J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2004 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 | package sun.tools.jstat; |
| 27 | |
| 28 | import java.io.*; |
| 29 | import java.util.*; |
| 30 | |
| 31 | /** |
| 32 | * A class implementing a simple predictive parser for output format |
| 33 | * specification language for the jstat command. |
| 34 | * |
| 35 | * @author Brian Doherty |
| 36 | * @since 1.5 |
| 37 | */ |
| 38 | public class Parser { |
| 39 | |
| 40 | private static boolean pdebug = Boolean.getBoolean("jstat.parser.debug"); |
| 41 | private static boolean ldebug = Boolean.getBoolean("jstat.lex.debug"); |
| 42 | |
| 43 | private static final char OPENBLOCK = '{'; |
| 44 | private static final char CLOSEBLOCK = '}'; |
| 45 | private static final char DOUBLEQUOTE = '"'; |
| 46 | private static final char PERCENT_CHAR = '%'; |
| 47 | private static final char OPENPAREN = '('; |
| 48 | private static final char CLOSEPAREN = ')'; |
| 49 | |
| 50 | private static final char OPERATOR_PLUS = '+'; |
| 51 | private static final char OPERATOR_MINUS = '-'; |
| 52 | private static final char OPERATOR_MULTIPLY = '*'; |
| 53 | private static final char OPERATOR_DIVIDE = '/'; |
| 54 | |
| 55 | private static final String OPTION = "option"; |
| 56 | private static final String COLUMN = "column"; |
| 57 | private static final String DATA = "data"; |
| 58 | private static final String HEADER = "header"; |
| 59 | private static final String WIDTH = "width"; |
| 60 | private static final String FORMAT = "format"; |
| 61 | private static final String ALIGN = "align"; |
| 62 | private static final String SCALE = "scale"; |
| 63 | |
| 64 | private static final String START = OPTION; |
| 65 | |
| 66 | private static final Set scaleKeyWords = Scale.keySet(); |
| 67 | private static final Set alignKeyWords = Alignment.keySet(); |
| 68 | private static String[] otherKeyWords = { |
| 69 | OPTION, COLUMN, DATA, HEADER, WIDTH, FORMAT, ALIGN, SCALE |
| 70 | }; |
| 71 | |
| 72 | private static char[] infixOps = { |
| 73 | OPERATOR_PLUS, OPERATOR_MINUS, OPERATOR_MULTIPLY, OPERATOR_DIVIDE |
| 74 | }; |
| 75 | |
| 76 | private static char[] delimiters = { |
| 77 | OPENBLOCK, CLOSEBLOCK, PERCENT_CHAR, OPENPAREN, CLOSEPAREN |
| 78 | }; |
| 79 | |
| 80 | |
| 81 | private static Set<String> reservedWords; |
| 82 | |
| 83 | private StreamTokenizer st; |
| 84 | private String filename; |
| 85 | private Token lookahead; |
| 86 | private Token previous; |
| 87 | private int columnCount; |
| 88 | private OptionFormat optionFormat; |
| 89 | |
| 90 | public Parser(String filename) throws FileNotFoundException { |
| 91 | this.filename = filename; |
| 92 | Reader r = new BufferedReader(new FileReader(filename)); |
| 93 | } |
| 94 | |
| 95 | public Parser(Reader r) { |
| 96 | st = new StreamTokenizer(r); |
| 97 | |
| 98 | // allow both c++ style comments |
| 99 | st.ordinaryChar('/'); |
| 100 | st.wordChars('_','_'); |
| 101 | st.slashSlashComments(true); |
| 102 | st.slashStarComments(true); |
| 103 | |
| 104 | reservedWords = new HashSet<String>(); |
