Add workflow metadata query (#2301)

Add workflow metadata query

temporal-sdk/src/main/java/io/temporal/client/WorkflowClient.java

@@ -115,6 +115,9 @@ public interface WorkflowClient {
   /** Use this constant as a query type to get a workflow stack trace. */
   String QUERY_TYPE_STACK_TRACE = "__stack_trace";
 
+  /** Use this constant as a query type to get the workflow metadata. */
+  String QUERY_TYPE_WORKFLOW_METADATA = "__temporal_workflow_metadata";
+
   /** Replays workflow to the current state and returns empty result or error if replay failed. */
   String QUERY_TYPE_REPLAY_ONLY = "__replay_only";
 

temporal-sdk/src/main/java/io/temporal/common/interceptors/WorkflowOutboundCallsInterceptor.java

@@ -452,6 +452,7 @@ public Header getHeader() {
 
   final class SignalRegistrationRequest {
     private final String signalType;
+    private final String description;
     private final HandlerUnfinishedPolicy unfinishedPolicy;
     private final Class<?>[] argTypes;
     private final Type[] genericArgTypes;
@@ -464,19 +465,37 @@ public SignalRegistrationRequest(
         Type[] genericArgTypes,
         Functions.Proc1<Object[]> callback) {
       this.signalType = signalType;
+      this.description = "";
       this.unfinishedPolicy = HandlerUnfinishedPolicy.WARN_AND_ABANDON;
       this.argTypes = argTypes;
       this.genericArgTypes = genericArgTypes;
       this.callback = callback;
     }
 
+    // Kept for backward compatibility
+    public SignalRegistrationRequest(
+        String signalType,
+        HandlerUnfinishedPolicy unfinishedPolicy,
+        Class<?>[] argTypes,
+        Type[] genericArgTypes,
+        Functions.Proc1<Object[]> callback) {
+      this.signalType = signalType;
+      this.description = "";
+      this.unfinishedPolicy = unfinishedPolicy;
+      this.argTypes = argTypes;
+      this.genericArgTypes = genericArgTypes;
+      this.callback = callback;
+    }
+
     public SignalRegistrationRequest(
         String signalType,
+        String description,
         HandlerUnfinishedPolicy unfinishedPolicy,
         Class<?>[] argTypes,
         Type[] genericArgTypes,
         Functions.Proc1<Object[]> callback) {
       this.signalType = signalType;
+      this.description = description;
       this.unfinishedPolicy = unfinishedPolicy;
       this.argTypes = argTypes;
       this.genericArgTypes = genericArgTypes;
@@ -487,6 +506,11 @@ public String getSignalType() {
       return signalType;
     }
 
+    @Experimental
+    public String getDescription() {
+      return description;
+    }
+
     public HandlerUnfinishedPolicy getUnfinishedPolicy() {
       return unfinishedPolicy;
     }
@@ -519,20 +543,40 @@ public List<SignalRegistrationRequest> getRequests() {
   @Experimental
   final class UpdateRegistrationRequest {
     private final String updateName;
+    private final String description;
     private final HandlerUnfinishedPolicy unfinishedPolicy;
     private final Class<?>[] argTypes;
     private final Type[] genericArgTypes;
     private final Functions.Func1<Object[], Object> executeCallback;
     private final Functions.Proc1<Object[]> validateCallback;
 
