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 #define MODE_TO_STRING(m) \
  60         (((m) == SDB_PARSE_DEFAULT) ? "statement" \
  61                 : ((m) == SDB_PARSE_COND) ? "condition" \
  62                 : ((m) == SDB_PARSE_EXPR) ? "expression" \
  63                 : "UNKNOWN")
  64
  65 %}
  66
  67 %pure-parser
  68 %lex-param {sdb_fe_yyscan_t scanner}
  69 %parse-param {sdb_fe_yyscan_t scanner}
  70 %locations
  71 %error-verbose
  72 %expect 0
  73 %name-prefix "sdb_fe_yy"
  74
  75 %union {
  76         const char *sstr; /* static string */
  77         char *str;
  78
  79         sdb_data_t data;
  80         sdb_time_t datetime;
  81
  82         sdb_llist_t     *list;
  83         sdb_conn_node_t *node;
  84
  85         sdb_store_matcher_t *m;
  86         sdb_store_expr_t *expr;
  87 }
  88
  89 %start statements
  90
  91 %token SCANNER_ERROR
  92
  93 %token AND OR IS NOT MATCHING FILTER
  94 %token CMP_EQUAL CMP_NEQUAL CMP_REGEX CMP_NREGEX
  95 %token CMP_LT CMP_LE CMP_GE CMP_GT
  96 %token CONCAT
  97
  98 %token START END
  99
 100 /* NULL token */
 101 %token NULL_T
 102
 103 %token FETCH LIST LOOKUP TIMESERIES
 104
 105 %token <str> IDENTIFIER STRING
 106
 107 %token <data> INTEGER FLOAT
 108
 109 %token <datetime> DATE TIME
 110
 111 /* Precedence (lowest first): */
 112 %left OR
 113 %left AND
 114 %right NOT
 115 %left CMP_EQUAL CMP_NEQUAL
 116 %left CMP_LT CMP_LE CMP_GE CMP_GT
 117 %nonassoc CMP_REGEX CMP_NREGEX
 118 %left CONCAT
 119 %nonassoc IS
 120 %left '+' '-'
 121 %left '*' '/' '%'
 122 %left '[' ']'
 123 %left '(' ')'
 124 %left '.'
 125
 126 %type <list> statements
 127 %type <node> statement
 128         fetch_statement
 129         list_statement
 130         lookup_statement
 131         timeseries_statement
 132         matching_clause
 133         filter_clause
 134         condition
 135
 136 %type <m> matcher
 137         compare_matcher
 138
 139 %type <expr> expression
 140
 141 %type <sstr> cmp
 142
 143 %type <data> data
 144         interval interval_elem
 145
 146 %type <datetime> datetime
 147         start_clause end_clause
 148
 149 %destructor { free($$); } <str>
 150 %destructor { sdb_object_deref(SDB_OBJ($$)); } <node> <m> <expr>
 151 %destructor { sdb_data_free_datum(&$$); } <data>
 152
 153 %%
 154
 155 statements:
 156         statements ';' statement
 157                 {
 158                         /* only accepted in default parse mode */
 159                         if (parser_mode != SDB_PARSE_DEFAULT) {
 160                                 char errmsg[1024];
 161                                 snprintf(errmsg, sizeof(errmsg),
 162                                                 YY_("syntax error, unexpected statement, "
 163                                                         "expecting %s"), MODE_TO_STRING(parser_mode));
 164                                 sdb_fe_yyerror(&yylloc, scanner, errmsg);
 165                                 sdb_object_deref(SDB_OBJ($3));
 166                                 YYABORT;
 167                         }
 168
 169                         if ($3) {
 170                                 sdb_llist_append(pt, SDB_OBJ($3));
 171                                 sdb_object_deref(SDB_OBJ($3));
 172                         }
 173                 }
 174         |
 175         statement
 176                 {
 177                         /* only accepted in default parse mode */
 178                         if (parser_mode != SDB_PARSE_DEFAULT) {
 179                                 char errmsg[1024];
 180                                 snprintf(errmsg, sizeof(errmsg),
 181                                                 YY_("syntax error, unexpected statement, "
 182                                                         "expecting %s"), MODE_TO_STRING(parser_mode));
 183                                 sdb_fe_yyerror(&yylloc, scanner, errmsg);
 184                                 sdb_object_deref(SDB_OBJ($1));
 185                                 YYABORT;
 186                         }
 187
 188                         if ($1) {
 189                                 sdb_llist_append(pt, SDB_OBJ($1));
 190                                 sdb_object_deref(SDB_OBJ($1));
 191                         }
