src/rrd_rpncalc.c

   1 /****************************************************************************
   2  * RRDtool 1.4.3  Copyright by Tobi Oetiker, 1997-2010
   3  ****************************************************************************
   4  * rrd_rpncalc.c  RPN calculator functions
   5  ****************************************************************************/
   6
   7 #include <limits.h>
   8 #include <locale.h>
   9 #include <stdlib.h>
  10
  11 #include "rrd_tool.h"
  12 #include "rrd_rpncalc.h"
  13 // #include "rrd_graph.h"
  14
  15 short     addop2str(
  16     enum op_en op,
  17     enum op_en op_type,
  18     char *op_str,
  19     char **result_str,
  20     unsigned short *offset);
  21 int       tzoffset(
  22     time_t);            /* used to implement LTIME */
  23
  24 short rpn_compact(
  25     rpnp_t *rpnp,
  26     rpn_cdefds_t **rpnc,
  27     short *count)
  28 {
  29     short     i;
  30
  31     *count = 0;
  32     /* count the number of rpn nodes */
  33     while (rpnp[*count].op != OP_END)
  34         (*count)++;
  35     if (++(*count) > DS_CDEF_MAX_RPN_NODES) {
  36         rrd_set_error("Maximum %d RPN nodes permitted",
  37                       DS_CDEF_MAX_RPN_NODES);
  38         return -1;
  39     }
  40
  41     /* allocate memory */
  42     *rpnc = (rpn_cdefds_t *) calloc(*count, sizeof(rpn_cdefds_t));
  43     for (i = 0; rpnp[i].op != OP_END; i++) {
  44         (*rpnc)[i].op = (char) rpnp[i].op;
  45         if (rpnp[i].op == OP_NUMBER) {
  46             /* rpnp.val is a double, rpnc.val is a short */
  47             double    temp = floor(rpnp[i].val);
  48
  49             if (temp < SHRT_MIN || temp > SHRT_MAX) {
  50                 rrd_set_error
  51                     ("constants must be integers in the interval (%d, %d)",
  52                      SHRT_MIN, SHRT_MAX);
  53                 free(*rpnc);
  54                 return -1;
  55             }
  56             (*rpnc)[i].val = (short) temp;
  57         } else if (rpnp[i].op == OP_VARIABLE || rpnp[i].op == OP_PREV_OTHER) {
  58             (*rpnc)[i].val = (short) rpnp[i].ptr;
  59         }
  60     }
  61     /* terminate the sequence */
  62     (*rpnc)[(*count) - 1].op = OP_END;
  63     return 0;
  64 }
  65
  66 rpnp_t   *rpn_expand(
  67     rpn_cdefds_t *rpnc)
  68 {
  69     short     i;
  70     rpnp_t   *rpnp;
  71
  72     /* DS_CDEF_MAX_RPN_NODES is small, so at the expense of some wasted
  73      * memory we avoid any reallocs */
  74     rpnp = (rpnp_t *) calloc(DS_CDEF_MAX_RPN_NODES, sizeof(rpnp_t));
  75     if (rpnp == NULL)
  76         return NULL;
  77     for (i = 0; rpnc[i].op != OP_END; ++i) {
  78         rpnp[i].op = rpnc[i].op;
  79         if (rpnp[i].op == OP_NUMBER) {
  80             rpnp[i].val = (double) rpnc[i].val;
  81         } else if (rpnp[i].op == OP_VARIABLE || rpnp[i].op == OP_PREV_OTHER) {
  82             rpnp[i].ptr = (long) rpnc[i].val;
  83         }
  84     }
  85     /* terminate the sequence */
  86     rpnp[i].op = OP_END;
  87     return rpnp;
  88 }
  89
  90 /* rpn_compact2str: convert a compact sequence of RPN operator nodes back
  91  * into a CDEF string. This function is used by rrd_dump.
