src/frontend/grammar.y

   1 /*
   2  * SysDB - src/frontend/grammar.y
   3  * Copyright (C) 2013 Sebastian 'tokkee' Harl <sh@tokkee.org>
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  16  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  17  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  18  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR
  19  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  20  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  21  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
  22  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  23  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  24  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  25  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  26  */
  27
  28 %{
  29
  30 #include "frontend/connection-private.h"
  31 #include "frontend/parser.h"
  32 #include "frontend/grammar.h"
  33
  34 #include "core/store.h"
  35 #include "core/store-private.h"
  36 #include "core/time.h"
  37
  38 #include "utils/error.h"
  39 #include "utils/llist.h"
  40
  41 #include <stdio.h>
  42 #include <string.h>
  43
  44 int
  45 sdb_fe_yylex(YYSTYPE *yylval, YYLTYPE *yylloc, sdb_fe_yyscan_t yyscanner);
  46
  47 sdb_fe_yyextra_t *
  48 sdb_fe_yyget_extra(sdb_fe_yyscan_t scanner);
  49
  50 void
  51 sdb_fe_yyerror(YYLTYPE *lval, sdb_fe_yyscan_t scanner, const char *msg);
  52
  53 /* quick access to the current parse tree */
  54 #define pt sdb_fe_yyget_extra(scanner)->parsetree
  55
  56 /* quick access to the parser mode */
  57 #define parser_mode sdb_fe_yyget_extra(scanner)->mode
  58
  59 %}
  60
  61 %pure-parser
  62 %lex-param {sdb_fe_yyscan_t scanner}
  63 %parse-param {sdb_fe_yyscan_t scanner}
  64 %locations
  65 %error-verbose
  66 %expect 0
  67 %name-prefix "sdb_fe_yy"
  68
  69 %union {
  70         const char *sstr; /* static string */
  71         char *str;
  72
  73         sdb_data_t data;
  74         sdb_time_t datetime;
  75
  76         sdb_llist_t     *list;
  77         sdb_conn_node_t *node;
  78
  79         sdb_store_matcher_t *m;
  80         sdb_store_expr_t *expr;
  81 }
  82
  83 %start statements
  84
  85 %token SCANNER_ERROR
  86
  87 %token AND OR IS NOT MATCHING FILTER
  88 %token CMP_EQUAL CMP_NEQUAL CMP_REGEX CMP_NREGEX
  89 %token CMP_LT CMP_LE CMP_GE CMP_GT
  90 %token CONCAT
  91
  92 %token START END
  93
  94 /* NULL token */
  95 %token NULL_T
  96
  97 %token FETCH LIST LOOKUP TIMESERIES
  98
  99 %token <str> IDENTIFIER STRING
 100
 101 %token <data> INTEGER FLOAT
 102
 103 %token <datetime> DATE TIME
 104
 105 /* Precedence (lowest first): */
 106 %left OR
 107 %left AND
 108 %right NOT
 109 %left CMP_EQUAL CMP_NEQUAL
 110 %left CMP_LT CMP_LE CMP_GE CMP_GT
 111 %nonassoc CMP_REGEX CMP_NREGEX
 112 %left CONCAT
 113 %nonassoc IS
 114 %left '+' '-'
 115 %left '*' '/' '%'
 116 %left '[' ']'
 117 %left '(' ')'
 118 %left '.'
