| /* |
| * 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.commons.jexl3.internal; |
| |
| import org.apache.commons.jexl3.JexlContext; |
| import org.apache.commons.jexl3.JexlEngine; |
| import org.apache.commons.jexl3.JexlScript; |
| import org.apache.commons.jexl3.JexlExpression; |
| import org.apache.commons.jexl3.parser.ASTJexlScript; |
| |
| import org.apache.commons.jexl3.parser.JexlNode; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Set; |
| |
| /** |
| * <p>A JexlScript implementation.</p> |
| * @since 1.1 |
| */ |
| public class Script implements JexlScript, JexlExpression { |
| /** |
| * The engine for this expression. |
| */ |
| protected final Engine jexl; |
| /** |
| * Original expression stripped from leading and trailing spaces. |
| */ |
| protected final String source; |
| /** |
| * The resulting AST we can interpret. |
| */ |
| protected final ASTJexlScript script; |
| /** |
| * The engine version (as class loader change count) that last evaluated this script. |
| */ |
| protected int version; |
| |
| /** |
| * Do not let this be generally instantiated with a 'new'. |
| * |
| * @param engine the interpreter to evaluate the expression |
| * @param expr the expression source. |
| * @param ref the parsed expression. |
| */ |
| protected Script(Engine engine, String expr, ASTJexlScript ref) { |
| jexl = engine; |
| source = expr; |
| script = ref; |
| version = jexl.getUberspect().getVersion(); |
| } |
| |
| /** |
| * Checks that this script cached methods (wrt introspection) matches the engine version. |
| * <p> |
| * If the engine class loader has changed since we last evaluated this script, the script local cache |
| * is invalidated to drop references to obsolete methods. It is not strictly necessary since the tryExecute |
| * will fail because the class wont match but it seems cleaner nevertheless. |
| * </p> |
| */ |
| protected void checkCacheVersion() { |
| int uberVersion = jexl.getUberspect().getVersion(); |
| if (version != uberVersion) { |
| script.clearCache(); |
| version = uberVersion; |
| } |
| } |
| |
| /** |
| * Creates this script frame for evaluation. |
| * @param args the arguments to bind to parameters |
| * @return the frame (may be null) |
| */ |
| protected Scope.Frame createFrame(Object[] args) { |
| return script.createFrame(args); |
| } |
| |
| /** |
| * Creates this script interpreter. |
| * @param context the context |
| * @param frame the calling frame |
| * @return the interpreter |
| */ |
| protected Interpreter createInterpreter(JexlContext context, Scope.Frame frame) { |
| return jexl.createInterpreter(context, frame); |
| } |
| |
| /** |
| * @return the engine that created this script |
| */ |
| public JexlEngine getEngine() { |
| return jexl; |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public String getSourceText() { |
| return source; |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public String getParsedText() { |
| return getParsedText(2); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public String getParsedText(int indent) { |
| Debugger debug = new Debugger(); |
| debug.setIndentation(indent); |
| debug.debug(script); |
| return debug.toString(); |
| } |
| |
| @Override |
| public int hashCode() { |
| // CSOFF: Magic number |
| int hash = 17; |
| hash = 31 * hash + (this.jexl != null ? this.jexl.hashCode() : 0); |
| hash = 31 * hash + (this.source != null ? this.source.hashCode() : 0); |
| return hash; |
| // CSON: Magic number |
| } |
| |
| @Override |
| public boolean equals(Object obj) { |
| if (obj == null) { |
| return false; |
| } |
| if (getClass() != obj.getClass()) { |
| return false; |
| } |
| final Script other = (Script) obj; |
| if (this.jexl != other.jexl) { |
| return false; |
| } |
| if ((this.source == null) ? (other.source != null) : !this.source.equals(other.source)) { |
| return false; |
| } |
| return true; |
| } |
| |
| @Override |
| public String toString() { |
| CharSequence src = source; |
| if (src == null) { |
| Debugger debug = new Debugger(); |
| debug.debug(script); |
| src = debug.toString(); |
| } |
| return src.toString(); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public Object evaluate(JexlContext context) { |
| if (script.jjtGetNumChildren() < 1) { |
| return null; |
| } |
| checkCacheVersion(); |
| Scope.Frame frame = createFrame((Object[]) null); |
| Interpreter interpreter = createInterpreter(context, frame); |
| return interpreter.interpret(script.jjtGetChild(0)); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public Object execute(JexlContext context) { |
| checkCacheVersion(); |
| Scope.Frame frame = createFrame((Object[]) null); |
| Interpreter interpreter = createInterpreter(context, frame); |
| return interpreter.interpret(script); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public Object execute(JexlContext context, Object... args) { |
| checkCacheVersion(); |
| Scope.Frame frame = createFrame(args != null && args.length > 0 ? args : null); |
| Interpreter interpreter = createInterpreter(context, frame); |
| return interpreter.interpret(script); |
| } |
| |
| /** |
| * A script whose parameters are (partially) bound. |
