J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2005-2007 Sun Microsystems, Inc. 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. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | |
| 27 | /* |
| 28 | * The contents of this file are subject to the Sun Public License |
| 29 | * Version 1.0 (the "License"); you may not use this file except in |
| 30 | * compliance with the License. A copy of the License is available at |
| 31 | * http://www.sun.com/, and in the file LICENSE.html in the |
| 32 | * doc directory. |
| 33 | * |
| 34 | * The Original Code is HAT. The Initial Developer of the |
| 35 | * Original Code is Bill Foote, with contributions from others |
| 36 | * at JavaSoft/Sun. Portions created by Bill Foote and others |
| 37 | * at Javasoft/Sun are Copyright (C) 1997-2004. All Rights Reserved. |
| 38 | * |
| 39 | * In addition to the formal license, I ask that you don't |
| 40 | * change the history or donations files without permission. |
| 41 | * |
| 42 | */ |
| 43 | |
| 44 | package com.sun.tools.hat.internal.oql; |
| 45 | |
| 46 | import com.sun.tools.hat.internal.model.*; |
| 47 | import java.io.*; |
| 48 | import java.lang.reflect.*; |
| 49 | import java.util.*; |
| 50 | |
| 51 | /** |
| 52 | * This is Object Query Language Interpreter |
| 53 | * |
| 54 | */ |
| 55 | public class OQLEngine { |
| 56 | static { |
| 57 | try { |
| 58 | // Do we have javax.script support? |
| 59 | // create ScriptEngineManager |
| 60 | Class<?> managerClass = Class.forName("javax.script.ScriptEngineManager"); |
| 61 | Object manager = managerClass.newInstance(); |
| 62 | |
| 63 | // create JavaScript engine |
| 64 | Method getEngineMethod = managerClass.getMethod("getEngineByName", |
| 65 | new Class[] { String.class }); |
| 66 | Object jse = getEngineMethod.invoke(manager, new Object[] {"js"}); |
| 67 | oqlSupported = (jse != null); |
| 68 | } catch (Exception exp) { |
| 69 | oqlSupported = false; |
| 70 | } |
| 71 | } |
| 72 | |
| 73 | // check OQL is supported or not before creating OQLEngine |
| 74 | public static boolean isOQLSupported() { |
| 75 | return oqlSupported; |
| 76 | } |
| 77 | |
| 78 | public OQLEngine(Snapshot snapshot) { |
| 79 | if (!isOQLSupported()) { |
| 80 | throw new UnsupportedOperationException("OQL not supported"); |
| 81 | } |
| 82 | init(snapshot); |
| 83 | } |
| 84 | |
| 85 | /** |
| 86 | Query is of the form |
| 87 | |
| 88 | select <java script code to select> |
| 89 | [ from [instanceof] <class name> [<identifier>] |
| 90 | [ where <java script boolean expression> ] |
| 91 | ] |
| 92 | */ |
| 93 | public synchronized void executeQuery(String query, ObjectVisitor visitor) |
| 94 | throws OQLException { |
| 95 | debugPrint("query : " + query); |
| 96 | StringTokenizer st = new StringTokenizer(query); |
| 97 | if (st.hasMoreTokens()) { |
| 98 | String first = st.nextToken(); |
| 99 | if (! first.equals("select") ) { |
| 100 | // Query does not start with 'select' keyword. |
| 101 | // Just treat it as plain JavaScript and eval it. |
| 102 | try { |
| 103 | Object res = evalScript(query); |
| 104 | visitor.visit(res); |
| 105 | } catch (Exception e) { |
| 106 | throw new OQLException(e); |
| 107 | } |
| 108 | return; |
| 109 | } |
| 110 | } else { |
| 111 | throw new OQLException("query syntax error: no 'select' clause"); |
| 112 | } |
| 113 | |
| 114 | String selectExpr = ""; |
| 115 | boolean seenFrom = false; |
| 116 | while (st.hasMoreTokens()) { |
| 117 | String tok = st.nextToken(); |
| 118 | if (tok.equals("from")) { |
| 119 | seenFrom = true; |
| 120 | break; |
| 121 | } |
| 122 | selectExpr += " " + tok; |
| 123 | } |
| 124 | |
| 125 | if (selectExpr.equals("")) { |