  92  * arguments:
  93  *  rpnc: an array of compact RPN operator nodes
  94  *  ds_def: a pointer to the data source definition section of an RRD header
  95  *   for lookup of data source names by index
  96  *  str: out string, memory is allocated by the function, must be freed by the
  97  *   the caller */
  98 void rpn_compact2str(
  99     rpn_cdefds_t *rpnc,
 100     ds_def_t *ds_def,
 101     char **str)
 102 {
 103     unsigned short i, offset = 0;
 104     char      buffer[7];    /* short as a string */
 105
 106     for (i = 0; rpnc[i].op != OP_END; i++) {
 107         if (i > 0)
 108             (*str)[offset++] = ',';
 109
 110 #define add_op(VV,VVV) \
 111           if (addop2str((enum op_en)(rpnc[i].op), VV, VVV, str, &offset) == 1) continue;
 112
 113         if (rpnc[i].op == OP_NUMBER) {
 114             /* convert a short into a string */
 115 #if defined(_WIN32) && !defined(__CYGWIN__) && !defined(__CYGWIN32__)
 116             _itoa(rpnc[i].val, buffer, 10);
 117 #else
 118             sprintf(buffer, "%d", rpnc[i].val);
 119 #endif
 120             add_op(OP_NUMBER, buffer)
 121         }
 122
 123         if (rpnc[i].op == OP_VARIABLE) {
 124             char     *ds_name = ds_def[rpnc[i].val].ds_nam;
 125
 126             add_op(OP_VARIABLE, ds_name)
 127         }
 128
 129         if (rpnc[i].op == OP_PREV_OTHER) {
 130             char     *ds_name = ds_def[rpnc[i].val].ds_nam;
 131
 132             add_op(OP_VARIABLE, ds_name)
 133         }
 134 #undef add_op
 135
 136 #define add_op(VV,VVV) \
 137           if (addop2str((enum op_en)rpnc[i].op, VV, #VVV, str, &offset) == 1) continue;
 138
 139         add_op(OP_ADD, +)
 140             add_op(OP_SUB, -)
 141             add_op(OP_MUL, *)
 142             add_op(OP_DIV, /)
 143             add_op(OP_MOD, %)
 144             add_op(OP_SIN, SIN)
 145             add_op(OP_COS, COS)
 146             add_op(OP_LOG, LOG)
 147             add_op(OP_FLOOR, FLOOR)
 148             add_op(OP_CEIL, CEIL)
 149             add_op(OP_EXP, EXP)
 150             add_op(OP_DUP, DUP)
 151             add_op(OP_EXC, EXC)
 152             add_op(OP_POP, POP)
 153             add_op(OP_LT, LT)
 154             add_op(OP_LE, LE)
 155             add_op(OP_GT, GT)
 156             add_op(OP_GE, GE)
 157             add_op(OP_EQ, EQ)
 158             add_op(OP_IF, IF)
 159             add_op(OP_MIN, MIN)
 160             add_op(OP_MAX, MAX)
 161             add_op(OP_LIMIT, LIMIT)
 162             add_op(OP_UNKN, UNKN)
 163             add_op(OP_UN, UN)
 164             add_op(OP_NEGINF, NEGINF)
 165             add_op(OP_NE, NE)
 166             add_op(OP_PREV, PREV)
 167             add_op(OP_INF, INF)
 168             add_op(OP_ISINF, ISINF)
 169             add_op(OP_NOW, NOW)
 170             add_op(OP_LTIME, LTIME)
 171             add_op(OP_TIME, TIME)
 172             add_op(OP_ATAN2, ATAN2)
 173             add_op(OP_ATAN, ATAN)
 174             add_op(OP_SQRT, SQRT)
 175             add_op(OP_SORT, SORT)
 176             add_op(OP_REV, REV)
 177             add_op(OP_TREND, TREND)
 178             add_op(OP_TRENDNAN, TRENDNAN)
 179             add_op(OP_PREDICT, PREDICT)
 180             add_op(OP_PREDICTSIGMA, PREDICTSIGMA)
 181             add_op(OP_RAD2DEG, RAD2DEG)
 182             add_op(OP_DEG2RAD, DEG2RAD)
 183             add_op(OP_AVG, AVG)
 184             add_op(OP_ABS, ABS)
 185             add_op(OP_ADDNAN, ADDNAN)
 186 #undef add_op
 187     }
 188     (*str)[offset] = '\0';
 189
 190 }
 191
 192 short addop2str(
 193     enum op_en op,
 194     enum op_en op_type,
 195     char *op_str,
 196     char **result_str,
 197     unsigned short *offset)
 198 {
 199     if (op == op_type) {
 200         short     op_len;
 201
 202         op_len = strlen(op_str);
 203         *result_str = (char *) rrd_realloc(*result_str,
 204                                            (op_len + 1 +
 205                                             *offset) * sizeof(char));
 206         if (*result_str == NULL) {
 207             rrd_set_error("failed to alloc memory in addop2str");
 208             return -1;
 209         }
 210         strncpy(&((*result_str)[*offset]), op_str, op_len);
 211         *offset += op_len;
 212         return 1;
 213     }
 214     return 0;
 215 }
 216
 217 void parseCDEF_DS(
 218     const char *def,
 219     rrd_t *rrd,
 220     int ds_idx)
 221 {
 222     rpnp_t   *rpnp = NULL;
 223     rpn_cdefds_t *rpnc = NULL;
 224     short     count, i;
 225
 226     rpnp = rpn_parse((void *) rrd, def, &lookup_DS);
 227     if (rpnp == NULL) {
 228         rrd_set_error("failed to parse computed data source");
 229         return;
 230     }
 231     /* Check for OP nodes not permitted in COMPUTE DS.