 192                 }
 193         |
 194         condition
 195                 {
 196                         /* only accepted in condition parse mode */
 197                         if (! (parser_mode & SDB_PARSE_COND)) {
 198                                 char errmsg[1024];
 199                                 snprintf(errmsg, sizeof(errmsg),
 200                                                 YY_("syntax error, unexpected condition, "
 201                                                         "expecting %s"), MODE_TO_STRING(parser_mode));
 202                                 sdb_fe_yyerror(&yylloc, scanner, errmsg);
 203                                 sdb_object_deref(SDB_OBJ($1));
 204                                 YYABORT;
 205                         }
 206
 207                         if ($1) {
 208                                 sdb_llist_append(pt, SDB_OBJ($1));
 209                                 sdb_object_deref(SDB_OBJ($1));
 210                         }
 211                 }
 212         |
 213         expression
 214                 {
 215                         /* only accepted in expression parse mode */
 216                         if (! (parser_mode & SDB_PARSE_EXPR)) {
 217                                 char errmsg[1024];
 218                                 snprintf(errmsg, sizeof(errmsg),
 219                                                 YY_("syntax error, unexpected expression, "
 220                                                         "expecting %s"), MODE_TO_STRING(parser_mode));
 221                                 sdb_fe_yyerror(&yylloc, scanner, errmsg);
 222                                 sdb_object_deref(SDB_OBJ($1));
 223                                 YYABORT;
 224                         }
 225
 226                         if ($1) {
 227                                 sdb_conn_node_t *n;
 228                                 n = SDB_CONN_NODE(sdb_object_create_dT(/* name = */ NULL,
 229                                                         conn_expr_t, conn_expr_destroy));
 230                                 n->cmd = CONNECTION_EXPR;
 231                                 CONN_EXPR(n)->expr = $1;
 232
 233                                 sdb_llist_append(pt, SDB_OBJ(n));
 234                                 sdb_object_deref(SDB_OBJ(n));
 235                         }
 236                 }
 237         ;
 238
 239 statement:
 240         fetch_statement
 241         |
 242         list_statement
 243         |
 244         lookup_statement
 245         |
 246         timeseries_statement
 247         |
 248         /* empty */
 249                 {
 250                         $$ = NULL;
 251                 }
 252         ;
 253
 254 /*
 255  * FETCH <type> <hostname> [FILTER <condition>];
 256  *
 257  * Retrieve detailed information about a single host.
 258  */
 259 fetch_statement:
 260         FETCH IDENTIFIER STRING filter_clause
 261                 {
 262                         /* TODO: support other types as well */
 263                         if (strcasecmp($2, "host")) {
 264                                 char errmsg[strlen($2) + 32];
 265                                 snprintf(errmsg, sizeof(errmsg),
 266                                                 YY_("unknown data-source %s"), $2);
 267                                 sdb_fe_yyerror(&yylloc, scanner, errmsg);
 268                                 free($2); $2 = NULL;
 269                                 free($3); $3 = NULL;
 270                                 sdb_object_deref(SDB_OBJ($4));
 271                                 YYABORT;
 272                         }
 273
 274                         $$ = SDB_CONN_NODE(sdb_object_create_dT(/* name = */ NULL,
 275                                                 conn_fetch_t, conn_fetch_destroy));
 276                         CONN_FETCH($$)->type = SDB_HOST;
 277                         CONN_FETCH($$)->name = $3;
 278                         CONN_FETCH($$)->filter = CONN_MATCHER($4);
 279                         $$->cmd = CONNECTION_FETCH;
 280                         free($2); $2 = NULL;
 281                 }
 282         ;
 283
 284 /*
 285  * LIST <type> [FILTER <condition>];
 286  *
 287  * Returns a list of all hosts in the store.