| 126 | throw new OQLException("query syntax error: 'select' expression can not be empty"); |
| 127 | } |
| 128 | |
| 129 | String className = null; |
| 130 | boolean isInstanceOf = false; |
| 131 | String whereExpr = null; |
| 132 | String identifier = null; |
| 133 | |
| 134 | if (seenFrom) { |
| 135 | if (st.hasMoreTokens()) { |
| 136 | String tmp = st.nextToken(); |
| 137 | if (tmp.equals("instanceof")) { |
| 138 | isInstanceOf = true; |
| 139 | if (! st.hasMoreTokens()) { |
| 140 | throw new OQLException("no class name after 'instanceof'"); |
| 141 | } |
| 142 | className = st.nextToken(); |
| 143 | } else { |
| 144 | className = tmp; |
| 145 | } |
| 146 | } else { |
| 147 | throw new OQLException("query syntax error: class name must follow 'from'"); |
| 148 | } |
| 149 | |
| 150 | if (st.hasMoreTokens()) { |
| 151 | identifier = st.nextToken(); |
| 152 | if (identifier.equals("where")) { |
| 153 | throw new OQLException("query syntax error: identifier should follow class name"); |
| 154 | } |
| 155 | if (st.hasMoreTokens()) { |
| 156 | String tmp = st.nextToken(); |
| 157 | if (! tmp.equals("where")) { |
| 158 | throw new OQLException("query syntax error: 'where' clause expected after 'from' clause"); |
| 159 | } |
| 160 | |
| 161 | whereExpr = ""; |
| 162 | while (st.hasMoreTokens()) { |
| 163 | whereExpr += " " + st.nextToken(); |
| 164 | } |
| 165 | if (whereExpr.equals("")) { |
| 166 | throw new OQLException("query syntax error: 'where' clause cannot have empty expression"); |
| 167 | } |
| 168 | } |
| 169 | } else { |
| 170 | throw new OQLException("query syntax error: identifier should follow class name"); |
| 171 | } |
| 172 | } |
| 173 | |
| 174 | executeQuery(new OQLQuery(selectExpr, isInstanceOf, className, |
| 175 | identifier, whereExpr), visitor); |
| 176 | } |
| 177 | |
| 178 | private void executeQuery(OQLQuery q, ObjectVisitor visitor) |
| 179 | throws OQLException { |
| 180 | JavaClass clazz = null; |
| 181 | if (q.className != null) { |
| 182 | clazz = snapshot.findClass(q.className); |
| 183 | if (clazz == null) { |
| 184 | throw new OQLException(q.className + " is not found!"); |
| 185 | } |
| 186 | } |
| 187 | |
| 188 | StringBuffer buf = new StringBuffer(); |
| 189 | buf.append("function __select__("); |
| 190 | if (q.identifier != null) { |
| 191 | buf.append(q.identifier); |
| 192 | } |
| 193 | buf.append(") { return "); |
| 194 | buf.append(q.selectExpr.replace('\n', ' ')); |
| 195 | buf.append("; }"); |
| 196 | |
| 197 | String selectCode = buf.toString(); |
| 198 | debugPrint(selectCode); |
| 199 | String whereCode = null; |
| 200 | if (q.whereExpr != null) { |
| 201 | buf = new StringBuffer(); |
| 202 | buf.append("function __where__("); |
| 203 | buf.append(q.identifier); |
| 204 | buf.append(") { return "); |
| 205 | buf.append(q.whereExpr.replace('\n', ' ')); |
| 206 | buf.append("; }"); |
| 207 | whereCode = buf.toString(); |
| 208 | } |
| 209 | debugPrint(whereCode); |
| 210 | |
| 211 | // compile select expression and where condition |
| 212 | try { |
| 213 | evalMethod.invoke(engine, new Object[] { selectCode }); |
| 214 | if (whereCode != null) { |
| 215 | evalMethod.invoke(engine, new Object[] { whereCode }); |
| 216 | } |
| 217 | |
| 218 | if (q.className != null) { |
| 219 | Enumeration objects = clazz.getInstances(q.isInstanceOf); |
| 220 | while (objects.hasMoreElements()) { |
| 221 | JavaHeapObject obj = (JavaHeapObject) objects.nextElement(); |
| 222 | Object[] args = new Object[] { wrapJavaObject(obj) }; |
| 223 | boolean b = (whereCode == null); |
| 224 | if (!b) { |
| 225 | Object res = call("__where__", args); |
| 226 | if (res instanceof Boolean) { |