| */ |
| public static class Curried extends Script { |
| /** The evaluation frame. */ |
| private final Scope.Frame frame; |
| |
| /** |
| * Creates a curried version of this script. |
| * @param base the base script |
| * @param args the arguments |
| */ |
| protected Curried(Script base, Object[] args) { |
| super(base.jexl, base.source, base.script); |
| Scope.Frame sf = (base instanceof Curried) ? ((Curried) base).frame : null; |
| if (sf != null) { |
| frame = sf.assign(args); |
| } else { |
| frame = script.createFrame(args); |
| } |
| } |
| |
| @Override |
| protected Scope.Frame createFrame(Object[] args) { |
| return frame != null? frame.assign(args) : super.createFrame(args); |
| } |
| |
| @Override |
| public boolean equals(Object obj) { |
| return this == obj; |
| } |
| |
| @Override |
| public int hashCode() { |
| return System.identityHashCode(this); |
| } |
| |
| @Override |
| public Object execute(JexlContext context) { |
| return execute(context, (Object[])null); |
| } |
| |
| @Override |
| public Object execute(JexlContext context, Object... args) { |
| Scope.Frame callFrame = null; |
| if (frame != null) { |
| callFrame = frame.assign(args); |
| } |
| Interpreter interpreter = jexl.createInterpreter(context, callFrame); |
| JexlNode block = script.jjtGetChild(script.jjtGetNumChildren() - 1); |
| return interpreter.interpret(block); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public JexlScript curry(Object... args) { |
| String[] parms = script.getParameters(); |
| if (parms == null || parms.length == 0) { |
| return this; |
| } |
| return new Curried(this, args); |
| } |
| |
| /** |
| * Gets this script parameters. |
| * @return the parameters or null |
| * @since 3.0 |
| */ |
| @Override |
| public String[] getParameters() { |
| return script.getParameters(); |
| } |
| |
| /** |
| * Gets this script local variables. |
| * @return the local variables or null |
| */ |
| @Override |
| public String[] getLocalVariables() { |
| return script.getLocalVariables(); |
| } |
| |
| /** |
| * Gets this script variables. |
| * <p>Note that since variables can be in an ant-ish form (ie foo.bar.quux), each variable is returned as |
| * a list of strings where each entry is a fragment of the variable ({"foo", "bar", "quux"} in the example.</p> |
| * @return the variables or null |
| */ |
| @Override |
| public Set<List<String>> getVariables() { |
| return jexl.getVariables(script); |
| } |
| |
| /** |
| * Get this script pragmas |
| * <p>Pragma keys are ant-ish variables, their values are scalar literals.. |
| * @return the pragmas |
| */ |
| @Override |
| public Map<String, Object> getPragmas() { |
| return script.getPragmas(); |
| } |
| |
| /** |
| * Creates a Callable from this script. |
| * <p>This allows to submit it to an executor pool and provides support for asynchronous calls.</p> |
| * <p>The interpreter will handle interruption/cancellation gracefully if needed.</p> |
| * @param context the context |
| * @return the callable |
| */ |
| @Override |
| public Callable callable(JexlContext context) { |
| return callable(context, (Object[]) null); |
| } |
| |
| /** |
| * Creates a Callable from this script. |
| * <p>This allows to submit it to an executor pool and provides support for asynchronous calls.</p> |
| * <p>The interpreter will handle interruption/cancellation gracefully if needed.</p> |
| * @param context the context |
| * @param args the script arguments |
| * @return the callable |
| */ |
| @Override |
| public Callable callable(JexlContext context, Object... args) { |
| return new Callable(jexl.createInterpreter(context, script.createFrame(args))); |
| } |
| |
| /** |
| * Implements the Future and Callable interfaces to help delegation. |
| */ |
| public class Callable implements java.util.concurrent.Callable<Object> { |
| /** The actual interpreter. */ |
| protected final Interpreter interpreter; |
| /** Use interpreter as marker for not having run. */ |
| protected volatile Object result; |
| |
| /** |
| * The base constructor. |
| * @param intrprtr the interpreter to use |
| */ |
| protected Callable(Interpreter intrprtr) { |
| this.interpreter = intrprtr; |
| this.result = intrprtr; |
| } |
| |
| /** |
| * Run the interpreter. |
| * @return the evaluation result |
| */ |
| protected Object interpret() { |
| return interpreter.interpret(script); |
| } |
| |
| @Override |
| public Object call() throws Exception { |
| synchronized(this) { |
| if (result == interpreter) { |
| checkCacheVersion(); |
| result = interpret(); |
| } |
| return result; |
| } |
| } |
| |
| /** |
| * Soft cancel the execution. |
| * @return true if cancel was successful, false otherwise |
| */ |
| public boolean cancel() { |
| return interpreter.cancel(); |
| } |
| |
| /** |
| * @return true if evaluation was cancelled, false otherwise |
| */ |
| public boolean isCancelled() { |
| return interpreter.isCancelled(); |
| } |
| |
| /** |
| * @return true if interruption will throw a JexlException.Cancel, false otherwise |
| */ |
| public boolean isCancellable() { |
| return interpreter.isCancellable(); |
| } |
| } |
| } |