| 105 | for (int i = 0; i < otherKeyWords.length; i++) { |
| 106 | reservedWords.add(otherKeyWords[i]); |
| 107 | } |
| 108 | |
| 109 | for (int i = 0; i < delimiters.length; i++ ) { |
| 110 | st.ordinaryChar(delimiters[i]); |
| 111 | } |
| 112 | |
| 113 | for (int i = 0; i < infixOps.length; i++ ) { |
| 114 | st.ordinaryChar(infixOps[i]); |
| 115 | } |
| 116 | } |
| 117 | |
| 118 | /** |
| 119 | * push back the lookahead token and restore the lookahead token |
| 120 | * to the previous token. |
| 121 | */ |
| 122 | private void pushBack() { |
| 123 | lookahead = previous; |
| 124 | st.pushBack(); |
| 125 | } |
| 126 | |
| 127 | /** |
| 128 | * retrieve the next token, placing the token value in the lookahead |
| 129 | * member variable, storing its previous value in the previous member |
| 130 | * variable. |
| 131 | */ |
| 132 | private void nextToken() throws ParserException, IOException { |
| 133 | int t = st.nextToken(); |
| 134 | previous = lookahead; |
| 135 | lookahead = new Token(st.ttype, st.sval, st.nval); |
| 136 | log(ldebug, "lookahead = " + lookahead); |
| 137 | } |
| 138 | |
| 139 | /** |
| 140 | * match one of the token values in the given set of key words |
| 141 | * token is assumed to be of type TT_WORD, and the set is assumed |
| 142 | * to contain String objects. |
| 143 | */ |
| 144 | private Token matchOne(Set keyWords) throws ParserException, IOException { |
| 145 | if ((lookahead.ttype == StreamTokenizer.TT_WORD) |
| 146 | && keyWords.contains(lookahead.sval)) { |
| 147 | Token t = lookahead; |
| 148 | nextToken(); |
| 149 | return t; |
| 150 | } |
| 151 | throw new SyntaxException(st.lineno(), keyWords, lookahead); |
| 152 | } |
| 153 | |
| 154 | /** |
| 155 | * match a token with TT_TYPE=type, and the token value is a given sequence |
| 156 | * of characters. |
| 157 | */ |
| 158 | private void match(int ttype, String token) |
| 159 | throws ParserException, IOException { |
| 160 | if (lookahead.ttype == ttype && lookahead.sval.compareTo(token) == 0) { |
| 161 | nextToken(); |
| 162 | } else { |
| 163 | throw new SyntaxException(st.lineno(), new Token(ttype, token), |
| 164 | lookahead); |
| 165 | } |
| 166 | } |
| 167 | |
| 168 | /** |
| 169 | * match a token with TT_TYPE=type |
| 170 | */ |
| 171 | private void match(int ttype) throws ParserException, IOException { |
| 172 | if (lookahead.ttype == ttype) { |
| 173 | nextToken(); |
| 174 | } else { |
| 175 | throw new SyntaxException(st.lineno(), new Token(ttype), lookahead); |
| 176 | } |
| 177 | } |
| 178 | |
| 179 | /** |
| 180 | * match a token with TT_TYPE=char, where the token value is the given char. |
| 181 | */ |
| 182 | private void match(char ttype) throws ParserException, IOException { |
| 183 | if (lookahead.ttype == (int)ttype) { |
| 184 | nextToken(); |
| 185 | } |
| 186 | else { |
| 187 | throw new SyntaxException(st.lineno(), new Token((int)ttype), |
| 188 | lookahead); |
| 189 | } |
| 190 | } |
| 191 | |
| 192 | /** |
| 193 | * match a token with TT_TYPE='"', where the token value is a sequence |
| 194 | * of characters between matching quote characters. |