| 227 | b = ((Boolean)res).booleanValue(); |
| 228 | } else if (res instanceof Number) { |
| 229 | b = ((Number)res).intValue() != 0; |
| 230 | } else { |
| 231 | b = (res != null); |
| 232 | } |
| 233 | } |
| 234 | |
| 235 | if (b) { |
| 236 | Object select = call("__select__", args); |
| 237 | if (visitor.visit(select)) return; |
| 238 | } |
| 239 | } |
| 240 | } else { |
| 241 | // simple "select <expr>" query |
| 242 | Object select = call("__select__", new Object[] {}); |
| 243 | visitor.visit(select); |
| 244 | } |
| 245 | } catch (Exception e) { |
| 246 | throw new OQLException(e); |
| 247 | } |
| 248 | } |
| 249 | |
| 250 | public Object evalScript(String script) throws Exception { |
| 251 | return evalMethod.invoke(engine, new Object[] { script }); |
| 252 | } |
| 253 | |
| 254 | public Object wrapJavaObject(JavaHeapObject obj) throws Exception { |
| 255 | return call("wrapJavaObject", new Object[] { obj }); |
| 256 | } |
| 257 | |
| 258 | public Object toHtml(Object obj) throws Exception { |
| 259 | return call("toHtml", new Object[] { obj }); |
| 260 | } |
| 261 | |
| 262 | public Object call(String func, Object[] args) throws Exception { |
| 263 | return invokeMethod.invoke(engine, new Object[] { func, args }); |
| 264 | } |
| 265 | |
| 266 | private static void debugPrint(String msg) { |
| 267 | if (debug) System.out.println(msg); |
| 268 | } |
| 269 | |
| 270 | private void init(Snapshot snapshot) throws RuntimeException { |
| 271 | this.snapshot = snapshot; |
| 272 | try { |
| 273 | // create ScriptEngineManager |
| 274 | Class<?> managerClass = Class.forName("javax.script.ScriptEngineManager"); |
| 275 | Object manager = managerClass.newInstance(); |
| 276 | |
| 277 | // create JavaScript engine |
| 278 | Method getEngineMethod = managerClass.getMethod("getEngineByName", |
| 279 | new Class[] { String.class }); |
| 280 | engine = getEngineMethod.invoke(manager, new Object[] {"js"}); |
| 281 | |
| 282 | // initialize engine with init file (hat.js) |
| 283 | InputStream strm = getInitStream(); |
| 284 | Class<?> engineClass = Class.forName("javax.script.ScriptEngine"); |
| 285 | evalMethod = engineClass.getMethod("eval", |
| 286 | new Class[] { Reader.class }); |
| 287 | evalMethod.invoke(engine, new Object[] {new InputStreamReader(strm)}); |
| 288 | |
| 289 | // initialize ScriptEngine.eval(String) and |
| 290 | // Invocable.invokeFunction(String, Object[]) methods. |
| 291 | Class<?> invocableClass = Class.forName("javax.script.Invocable"); |
| 292 | |
| 293 | evalMethod = engineClass.getMethod("eval", |
| 294 | new Class[] { String.class }); |
| 295 | invokeMethod = invocableClass.getMethod("invokeFunction", |
| 296 | new Class[] { String.class, Object[].class }); |
| 297 | |
| 298 | // initialize ScriptEngine.put(String, Object) method |
| 299 | Method putMethod = engineClass.getMethod("put", |
| 300 | new Class[] { String.class, Object.class }); |
| 301 | |
| 302 | // call ScriptEngine.put to initialize built-in heap object |
| 303 | putMethod.invoke(engine, new Object[] { |
| 304 | "heap", call("wrapHeapSnapshot", new Object[] { snapshot }) |
| 305 | }); |
| 306 | } catch (Exception e) { |
| 307 | if (debug) e.printStackTrace(); |
| 308 | throw new RuntimeException(e); |
| 309 | } |
| 310 | } |
| 311 | |
| 312 | private InputStream getInitStream() { |
| 313 | return getClass().getResourceAsStream("/com/sun/tools/hat/resources/hat.js"); |
| 314 | } |
| 315 | |
| 316 | private Object engine; |
| 317 | private Method evalMethod; |
| 318 | private Method invokeMethod; |
| 319 | private Snapshot snapshot; |
| 320 | private static boolean debug = false; |
| 321 | private static boolean oqlSupported; |
| 322 | } |