractStateGraph {
 
         public ErrorHurdles(StateFactory stateFactory) {
             super(stateFactory);
@@ -71,17 +70,15 @@ public class StateMachineErrorTest {
         }
         @GraphState(name = "OK", next = "END")
         public void ok() {
-            
+
         }
 
     }
 
     @Test
     public void smResumeResumableFromNew() throws Exception {
-        var sm = new StateMachine(persistence, inboxId, UUID.randomUUID());
         var stateFactory = new StateFactory(new GsonBuilder().create());
-
+        var sm = new StateMachine(persistence, inboxId, UUID.randomUUID(), new ErrorHurdles(stateFactory));
-        sm.registerStates(new ErrorHurdles(stateFactory).asStateList());
 
         sm.init();
 

code/common/message-queue/src/test/java/nu/marginalia/mqsm/StateMachineResumeTest.java

@@ -8,8 +8,8 @@ import nu.marginalia.mq.MqMessageState;
 import nu.marginalia.mq.MqTestUtil;
 import nu.marginalia.mq.persistence.MqPersistence;
 import nu.marginalia.mqsm.graph.GraphState;
-import nu.marginalia.mqsm.graph.StateGraph;
+import nu.marginalia.mqsm.graph.AbstractStateGraph;
-import nu.marginalia.mqsm.state.ResumeBehavior;
+import nu.marginalia.mqsm.graph.ResumeBehavior;
 import org.junit.jupiter.api.*;
 import org.testcontainers.containers.MariaDBContainer;
 import org.testcontainers.junit.jupiter.Container;
@@ -55,7 +55,7 @@ public class StateMachineResumeTest {
         dataSource.close();
     }
 
-    public static class ResumeTrialsGraph extends StateGraph {
+    public static class ResumeTrialsGraph extends AbstractStateGraph {
 
         public ResumeTrialsGraph(StateFactory stateFactory) {
             super(stateFactory);
@@ -75,10 +75,8 @@ public class StateMachineResumeTest {
 
     @Test
     public void smResumeResumableFromNew() throws Exception {
-        var sm = new StateMachine(persistence, inboxId, UUID.randomUUID());
         var stateFactory = new StateFactory(new GsonBuilder().create());
-
+        var sm = new StateMachine(persistence, inboxId, UUID.randomUUID(), new ResumeTrialsGraph(stateFactory));
-        sm.registerStates(new ResumeTrialsGraph(stateFactory).asStateList());
 
         persistence.sendNewMessage(inboxId,  null,"RESUMABLE", "", null);
 
@@ -98,10 +96,8 @@ public class StateMachineResumeTest {
 
     @Test
     public void smResumeFromAck() throws Exception {
-        var sm = new StateMachine(persistence, inboxId, UUID.randomUUID());
         var stateFactory = new StateFactory(new GsonBuilder().create());
-
+        var sm = new StateMachine(persistence, inboxId, UUID.randomUUID(), new ResumeTrialsGraph(stateFactory));
-        sm.registerStates(new ResumeTrialsGraph(stateFactory));
 
         long id = persistence.sendNewMessage(inboxId,  null,"RESUMABLE", "", null);
         persistence.updateMessageState(id, MqMessageState.ACK);
@@ -123,10 +119,8 @@ public class StateMachineResumeTest {
 
     @Test
     public void smResumeNonResumableFromNew() throws Exception {
-        var sm = new StateMachine(persistence, inboxId, UUID.randomUUID());
         var stateFactory = new StateFactory(new GsonBuilder().create());
-
+        var sm = new StateMachine(persistence, inboxId, UUID.randomUUID(), new ResumeTrialsGraph(stateFactory));
-        sm.registerStates(new ResumeTrialsGraph(stateFactory));
 
         persistence.sendNewMessage(inboxId,  null,"NON-RESUMABLE", "", null);
 
@@ -146,10 +140,8 @@ public class StateMachineResumeTest {
 
     @Test
     public void smResumeNonResumableFromAck() throws Exception {
-        var sm = new StateMachine(persistence, inboxId, UUID.randomUUID());
         var stateFactory = new StateFactory(new GsonBuilder().create());
-
+        var sm = new StateMachine(persistence, inboxId, UUID.randomUUID(), new ResumeTrialsGraph(stateFactory));
-        sm.registerStates(new ResumeTrialsGraph(stateFactory));
 
         long id = persistence.sendNewMessage(inboxId,  null,"NON-RESUMABLE", "", null);
         persistence.updateMessageState(id, MqMessageState.ACK);
@@ -170,10 +162,8 @@ public class StateMachineResumeTest {
 