 232      * Moved this check from within rpn_compact() because it really is
 233      * COMPUTE DS specific. This is less efficient, but creation doesn't
 234      * occur too often. */
 235     for (i = 0; rpnp[i].op != OP_END; i++) {
 236         if (rpnp[i].op == OP_TIME || rpnp[i].op == OP_LTIME ||
 237             rpnp[i].op == OP_PREV || rpnp[i].op == OP_COUNT) {
 238             rrd_set_error
 239                 ("operators time, ltime, prev and count not supported with DS COMPUTE");
 240             free(rpnp);
 241             return;
 242         }
 243     }
 244     if (rpn_compact(rpnp, &rpnc, &count) == -1) {
 245         free(rpnp);
 246         return;
 247     }
 248     /* copy the compact rpn representation over the ds_def par array */
 249     memcpy((void *) &(rrd->ds_def[ds_idx].par[DS_cdef]),
 250            (void *) rpnc, count * sizeof(rpn_cdefds_t));
 251     free(rpnp);
 252     free(rpnc);
 253 }
 254
 255 /* lookup a data source name in the rrd struct and return the index,
 256  * should use ds_match() here except:
 257  * (1) need a void * pointer to the rrd
 258  * (2) error handling is left to the caller
 259  */
 260 long lookup_DS(
 261     void *rrd_vptr,
 262     char *ds_name)
 263 {
 264     unsigned int i;
 265     rrd_t    *rrd;
 266
 267     rrd = (rrd_t *) rrd_vptr;
 268
 269     for (i = 0; i < rrd->stat_head->ds_cnt; ++i) {
 270         if (strcmp(ds_name, rrd->ds_def[i].ds_nam) == 0)
 271             return i;
 272     }
 273     /* the caller handles a bad data source name in the rpn string */
 274     return -1;
 275 }
 276
 277 /* rpn_parse : parse a string and generate a rpnp array; modified
 278  * str2rpn() originally included in rrd_graph.c
 279  * arguments:
 280  * key_hash: a transparent argument passed to lookup(); conceptually this
 281  *    is a hash object for lookup of a numeric key given a variable name
 282  * expr: the string RPN expression, including variable names
 283  * lookup(): a function that retrieves a numeric key given a variable name
 284  */
 285 rpnp_t   *rpn_parse(
 286     void *key_hash,
 287     const char *const expr_const,
 288     long      (*lookup) (void *,
 289                          char *))
 290 {
 291     int       pos = 0;
 292     char     *expr;
 293     long      steps = -1;
 294     rpnp_t   *rpnp;
 295     char      vname[MAX_VNAME_LEN + 10];
 296     char     *old_locale;
 297
 298     old_locale = setlocale(LC_NUMERIC, "C");
 299
 300     rpnp = NULL;
 301     expr = (char *) expr_const;
 302
 303     while (*expr) {
 304         if ((rpnp = (rpnp_t *) rrd_realloc(rpnp, (++steps + 2) *
 305                                            sizeof(rpnp_t))) == NULL) {
 306             setlocale(LC_NUMERIC, old_locale);
 307             return NULL;
 308         }
 309
 310         else if ((sscanf(expr, "%lf%n", &rpnp[steps].val, &pos) == 1)
 311                  && (expr[pos] == ',')) {
 312             rpnp[steps].op = OP_NUMBER;
 313             expr += pos;
 314         }
 315 #define match_op(VV,VVV) \
 316         else if (strncmp(expr, #VVV, strlen(#VVV))==0 && ( expr[strlen(#VVV)] == ',' || expr[strlen(#VVV)] == '\0' )){ \
 317             rpnp[steps].op = VV; \
 318             expr+=strlen(#VVV); \
 319         }
 320
 321 #define match_op_param(VV,VVV) \
 322         else if (sscanf(expr, #VVV "(" DEF_NAM_FMT ")",vname) == 1) { \
 323           int length = 0; \
 324           if ((length = strlen(#VVV)+strlen(vname)+2, \
 325               expr[length] == ',' || expr[length] == '\0') ) { \
 326              rpnp[steps].op = VV; \
 327              rpnp[steps].ptr = (*lookup)(key_hash,vname); \
 328              if (rpnp[steps].ptr < 0) { \
 329                            free(rpnp); \
 330                            return NULL; \
 331                          } else expr+=length; \
 332           } \
 333         }
 334
 335         match_op(OP_ADD, +)
 336             match_op(OP_SUB, -)
 337             match_op(OP_MUL, *)
 338             match_op(OP_DIV, /)
 339             match_op(OP_MOD, %)
 340             match_op(OP_SIN, SIN)
 341             match_op(OP_COS, COS)
 342             match_op(OP_LOG, LOG)
 343             match_op(OP_FLOOR, FLOOR)
 344             match_op(OP_CEIL, CEIL)
 345             match_op(OP_EXP, EXP)
 346             match_op(OP_DUP, DUP)
 347             match_op(OP_EXC, EXC)
 348             match_op(OP_POP, POP)
 349             match_op(OP_LTIME, LTIME)
 350             match_op(OP_LT, LT)
 351             match_op(OP_LE, LE)
 352             match_op(OP_GT, GT)
 353             match_op(OP_GE, GE)
 354             match_op(OP_EQ, EQ)
 355             match_op(OP_IF, IF)
 356             match_op(OP_MIN, MIN)
 357             match_op(OP_MAX, MAX)
 358             match_op(OP_LIMIT, LIMIT)
 359             /* order is important here ! .. match longest first */
 360             match_op(OP_UNKN, UNKN)