| 195 | */ |
| 196 | private void matchQuotedString() throws ParserException, IOException { |
| 197 | match(DOUBLEQUOTE); |
| 198 | } |
| 199 | |
| 200 | /** |
| 201 | * match a TT_NUMBER token that matches a parsed number value |
| 202 | */ |
| 203 | private void matchNumber() throws ParserException, IOException { |
| 204 | match(StreamTokenizer.TT_NUMBER); |
| 205 | } |
| 206 | |
| 207 | /** |
| 208 | * match a TT_WORD token that matches an arbitrary, not quoted token. |
| 209 | */ |
| 210 | private void matchID() throws ParserException, IOException { |
| 211 | match(StreamTokenizer.TT_WORD); |
| 212 | } |
| 213 | |
| 214 | /** |
| 215 | * match a TT_WORD token that matches the given string |
| 216 | */ |
| 217 | private void match(String token) throws ParserException, IOException { |
| 218 | match(StreamTokenizer.TT_WORD, token); |
| 219 | } |
| 220 | |
| 221 | /** |
| 222 | * determine if the given word is a reserved key word |
| 223 | */ |
| 224 | private boolean isReservedWord(String word) { |
| 225 | return reservedWords.contains(word); |
| 226 | } |
| 227 | |
| 228 | /** |
| 229 | * determine if the give work is a reserved key word |
| 230 | */ |
| 231 | private boolean isInfixOperator(char op) { |
| 232 | for (int i = 0; i < infixOps.length; i++) { |
| 233 | if (op == infixOps[i]) { |
| 234 | return true; |
| 235 | } |
| 236 | } |
| 237 | return false; |
| 238 | } |
| 239 | |
| 240 | /** |
| 241 | * scalestmt -> 'scale' scalespec |
| 242 | * scalespec -> <see above scaleTerminals array> |
| 243 | */ |
| 244 | private void scaleStmt(ColumnFormat cf) |
| 245 | throws ParserException, IOException { |
| 246 | match(SCALE); |
| 247 | Token t = matchOne(scaleKeyWords); |
| 248 | cf.setScale(Scale.toScale(t.sval)); |
| 249 | String scaleString = t.sval; |
| 250 | log(pdebug, "Parsed: scale -> " + scaleString); |
| 251 | } |
| 252 | |
| 253 | /** |
| 254 | * alignstmt -> 'align' alignspec |
| 255 | * alignspec -> <see above alignTerminals array> |
| 256 | */ |
| 257 | private void alignStmt(ColumnFormat cf) |
| 258 | throws ParserException, IOException { |
| 259 | match(ALIGN); |
| 260 | Token t = matchOne(alignKeyWords); |
| 261 | cf.setAlignment(Alignment.toAlignment(t.sval)); |
| 262 | String alignString = t.sval; |
| 263 | log(pdebug, "Parsed: align -> " + alignString); |
| 264 | } |
| 265 | |
| 266 | /** |
| 267 | * headerstmt -> 'header' quotedstring |
| 268 | */ |
| 269 | private void headerStmt(ColumnFormat cf) |
| 270 | throws ParserException, IOException { |
| 271 | match(HEADER); |
| 272 | String headerString = lookahead.sval; |
| 273 | matchQuotedString(); |
| 274 | cf.setHeader(headerString); |
| 275 | log(pdebug, "Parsed: header -> " + headerString); |
| 276 | } |
| 277 | |
| 278 | /** |
| 279 | * widthstmt -> 'width' integer |
| 280 | */ |
| 281 | private void widthStmt(ColumnFormat cf) |
| 282 | throws ParserException, IOException { |
| 283 | match(WIDTH); |
| 284 | double width = lookahead.nval; |
| 285 | matchNumber(); |
| 286 | cf.setWidth((int)width); |
| 287 | log(pdebug, "Parsed: width -> " + width ); |
| 288 | } |
| 289 | |