 119
 120 %type <list> statements
 121 %type <node> statement
 122         fetch_statement
 123         list_statement
 124         lookup_statement
 125         timeseries_statement
 126         matching_clause
 127         filter_clause
 128         condition
 129
 130 %type <m> matcher
 131         compare_matcher
 132
 133 %type <expr> expression
 134
 135 %type <sstr> cmp
 136
 137 %type <data> data
 138         interval interval_elem
 139
 140 %type <datetime> datetime
 141         start_clause end_clause
 142
 143 %destructor { free($$); } <str>
 144 %destructor { sdb_object_deref(SDB_OBJ($$)); } <node> <m> <expr>
 145
 146 %%
 147
 148 statements:
 149         statements ';' statement
 150                 {
 151                         /* only accept this in default parse mode */
 152                         if (parser_mode != SDB_PARSE_DEFAULT) {
 153                                 sdb_fe_yyerror(&yylloc, scanner,
 154                                                 YY_("syntax error, unexpected statement, "
 155                                                         "expecting condition"));
 156                                 sdb_object_deref(SDB_OBJ($3));
 157                                 YYABORT;
 158                         }
 159
 160                         if ($3) {
 161                                 sdb_llist_append(pt, SDB_OBJ($3));
 162                                 sdb_object_deref(SDB_OBJ($3));
 163                         }
 164                 }
 165         |
 166         statement
 167                 {
 168                         /* only accept this in default parse mode */
 169                         if (parser_mode != SDB_PARSE_DEFAULT) {
 170                                 sdb_fe_yyerror(&yylloc, scanner,
 171                                                 YY_("syntax error, unexpected statement, "
 172                                                         "expecting condition"));
 173                                 sdb_object_deref(SDB_OBJ($1));
 174                                 YYABORT;
 175                         }
 176
 177                         if ($1) {
 178                                 sdb_llist_append(pt, SDB_OBJ($1));
 179                                 sdb_object_deref(SDB_OBJ($1));
 180                         }
 181                 }
 182         |
 183         condition
 184                 {
 185                         /* only accept this in condition parse mode */
 186                         if (! (parser_mode & SDB_PARSE_COND)) {
 187                                 sdb_fe_yyerror(&yylloc, scanner,
 188                                                 YY_("syntax error, unexpected condition, "
 189                                                         "expecting statement"));
 190                                 sdb_object_deref(SDB_OBJ($1));
 191                                 YYABORT;
 192                         }
 193
 194                         if ($1) {
 195                                 sdb_llist_append(pt, SDB_OBJ($1));
 196                                 sdb_object_deref(SDB_OBJ($1));
 197                         }
 198                 }
 199         ;
 200
 201 statement:
 202         fetch_statement
 203         |
 204         list_statement
 205         |
 206         lookup_statement
 207         |
 208         timeseries_statement
 209         |
 210         /* empty */
 211                 {
 212                         $$ = NULL;
 213                 }
 214         ;
 215
 216 /*
 217  * FETCH <type> <hostname> [FILTER <condition>];
 218  *
 219  * Retrieve detailed information about a single host.
 220  */
 221 fetch_statement:
 222         FETCH IDENTIFIER STRING filter_clause
 223                 {
 224                         /* TODO: support other types as well */
 225                         if (strcasecmp($2, "host")) {
 226                                 char errmsg[strlen($2) + 32];
 227                                 snprintf(errmsg, sizeof(errmsg),
 228                                                 YY_("unknown data-source %s"), $2);
 229                                 sdb_fe_yyerror(&yylloc, scanner, errmsg);
 230                                 free($2); $2 = NULL;
 231                                 free($3); $3 = NULL;
 232                                 sdb_object_deref(SDB_OBJ($4));
 233                                 YYABORT;
 234                         }
 235
 236                         $$ = SDB_CONN_NODE(sdb_object_create_dT(/* name = */ NULL,
 237                                                 conn_fetch_t, conn_fetch_destroy));
 238                         CONN_FETCH($$)->type = SDB_HOST;
 239                         CONN_FETCH($$)->name = $3;
 240                         CONN_FETCH($$)->filter = CONN_MATCHER($4);
 241                         $$->cmd = CONNECTION_FETCH;
 242                         free($2); $2 = NULL;
 243                 }
 244         ;
 245
 246 /*
 247  * LIST <type> [FILTER <condition>];
 248  *
 249  * Returns a list of all hosts in the store.
 250  */
 251 list_statement:
 252         LIST IDENTIFIER filter_clause
 253                 {
 254                         int type = sdb_store_parse_object_type_plural($2);
 255                         if (type < 0) {
 256                                 char errmsg[strlen($2) + 32];
 257                                 snprintf(errmsg, sizeof(errmsg),
 258                                                 YY_("unknown data-source %s"), $2);
 259                                 sdb_fe_yyerror(&yylloc, scanner, errmsg);
 260                                 free($2); $2 = NULL;
 261                                 sdb_object_deref(SDB_OBJ($3));
 262                                 YYABORT;
 263                         }
 264
 265                         $$ = SDB_CONN_NODE(sdb_object_create_dT(/* name = */ NULL,
 266                                                 conn_list_t, conn_list_destroy));
 267                         CONN_LIST($$)->type = type;
 268                         CONN_LIST($$)->filter = CONN_MATCHER($3);
 269                         $$->cmd = CONNECTION_LIST;
 270                         free($2); $2 = NULL;
 271                 }
 272         ;
 273
 274 /*
 275  * LOOKUP <type> MATCHING <condition> [FILTER <condition>];
 276  *
 277  * Returns detailed information about <type> matching condition.
