runtime-v2: save out variables for failed process

runtime/v2/runner/src/main/java/com/walmartlabs/concord/runtime/v2/runner/OutVariablesProcessor.java

@@ -9,9 +9,9 @@
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *      http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -20,6 +20,7 @@
  * =====
  */
 
+import com.fasterxml.jackson.core.type.TypeReference;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.walmartlabs.concord.runtime.v2.sdk.EvalContext;
 import com.walmartlabs.concord.runtime.v2.sdk.EvalContextFactory;
@@ -43,6 +44,9 @@
  */
 public class OutVariablesProcessor implements ExecutionListener {
 
+    private static final TypeReference<Map<String, Object>> MAP_TYPE = new TypeReference<>() {
+    };
+
     private final ObjectMapper objectMapper;
     private final PersistenceService persistenceService;
     private final List<String> outVariables;
@@ -84,7 +88,13 @@ public void afterProcessEnds(Runtime runtime, State state, Frame lastFrame) {
             return;
         }
 
+        Map<String, Object> currentOut = persistenceService.loadPersistedFile(Constants.Files.OUT_VALUES_FILE_NAME,
+                in -> objectMapper.readValue(in, MAP_TYPE));
+
+        Map<String, Object> result = new HashMap<>(currentOut != null ? currentOut : Collections.emptyMap());
+        result.putAll(outValues);
+
         persistenceService.persistFile(Constants.Files.OUT_VALUES_FILE_NAME,
-                out -> objectMapper.writeValue(out, outValues));
+                out -> objectMapper.writeValue(out, result));
     }
 }

runtime/v2/runner/src/main/java/com/walmartlabs/concord/runtime/v2/runner/Runner.java

@@ -26,9 +26,7 @@
 import com.walmartlabs.concord.runtime.common.injector.InstanceId;
 import com.walmartlabs.concord.runtime.v2.model.ProcessDefinition;
 import com.walmartlabs.concord.runtime.v2.runner.compiler.CompilerUtils;
-import com.walmartlabs.concord.runtime.v2.runner.vm.SaveLastErrorCommand;
-import com.walmartlabs.concord.runtime.v2.runner.vm.UpdateLocalsCommand;
-import com.walmartlabs.concord.runtime.v2.runner.vm.VMUtils;
+import com.walmartlabs.concord.runtime.v2.runner.vm.*;
 import com.walmartlabs.concord.runtime.v2.sdk.Compiler;
 import com.walmartlabs.concord.runtime.v2.sdk.ProcessConfiguration;
 import com.walmartlabs.concord.svm.*;
@@ -77,7 +75,7 @@ public ProcessSnapshot start(ProcessConfiguration processConfiguration, ProcessD
         // install the exception handler into the root frame
         // takes care of all unhandled errors bubbling up
         VMUtils.assertNearestRoot(state, state.getRootThreadId())
-                .setExceptionHandler(new SaveLastErrorCommand());
+                .setExceptionHandler(new BlockCommand(new SaveOutVariablesOnErrorCommand(), new SaveLastErrorCommand()));
 
         VM vm = createVM(processDefinition);
         // update the global variables using the input map by running a special command

runtime/v2/runner/src/main/java/com/walmartlabs/concord/runtime/v2/runner/vm/SaveOutVariablesOnErrorCommand.java

@@ -0,0 +1,41 @@
+package com.walmartlabs.concord.runtime.v2.runner.vm;
+
+/*-
+ * *****
+ * Concord
+ * -----
+ * Copyright (C) 2017 - 2023 Walmart Inc.
+ * -----
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * =====
+ */
+
+import com.walmartlabs.concord.runtime.v2.runner.OutVariablesProcessor;
+import com.walmartlabs.concord.svm.Runtime;
+import com.walmartlabs.concord.svm.*;
+
+import java.io.Serial;
+
+public class SaveOutVariablesOnErrorCommand implements Command {
+
+    @Serial
+    private static final long serialVersionUID = 1L;
+
+    @Override
+    public void eval(Runtime runtime, State state, ThreadId threadId) throws Exception {
+        Frame frame = state.peekFrame(threadId);
+        frame.pop();
+
+        runtime.getService(OutVariablesProcessor.class).afterProcessEnds(runtime, state, frame);
+    }
+}