Match Rest Path registry with RestController using SDKMethodHandlers (#…

…658)

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

src/main/java/org/opensearch/sdk/ExtensionsRunner.java

@@ -46,6 +46,7 @@
 import org.opensearch.sdk.handlers.ExtensionsInitRequestHandler;
 import org.opensearch.sdk.handlers.ExtensionsRestRequestHandler;
 import org.opensearch.sdk.handlers.UpdateSettingsRequestHandler;
+import org.opensearch.sdk.rest.ExtensionRestPathRegistry;
 import org.opensearch.tasks.TaskManager;
 import org.opensearch.threadpool.ExecutorBuilder;
 import org.opensearch.threadpool.RunnableTaskExecutionListener;

src/main/java/org/opensearch/sdk/handlers/ExtensionsRestRequestHandler.java

@@ -18,11 +18,10 @@
 import org.opensearch.sdk.ExtensionRestHandler;
 import org.opensearch.sdk.ExtensionsRunner;
 import org.opensearch.sdk.SDKNamedXContentRegistry;
+import org.opensearch.sdk.rest.ExtensionRestPathRegistry;
 import org.opensearch.sdk.rest.SDKHttpRequest;
 import org.opensearch.sdk.rest.SDKRestRequest;
 
-import org.opensearch.sdk.ExtensionRestPathRegistry;
-
 import static java.nio.charset.StandardCharsets.UTF_8;
 import static java.util.Collections.emptyMap;
 import static java.util.Collections.emptyList;

src/main/java/org/opensearch/sdk/ExtensionRestPathRegistry.java → src/main/java/org/opensearch/sdk/rest/ExtensionRestPathRegistry.java

@@ -7,22 +7,24 @@
  * compatible open source license.
  */
 
-package org.opensearch.sdk;
+package org.opensearch.sdk.rest;
 
 import java.util.ArrayList;
 import java.util.List;
 
+import org.opensearch.common.Nullable;
 import org.opensearch.common.path.PathTrie;
 import org.opensearch.rest.RestUtils;
 import org.opensearch.rest.RestRequest.Method;
+import org.opensearch.sdk.ExtensionRestHandler;
 
 /**
  * This class registers REST paths from extension Rest Handlers.
  */
 public class ExtensionRestPathRegistry {
 
  // PathTrie to match paths to handlers
- private PathTrie<ExtensionRestHandler> pathTrie = new PathTrie<>(RestUtils.REST_DECODER);
+ private PathTrie<SDKMethodHandlers> pathTrie = new PathTrie<>(RestUtils.REST_DECODER);
  // List to return registered handlers
  private List<String> registeredPaths = new ArrayList<>();
 
@@ -34,20 +36,25 @@ public class ExtensionRestPathRegistry {
  * @param extensionRestHandler The RestHandler to handle this route
  */
  public void registerHandler(Method method, String path, ExtensionRestHandler extensionRestHandler) {
- String restPath = restPathToString(method, path);
- pathTrie.insert(restPath, extensionRestHandler);
- registeredPaths.add(restPath);
+ pathTrie.insertOrUpdate(
+ path,
+ new SDKMethodHandlers(path, extensionRestHandler, method),
+ (mHandlers, newMHandler) -> mHandlers.addMethods(extensionRestHandler, method)
+ );
+ registeredPaths.add(restPathToString(method, path));
  }
 
  /**
- * Get the registered REST handler for the specified method and URI.
+ * Get the registered REST handler for the specified method and path.
  *
  * @param method the registered method.
  * @param path the registered path.
- * @return The REST handler registered to handle this method and URI combination if found, null otherwise.
+ * @return The REST handler registered to handle this method and path combination if found, null otherwise.
  */
+ @Nullable
  public ExtensionRestHandler getHandler(Method method, String path) {
- return pathTrie.retrieve(restPathToString(method, path));
+ SDKMethodHandlers mHandlers = pathTrie.retrieve(path);
+ return mHandlers == null ? null : mHandlers.getHandler(method);
  }
 