 361             match_op(OP_UN, UN)
 362             match_op(OP_NEGINF, NEGINF)
 363             match_op(OP_NE, NE)
 364             match_op(OP_COUNT, COUNT)
 365             match_op_param(OP_PREV_OTHER, PREV)
 366             match_op(OP_PREV, PREV)
 367             match_op(OP_INF, INF)
 368             match_op(OP_ISINF, ISINF)
 369             match_op(OP_NOW, NOW)
 370             match_op(OP_TIME, TIME)
 371             match_op(OP_ATAN2, ATAN2)
 372             match_op(OP_ATAN, ATAN)
 373             match_op(OP_SQRT, SQRT)
 374             match_op(OP_SORT, SORT)
 375             match_op(OP_REV, REV)
 376             match_op(OP_TREND, TREND)
 377             match_op(OP_TRENDNAN, TRENDNAN)
 378             match_op(OP_PREDICT, PREDICT)
 379             match_op(OP_PREDICTSIGMA, PREDICTSIGMA)
 380             match_op(OP_RAD2DEG, RAD2DEG)
 381             match_op(OP_DEG2RAD, DEG2RAD)
 382             match_op(OP_AVG, AVG)
 383             match_op(OP_ABS, ABS)
 384             match_op(OP_ADDNAN, ADDNAN)
 385 #undef match_op
 386             else if ((sscanf(expr, DEF_NAM_FMT "%n", vname, &pos) == 1)
 387                      && ((rpnp[steps].ptr = (*lookup) (key_hash, vname)) !=
 388                          -1)) {
 389             rpnp[steps].op = OP_VARIABLE;
 390             expr += pos;
 391         }
 392
 393         else {
 394             setlocale(LC_NUMERIC, old_locale);
 395             free(rpnp);
 396             return NULL;
 397         }
 398
 399         if (*expr == 0)
 400             break;
 401         if (*expr == ',')
 402             expr++;
 403         else {
 404             setlocale(LC_NUMERIC, old_locale);
 405             free(rpnp);
 406             return NULL;
 407         }
 408     }
 409     rpnp[steps + 1].op = OP_END;
 410     setlocale(LC_NUMERIC, old_locale);
 411     return rpnp;
 412 }
 413
 414 void rpnstack_init(
 415     rpnstack_t *rpnstack)
 416 {
 417     rpnstack->s = NULL;
 418     rpnstack->dc_stacksize = 0;
 419     rpnstack->dc_stackblock = 100;
 420 }
 421
 422 void rpnstack_free(
 423     rpnstack_t *rpnstack)
 424 {
 425     if (rpnstack->s != NULL)
 426         free(rpnstack->s);
 427     rpnstack->dc_stacksize = 0;
 428 }
 429
 430 static int rpn_compare_double(
 431     const void *x,
 432     const void *y)
 433 {
 434     double    diff = *((const double *) x) - *((const double *) y);
 435
 436     return (diff < 0) ? -1 : (diff > 0) ? 1 : 0;
 437 }
 438
 439 /* rpn_calc: run the RPN calculator; also performs variable substitution;
 440  * moved and modified from data_calc() originally included in rrd_graph.c
 441  * arguments:
 442  * rpnp : an array of RPN operators (including variable references)
 443  * rpnstack : the initialized stack
 444  * data_idx : when data_idx is a multiple of rpnp.step, the rpnp.data pointer
 445  *   is advanced by rpnp.ds_cnt; used only for variable substitution
 446  * output : an array of output values; OP_PREV assumes this array contains
 447  *   the "previous" value at index position output_idx-1; the definition of
 448  *   "previous" depends on the calling environment
 449  * output_idx : an index into the output array in which to store the output
 450  *   of the RPN calculator
 451  * returns: -1 if the computation failed (also calls rrd_set_error)
 452  *           0 on success
 453  */
 454 short rpn_calc(
 455     rpnp_t *rpnp,
 456     rpnstack_t *rpnstack,
 457     long data_idx,
 458     rrd_value_t *output,
 459     int output_idx)
 460 {
 461     int       rpi;
 462     long      stptr = -1;
 463
 464     /* process each op from the rpn in turn */
 465     for (rpi = 0; rpnp[rpi].op != OP_END; rpi++) {
 466         /* allocate or grow the stack */
 467         if (stptr + 5 > rpnstack->dc_stacksize) {
 468             /* could move this to a separate function */
 469             rpnstack->dc_stacksize += rpnstack->dc_stackblock;
 470             rpnstack->s = (double*)rrd_realloc(rpnstack->s,
 471                                       (rpnstack->dc_stacksize) *
 472                                       sizeof(*(rpnstack->s)));
 473             if (rpnstack->s == NULL) {
 474                 rrd_set_error("RPN stack overflow");
 475                 return -1;
 476             }
 477         }
 478 #define stackunderflow(MINSIZE)                         \
 479         if(stptr<MINSIZE){                              \
 480             rrd_set_error("RPN stack underflow");       \
 481             return -1;                                  \
 482         }
 483
 484         switch (rpnp[rpi].op) {
 485         case OP_NUMBER:
 486             rpnstack->s[++stptr] = rpnp[rpi].val;
 487             break;
 488         case OP_VARIABLE:
 489         case OP_PREV_OTHER:
 490             /* Sanity check: VDEFs shouldn't make it here */
 491             if (rpnp[rpi].ds_cnt == 0) {