| 290 | /** |
| 291 | * formatstmt -> 'format' quotedstring |
| 292 | */ |
| 293 | private void formatStmt(ColumnFormat cf) |
| 294 | throws ParserException, IOException { |
| 295 | match(FORMAT); |
| 296 | String formatString = lookahead.sval; |
| 297 | matchQuotedString(); |
| 298 | cf.setFormat(formatString); |
| 299 | log(pdebug, "Parsed: format -> " + formatString); |
| 300 | } |
| 301 | |
| 302 | /** |
| 303 | * Primary -> Literal | Identifier | '(' Expression ')' |
| 304 | */ |
| 305 | private Expression primary() throws ParserException, IOException { |
| 306 | Expression e = null; |
| 307 | |
| 308 | switch (lookahead.ttype) { |
| 309 | case OPENPAREN: |
| 310 | match(OPENPAREN); |
| 311 | e = expression(); |
| 312 | match(CLOSEPAREN); |
| 313 | break; |
| 314 | case StreamTokenizer.TT_WORD: |
| 315 | String s = lookahead.sval; |
| 316 | if (isReservedWord(s)) { |
| 317 | throw new SyntaxException(st.lineno(), "IDENTIFIER", |
| 318 | "Reserved Word: " + lookahead.sval); |
| 319 | } |
| 320 | matchID(); |
| 321 | e = new Identifier(s); |
| 322 | log(pdebug, "Parsed: ID -> " + s); |
| 323 | break; |
| 324 | case StreamTokenizer.TT_NUMBER: |
| 325 | double literal = lookahead.nval; |
| 326 | matchNumber(); |
| 327 | e = new Literal(new Double(literal)); |
| 328 | log(pdebug, "Parsed: number -> " + literal); |
| 329 | break; |
| 330 | default: |
| 331 | throw new SyntaxException(st.lineno(), "IDENTIFIER", lookahead); |
| 332 | } |
| 333 | log(pdebug, "Parsed: primary -> " + e); |
| 334 | return e; |
| 335 | } |
| 336 | |
| 337 | /** |
| 338 | * Unary -> ('+'|'-') Unary | Primary |
| 339 | */ |
| 340 | private Expression unary() throws ParserException, IOException { |
| 341 | Expression e = null; |
| 342 | Operator op = null; |
| 343 | |
| 344 | while (true) { |
| 345 | switch (lookahead.ttype) { |
| 346 | case OPERATOR_PLUS: |
| 347 | match(OPERATOR_PLUS); |
| 348 | op = Operator.PLUS; |
| 349 | break; |
| 350 | case OPERATOR_MINUS: |
| 351 | match(OPERATOR_MINUS); |
| 352 | op = Operator.MINUS; |
| 353 | break; |
| 354 | default: |
| 355 | e = primary(); |
| 356 | log(pdebug, "Parsed: unary -> " + e); |
| 357 | return e; |
| 358 | } |
| 359 | Expression e1 = new Expression(); |
| 360 | e1.setOperator(op); |
| 361 | e1.setRight(e); |
| 362 | log(pdebug, "Parsed: unary -> " + e1); |
| 363 | e1.setLeft(new Literal(new Double(0))); |
| 364 | e = e1; |
| 365 | } |
| 366 | } |
| 367 | |
| 368 | /** |
| 369 | * MultExpression -> Unary (('*' | '/') Unary)* |
| 370 | */ |
| 371 | private Expression multExpression() throws ParserException, IOException { |
| 372 | Expression e = unary(); |
| 373 | Operator op = null; |
| 374 | |
| 375 | while (true) { |
| 376 | switch (lookahead.ttype) { |
| 377 | case OPERATOR_MULTIPLY: |
| 378 | match(OPERATOR_MULTIPLY); |
| 379 | op = Operator.MULTIPLY; |
| 380 | break; |
| 381 | case OPERATOR_DIVIDE: |
| 382 | match(OPERATOR_DIVIDE); |
| 383 | op = Operator.DIVIDE; |
| 384 | break; |
| 385 | default: |
| 386 | log(pdebug, "Parsed: multExpression -> " + e); |
| 387 | return e; |
| 388 | } |
| 389 | Expression e1 = new Expression(); |
