1 /*
   2  * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package jdk.nashorn.internal.runtime;
  27 
  28 import java.lang.invoke.MethodHandle;
  29 import java.util.Iterator;
  30 import java.util.List;
  31 import jdk.nashorn.internal.ir.LiteralNode;
  32 import jdk.nashorn.internal.ir.Node;
  33 import jdk.nashorn.internal.ir.ObjectNode;
  34 import jdk.nashorn.internal.ir.PropertyNode;
  35 import jdk.nashorn.internal.ir.UnaryNode;
  36 import jdk.nashorn.internal.parser.JSONParser;
  37 import jdk.nashorn.internal.parser.TokenType;
  38 import jdk.nashorn.internal.runtime.linker.Bootstrap;
  39 
  40 /**
  41  * Utilities used by "JSON" object implementation.
  42  */
  43 public final class JSONFunctions {
  44     private JSONFunctions() {}
  45     private static final MethodHandle REVIVER_INVOKER = Bootstrap.createDynamicInvoker("dyn:call", Object.class,
  46             ScriptFunction.class, ScriptObject.class, String.class, Object.class);
  47 
  48     /**
  49      * Returns JSON-compatible quoted version of the given string.
  50      *
  51      * @param str String to be quoted
  52      * @return JSON-compatible quoted string
  53      */
  54     public static String quote(final String str) {
  55         return JSONParser.quote(str);
  56     }
  57 
  58     /**
  59      * Parses the given JSON text string and returns object representation.
  60      *
  61      * @param text JSON text to be parsed
  62      * @param reviver  optional value: function that takes two parameters (key, value)
  63      * @return Object representation of JSON text given
  64      */
  65     public static Object parse(final Object text, final Object reviver) {
  66         final String     str     = JSType.toString(text);
  67         final Context    context = Context.getContextTrusted();
  68         final JSONParser parser  = new JSONParser(
  69                 new Source("<json>", str),
  70                 new Context.ThrowErrorManager(),
  71                 (context != null) ?
  72                     context.getEnv()._strict :
  73                     false);
  74 
  75         Node node;
  76 
  77         try {
  78             node = parser.parse();
  79         } catch (final ParserException e) {
  80             throw ECMAErrors.syntaxError(e, "invalid.json", e.getMessage());
  81         }
  82 
  83         final ScriptObject global = Context.getGlobalTrusted();
  84         Object unfiltered = convertNode(global, node);
  85         return applyReviver(global, unfiltered, reviver);
  86     }
  87 
  88     // -- Internals only below this point
  89 
  90     // parse helpers
  91 
  92     // apply 'reviver' function if available
  93     private static Object applyReviver(final ScriptObject global, final Object unfiltered, final Object reviver) {
  94         if (reviver instanceof ScriptFunction) {
  95             assert global instanceof GlobalObject;
  96             final ScriptObject root = ((GlobalObject)global).newObject();
  97             root.set("", unfiltered, root.isStrictContext());
  98             return walk(root, "", (ScriptFunction)reviver);
  99         }
 100         return unfiltered;
 101     }
 102 
 103     // This is the abstract "Walk" operation from the spec.
 104     private static Object walk(final ScriptObject holder, final Object name, final ScriptFunction reviver) {
 105         final Object val = holder.get(name);
 106         if (val instanceof ScriptObject) {
 107             final ScriptObject     valueObj = (ScriptObject)val;
 108             final boolean          strict   = valueObj.isStrictContext();
 109             final Iterator<String> iter     = valueObj.propertyIterator();
 110 
 111             while (iter.hasNext()) {
 112                 final String key        = iter.next();
 113                 final Object newElement = walk(valueObj, key, reviver);
 114 
 115                 if (newElement == ScriptRuntime.UNDEFINED) {
 116                     valueObj.delete(key, strict);
 117                 } else {
 118                     valueObj.set(key, newElement, strict);
 119                 }
 120             }
 121         }
 122 
 123         try {
 124              // Object.class, ScriptFunction.class, ScriptObject.class, String.class, Object.class);
 125              return REVIVER_INVOKER.invokeExact(reviver, holder, JSType.toString(name), val);
 126         } catch(Error|RuntimeException t) {
 127             throw t;
 128         } catch(final Throwable t) {
 129             throw new RuntimeException(t);
 130         }
 131     }
 132 
 133     // Converts IR node to runtime value
 134     private static Object convertNode(final ScriptObject global, final Node node) {
 135         assert global instanceof GlobalObject;
 136 
 137         if (node instanceof LiteralNode) {
 138             // check for array literal
 139             if (node.tokenType() == TokenType.ARRAY) {
 140                 assert node instanceof LiteralNode.ArrayLiteralNode;
 141                 final Node[] elements = ((LiteralNode.ArrayLiteralNode)node).getValue();
 142 
 143                 // NOTE: We cannot use LiteralNode.isNumericArray() here as that
 144                 // method uses symbols of element nodes. Since we don't do lower
 145                 // pass, there won't be any symbols!
 146                 if (isNumericArray(elements)) {
 147                     final double[] values = new double[elements.length];
 148                     int   index = 0;
 149 
 150                     for (final Node elem : elements) {
 151                         values[index++] = JSType.toNumber(convertNode(global, elem));
 152                     }
 153                     return ((GlobalObject)global).wrapAsObject(values);
 154                 }
 155 
 156                 final Object[] values = new Object[elements.length];
 157                 int   index = 0;
 158 
 159                 for (final Node elem : elements) {
 160                     values[index++] = convertNode(global, elem);
 161                 }
 162 
 163                 return ((GlobalObject)global).wrapAsObject(values);
 164             }
 165 
 166             return ((LiteralNode<?>)node).getValue();
 167 
 168         } else if (node instanceof ObjectNode) {
 169             final ObjectNode   objNode  = (ObjectNode) node;
 170             final ScriptObject object   = ((GlobalObject)global).newObject();
 171             final boolean      strict   = global.isStrictContext();
 172             final List<Node>   elements = objNode.getElements();
 173 
 174             for (final Node elem : elements) {
 175                 final PropertyNode pNode     = (PropertyNode) elem;
 176                 final Node         valueNode = pNode.getValue();
 177 
 178                 object.set(pNode.getKeyName(), convertNode(global, valueNode), strict);
 179             }
 180 
 181             return object;
 182         } else if (node instanceof UnaryNode) {
 183             // UnaryNode used only to represent negative number JSON value
 184             final UnaryNode unaryNode = (UnaryNode)node;
 185             return -((LiteralNode<?>)unaryNode.rhs()).getNumber();
 186         } else {
 187             return null;
 188         }
 189     }
 190 
 191     // does the given IR node represent a numeric array?
 192     private static boolean isNumericArray(final Node[] values) {
 193         for (final Node node : values) {
 194             if (node instanceof LiteralNode && ((LiteralNode<?>)node).getValue() instanceof Number) {
 195                 continue;
 196             }
 197             return false;
 198         }
 199         return true;
 200     }
 201 }