Refactor TemplateParser to WorkflowProcessSorter

Signed-off-by: Daniel Widdis <[email protected]>

src/main/java/demo/DataDemo.java

@@ -14,7 +14,7 @@
 import org.opensearch.common.io.PathUtils;
 import org.opensearch.flowframework.template.ProcessNode;
 import org.opensearch.flowframework.template.Template;
-import org.opensearch.flowframework.template.TemplateParser;
+import org.opensearch.flowframework.template.WorkflowProcessSorter;
 
 import java.io.IOException;
 import java.nio.charset.StandardCharsets;
@@ -26,7 +26,7 @@
 import java.util.stream.Collectors;
 
 /**
- * Demo class exercising {@link TemplateParser}. This will be moved to a unit test.
+ * Demo class exercising {@link WorkflowProcessSorter}. This will be moved to a unit test.
  */
 public class DataDemo {
 
@@ -50,8 +50,8 @@ public static void main(String[] args) throws IOException {
         }
 
         logger.info("Parsing graph to sequence...");
-        Template t = TemplateParser.parseJsonToTemplate(json);
-        List<ProcessNode> processSequence = TemplateParser.parseWorkflowToSequence(t.workflows().get("datademo"));
+        Template t = Template.parse(json);
+        List<ProcessNode> processSequence = WorkflowProcessSorter.sortProcessNodes(t.workflows().get("datademo"));
         List<CompletableFuture<?>> futureList = new ArrayList<>();
 
         for (ProcessNode n : processSequence) {

src/main/java/demo/Demo.java

@@ -14,7 +14,7 @@
 import org.opensearch.common.io.PathUtils;
 import org.opensearch.flowframework.template.ProcessNode;
 import org.opensearch.flowframework.template.Template;
-import org.opensearch.flowframework.template.TemplateParser;
+import org.opensearch.flowframework.template.WorkflowProcessSorter;
 
 import java.io.IOException;
 import java.nio.charset.StandardCharsets;
@@ -26,7 +26,7 @@
 import java.util.stream.Collectors;
 
 /**
- * Demo class exercising {@link TemplateParser}. This will be moved to a unit test.
+ * Demo class exercising {@link WorkflowProcessSorter}. This will be moved to a unit test.
  */
 public class Demo {
 
@@ -50,8 +50,8 @@ public static void main(String[] args) throws IOException {
         }
 
         logger.info("Parsing graph to sequence...");
-        Template t = TemplateParser.parseJsonToTemplate(json);
-        List<ProcessNode> processSequence = TemplateParser.parseWorkflowToSequence(t.workflows().get("demo"));
+        Template t = Template.parse(json);
+        List<ProcessNode> processSequence = WorkflowProcessSorter.sortProcessNodes(t.workflows().get("demo"));
         List<CompletableFuture<?>> futureList = new ArrayList<>();
 
         for (ProcessNode n : processSequence) {

src/main/java/demo/TemplateParseDemo.java

@@ -13,7 +13,7 @@
 import org.opensearch.common.SuppressForbidden;
 import org.opensearch.common.io.PathUtils;
 import org.opensearch.flowframework.template.Template;
-import org.opensearch.flowframework.template.TemplateParser;
+import org.opensearch.flowframework.template.WorkflowProcessSorter;
 import org.opensearch.flowframework.workflow.Workflow;
 
 import java.io.IOException;
@@ -22,7 +22,7 @@
 import java.util.Map.Entry;
 
 /**
- * Demo class exercising {@link TemplateParser}. This will be moved to a unit test.
+ * Demo class exercising {@link WorkflowProcessSorter}. This will be moved to a unit test.
  */
 public class TemplateParseDemo {
 
@@ -45,14 +45,14 @@ public static void main(String[] args) throws IOException {
             return;
         }
 
-        Template t = TemplateParser.parseJsonToTemplate(json);
+        Template t = Template.parse(json);
 
         System.out.println(t.toJson());
         System.out.println(t.toYaml());
 
         for (Entry<String, Workflow> e : t.workflows().entrySet()) {
             logger.info("Parsing {} workflow.", e.getKey());
-            TemplateParser.parseWorkflowToSequence(e.getValue());
+            WorkflowProcessSorter.sortProcessNodes(e.getValue());
         }
     }
 }

src/main/java/org/opensearch/flowframework/template/Template.java

@@ -9,8 +9,10 @@
 package org.opensearch.flowframework.template;
 
 import org.opensearch.Version;
+import org.opensearch.common.xcontent.LoggingDeprecationHandler;
 import org.opensearch.common.xcontent.json.JsonXContent;
 import org.opensearch.common.xcontent.yaml.YamlXContent;
+import org.opensearch.core.xcontent.NamedXContentRegistry;
 import org.opensearch.core.xcontent.ToXContentObject;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.core.xcontent.XContentParser;
@@ -227,6 +229,23 @@ public static Template parse(XContentParser parser) throws IOException {
         return new Template(name, description, useCase, operations, templateVersion, compatibilityVersion, userInputs, workflows);
     }
 