| 390 | e1.setOperator(op); |
| 391 | e1.setLeft(e); |
| 392 | e1.setRight(unary()); |
| 393 | e = e1; |
| 394 | log(pdebug, "Parsed: multExpression -> " + e); |
| 395 | } |
| 396 | } |
| 397 | |
| 398 | /** |
| 399 | * AddExpression -> MultExpression (('+' | '-') MultExpression)* |
| 400 | */ |
| 401 | private Expression addExpression() throws ParserException, IOException { |
| 402 | Expression e = multExpression(); |
| 403 | Operator op = null; |
| 404 | |
| 405 | while (true) { |
| 406 | switch (lookahead.ttype) { |
| 407 | case OPERATOR_PLUS: |
| 408 | match(OPERATOR_PLUS); |
| 409 | op = Operator.PLUS; |
| 410 | break; |
| 411 | case OPERATOR_MINUS: |
| 412 | match(OPERATOR_MINUS); |
| 413 | op = Operator.MINUS; |
| 414 | break; |
| 415 | default: |
| 416 | log(pdebug, "Parsed: addExpression -> " + e); |
| 417 | return e; |
| 418 | } |
| 419 | Expression e1 = new Expression(); |
| 420 | e1.setOperator(op); |
| 421 | e1.setLeft(e); |
| 422 | e1.setRight(multExpression()); |
| 423 | e = e1; |
| 424 | log(pdebug, "Parsed: addExpression -> " + e); |
| 425 | } |
| 426 | } |
| 427 | |
| 428 | /** |
| 429 | * Expression -> AddExpression |
| 430 | */ |
| 431 | private Expression expression() throws ParserException, IOException { |
| 432 | Expression e = addExpression(); |
| 433 | log(pdebug, "Parsed: expression -> " + e); |
| 434 | return e; |
| 435 | } |
| 436 | |
| 437 | /** |
| 438 | * datastmt -> 'data' expression |
| 439 | */ |
| 440 | private void dataStmt(ColumnFormat cf) throws ParserException, IOException { |
| 441 | match(DATA); |
| 442 | Expression e = expression(); |
| 443 | cf.setExpression(e); |
| 444 | log(pdebug, "Parsed: data -> " + e); |
| 445 | } |
| 446 | |
| 447 | /** |
| 448 | * statementlist -> optionalstmt statementlist |
| 449 | * optionalstmt -> 'data' expression |
| 450 | * 'header' quotedstring |
| 451 | * 'width' integer |
| 452 | * 'format' formatstring |
| 453 | * 'align' alignspec |
| 454 | * 'scale' scalespec |
| 455 | */ |
| 456 | private void statementList(ColumnFormat cf) |
| 457 | throws ParserException, IOException { |
| 458 | while (true) { |
| 459 | if (lookahead.ttype != StreamTokenizer.TT_WORD) { |
| 460 | return; |
| 461 | } |
| 462 | |
| 463 | if (lookahead.sval.compareTo(DATA) == 0) { |
| 464 | dataStmt(cf); |
| 465 | } else if (lookahead.sval.compareTo(HEADER) == 0) { |
| 466 | headerStmt(cf); |
| 467 | } else if (lookahead.sval.compareTo(WIDTH) == 0) { |
| 468 | widthStmt(cf); |
| 469 | } else if (lookahead.sval.compareTo(FORMAT) == 0) { |
| 470 | formatStmt(cf); |
| 471 | } else if (lookahead.sval.compareTo(ALIGN) == 0) { |
| 472 | alignStmt(cf); |
| 473 | } else if (lookahead.sval.compareTo(SCALE) == 0) { |
| 474 | scaleStmt(cf); |
| 475 | } else { |
| 476 | return; |
| 477 | } |
| 478 | } |
| 479 | } |
| 480 | |
| 481 | /** |
| 482 | * optionlist -> columspec optionlist |
| 483 | * null |
| 484 | * columspec -> 'column' '{' statementlist '}' |
| 485 | */ |
| 486 | private void optionList(OptionFormat of) |
| 487 | throws ParserException, IOException { |
| 488 | while (true) { |
