Interceptor refactoring to support headers (#311)

Author: mfateev

temporal-sdk/src/main/java/io/temporal/common/interceptors/ActivityInterceptor.java renamed to temporal-sdk/src/main/java/io/temporal/common/interceptors/Header.java

@@ -19,6 +19,26 @@
 
 package io.temporal.common.interceptors;
 
-public interface ActivityInterceptor {
-  ActivityInboundCallsInterceptor interceptActivity(ActivityInboundCallsInterceptor next);
+import io.temporal.api.common.v1.Payload;
+import java.util.HashMap;
+import java.util.Map;
+
+public class Header {
+  private final Map<String, Payload> values;
+
+  public Header(io.temporal.api.common.v1.Header header) {
+    values = header.getFieldsMap();
+  }
+
+  public static Header empty() {
+    return new Header(new HashMap<>());
+  }
+
+  public Header(Map<String, Payload> values) {
+    this.values = values;
+  }
+
+  public Map<String, Payload> getValues() {
+    return values;
+  }
 }

temporal-sdk/src/main/java/io/temporal/common/interceptors/WorkflowInterceptor.java renamed to temporal-sdk/src/main/java/io/temporal/common/interceptors/WorkerInterceptor.java

@@ -20,10 +20,12 @@
 package io.temporal.common.interceptors;
 
 /**
- * Intercepts workflow execution.
+ * Intercepts workflow and activity executions.
  *
  * <p>TODO(maxim): JavaDoc with sample
  */
-public interface WorkflowInterceptor {
+public interface WorkerInterceptor {
   WorkflowInboundCallsInterceptor interceptWorkflow(WorkflowInboundCallsInterceptor next);
+
+  ActivityInboundCallsInterceptor interceptActivity(ActivityInboundCallsInterceptor next);
 }

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

@@ -24,6 +24,91 @@
  * restrictions on the workflow code should be obeyed.
  */
 public interface WorkflowInboundCallsInterceptor {
+
+  final class WorkflowInput {
+    private final Header header;
+    private final Object[] arguments;
+
+    public WorkflowInput(Header header, Object[] arguments) {
+      this.header = header;
+      this.arguments = arguments;
+    }
+
+    public Header getHeader() {
+      return header;
+    }
+
+    public Object[] getArguments() {
+      return arguments;
+    }
+  }
+
+  final class WorkflowOutput {
+    private final Object result;
+
+    public WorkflowOutput(Object result) {
+      this.result = result;
+    }
+
+    public Object getResult() {
+      return result;
+    }
+  }
+
+  final class SignalInput {
+    private final String signalName;
+    private final Object[] arguments;
+    private final long EventId;
+
+    public SignalInput(String signalName, Object[] arguments, long eventId) {
+      this.signalName = signalName;
+      this.arguments = arguments;
+      EventId = eventId;
+    }
+
+    public String getSignalName() {
+      return signalName;
+    }
+
+    public Object[] getArguments() {
+      return arguments;
+    }
+
+    public long getEventId() {
+      return EventId;
+    }
+  }
+
+  final class QueryInput {
+    private final String queryName;
+    private final Object[] arguments;
+
+    public QueryInput(String signalName, Object[] arguments) {
+      this.queryName = signalName;
+      this.arguments = arguments;
+    }
+
+    public String getQueryName() {
+      return queryName;
+    }
+
+    public Object[] getArguments() {
+      return arguments;
+    }
+  }
+
+  final class QueryOutput {
+    private final Object result;
+
+    public QueryOutput(Object result) {
+      this.result = result;
+    }
+
+    public Object getResult() {
+      return result;
+    }
+  }
+
   /**
    * Called when workflow class is instantiated.
    *
@@ -36,8 +121,11 @@ public interface WorkflowInboundCallsInterceptor {
    *
    * @return result of the workflow execution.
    */
-  Object execute(Object[] arguments);
+  WorkflowOutput execute(WorkflowInput input);
+
+  /** Called when signal is delivered to a workflow execution. */
+  void handleSignal(SignalInput input);
 
-  /** Called when signal is delivered to the workflow instance. */
-  void processSignal(String signalName, Object[] arguments, long EventId);
+  /** Called when a workflow is queried. */
+  QueryOutput handleQuery(QueryInput input);
 }

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

@@ -33,12 +33,17 @@ public void init(WorkflowOutboundCallsInterceptor outboundCalls) {
   }
 
   @Override
-  public Object execute(Object[] arguments) {
-    return next.execute(arguments);
+  public WorkflowOutput execute(WorkflowInput input) {
+    return next.execute(input);
   }
 
   @Override
-  public void processSignal(String signalName, Object[] arguments, long eventId) {
-    next.processSignal(signalName, arguments, eventId);
+  public void handleSignal(SignalInput input) {
+    next.handleSignal(input);
+  }
+
+  @Override
+  public QueryOutput handleQuery(QueryInput input) {
+    return next.handleQuery(input);
   }
 }