 492                 rrd_set_error("VDEF made it into rpn_calc... aborting");
 493                 return -1;
 494             } else {
 495                 /* make sure we pull the correct value from
 496                  * the *.data array. Adjust the pointer into
 497                  * the array acordingly. Advance the ptr one
 498                  * row in the rra (skip over non-relevant
 499                  * data sources)
 500                  */
 501                 if (rpnp[rpi].op == OP_VARIABLE) {
 502                     rpnstack->s[++stptr] = *(rpnp[rpi].data);
 503                 } else {
 504                     if ((output_idx) <= 0) {
 505                         rpnstack->s[++stptr] = DNAN;
 506                     } else {
 507                         rpnstack->s[++stptr] =
 508                             *(rpnp[rpi].data - rpnp[rpi].ds_cnt);
 509                     }
 510
 511                 }
 512                 if (data_idx % rpnp[rpi].step == 0) {
 513                     rpnp[rpi].data += rpnp[rpi].ds_cnt;
 514                 }
 515             }
 516             break;
 517         case OP_COUNT:
 518             rpnstack->s[++stptr] = (output_idx + 1);    /* Note: Counter starts at 1 */
 519             break;
 520         case OP_PREV:
 521             if ((output_idx) <= 0) {
 522                 rpnstack->s[++stptr] = DNAN;
 523             } else {
 524                 rpnstack->s[++stptr] = output[output_idx - 1];
 525             }
 526             break;
 527         case OP_UNKN:
 528             rpnstack->s[++stptr] = DNAN;
 529             break;
 530         case OP_INF:
 531             rpnstack->s[++stptr] = DINF;
 532             break;
 533         case OP_NEGINF:
 534             rpnstack->s[++stptr] = -DINF;
 535             break;
 536         case OP_NOW:
 537             rpnstack->s[++stptr] = (double) time(NULL);
 538             break;
 539         case OP_TIME:
 540             /* HACK: this relies on the data_idx being the time,
 541              ** which the within-function scope is unaware of */
 542             rpnstack->s[++stptr] = (double) data_idx;
 543             break;
 544         case OP_LTIME:
 545             rpnstack->s[++stptr] =
 546                 (double) tzoffset(data_idx) + (double) data_idx;
 547             break;
 548         case OP_ADD:
 549             stackunderflow(1);
 550             rpnstack->s[stptr - 1] = rpnstack->s[stptr - 1]
 551                 + rpnstack->s[stptr];
 552             stptr--;
 553             break;
 554         case OP_ADDNAN:
 555             stackunderflow(1);
 556             if (isnan(rpnstack->s[stptr - 1])) {
 557                 rpnstack->s[stptr - 1] = rpnstack->s[stptr];
 558             } else if (isnan(rpnstack->s[stptr])) {
 559                 /* NOOP */
 560                 /* rpnstack->s[stptr - 1] = rpnstack->s[stptr - 1]; */
 561             } else {
 562                 rpnstack->s[stptr - 1] = rpnstack->s[stptr - 1]
 563                     + rpnstack->s[stptr];
 564             }
 565
 566             stptr--;
 567             break;
 568         case OP_SUB:
 569             stackunderflow(1);
 570             rpnstack->s[stptr - 1] = rpnstack->s[stptr - 1]
 571                 - rpnstack->s[stptr];
 572             stptr--;
 573             break;
 574         case OP_MUL:
 575             stackunderflow(1);
 576             rpnstack->s[stptr - 1] = (rpnstack->s[stptr - 1])
 577                 * (rpnstack->s[stptr]);
 578             stptr--;
 579             break;
 580         case OP_DIV:
 581             stackunderflow(1);
 582             rpnstack->s[stptr - 1] = rpnstack->s[stptr - 1]
 583                 / rpnstack->s[stptr];
 584             stptr--;
 585             break;
 586         case OP_MOD:
 587             stackunderflow(1);
 588             rpnstack->s[stptr - 1] = fmod(rpnstack->s[stptr - 1]
 589                                           , rpnstack->s[stptr]);
 590             stptr--;
 591             break;
 592         case OP_SIN:
 593             stackunderflow(0);
 594             rpnstack->s[stptr] = sin(rpnstack->s[stptr]);
 595             break;
 596         case OP_ATAN:
 597             stackunderflow(0);
 598             rpnstack->s[stptr] = atan(rpnstack->s[stptr]);
 599             break;
 600         case OP_RAD2DEG:
 601             stackunderflow(0);
 602             rpnstack->s[stptr] = 57.29577951 * rpnstack->s[stptr];
 603             break;
 604         case OP_DEG2RAD:
 605             stackunderflow(0);
 606             rpnstack->s[stptr] = 0.0174532952 * rpnstack->s[stptr];
 607             break;
 608         case OP_ATAN2:
 609             stackunderflow(1);
 610             rpnstack->s[stptr - 1] = atan2(rpnstack->s[stptr - 1],
 611                                            rpnstack->s[stptr]);
 612             stptr--;
 613             break;
 614         case OP_COS:
 615             stackunderflow(0);
 616             rpnstack->s[stptr] = cos(rpnstack->s[stptr]);
 617             break;
 618         case OP_CEIL:
 619             stackunderflow(0);
 620             rpnstack->s[stptr] = ceil(rpnstack->s[stptr]);
 621             break;
 622         case OP_FLOOR:
 623             stackunderflow(0);
 624             rpnstack->s[stptr] = floor(rpnstack->s[stptr]);
 625             break;
 626         case OP_LOG:
 627             stackunderflow(0);
 628             rpnstack->s[stptr] = log(rpnstack->s[stptr]);
 629             break;
 630         case OP_DUP:
 631             stackunderflow(0);
 632             rpnstack->s[stptr + 1] = rpnstack->s[stptr];
 633             stptr++;
 634             break;
 635         case OP_POP:
 636             stackunderflow(0);
 637             stptr--;
 638             break;
 639         case OP_EXC:
 640             stackunderflow(1);
 641             {
 642                 double    dummy;
 643
 644                 dummy = rpnstack->s[stptr];
 645                 rpnstack->s[stptr] = rpnstack->s[stptr - 1];
 646                 rpnstack->s[stptr - 1] = dummy;
 647             }
 648             break;
 649         case OP_EXP:
 650             stackunderflow(0);
 651             rpnstack->s[stptr] = exp(rpnstack->s[stptr]);
 652             break;
 653         case OP_LT:
 654             stackunderflow(1);
 655             if (isnan(rpnstack->s[stptr - 1]));
 656             else if (isnan(rpnstack->s[stptr]))
 657                 rpnstack->s[stptr - 1] = rpnstack->s[stptr];
 658             else
 659                 rpnstack->s[stptr - 1] = rpnstack->s[stptr - 1] <
 660                     rpnstack->s[stptr] ? 1.0 : 0.0;
 661             stptr--;
 662             break;
 663         case OP_LE:
 664             stackunderflow(1);
 665             if (isnan(rpnstack->s[stptr - 1]));
 666             else if (isnan(rpnstack->s[stptr]))
 667                 rpnstack->s[stptr - 1] = rpnstack->s[stptr];
 668             else
 669                 rpnstack->s[stptr - 1] = rpnstack->s[stptr - 1] <=
 670                     rpnstack->s[stptr] ? 1.0 : 0.0;
 671             stptr--;
 672             break;
 673         case OP_GT:
 674             stackunderflow(1);
 675             if (isnan(rpnstack->s[stptr - 1]));
 676             else if (isnan(rpnstack->s[stptr]))
 677                 rpnstack->s[stptr - 1] = rpnstack->s[stptr];
 678             else
 679                 rpnstack->s[stptr - 1] = rpnstack->s[stptr - 1] >
 680                     rpnstack->s[stptr] ? 1.0 : 0.0;
 681             stptr--;
 682             break;
 683         case OP_GE:
 684             stackunderflow(1);
 685             if (isnan(rpnstack->s[stptr - 1]));
 686             else if (isnan(rpnstack->s[stptr]))
 687                 rpnstack->s[stptr - 1] = rpnstack->s[stptr];
 688             else
 689                 rpnstack->s[stptr - 1] = rpnstack->s[stptr - 1] >=
 690                     rpnstack->s[stptr] ? 1.0 : 0.0;
 691             stptr--;
 692             break;
 693         case OP_NE:
 694             stackunderflow(1);
 695             if (isnan(rpnstack->s[stptr - 1]));
 696             else if (isnan(rpnstack->s[stptr]))
 697                 rpnstack->s[stptr - 1] = rpnstack->s[stptr];
 698             else
 699                 rpnstack->s[stptr - 1] = rpnstack->s[stptr - 1] ==
 700                     rpnstack->s[stptr] ? 0.0 : 1.0;
 701             stptr--;
 702             break;
 703         case OP_EQ:
 704             stackunderflow(1);
 705             if (isnan(rpnstack->s[stptr - 1]));
 706             else if (isnan(rpnstack->s[stptr]))
 707                 rpnstack->s[stptr - 1] = rpnstack->s[stptr];
 708             else
 709                 rpnstack->s[stptr - 1] = rpnstack->s[stptr - 1] ==
 710                     rpnstack->s[stptr] ? 1.0 : 0.0;
 711             stptr--;
 712             break;
 713         case OP_IF:
 714             stackunderflow(2);
 715             rpnstack->s[stptr - 2] = (isnan(rpnstack->s[stptr - 2])
 716                                       || rpnstack->s[stptr - 2] ==
 717                                       0.0) ? rpnstack->s[stptr] : rpnstack->
 718                 s[stptr - 1];
 719             stptr--;
 720             stptr--;
 721             break;
 722         case OP_MIN:
 723             stackunderflow(1);
 724             if (isnan(rpnstack->s[stptr - 1]));
 725             else if (isnan(rpnstack->s[stptr]))
 726                 rpnstack->s[stptr - 1] = rpnstack->s[stptr];
 727             else if (rpnstack->s[stptr - 1] > rpnstack->s[stptr])
 728                 rpnstack->s[stptr - 1] = rpnstack->s[stptr];
 729             stptr--;
 730             break;
 731         case OP_MAX:
 732             stackunderflow(1);
 733             if (isnan(rpnstack->s[stptr - 1]));
 734             else if (isnan(rpnstack->s[stptr]))