 278  */
 279 lookup_statement:
 280         LOOKUP IDENTIFIER matching_clause filter_clause
 281                 {
 282                         /* TODO: support other types as well */
 283                         if (strcasecmp($2, "hosts")) {
 284                                 char errmsg[strlen($2) + 32];
 285                                 snprintf(errmsg, sizeof(errmsg),
 286                                                 YY_("unknown data-source %s"), $2);
 287                                 sdb_fe_yyerror(&yylloc, scanner, errmsg);
 288                                 free($2); $2 = NULL;
 289                                 sdb_object_deref(SDB_OBJ($3));
 290                                 sdb_object_deref(SDB_OBJ($4));
 291                                 YYABORT;
 292                         }
 293
 294                         $$ = SDB_CONN_NODE(sdb_object_create_dT(/* name = */ NULL,
 295                                                 conn_lookup_t, conn_lookup_destroy));
 296                         CONN_LOOKUP($$)->type = SDB_HOST;
 297                         CONN_LOOKUP($$)->matcher = CONN_MATCHER($3);
 298                         CONN_LOOKUP($$)->filter = CONN_MATCHER($4);
 299                         $$->cmd = CONNECTION_LOOKUP;
 300                         free($2); $2 = NULL;
 301                 }
 302         ;
 303
 304 matching_clause:
 305         MATCHING condition { $$ = $2; }
 306         |
 307         /* empty */ { $$ = NULL; }
 308
 309 filter_clause:
 310         FILTER condition { $$ = $2; }
 311         |
 312         /* empty */ { $$ = NULL; }
 313
 314 /*
 315  * TIMESERIES <host>.<metric> [START <datetime>] [END <datetime>];
 316  *
 317  * Returns a time-series for the specified host's metric.
 318  */
 319 timeseries_statement:
 320         TIMESERIES STRING '.' STRING start_clause end_clause
 321                 {
 322                         $$ = SDB_CONN_NODE(sdb_object_create_dT(/* name = */ NULL,
 323                                                 conn_ts_t, conn_ts_destroy));
 324                         CONN_TS($$)->hostname = $2;
 325                         CONN_TS($$)->metric = $4;
 326                         CONN_TS($$)->opts.start = $5;
 327                         CONN_TS($$)->opts.end = $6;
 328                         $$->cmd = CONNECTION_TIMESERIES;
 329                 }
 330         ;
 331
 332 start_clause:
 333         START datetime { $$ = $2; }
 334         |
 335         /* empty */ { $$ = sdb_gettime() - SDB_INTERVAL_HOUR; }
 336
 337 end_clause:
 338         END datetime { $$ = $2; }
 339         |
 340         /* empty */ { $$ = sdb_gettime(); }
 341
 342 /*
 343  * Basic expressions.