 288  */
 289 list_statement:
 290         LIST IDENTIFIER filter_clause
 291                 {
 292                         int type = sdb_store_parse_object_type_plural($2);
 293                         if (type < 0) {
 294                                 char errmsg[strlen($2) + 32];
 295                                 snprintf(errmsg, sizeof(errmsg),
 296                                                 YY_("unknown data-source %s"), $2);
 297                                 sdb_fe_yyerror(&yylloc, scanner, errmsg);
 298                                 free($2); $2 = NULL;
 299                                 sdb_object_deref(SDB_OBJ($3));
 300                                 YYABORT;
 301                         }
 302
 303                         $$ = SDB_CONN_NODE(sdb_object_create_dT(/* name = */ NULL,
 304                                                 conn_list_t, conn_list_destroy));
 305                         CONN_LIST($$)->type = type;
 306                         CONN_LIST($$)->filter = CONN_MATCHER($3);
 307                         $$->cmd = CONNECTION_LIST;
 308                         free($2); $2 = NULL;
 309                 }
 310         ;
 311
 312 /*
 313  * LOOKUP <type> MATCHING <condition> [FILTER <condition>];
 314  *
 315  * Returns detailed information about <type> matching condition.
 316  */
 317 lookup_statement:
 318         LOOKUP IDENTIFIER matching_clause filter_clause
 319                 {
 320                         /* TODO: support other types as well */
 321                         if (strcasecmp($2, "hosts")) {
 322                                 char errmsg[strlen($2) + 32];
 323                                 snprintf(errmsg, sizeof(errmsg),
 324                                                 YY_("unknown data-source %s"), $2);
 325                                 sdb_fe_yyerror(&yylloc, scanner, errmsg);
 326                                 free($2); $2 = NULL;
 327                                 sdb_object_deref(SDB_OBJ($3));
 328                                 sdb_object_deref(SDB_OBJ($4));
 329                                 YYABORT;
 330                         }
 331
 332                         $$ = SDB_CONN_NODE(sdb_object_create_dT(/* name = */ NULL,
 333                                                 conn_lookup_t, conn_lookup_destroy));
 334                         CONN_LOOKUP($$)->type = SDB_HOST;
 335                         CONN_LOOKUP($$)->matcher = CONN_MATCHER($3);
 336                         CONN_LOOKUP($$)->filter = CONN_MATCHER($4);
 337                         $$->cmd = CONNECTION_LOOKUP;
 338                         free($2); $2 = NULL;
 339                 }
 340         ;
 341
 342 matching_clause:
 343         MATCHING condition { $$ = $2; }
 344         |
 345         /* empty */ { $$ = NULL; }
 346
 347 filter_clause:
 348         FILTER condition { $$ = $2; }
 349         |
 350         /* empty */ { $$ = NULL; }
 351
 352 /*
 353  * TIMESERIES <host>.<metric> [START <datetime>] [END <datetime>];
 354  *
 355  * Returns a time-series for the specified host's metric.
 356  */
 357 timeseries_statement:
 358         TIMESERIES STRING '.' STRING start_clause end_clause
 359                 {
 360                         $$ = SDB_CONN_NODE(sdb_object_create_dT(/* name = */ NULL,
 361                                                 conn_ts_t, conn_ts_destroy));
 362                         CONN_TS($$)->hostname = $2;
 363                         CONN_TS($$)->metric = $4;
 364                         CONN_TS($$)->opts.start = $5;
 365                         CONN_TS($$)->opts.end = $6;
 366                         $$->cmd = CONNECTION_TIMESERIES;
 367                 }
 368         ;
 369
 370 start_clause:
 371         START datetime { $$ = $2; }
 372         |
 373         /* empty */ { $$ = sdb_gettime() - SDB_INTERVAL_HOUR; }
 374
 375 end_clause:
 376         END datetime { $$ = $2; }
 377         |
 378         /* empty */ { $$ = sdb_gettime(); }
 379
 380 /*
 381  * Basic expressions.