 735                 rpnstack->s[stptr - 1] = rpnstack->s[stptr];
 736             else if (rpnstack->s[stptr - 1] < rpnstack->s[stptr])
 737                 rpnstack->s[stptr - 1] = rpnstack->s[stptr];
 738             stptr--;
 739             break;
 740         case OP_LIMIT:
 741             stackunderflow(2);
 742             if (isnan(rpnstack->s[stptr - 2]));
 743             else if (isnan(rpnstack->s[stptr - 1]))
 744                 rpnstack->s[stptr - 2] = rpnstack->s[stptr - 1];
 745             else if (isnan(rpnstack->s[stptr]))
 746                 rpnstack->s[stptr - 2] = rpnstack->s[stptr];
 747             else if (rpnstack->s[stptr - 2] < rpnstack->s[stptr - 1])
 748                 rpnstack->s[stptr - 2] = DNAN;
 749             else if (rpnstack->s[stptr - 2] > rpnstack->s[stptr])
 750                 rpnstack->s[stptr - 2] = DNAN;
 751             stptr -= 2;
 752             break;
 753         case OP_UN:
 754             stackunderflow(0);
 755             rpnstack->s[stptr] = isnan(rpnstack->s[stptr]) ? 1.0 : 0.0;
 756             break;
 757         case OP_ISINF:
 758             stackunderflow(0);
 759             rpnstack->s[stptr] = isinf(rpnstack->s[stptr]) ? 1.0 : 0.0;
 760             break;
 761         case OP_SQRT:
 762             stackunderflow(0);
 763             rpnstack->s[stptr] = sqrt(rpnstack->s[stptr]);
 764             break;
 765         case OP_SORT:
 766             stackunderflow(0);
 767             {
 768                 int       spn = (int) rpnstack->s[stptr--];
 769
 770                 stackunderflow(spn - 1);
 771                 qsort(rpnstack->s + stptr - spn + 1, spn, sizeof(double),
 772                       rpn_compare_double);
 773             }
 774             break;
 775         case OP_REV:
 776             stackunderflow(0);
 777             {
 778                 int       spn = (int) rpnstack->s[stptr--];
 779                 double   *p, *q;
 780
 781                 stackunderflow(spn - 1);
 782
 783                 p = rpnstack->s + stptr - spn + 1;
 784                 q = rpnstack->s + stptr;
 785                 while (p < q) {
 786                     double    x = *q;
 787
 788                     *q-- = *p;
 789                     *p++ = x;
 790                 }
 791             }
 792             break;
 793         case OP_PREDICT:
 794         case OP_PREDICTSIGMA:
 795             stackunderflow(2);
 796             {
 797                 /* the local averaging window (similar to trend, but better here, as we get better statistics thru numbers)*/
 798                 int   locstepsize = rpnstack->s[--stptr];
 799                 /* the number of shifts and range-checking*/
 800                 int     shifts = rpnstack->s[--stptr];
 801                 stackunderflow(shifts);
 802                 // handle negative shifts special
 803                 if (shifts<0) {
 804                     stptr--;
 805                 } else {
 806                     stptr-=shifts;
 807                 }
 808                 /* the real calculation */
 809                 double val=DNAN;
 810                 /* the info on the datasource */
 811                 time_t  dsstep = (time_t) rpnp[rpi - 1].step;
 812                 int    dscount = rpnp[rpi - 1].ds_cnt;
 813                 int   locstep = (int)ceil((float)locstepsize/(float)dsstep);
 814
 815                 /* the sums */
 816                 double    sum = 0;
 817                 double    sum2 = 0;
 818                 int       count = 0;
 819                 /* now loop for each position */
 820                 int doshifts=shifts;
 821                 if (shifts<0) { doshifts=-shifts; }
 822                 for(int loop=0;loop<doshifts;loop++) {
 823                     /* calculate shift step */
 824                     int shiftstep=1;
 825                     if (shifts<0) {
 826                         shiftstep = loop*rpnstack->s[stptr];
 827                     } else {
 828                         shiftstep = rpnstack->s[stptr+loop];
 829                     }
 830                     if(shiftstep <0) {
 831                         rrd_set_error("negative shift step not allowed: %i",shiftstep);
 832                         return -1;
 833                     }
 834                     shiftstep=(int)ceil((float)shiftstep/(float)dsstep);
 835                     /* loop all local shifts */
 836                     for(int i=0;i<=locstep;i++) {
 837                         /* now calculate offset into data-array - relative to output_idx*/
 838                         int offset=shiftstep+i;
 839                         /* and process if we have index 0 of above */
 840                         if ((offset>=0)&&(offset<output_idx)) {
 841                             /* get the value */
 842                             val =rpnp[rpi - 1].data[-dscount * offset];