+    // Kept for backward compatibility
+    public UpdateRegistrationRequest(
+        String updateName,
+        HandlerUnfinishedPolicy unfinishedPolicy,
+        Class<?>[] argTypes,
+        Type[] genericArgTypes,
+        Functions.Proc1<Object[]> validateCallback,
+        Functions.Func1<Object[], Object> executeCallback) {
+      this.updateName = updateName;
+      this.description = "";
+      this.unfinishedPolicy = unfinishedPolicy;
+      this.argTypes = argTypes;
+      this.genericArgTypes = genericArgTypes;
+      this.validateCallback = validateCallback;
+      this.executeCallback = executeCallback;
+    }
+
     public UpdateRegistrationRequest(
         String updateName,
+        String description,
         HandlerUnfinishedPolicy unfinishedPolicy,
         Class<?>[] argTypes,
         Type[] genericArgTypes,
         Functions.Proc1<Object[]> validateCallback,
         Functions.Func1<Object[], Object> executeCallback) {
       this.updateName = updateName;
+      this.description = description;
       this.unfinishedPolicy = unfinishedPolicy;
       this.argTypes = argTypes;
       this.genericArgTypes = genericArgTypes;
@@ -544,6 +588,11 @@ public String getUpdateName() {
       return updateName;
     }
 
+    @Experimental
+    public String getDescription() {
+      return description;
+    }
+
     public HandlerUnfinishedPolicy getUnfinishedPolicy() {
       return unfinishedPolicy;
     }
@@ -580,16 +629,32 @@ public List<UpdateRegistrationRequest> getRequests() {
 
   final class RegisterQueryInput {
     private final String queryType;
+    private final String description;
     private final Class<?>[] argTypes;
     private final Type[] genericArgTypes;
     private final Functions.Func1<Object[], Object> callback;
 
+    // Kept for backward compatibility
+    public RegisterQueryInput(
+        String queryType,
+        Class<?>[] argTypes,
+        Type[] genericArgTypes,
+        Functions.Func1<Object[], Object> callback) {
+      this.queryType = queryType;
+      this.description = "";
+      this.argTypes = argTypes;
+      this.genericArgTypes = genericArgTypes;
+      this.callback = callback;
+    }
+
     public RegisterQueryInput(
         String queryType,
+        String description,
         Class<?>[] argTypes,
         Type[] genericArgTypes,
         Functions.Func1<Object[], Object> callback) {
       this.queryType = queryType;
+      this.description = description;
       this.argTypes = argTypes;
       this.genericArgTypes = genericArgTypes;
       this.callback = callback;
@@ -599,6 +664,11 @@ public String getQueryType() {
       return queryType;
     }
 
+    @Experimental
+    public String getDescription() {
+      return description;
+    }
+
     public Class<?>[] getArgTypes() {
       return argTypes;
     }

temporal-sdk/src/main/java/io/temporal/common/metadata/POJOWorkflowMethod.java

@@ -31,6 +31,7 @@ final class POJOWorkflowMethod {
   private final WorkflowMethodType type;
   private final Method method;
   private final Optional<String> nameFromAnnotation;
+  private final Optional<String> descriptionFromAnnotation;
 
   POJOWorkflowMethod(Method method) {
     this.method = Objects.requireNonNull(method);
@@ -43,6 +44,7 @@ final class POJOWorkflowMethod {
     int count = 0;
     WorkflowMethodType type = null;
     String name = null;
+    String description = null;
     if (workflowMethod != null) {
       type = WorkflowMethodType.WORKFLOW;
       count++;
@@ -56,6 +58,7 @@ final class POJOWorkflowMethod {
       }
       count++;
       name = signalMethod.name();
+      description = signalMethod.description();
     }
     if (queryMethod != null) {
       type = WorkflowMethodType.QUERY;
@@ -65,11 +68,13 @@ final class POJOWorkflowMethod {
       }
       count++;
       name = queryMethod.name();
+      description = queryMethod.description();
     }
     if (updateMethod != null) {
       type = WorkflowMethodType.UPDATE;
       count++;
       name = updateMethod.name();
+      description = updateMethod.description();
     }
     if (updateValidatorMethod != null) {
       type = WorkflowMethodType.UPDATE_VALIDATOR;
@@ -86,13 +91,19 @@ final class POJOWorkflowMethod {
       throw new IllegalArgumentException(
           method
               + " must contain exactly one annotation "
-              + "of @WorkflowMethod, @QueryMethod or @SignalMethod");
+              + "of @WorkflowMethod, @QueryMethod @UpdateMethod or @SignalMethod");
     }
     if (Strings.isNullOrEmpty(name)) {
       this.nameFromAnnotation = Optional.empty();
     } else {
       this.nameFromAnnotation = Optional.of(name);
     }
+
+    if (Strings.isNullOrEmpty(description)) {
+      this.descriptionFromAnnotation = Optional.empty();
+    } else {
+      this.descriptionFromAnnotation = Optional.of(description);
+    }
     this.type = Objects.requireNonNull(type);
   }
 