+    /**
+     * Parse a JSON use case template
+     *
+     * @param json A string containing a JSON representation of a use case template
+     * @return A {@link Template} represented by the JSON.
+     * @throws IOException on failure to parse
+     */
+    public static Template parse(String json) throws IOException {
+        XContentParser parser = JsonXContent.jsonXContent.createParser(
+            NamedXContentRegistry.EMPTY,
+            LoggingDeprecationHandler.INSTANCE,
+            json
+        );
+        ensureExpectedToken(XContentParser.Token.START_OBJECT, parser.nextToken(), parser);
+        return parse(parser);
+    }
+
     /**
      * Builds an XContent object representing a map of String keys to String values.
      *

src/main/java/org/opensearch/flowframework/template/TemplateParser.java → src/main/java/org/opensearch/flowframework/template/WorkflowProcessSorter.java

@@ -10,16 +10,11 @@
 
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
-import org.opensearch.common.xcontent.LoggingDeprecationHandler;
-import org.opensearch.common.xcontent.json.JsonXContent;
-import org.opensearch.core.xcontent.NamedXContentRegistry;
-import org.opensearch.core.xcontent.XContentParser;
 import org.opensearch.flowframework.workflow.Workflow;
 import org.opensearch.flowframework.workflow.WorkflowData;
 import org.opensearch.flowframework.workflow.WorkflowStep;
 import org.opensearch.flowframework.workflow.WorkflowStepFactory;
 
-import java.io.IOException;
 import java.util.ArrayDeque;
 import java.util.ArrayList;
 import java.util.Collections;
@@ -32,44 +27,24 @@
 import java.util.function.Function;
 import java.util.stream.Collectors;
 
-import static org.opensearch.core.xcontent.XContentParserUtils.ensureExpectedToken;
-
 /**
- * Utility class for parsing templates.
+ * Utility class converting a workflow of nodes and edges into a topologically sorted list of Process Nodes.
  */
-public class TemplateParser {
+public class WorkflowProcessSorter {
 
-    private static final Logger logger = LogManager.getLogger(TemplateParser.class);
+    private static final Logger logger = LogManager.getLogger(WorkflowProcessSorter.class);
 
     /**
      * Prevent instantiating this class.
      */
-    private TemplateParser() {}
-
-    /**
-     * Parse a JSON use case template
-     *
-     * @param json A string containing a JSON representation of a use case template
-     * @return A {@link Template} represented by the JSON.
-     * @throws IOException on failure to parse
-     */
-    public static Template parseJsonToTemplate(String json) throws IOException {
-        logger.info("Parsing template...");
-        XContentParser parser = JsonXContent.jsonXContent.createParser(
-            NamedXContentRegistry.EMPTY,
-            LoggingDeprecationHandler.INSTANCE,
-            json
-        );
-        ensureExpectedToken(XContentParser.Token.START_OBJECT, parser.nextToken(), parser);
-        return Template.parse(parser);
-    }
+    private WorkflowProcessSorter() {}
 
     /**
-     * Parse a JSON representation of nodes and edges into a topologically sorted list of process nodes.
-     * @param workflow A string containing a JSON representation of nodes and edges
+     * Sort a workflow into a topologically sorted list of process nodes.
+     * @param workflow A workflow with (unsorted) nodes and edges which define predecessors and successors
      * @return A list of Process Nodes sorted topologically.  All predecessors of any node will occur prior to it in the list.
      */
-    public static List<ProcessNode> parseWorkflowToSequence(Workflow workflow) {
+    public static List<ProcessNode> sortProcessNodes(Workflow workflow) {
         List<WorkflowNode> sortedNodes = topologicalSort(workflow.nodes(), workflow.edges());
 
         List<ProcessNode> nodes = new ArrayList<>();

src/test/java/org/opensearch/flowframework/template/TemplateParserTests.java

@@ -31,7 +31,7 @@ public class TemplateParserTests extends OpenSearchTestCase {
     private static List<String> parse(String json) throws IOException {
         XContentParser parser = TemplateTestJsonUtil.jsonToParser(json);
         Workflow w = Workflow.parse(parser);
-        return TemplateParser.parseWorkflowToSequence(w).stream().map(ProcessNode::id).collect(Collectors.toList());
+        return WorkflowProcessSorter.sortProcessNodes(w).stream().map(ProcessNode::id).collect(Collectors.toList());
     }
 
     @Override

src/test/java/org/opensearch/flowframework/template/TemplateTests.java

@@ -65,7 +65,7 @@ public void testTemplate() throws IOException {
         String json = TemplateTestJsonUtil.parseToJson(template);
         assertEquals(expectedJson, json);
 
-        Template templateX = TemplateParser.parseJsonToTemplate(json);
+        Template templateX = Template.parse(json);
         assertEquals("test", templateX.name());
         assertEquals("a test template", templateX.description());
         assertEquals("test use case", templateX.useCase());