| 489 | if (lookahead.ttype != StreamTokenizer.TT_WORD) { |
| 490 | return; |
| 491 | } |
| 492 | |
| 493 | match(COLUMN); |
| 494 | match(OPENBLOCK); |
| 495 | ColumnFormat cf = new ColumnFormat(columnCount++); |
| 496 | statementList(cf); |
| 497 | match(CLOSEBLOCK); |
| 498 | cf.validate(); |
| 499 | of.addSubFormat(cf); |
| 500 | } |
| 501 | } |
| 502 | |
| 503 | /** |
| 504 | * optionstmt -> 'option' ID '{' optionlist '}' |
| 505 | */ |
| 506 | private OptionFormat optionStmt() throws ParserException, IOException { |
| 507 | match(OPTION); |
| 508 | String optionName=lookahead.sval; |
| 509 | matchID(); |
| 510 | match(OPENBLOCK); |
| 511 | OptionFormat of = new OptionFormat(optionName); |
| 512 | optionList(of); |
| 513 | match(CLOSEBLOCK); |
| 514 | return of; |
| 515 | } |
| 516 | |
| 517 | /** |
| 518 | * parse the specification for the given option identifier |
| 519 | */ |
| 520 | public OptionFormat parse(String option) |
| 521 | throws ParserException, IOException { |
| 522 | nextToken(); |
| 523 | |
| 524 | /* |
| 525 | * this search stops on the first occurance of an option |
| 526 | * statement with a name matching the given option. Any |
| 527 | * duplicate options are ignored. |
| 528 | */ |
| 529 | while (lookahead.ttype != StreamTokenizer.TT_EOF) { |
| 530 | // look for the start symbol |
| 531 | if ((lookahead.ttype != StreamTokenizer.TT_WORD) |
| 532 | || (lookahead.sval.compareTo(START) != 0)) { |
| 533 | // skip tokens until a start symbol is found |
| 534 | nextToken(); |
| 535 | continue; |
| 536 | } |
| 537 | |
| 538 | // check if the option name is the one we are interested in |
| 539 | match(START); |
| 540 | |
| 541 | if ((lookahead.ttype == StreamTokenizer.TT_WORD) |
| 542 | && (lookahead.sval.compareTo(option) == 0)) { |
| 543 | // this is the one we are looking for, parse it |
| 544 | pushBack(); |
| 545 | return optionStmt(); |
| 546 | } else { |
| 547 | // not what we are looking for, start skipping tokens |
| 548 | nextToken(); |
| 549 | } |
| 550 | } |
| 551 | return null; |
| 552 | } |
| 553 | |
| 554 | public Set<OptionFormat> parseOptions() throws ParserException, IOException { |
| 555 | Set<OptionFormat> options = new HashSet<OptionFormat>(); |
| 556 | |
| 557 | nextToken(); |
| 558 | |
| 559 | while (lookahead.ttype != StreamTokenizer.TT_EOF) { |
| 560 | // look for the start symbol |
| 561 | if ((lookahead.ttype != StreamTokenizer.TT_WORD) |
| 562 | || (lookahead.sval.compareTo(START) != 0)) { |
| 563 | // skip tokens until a start symbol is found |
| 564 | nextToken(); |
| 565 | continue; |
| 566 | } |
| 567 | |
| 568 | // note: if a duplicate option statement exists, then |
| 569 | // first one encountered is the chosen definition. |
| 570 | OptionFormat of = optionStmt(); |
| 571 | options.add(of); |
| 572 | } |
| 573 | return options; |
| 574 | } |
| 575 | |
| 576 | OptionFormat getOptionFormat() { |
| 577 | return optionFormat; |
| 578 | } |
| 579 | |
| 580 | private void log(boolean logging, String s) { |
| 581 | if (logging) { |
| 582 | System.out.println(s); |
| 583 | } |
| 584 | } |
| 585 | } |