     @Test
     public void smResumeEmptyQueue() throws Exception {
-        var sm = new StateMachine(persistence, inboxId, UUID.randomUUID());
         var stateFactory = new StateFactory(new GsonBuilder().create());
-
+        var sm = new StateMachine(persistence, inboxId, UUID.randomUUID(), new ResumeTrialsGraph(stateFactory));
-        sm.registerStates(new ResumeTrialsGraph(stateFactory));
 
         sm.resume();
 

code/common/message-queue/src/test/java/nu/marginalia/mqsm/StateMachineTest.java

@@ -3,19 +3,15 @@ package nu.marginalia.mqsm;
 import com.google.gson.GsonBuilder;
 import com.zaxxer.hikari.HikariConfig;
 import com.zaxxer.hikari.HikariDataSource;
-import nu.marginalia.mq.MqMessageRow;
-import nu.marginalia.mq.MqMessageState;
 import nu.marginalia.mq.MqTestUtil;
 import nu.marginalia.mq.persistence.MqPersistence;
 import nu.marginalia.mqsm.graph.GraphState;
-import nu.marginalia.mqsm.graph.StateGraph;
+import nu.marginalia.mqsm.graph.AbstractStateGraph;
-import nu.marginalia.mqsm.state.ResumeBehavior;
 import org.junit.jupiter.api.*;
 import org.testcontainers.containers.MariaDBContainer;
 import org.testcontainers.junit.jupiter.Container;
 import org.testcontainers.junit.jupiter.Testcontainers;
 
-import java.util.List;
 import java.util.UUID;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
@@ -55,7 +51,7 @@ public class StateMachineTest {
         dataSource.close();
     }
 
-    public static class TestGraph extends StateGraph {
+    public static class TestGraph extends AbstractStateGraph {
         public TestGraph(StateFactory stateFactory) {
             super(stateFactory);
         }
@@ -87,8 +83,8 @@ public class StateMachineTest {
         var graph = new TestGraph(stateFactory);
 
 
-        var sm = new StateMachine(persistence, inboxId, UUID.randomUUID());
+        var sm = new StateMachine(persistence, inboxId, UUID.randomUUID(), graph);
-        sm.registerStates(graph.asStateList());
+        sm.registerStates(graph);
 
         sm.init();
 
@@ -101,34 +97,17 @@ public class StateMachineTest {
 
     @Test
     public void testStartStopStartStop() throws Exception {
-        var sm = new StateMachine(persistence, inboxId, UUID.randomUUID());
         var stateFactory = new StateFactory(new GsonBuilder().create());
-
+        var sm = new StateMachine(persistence, inboxId, UUID.randomUUID(), new TestGraph(stateFactory));
-        var initial = stateFactory.create("INITIAL", ResumeBehavior.RETRY,  () -> stateFactory.transition("GREET", "World"));
-
-        var greet = stateFactory.create("GREET", ResumeBehavior.RETRY,  String.class, (String message) -> {
-            System.out.println("Hello, " + message + "!");
-            return stateFactory.transition("COUNT-TO-FIVE", 0);
-        });
-
-        var ctf = stateFactory.create("COUNT-TO-FIVE", ResumeBehavior.RETRY,  Integer.class, (Integer count) -> {
-            System.out.println(count);
-            if (count < 5) {
-                return stateFactory.transition("COUNT-TO-FIVE", count + 1);
-            } else {
-                return stateFactory.transition("END");
-            }
-        });
-
-        sm.registerStates(initial, greet, ctf);
 
         sm.init();
 
-        Thread.sleep(300);
+        Thread.sleep(150);
         sm.stop();
 
-        var sm2 = new StateMachine(persistence, inboxId, UUID.randomUUID());
+        System.out.println("-------------------- ");
-        sm2.registerStates(initial, greet, ctf);
+
+        var sm2 = new StateMachine(persistence, inboxId, UUID.randomUUID(), new TestGraph(stateFactory));
         sm2.resume();
         sm2.join();
         sm2.stop();