/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You 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. */ package org.apache.zeppelin.interpreter; import java.util.HashMap; import java.util.Map; /** * The InterpreterinterpreterHookRegistry specifies code to be conditionally executed by an * interpreter. The constants defined in this class denote currently * supported events. Each instance is bound to a single InterpreterGroup. * Scope is determined on a per-note basis (except when null for global scope). */ public class InterpreterHookRegistry { public static final String GLOBAL_KEY = "_GLOBAL_"; private String interpreterId; private Map<String, Map<String, Map<String, String>>> registry = new HashMap<>(); /** * hookRegistry constructor. * * @param interpreterId The Id of the InterpreterGroup instance to bind to */ public InterpreterHookRegistry(final String interpreterId) { this.interpreterId = interpreterId; } /** * Get the interpreterGroup id this instance is bound to */ public String getInterpreterId() { return interpreterId; } /** * Adds a note to the registry * * @param noteId The Id of the Note instance to add */ public void addNote(String noteId) { synchronized (registry) { if (registry.get(noteId) == null) { registry.put(noteId, new HashMap<String, Map<String, String>>()); } } } /** * Adds a className to the registry * * @param noteId The note id * @param className The name of the interpreter repl to map the hooks to */ public void addRepl(String noteId, String className) { synchronized (registry) { addNote(noteId); if (registry.get(noteId).get(className) == null) { registry.get(noteId).put(className, new HashMap<String, String>()); } } } /** * Register a hook for a specific event. * * @param noteId Denotes the note this instance belongs to * @param className The name of the interpreter repl to map the hooks to * @param event hook event (see constants defined in this class) * @param cmd Code to be executed by the interpreter */ public void register(String noteId, String className, String event, String cmd) throws IllegalArgumentException { synchronized (registry) { if (noteId == null) { noteId = GLOBAL_KEY; } addRepl(noteId, className); if (!event.equals(HookType.POST_EXEC) && !event.equals(HookType.PRE_EXEC) && !event.equals(HookType.POST_EXEC_DEV) && !event.equals(HookType.PRE_EXEC_DEV)) { throw new IllegalArgumentException("Must be " + HookType.POST_EXEC + ", " + HookType.POST_EXEC_DEV + ", " + HookType.PRE_EXEC + " or " + HookType.PRE_EXEC_DEV); } registry.get(noteId).get(className).put(event, cmd); } } /** * Unregister a hook for a specific event. * * @param noteId Denotes the note this instance belongs to * @param className The name of the interpreter repl to map the hooks to * @param event hook event (see constants defined in this class) */ public void unregister(String noteId, String className, String event) { synchronized (registry) { if (noteId == null) { noteId = GLOBAL_KEY; } addRepl(noteId, className); registry.get(noteId).get(className).remove(event); } } /** * Get a hook for a specific event. * * @param noteId Denotes the note this instance belongs to * @param className The name of the interpreter repl to map the hooks to * @param event hook event (see constants defined in this class) */ public String get(String noteId, String className, String event) { synchronized (registry) { if (noteId == null) { noteId = GLOBAL_KEY; } addRepl(noteId, className); return registry.get(noteId).get(className).get(event); } } /** * Container for hook event type constants */ public static final class HookType { // Execute the hook code PRIOR to main paragraph code execution public static final String PRE_EXEC = "pre_exec"; // Execute the hook code AFTER main paragraph code execution public static final String POST_EXEC = "post_exec"; // Same as above but reserved for interpreter developers, in order to allow // notebook users to use the above without overwriting registry settings // that are initialized directly in subclasses of Interpreter. public static final String PRE_EXEC_DEV = "pre_exec_dev"; public static final String POST_EXEC_DEV = "post_exec_dev"; } }