@@ -108,6 +119,10 @@ public Optional<String> getNameFromAnnotation() {
     return nameFromAnnotation;
   }
 
+  public Optional<String> getDescriptionFromAnnotation() {
+    return descriptionFromAnnotation;
+  }
+
   /** Compare and hash on method only. */
   @Override
   public boolean equals(Object o) {

temporal-sdk/src/main/java/io/temporal/common/metadata/POJOWorkflowMethodMetadata.java

@@ -29,6 +29,7 @@ public final class POJOWorkflowMethodMetadata {
 
   private final POJOWorkflowMethod workflowMethod;
   private final String name;
+  private final String description;
   private final Class<?> workflowInterface;
 
   POJOWorkflowMethodMetadata(POJOWorkflowMethod methodMetadata, Class<?> workflowInterface) {
@@ -47,6 +48,7 @@ public final class POJOWorkflowMethodMetadata {
     } else {
       this.name = nameFromAnnotation.orElse(methodMetadata.getMethod().getName());
     }
+    this.description = workflowMethod.getDescriptionFromAnnotation().orElse("");
   }
 
   public WorkflowMethodType getType() {
@@ -62,6 +64,10 @@ public String getName() {
     return name;
   }
 
+  public String getDescription() {
+    return description;
+  }
+
   public Method getWorkflowMethod() {
     return workflowMethod.getMethod();
   }

temporal-sdk/src/main/java/io/temporal/internal/sync/QueryDispatcher.java

@@ -21,15 +21,14 @@
 package io.temporal.internal.sync;
 
 import io.temporal.api.common.v1.Payloads;
+import io.temporal.api.sdk.v1.WorkflowInteractionDefinition;
 import io.temporal.common.converter.DataConverter;
 import io.temporal.common.converter.EncodedValues;
 import io.temporal.common.interceptors.Header;
 import io.temporal.common.interceptors.WorkflowInboundCallsInterceptor;
 import io.temporal.common.interceptors.WorkflowOutboundCallsInterceptor;
 import io.temporal.workflow.DynamicQueryHandler;
-import java.util.HashMap;
-import java.util.Map;
-import java.util.Optional;
+import java.util.*;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -103,4 +102,25 @@ public void registerDynamicQueryHandler(
       WorkflowOutboundCallsInterceptor.RegisterDynamicQueryHandlerInput input) {
     dynamicQueryHandler = input.getHandler();
   }
+
+  public List<WorkflowInteractionDefinition> getQueryHandlers() {
+    List<WorkflowInteractionDefinition> handlers = new ArrayList<>(queryCallbacks.size() + 1);
+    for (Map.Entry<String, WorkflowOutboundCallsInterceptor.RegisterQueryInput> entry :
+        queryCallbacks.entrySet()) {
+      WorkflowOutboundCallsInterceptor.RegisterQueryInput handler = entry.getValue();
+      handlers.add(
+          WorkflowInteractionDefinition.newBuilder()
+              .setName(handler.getQueryType())
+              .setDescription(handler.getDescription())
+              .build());
+    }
+    if (dynamicQueryHandler != null) {
+      handlers.add(
+          WorkflowInteractionDefinition.newBuilder()
+              .setDescription(dynamicQueryHandler.getDescription())
+              .build());
+    }
+    handlers.sort(Comparator.comparing(WorkflowInteractionDefinition::getName));
+    return handlers;
+  }
 }

