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