 344  */
 345
 346 condition:
 347         matcher
 348                 {
 349                         if (! $1) {
 350                                 /* TODO: improve error reporting */
 351                                 sdb_fe_yyerror(&yylloc, scanner,
 352                                                 YY_("syntax error, invalid condition"));
 353                                 YYABORT;
 354                         }
 355
 356                         $$ = SDB_CONN_NODE(sdb_object_create_dT(/* name = */ NULL,
 357                                                 conn_matcher_t, conn_matcher_destroy));
 358                         $$->cmd = CONNECTION_MATCHER;
 359                         CONN_MATCHER($$)->matcher = $1;
 360                 }
 361         ;
 362
 363 matcher:
 364         '(' matcher ')'
 365                 {
 366                         $$ = $2;
 367                 }
 368         |
 369         matcher AND matcher
 370                 {
 371                         $$ = sdb_store_con_matcher($1, $3);
 372                         sdb_object_deref(SDB_OBJ($1));
 373                         sdb_object_deref(SDB_OBJ($3));
 374                 }
 375         |
 376         matcher OR matcher
 377                 {
 378                         $$ = sdb_store_dis_matcher($1, $3);
 379                         sdb_object_deref(SDB_OBJ($1));
 380                         sdb_object_deref(SDB_OBJ($3));
 381                 }
 382         |
 383         NOT matcher
 384                 {
 385                         $$ = sdb_store_inv_matcher($2);
 386                         sdb_object_deref(SDB_OBJ($2));
 387                 }
 388         |
 389         compare_matcher
 390                 {
 391                         $$ = $1;
 392                 }
 393         ;
 394
 395 /*
 396  * <object_type>.<object_attr> <cmp> <value>
 397  *
 398  * Parse matchers comparing object attributes with a value.
 399  */
 400 compare_matcher:
 401         '.' IDENTIFIER cmp expression
 402                 {
 403                         $$ = sdb_store_matcher_parse_field_cmp($2, $3, $4);
 404                         free($2); $2 = NULL;
 405                         sdb_object_deref(SDB_OBJ($4));
 406                 }
 407         |
 408         IDENTIFIER cmp expression
 409                 {
 410                         $$ = sdb_store_matcher_parse_cmp($1, NULL, $2, $3);
 411                         free($1); $1 = NULL;
 412                         sdb_object_deref(SDB_OBJ($3));
 413                 }
 414         |
 415         IDENTIFIER '[' IDENTIFIER ']' cmp expression
 416                 {
 417                         $$ = sdb_store_matcher_parse_cmp($1, $3, $5, $6);
 418                         free($1); $1 = NULL;
 419                         free($3); $3 = NULL;
 420                         sdb_object_deref(SDB_OBJ($6));
 421                 }
 422         |
 423         IDENTIFIER '[' IDENTIFIER ']' IS NULL_T
 424                 {
 425                         $$ = sdb_store_matcher_parse_cmp($1, $3, "IS", NULL);
 426                         free($1); $1 = NULL;
 427                         free($3); $3 = NULL;
 428                 }
 429         |
 430         IDENTIFIER '[' IDENTIFIER ']' IS NOT NULL_T
 431                 {
 432                         sdb_store_matcher_t *m;
 433                         m = sdb_store_matcher_parse_cmp($1, $3, "IS", NULL);
 434                         free($1); $1 = NULL;
 435                         free($3); $3 = NULL;
 436
 437                         /* sdb_store_inv_matcher return NULL if m==NULL */
 438                         $$ = sdb_store_inv_matcher(m);
 439                         sdb_object_deref(SDB_OBJ(m));
 440                 }
 441         ;
 442
 443 expression:
 444         '(' expression ')'
 445                 {
 446                         $$ = $2;
 447                 }
 448         |
 449         expression '+' expression
 450                 {
 451                         $$ = sdb_store_expr_create(SDB_DATA_ADD, $1, $3);
 452                         sdb_object_deref(SDB_OBJ($1)); $1 = NULL;
 453                         sdb_object_deref(SDB_OBJ($3)); $3 = NULL;
 454                 }
 455         |
 456         expression '-' expression
 457                 {
 458                         $$ = sdb_store_expr_create(SDB_DATA_SUB, $1, $3);
 459                         sdb_object_deref(SDB_OBJ($1)); $1 = NULL;
 460                         sdb_object_deref(SDB_OBJ($3)); $3 = NULL;
 461                 }
 462         |
 463         expression '*' expression
 464                 {