 382  */
 383
 384 condition:
 385         matcher
 386                 {
 387                         if (! $1) {
 388                                 /* TODO: improve error reporting */
 389                                 sdb_fe_yyerror(&yylloc, scanner,
 390                                                 YY_("syntax error, invalid condition"));
 391                                 YYABORT;
 392                         }
 393
 394                         $$ = SDB_CONN_NODE(sdb_object_create_dT(/* name = */ NULL,
 395                                                 conn_matcher_t, conn_matcher_destroy));
 396                         $$->cmd = CONNECTION_MATCHER;
 397                         CONN_MATCHER($$)->matcher = $1;
 398                 }
 399         ;
 400
 401 matcher:
 402         '(' matcher ')'
 403                 {
 404                         $$ = $2;
 405                 }
 406         |
 407         matcher AND matcher
 408                 {
 409                         $$ = sdb_store_con_matcher($1, $3);
 410                         sdb_object_deref(SDB_OBJ($1));
 411                         sdb_object_deref(SDB_OBJ($3));
 412                 }
 413         |
 414         matcher OR matcher
 415                 {
 416                         $$ = sdb_store_dis_matcher($1, $3);
 417                         sdb_object_deref(SDB_OBJ($1));
 418                         sdb_object_deref(SDB_OBJ($3));
 419                 }
 420         |
 421         NOT matcher
 422                 {
 423                         $$ = sdb_store_inv_matcher($2);
 424                         sdb_object_deref(SDB_OBJ($2));
 425                 }
 426         |
 427         compare_matcher
 428                 {
 429                         $$ = $1;
 430                 }
 431         ;
 432
 433 /*
 434  * <object_type>.<object_attr> <cmp> <value>
 435  *
 436  * Parse matchers comparing object attributes with a value.
 437  */
 438 compare_matcher:
 439         '.' IDENTIFIER cmp expression
 440                 {
 441                         $$ = sdb_store_matcher_parse_field_cmp($2, $3, $4);
 442                         free($2); $2 = NULL;
 443                         sdb_object_deref(SDB_OBJ($4));
 444                 }
 445         |
 446         IDENTIFIER cmp expression
 447                 {
 448                         $$ = sdb_store_matcher_parse_cmp($1, NULL, $2, $3);
 449                         free($1); $1 = NULL;
 450                         sdb_object_deref(SDB_OBJ($3));
 451                 }
 452         |
 453         IDENTIFIER '[' STRING ']' cmp expression
 454                 {
 455                         $$ = sdb_store_matcher_parse_cmp($1, $3, $5, $6);
 456                         free($1); $1 = NULL;
 457                         free($3); $3 = NULL;
 458                         sdb_object_deref(SDB_OBJ($6));
 459                 }
 460         |
 461         expression IS NULL_T
 462                 {
 463                         $$ = sdb_store_isnull_matcher($1);
 464                         sdb_object_deref(SDB_OBJ($1));
 465                 }
 466         |
 467         expression IS NOT NULL_T
 468                 {
 469                         $$ = sdb_store_isnnull_matcher($1);
 470                         sdb_object_deref(SDB_OBJ($1));
 471                 }
 472         ;
 473
 474 expression:
 475         '(' expression ')'
 476                 {
 477                         $$ = $2;
 478                 }
 479         |
 480         expression '+' expression
 481                 {
 482                         $$ = sdb_store_expr_create(SDB_DATA_ADD, $1, $3);
 483                         sdb_object_deref(SDB_OBJ($1)); $1 = NULL;
 484                         sdb_object_deref(SDB_OBJ($3)); $3 = NULL;
 485                 }
 486         |
 487         expression '-' expression
 488                 {
 489                         $$ = sdb_store_expr_create(SDB_DATA_SUB, $1, $3);
 490                         sdb_object_deref(SDB_OBJ($1)); $1 = NULL;
 491                         sdb_object_deref(SDB_OBJ($3)); $3 = NULL;
 492                 }
 493         |
 494         expression '*' expression
 495                 {
 496                         $$ = sdb_store_expr_create(SDB_DATA_MUL, $1, $3);
 497                         sdb_object_deref(SDB_OBJ($1)); $1 = NULL;
 498                         sdb_object_deref(SDB_OBJ($3)); $3 = NULL;