  /**
@@ -60,7 +67,9 @@ public List<String> getRegisteredPaths() {
  }
 
  /**
- * Converts a REST method and path to a space delimited string to be used as a map lookup key.
+ * Converts a REST method and path to a space delimited string.
+ * <p>
+ * This provides convenience for logging and serialization over transport.
  *
  * @param method the method.
  * @param path the path.

src/main/java/org/opensearch/sdk/rest/SDKMethodHandlers.java

@@ -0,0 +1,67 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.sdk.rest;
+
+import org.opensearch.common.Nullable;
+import org.opensearch.sdk.ExtensionRestHandler;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Set;
+
+import static org.opensearch.rest.RestRequest.Method;
+
+/**
+ * Encapsulate multiple handlers for the same path, allowing different handlers for different HTTP verbs.
+ * <p>
+ * Used in SDK to provide identical path-matching functionality as OpenSearch, with Extension-based classes.
+ */
+final class SDKMethodHandlers {
+
+ private final String path;
+ private final Map<Method, ExtensionRestHandler> methodHandlers;
+
+ SDKMethodHandlers(String path, ExtensionRestHandler handler, Method... methods) {
+ this.path = path;
+ this.methodHandlers = new HashMap<>(methods.length);
+ for (Method method : methods) {
+ methodHandlers.put(method, handler);
+ }
+ }
+
+ /**
+ * Add a handler for an additional array of methods. Note that {@code SDKMethodHandlers}
+ * does not allow replacing the handler for an already existing method.
+ */
+ SDKMethodHandlers addMethods(ExtensionRestHandler handler, Method... methods) {
+ for (Method method : methods) {
+ ExtensionRestHandler existing = methodHandlers.putIfAbsent(method, handler);
+ if (existing != null) {
+ throw new IllegalArgumentException("Cannot replace existing handler for [" + path + "] for method: " + method);
+ }
+ }
+ return this;
+ }
+
+ /**
+ * Returns the handler for the given method or {@code null} if none exists.
+ */
+ @Nullable
+ ExtensionRestHandler getHandler(Method method) {
+ return methodHandlers.get(method);
+ }
+
+ /**
+ * Return a set of all valid HTTP methods for the particular path
+ */
+ Set<Method> getValidMethods() {
+ return methodHandlers.keySet();
+ }
+}

src/test/java/org/opensearch/sdk/TestExtensionRestPathRegistry.java

@@ -17,6 +17,7 @@
 import org.opensearch.rest.RestHandler.Route;
 import org.opensearch.rest.RestRequest;
 import org.opensearch.rest.RestRequest.Method;
+import org.opensearch.sdk.rest.ExtensionRestPathRegistry;
 import org.opensearch.test.OpenSearchTestCase;
 
 public class TestExtensionRestPathRegistry extends OpenSearchTestCase {
@@ -73,10 +74,10 @@ public void setUp() throws Exception {
  public void testRegisterConflicts() {
  // Can't register same exact name
  assertThrows(IllegalArgumentException.class, () -> extensionRestPathRegistry.registerHandler(Method.GET, "/foo", fooHandler));
- // Can't register conflicting named wildcards
+ // Can't register conflicting named wildcards, even if method is different
  assertThrows(
  IllegalArgumentException.class,
- () -> extensionRestPathRegistry.registerHandler(Method.PUT, "/bar/{none}", barHandler)
+ () -> extensionRestPathRegistry.registerHandler(Method.GET, "/bar/{none}", barHandler)
  );
  }
 

src/test/java/org/opensearch/sdk/TestExtensionsRunner.java

@@ -56,6 +56,7 @@
 import org.opensearch.sdk.handlers.EnvironmentSettingsResponseHandler;
 import org.opensearch.sdk.handlers.ExtensionsInitRequestHandler;
 import org.opensearch.sdk.handlers.ExtensionsRestRequestHandler;
+import org.opensearch.sdk.rest.ExtensionRestPathRegistry;
 import org.opensearch.sdk.handlers.AcknowledgedResponseHandler;
 import org.opensearch.test.OpenSearchTestCase;
 import org.opensearch.transport.Transport;