[Refactor] OpenSearchException streamables to a registry (opensearch-…

…project#7646)

* [Refactor] OpenSearchException streamables to a registry

OpenSearchException uses an enumerator to create a handler for each
serializable Exception implementation. The enumerator is to make it easy
to store in an immutable map. The problem with this Hack is that it
makes it difficult to unwind the tight coupling of StreamInput with the
OpenSearchException class. This commit switches from using an enumerator
to a registry in the opensearch-core library in order to support
serverless and cloud native implementations outside of the server
module.

This commit also refactors base primitive serialization readers and
writers from StreamInput and StreamOutput to BaseStreamInput and
BaseStreamOutput, respectively.

Signed-off-by: Nicholas Walter Knize <[email protected]>

* revert Project_Default

Signed-off-by: Nicholas Walter Knize <[email protected]>

---------

Signed-off-by: Nicholas Walter Knize <[email protected]>
Signed-off-by: Shivansh Arora <[email protected]>

libs/core/src/main/java/org/opensearch/BaseOpenSearchException.java

@@ -31,8 +31,10 @@
  */
 package org.opensearch;
 
+import org.opensearch.common.CheckedFunction;
 import org.opensearch.common.Nullable;
 import org.opensearch.core.common.Strings;
+import org.opensearch.core.common.io.stream.BaseStreamInput;
 import org.opensearch.core.common.logging.LoggerMessageFormat;
 import org.opensearch.core.xcontent.ToXContent;
 import org.opensearch.core.xcontent.ToXContentFragment;
@@ -41,10 +43,12 @@
 
 import java.io.IOException;
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
 
 import static java.util.Collections.singletonMap;
 
@@ -434,4 +438,98 @@ private String getShardIdString() {
         }
         return null;
     }
+
+    /**
+     * An ExceptionHandle for registering Exceptions that can be serialized over the transport wire
+     *
+     * @opensearch.internal
+     */
+    protected static abstract class BaseOpenSearchExceptionHandle {
+        final Class<? extends BaseOpenSearchException> exceptionClass;
+        final CheckedFunction<? extends BaseStreamInput, ? extends BaseOpenSearchException, IOException> constructor;
+        final int id;
+        final Version versionAdded;
+
+        <E extends BaseOpenSearchException, S extends BaseStreamInput> BaseOpenSearchExceptionHandle(
+            Class<E> exceptionClass,
+            CheckedFunction<S, E, IOException> constructor,
+            int id,
+            Version versionAdded
+        ) {
+            // We need the exceptionClass because you can't dig it out of the constructor reliably.
+            this.exceptionClass = exceptionClass;
+            this.constructor = constructor;
+            this.versionAdded = versionAdded;
+            this.id = id;
+        }
+    }
+
+    @SuppressWarnings("unchecked")
+    public static <T extends BaseStreamInput> BaseOpenSearchException readException(T input, int id) throws IOException {
+        CheckedFunction<T, ? extends BaseOpenSearchException, IOException> opensearchException = (CheckedFunction<
+            T,
+            ? extends BaseOpenSearchException,
+            IOException>) OpenSearchExceptionHandleRegistry.getSupplier(id);
+        if (opensearchException == null) {
+            throw new IllegalStateException("unknown exception for id: " + id);
+        }
+        return opensearchException.apply(input);
+    }
+
+    /**
+     * Registry of ExceptionHandlers
+     *
+     * @opensearch.internal
+     */
+    public static class OpenSearchExceptionHandleRegistry {
+        /** Registry mapping from unique Ordinal to the Exception Constructor */
+        private static final Map<
+            Integer,
+            CheckedFunction<? extends BaseStreamInput, ? extends BaseOpenSearchException, IOException>> ID_TO_SUPPLIER_REGISTRY =
+                new ConcurrentHashMap<>();
+        /** Registry mapping from Exception class to the Exception Handler  */
+        private static final Map<
+            Class<? extends BaseOpenSearchException>,
+            BaseOpenSearchExceptionHandle> CLASS_TO_OPENSEARCH_EXCEPTION_HANDLE_REGISTRY = new ConcurrentHashMap<>();
+
+        /** returns the Exception constructor function from a given ordinal */
+        public static CheckedFunction<? extends BaseStreamInput, ? extends BaseOpenSearchException, IOException> getSupplier(final int id) {
+            return ID_TO_SUPPLIER_REGISTRY.get(id);
+        }
+
+        /** registers the Exception handler */
+        public static void registerExceptionHandle(final BaseOpenSearchExceptionHandle handle) {
+            ID_TO_SUPPLIER_REGISTRY.put(handle.id, handle.constructor);
+            CLASS_TO_OPENSEARCH_EXCEPTION_HANDLE_REGISTRY.put(handle.exceptionClass, handle);
+        }
+
+        /** Gets the unique ordinal id of the Exception from the given class */
+        public static int getId(final Class<? extends BaseOpenSearchException> exception) {
+            return CLASS_TO_OPENSEARCH_EXCEPTION_HANDLE_REGISTRY.get(exception).id;
+        }
+
+        /** returns a set of ids */
+        public static Set<Integer> ids() {
+            return ID_TO_SUPPLIER_REGISTRY.keySet();
+        }
+
+        /** returns a collection of handles */
+        public static Collection<BaseOpenSearchExceptionHandle> handles() {
+            return CLASS_TO_OPENSEARCH_EXCEPTION_HANDLE_REGISTRY.values();
+        }
+
+        /** checks that the exception class is registered */
+        public static boolean isRegistered(final Class<? extends Throwable> exception, final Version version) {
+            BaseOpenSearchExceptionHandle openSearchExceptionHandle = CLASS_TO_OPENSEARCH_EXCEPTION_HANDLE_REGISTRY.get(exception);
+            if (openSearchExceptionHandle != null) {
+                return version.onOrAfter(openSearchExceptionHandle.versionAdded);
+            }
+            return false;
+        }
+
+        /** returns a set of registered exception classes */
+        public static Set<Class<? extends BaseOpenSearchException>> getRegisteredKeys() { // for testing
+            return CLASS_TO_OPENSEARCH_EXCEPTION_HANDLE_REGISTRY.keySet();
+        }
+    }
 }