 499                 }
 500         |
 501         expression '/' expression
 502                 {
 503                         $$ = sdb_store_expr_create(SDB_DATA_DIV, $1, $3);
 504                         sdb_object_deref(SDB_OBJ($1)); $1 = NULL;
 505                         sdb_object_deref(SDB_OBJ($3)); $3 = NULL;
 506                 }
 507         |
 508         expression '%' expression
 509                 {
 510                         $$ = sdb_store_expr_create(SDB_DATA_MOD, $1, $3);
 511                         sdb_object_deref(SDB_OBJ($1)); $1 = NULL;
 512                         sdb_object_deref(SDB_OBJ($3)); $3 = NULL;
 513                 }
 514         |
 515         expression CONCAT expression
 516                 {
 517                         $$ = sdb_store_expr_create(SDB_DATA_CONCAT, $1, $3);
 518                         sdb_object_deref(SDB_OBJ($1)); $1 = NULL;
 519                         sdb_object_deref(SDB_OBJ($3)); $3 = NULL;
 520                 }
 521         |
 522         '.' IDENTIFIER
 523                 {
 524                         int field = sdb_store_parse_field_name($2);
 525                         free($2); $2 = NULL;
 526                         $$ = sdb_store_expr_fieldvalue(field);
 527                 }
 528         |
 529         IDENTIFIER '[' STRING ']'
 530                 {
 531                         $$ = sdb_store_expr_attrvalue($3);
 532                         free($1); $1 = NULL;
 533                         free($3); $3 = NULL;
 534                 }
 535         |
 536         data
 537                 {
 538                         $$ = sdb_store_expr_constvalue(&$1);
 539                         sdb_data_free_datum(&$1);
 540                 }
 541         ;
 542
 543 cmp:
 544         CMP_EQUAL { $$ = "="; }
 545         |
 546         CMP_NEQUAL { $$ = "!="; }
 547         |
 548         CMP_REGEX { $$ = "=~"; }
 549         |
 550         CMP_NREGEX { $$ = "!~"; }
 551         |
 552         CMP_LT { $$ = "<"; }
 553         |
 554         CMP_LE { $$ = "<="; }
 555         |
 556         CMP_GE { $$ = ">="; }
 557         |
 558         CMP_GT { $$ = ">"; }
 559         ;
 560
 561 data:
 562         STRING { $$.type = SDB_TYPE_STRING; $$.data.string = $1; }
 563         |
 564         INTEGER { $$ = $1; }
 565         |
 566         FLOAT { $$ = $1; }
 567         |
 568         datetime { $$.type = SDB_TYPE_DATETIME; $$.data.datetime = $1; }
 569         |
 570         interval { $$ = $1; }
 571         ;
 572
 573 datetime:
 574         DATE TIME { $$ = $1 + $2; }
 575         |
 576         DATE { $$ = $1; }
 577         |
 578         TIME { $$ = $1; }
 579         ;
 580
 581 interval:
 582         interval interval_elem
 583                 {
 584                         $$.data.datetime = $1.data.datetime + $2.data.datetime;
 585                 }
 586         |
 587         interval_elem { $$ = $1; }
 588         ;
 589
 590 interval_elem:
 591         INTEGER IDENTIFIER
 592                 {
 593                         sdb_time_t unit = 1;
 594
 595                         unit = sdb_strpunit($2);
 596                         if (! unit) {
 597                                 char errmsg[strlen($2) + 32];
 598                                 snprintf(errmsg, sizeof(errmsg),
 599                                                 YY_("invalid time unit %s"), $2);
 600                                 sdb_fe_yyerror(&yylloc, scanner, errmsg);
 601                                 free($2); $2 = NULL;
 602                                 YYABORT;
 603                         }
 604                         free($2); $2 = NULL;
 605
 606                         $$.type = SDB_TYPE_DATETIME;
 607                         $$.data.datetime = (sdb_time_t)$1.data.integer * unit;
 608
 609                         if ($1.data.integer < 0) {
 610                                 sdb_fe_yyerror(&yylloc, scanner,
 611                                                 YY_("syntax error, negative intervals not supported"));
 612                                 YYABORT;
 613                         }
 614                 }
 615         ;
 616
 617 %%
 618
 619 void
 620 sdb_fe_yyerror(YYLTYPE *lval, sdb_fe_yyscan_t scanner, const char *msg)
 621 {
 622         sdb_log(SDB_LOG_ERR, "frontend: parse error: %s", msg);
 623 } /* sdb_fe_yyerror */
 624
 625 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */
 626