 465                         $$ = sdb_store_expr_create(SDB_DATA_MUL, $1, $3);
 466                         sdb_object_deref(SDB_OBJ($1)); $1 = NULL;
 467                         sdb_object_deref(SDB_OBJ($3)); $3 = NULL;
 468                 }
 469         |
 470         expression '/' expression
 471                 {
 472                         $$ = sdb_store_expr_create(SDB_DATA_DIV, $1, $3);
 473                         sdb_object_deref(SDB_OBJ($1)); $1 = NULL;
 474                         sdb_object_deref(SDB_OBJ($3)); $3 = NULL;
 475                 }
 476         |
 477         expression '%' expression
 478                 {
 479                         $$ = sdb_store_expr_create(SDB_DATA_MOD, $1, $3);
 480                         sdb_object_deref(SDB_OBJ($1)); $1 = NULL;
 481                         sdb_object_deref(SDB_OBJ($3)); $3 = NULL;
 482                 }
 483         |
 484         expression CONCAT expression
 485                 {
 486                         $$ = sdb_store_expr_create(SDB_DATA_CONCAT, $1, $3);
 487                         sdb_object_deref(SDB_OBJ($1)); $1 = NULL;
 488                         sdb_object_deref(SDB_OBJ($3)); $3 = NULL;
 489                 }
 490         |
 491         '.' IDENTIFIER
 492                 {
 493                         int field = sdb_store_parse_field_name($2);
 494                         free($2); $2 = NULL;
 495                         $$ = sdb_store_expr_fieldvalue(field);
 496                 }
 497         |
 498         IDENTIFIER '[' IDENTIFIER ']'
 499                 {
 500                         $$ = sdb_store_expr_attrvalue($3);
 501                         free($1); $1 = NULL;
 502                         free($3); $3 = NULL;
 503                 }
 504         |
 505         data
 506                 {
 507                         $$ = sdb_store_expr_constvalue(&$1);
 508                         sdb_data_free_datum(&$1);
 509                 }
 510         ;
 511
 512 cmp:
 513         CMP_EQUAL { $$ = "="; }
 514         |
 515         CMP_NEQUAL { $$ = "!="; }
 516         |
 517         CMP_REGEX { $$ = "=~"; }
 518         |
 519         CMP_NREGEX { $$ = "!~"; }
 520         |
 521         CMP_LT { $$ = "<"; }
 522         |
 523         CMP_LE { $$ = "<="; }
 524         |
 525         CMP_GE { $$ = ">="; }
 526         |
 527         CMP_GT { $$ = ">"; }
 528         ;
 529
 530 data:
 531         STRING { $$.type = SDB_TYPE_STRING; $$.data.string = $1; }
 532         |
 533         INTEGER { $$ = $1; }
 534         |
 535         FLOAT { $$ = $1; }
 536         |
 537         datetime { $$.type = SDB_TYPE_DATETIME; $$.data.datetime = $1; }
 538         |
 539         interval { $$ = $1; }
 540         ;
 541
 542 datetime:
 543         DATE TIME { $$ = $1 + $2; }
 544         |
 545         DATE { $$ = $1; }
 546         |
 547         TIME { $$ = $1; }
 548         ;
 549
 550 interval:
 551         interval interval_elem
 552                 {
 553                         $$.data.datetime = $1.data.datetime + $2.data.datetime;
 554                 }
 555         |
 556         interval_elem { $$ = $1; }
 557         ;
 558
 559 interval_elem:
 560         INTEGER IDENTIFIER
 561                 {
 562                         sdb_time_t unit = 1;
 563
 564                         unit = sdb_strpunit($2);
 565                         if (! unit) {
 566                                 char errmsg[strlen($2) + 32];
 567                                 snprintf(errmsg, sizeof(errmsg),
 568                                                 YY_("invalid time unit %s"), $2);
 569                                 sdb_fe_yyerror(&yylloc, scanner, errmsg);
 570                                 free($2); $2 = NULL;
 571                                 YYABORT;
 572                         }
 573                         free($2); $2 = NULL;
 574
 575                         $$.type = SDB_TYPE_DATETIME;
 576                         $$.data.datetime = (sdb_time_t)$1.data.integer * unit;
 577
 578                         if ($1.data.integer < 0) {
 579                                 sdb_fe_yyerror(&yylloc, scanner,
 580                                                 YY_("syntax error, negative intervals not supported"));
 581                                 YYABORT;
 582                         }
 583                 }
 584         ;
 585
 586 %%
 587
 588 void
 589 sdb_fe_yyerror(YYLTYPE *lval, sdb_fe_yyscan_t scanner, const char *msg)
 590 {
 591         sdb_log(SDB_LOG_ERR, "frontend: parse error: %s", msg);
 592 } /* sdb_fe_yyerror */
 593
 594 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */
 595