 843                             /* and handle the non NAN case only*/
 844                             if (! isnan(val)) {
 845                                 sum+=val;
 846                                 sum2+=val*val;
 847                                 count++;
 848                             }
 849                         }
 850                     }
 851                 }
 852                 /* do the final calculations */
 853                 val=DNAN;
 854                 if (rpnp[rpi].op == OP_PREDICT) {  /* the average */
 855                     if (count>0) {
 856                         val = sum/(double)count;
 857                     }
 858                 } else {
 859                     if (count>1) { /* the sigma case */
 860                         val=count*sum2-sum*sum;
 861                         if (val<0) {
 862                             val=DNAN;
 863                         } else {
 864                             val=sqrt(val/((float)count*((float)count-1.0)));
 865                         }
 866                     }
 867                 }
 868                 rpnstack->s[stptr] = val;
 869             }
 870             break;
 871         case OP_TREND:
 872         case OP_TRENDNAN:
 873             stackunderflow(1);
 874             if ((rpi < 2) || (rpnp[rpi - 2].op != OP_VARIABLE)) {
 875                 rrd_set_error("malformed trend arguments");
 876                 return -1;
 877             } else {
 878                 time_t    dur = (time_t) rpnstack->s[stptr];
 879                 time_t    step = (time_t) rpnp[rpi - 2].step;
 880
 881                 if (output_idx > (int) ceil((float) dur / (float) step)) {
 882                     int       ignorenan = (rpnp[rpi].op == OP_TREND);
 883                     double    accum = 0.0;
 884                     int       i = 0;
 885                     int       count = 0;
 886
 887                     do {
 888                         double    val =
 889                             rpnp[rpi - 2].data[rpnp[rpi - 2].ds_cnt * i--];
 890                         if (ignorenan || !isnan(val)) {
 891                             accum += val;
 892                             ++count;
 893                         }
 894
 895                         dur -= step;
 896                     } while (dur > 0);
 897
 898                     rpnstack->s[--stptr] =
 899                         (count == 0) ? DNAN : (accum / count);
 900                 } else
 901                     rpnstack->s[--stptr] = DNAN;
 902             }
 903             break;
 904         case OP_AVG:
 905             stackunderflow(0);
 906             {
 907                 int       i = (int) rpnstack->s[stptr--];
 908                 double    sum = 0;
 909                 int       count = 0;
 910
 911                 stackunderflow(i - 1);
 912                 while (i > 0) {
 913                     double    val = rpnstack->s[stptr--];
 914
 915                     i--;
 916                     if (isnan(val)) {
 917                         continue;
 918                     }
 919                     count++;
 920                     sum += val;
 921                 }
 922                 /* now push the result back on stack */
 923                 if (count > 0) {
 924                     rpnstack->s[++stptr] = sum / count;
 925                 } else {
 926                     rpnstack->s[++stptr] = DNAN;
 927                 }
 928             }
 929             break;
 930         case OP_ABS:
 931             stackunderflow(0);
 932             rpnstack->s[stptr] = fabs(rpnstack->s[stptr]);
 933             break;
 934         case OP_END:
 935             break;
 936         }
 937 #undef stackunderflow
 938     }
 939     if (stptr != 0) {
 940         rrd_set_error("RPN final stack size != 1");
 941         return -1;
 942     }
 943
 944     output[output_idx] = rpnstack->s[0];
 945     return 0;
 946 }
 947
 948 /* figure out what the local timezone offset for any point in
 949    time was. Return it in seconds */
 950 int tzoffset(
 951     time_t now)
 952 {
 953     int       gm_sec, gm_min, gm_hour, gm_yday, gm_year,
 954         l_sec, l_min, l_hour, l_yday, l_year;
 955     struct tm t;
 956     int       off;
 957
 958     gmtime_r(&now, &t);
 959     gm_sec = t.tm_sec;
 960     gm_min = t.tm_min;
 961     gm_hour = t.tm_hour;
 962     gm_yday = t.tm_yday;
 963     gm_year = t.tm_year;
 964     localtime_r(&now, &t);
 965     l_sec = t.tm_sec;
 966     l_min = t.tm_min;
 967     l_hour = t.tm_hour;
 968     l_yday = t.tm_yday;
 969     l_year = t.tm_year;
 970     off =
 971         (l_sec - gm_sec) + (l_min - gm_min) * 60 + (l_hour - gm_hour) * 3600;
 972     if (l_yday > gm_yday || l_year > gm_year) {
 973         off += 24 * 3600;
 974     } else if (l_yday < gm_yday || l_year < gm_year) {
 975         off -= 24 * 3600;
 976     }
 977     return off;
 978 }