temporal-sdk/src/main/java/io/temporal/internal/sync/SignalDispatcher.java

@@ -21,6 +21,7 @@
 package io.temporal.internal.sync;
 
 import io.temporal.api.common.v1.Payloads;
+import io.temporal.api.sdk.v1.WorkflowInteractionDefinition;
 import io.temporal.common.converter.DataConverter;
 import io.temporal.common.converter.DataConverterException;
 import io.temporal.common.converter.EncodedValues;
@@ -160,6 +161,27 @@ private void logSerializationException(
     Workflow.getMetricsScope().counter(MetricsType.CORRUPTED_SIGNALS_COUNTER).inc(1);
   }
 
+  public List<WorkflowInteractionDefinition> getSignalHandlers() {
+    List<WorkflowInteractionDefinition> handlers = new ArrayList<>(signalCallbacks.size() + 1);
+    for (Map.Entry<String, WorkflowOutboundCallsInterceptor.SignalRegistrationRequest> entry :
+        signalCallbacks.entrySet()) {
+      WorkflowOutboundCallsInterceptor.SignalRegistrationRequest handler = entry.getValue();
+      handlers.add(
+          WorkflowInteractionDefinition.newBuilder()
+              .setName(handler.getSignalType())
+              .setDescription(handler.getDescription())
+              .build());
+    }
+    if (dynamicSignalHandler != null) {
+      handlers.add(
+          WorkflowInteractionDefinition.newBuilder()
+              .setDescription(dynamicSignalHandler.getDescription())
+              .build());
+    }
+    handlers.sort(Comparator.comparing(WorkflowInteractionDefinition::getName));
+    return handlers;
+  }
+
   private static class SignalData {
     private final String signalName;
     private final Optional<Payloads> payload;

temporal-sdk/src/main/java/io/temporal/internal/sync/SyncWorkflow.java

@@ -39,6 +39,7 @@
 import io.temporal.internal.statemachines.UpdateProtocolCallback;
 import io.temporal.internal.worker.WorkflowExecutionException;
 import io.temporal.internal.worker.WorkflowExecutorCache;
+import io.temporal.payload.context.WorkflowSerializationContext;
 import io.temporal.worker.WorkflowImplementationOptions;
 import io.temporal.workflow.UpdateInfo;
 import java.util.List;
@@ -69,6 +70,7 @@ class SyncWorkflow implements ReplayWorkflow {
   private WorkflowExecutionHandler workflowProc;
   private DeterministicRunner runner;
   private DataConverter dataConverter;
+  private DataConverter dataConverterWithWorkflowContext;
 
   public SyncWorkflow(
       String namespace,
@@ -92,6 +94,9 @@ public SyncWorkflow(
     this.cache = cache;
     this.defaultDeadlockDetectionTimeout = defaultDeadlockDetectionTimeout;
     this.dataConverter = dataConverter;
+    this.dataConverterWithWorkflowContext =
+        dataConverter.withContext(
+            new WorkflowSerializationContext(namespace, workflowExecution.getWorkflowId()));
     this.workflowContext =
         new SyncWorkflowContext(
             namespace,
@@ -238,6 +243,9 @@ public Optional<Payloads> query(WorkflowQuery query) {
       // converter
       return DefaultDataConverter.STANDARD_INSTANCE.toPayloads(runner.stackTrace());
     }
+    if (WorkflowClient.QUERY_TYPE_WORKFLOW_METADATA.equals(query.getQueryType())) {
+      return dataConverterWithWorkflowContext.toPayloads(workflowContext.getWorkflowMetadata());
+    }
     Optional<Payloads> args =
         query.hasQueryArgs() ? Optional.of(query.getQueryArgs()) : Optional.empty();
     return workflowProc.handleQuery(query.getQueryType(), query.getHeader(), args);