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         rrd_set_error("failed allocating rpnp array");
  77         return NULL;
  78     }
  79     for (i = 0; rpnc[i].op != OP_END; ++i) {
  80         rpnp[i].op = (enum op_en)rpnc[i].op;
  81         if (rpnp[i].op == OP_NUMBER) {
  82             rpnp[i].val = (double) rpnc[i].val;
  83         } else if (rpnp[i].op == OP_VARIABLE || rpnp[i].op == OP_PREV_OTHER) {
  84             rpnp[i].ptr = (long) rpnc[i].val;
  85         }
  86     }
  87     /* terminate the sequence */
  88     rpnp[i].op = OP_END;
  89     return rpnp;
  90 }
  91
  92 /* rpn_compact2str: convert a compact sequence of RPN operator nodes back
  93  * into a CDEF string. This function is used by rrd_dump.
  94  * arguments:
  95  *  rpnc: an array of compact RPN operator nodes
  96  *  ds_def: a pointer to the data source definition section of an RRD header
  97  *   for lookup of data source names by index
  98  *  str: out string, memory is allocated by the function, must be freed by the
  99  *   the caller */
 100 void rpn_compact2str(
 101     rpn_cdefds_t *rpnc,
 102     ds_def_t *ds_def,
 103     char **str)
 104 {
 105     unsigned short i, offset = 0;
 106     char      buffer[7];    /* short as a string */
 107
 108     for (i = 0; rpnc[i].op != OP_END; i++) {
 109         if (i > 0)
 110             (*str)[offset++] = ',';
 111
 112 #define add_op(VV,VVV) \
 113           if (addop2str((enum op_en)(rpnc[i].op), VV, VVV, str, &offset) == 1) continue;
 114
 115         if (rpnc[i].op == OP_NUMBER) {
 116             /* convert a short into a string */
 117 #if defined(_WIN32) && !defined(__CYGWIN__) && !defined(__CYGWIN32__)
 118             _itoa(rpnc[i].val, buffer, 10);
 119 #else
 120             sprintf(buffer, "%d", rpnc[i].val);
 121 #endif
 122             add_op(OP_NUMBER, buffer)
 123         }
 124
 125         if (rpnc[i].op == OP_VARIABLE) {
 126             char     *ds_name = ds_def[rpnc[i].val].ds_nam;
 127
 128             add_op(OP_VARIABLE, ds_name)
 129         }
 130
 131         if (rpnc[i].op == OP_PREV_OTHER) {
 132             char     *ds_name = ds_def[rpnc[i].val].ds_nam;
 133
 134             add_op(OP_VARIABLE, ds_name)
 135         }
 136 #undef add_op
 137
 138 #define add_op(VV,VVV) \
 139           if (addop2str((enum op_en)rpnc[i].op, VV, #VVV, str, &offset) == 1) continue;
 140
 141         add_op(OP_ADD, +)
 142             add_op(OP_SUB, -)
 143             add_op(OP_MUL, *)
 144             add_op(OP_DIV, /)
 145             add_op(OP_MOD, %)
 146             add_op(OP_SIN, SIN)
 147             add_op(OP_COS, COS)
 148             add_op(OP_LOG, LOG)
 149             add_op(OP_FLOOR, FLOOR)
 150             add_op(OP_CEIL, CEIL)
 151             add_op(OP_EXP, EXP)
 152             add_op(OP_DUP, DUP)
 153             add_op(OP_EXC, EXC)
 154             add_op(OP_POP, POP)
 155             add_op(OP_LT, LT)
 156             add_op(OP_LE, LE)
 157             add_op(OP_GT, GT)
 158             add_op(OP_GE, GE)
 159             add_op(OP_EQ, EQ)
 160             add_op(OP_IF, IF)
 161             add_op(OP_MIN, MIN)
 162             add_op(OP_MAX, MAX)
 163             add_op(OP_LIMIT, LIMIT)
 164             add_op(OP_UNKN, UNKN)
 165             add_op(OP_UN, UN)
 166             add_op(OP_NEGINF, NEGINF)
 167             add_op(OP_NE, NE)
 168             add_op(OP_PREV, PREV)
 169             add_op(OP_INF, INF)
 170             add_op(OP_ISINF, ISINF)
 171             add_op(OP_NOW, NOW)
 172             add_op(OP_LTIME, LTIME)
 173             add_op(OP_TIME, TIME)
 174             add_op(OP_ATAN2, ATAN2)
 175             add_op(OP_ATAN, ATAN)
 176             add_op(OP_SQRT, SQRT)
 177             add_op(OP_SORT, SORT)
 178             add_op(OP_REV, REV)
 179             add_op(OP_TREND, TREND)
 180             add_op(OP_TRENDNAN, TRENDNAN)
 181             add_op(OP_PREDICT, PREDICT)
 182             add_op(OP_PREDICTSIGMA, PREDICTSIGMA)
 183             add_op(OP_RAD2DEG, RAD2DEG)
 184             add_op(OP_DEG2RAD, DEG2RAD)
 185             add_op(OP_AVG, AVG)
 186             add_op(OP_ABS, ABS)
 187             add_op(OP_ADDNAN, ADDNAN)
 188 #undef add_op
 189     }
 190     (*str)[offset] = '\0';
 191
 192 }
 193
 194 short addop2str(
 195     enum op_en op,
 196     enum op_en op_type,
 197     char *op_str,
 198     char **result_str,
 199     unsigned short *offset)
 200 {
 201     if (op == op_type) {
 202         short     op_len;
 203
 204         op_len = strlen(op_str);
 205         *result_str = (char *) rrd_realloc(*result_str,
 206                                            (op_len + 1 +
 207                                             *offset) * sizeof(char));
 208         if (*result_str == NULL) {
 209             rrd_set_error("failed to alloc memory in addop2str");
 210             return -1;
 211         }
 212         strncpy(&((*result_str)[*offset]), op_str, op_len);
 213         *offset += op_len;
 214         return 1;
 215     }
 216     return 0;
 217 }
 218
 219 void parseCDEF_DS(
 220     const char *def,
 221     rrd_t *rrd,
 222     int ds_idx)
 223 {
 224     rpnp_t   *rpnp = NULL;
 225     rpn_cdefds_t *rpnc = NULL;
 226     short     count, i;
 227
 228     rpnp = rpn_parse((void *) rrd, def, &lookup_DS);
 229     if (rpnp == NULL) {
 230         rrd_set_error("failed to parse computed data source");
 231         return;
 232     }
 233     /* Check for OP nodes not permitted in COMPUTE DS.
 234      * Moved this check from within rpn_compact() because it really is
 235      * COMPUTE DS specific. This is less efficient, but creation doesn't
 236      * occur too often. */
 237     for (i = 0; rpnp[i].op != OP_END; i++) {
 238         if (rpnp[i].op == OP_TIME || rpnp[i].op == OP_LTIME ||
 239             rpnp[i].op == OP_PREV || rpnp[i].op == OP_COUNT) {
 240             rrd_set_error
 241                 ("operators time, ltime, prev and count not supported with DS COMPUTE");
 242             free(rpnp);
 243             return;
 244         }
 245     }
 246     if (rpn_compact(rpnp, &rpnc, &count) == -1) {
 247         free(rpnp);
 248         return;
 249     }
 250     /* copy the compact rpn representation over the ds_def par array */
 251     memcpy((void *) &(rrd->ds_def[ds_idx].par[DS_cdef]),
 252            (void *) rpnc, count * sizeof(rpn_cdefds_t));
 253     free(rpnp);
 254     free(rpnc);
 255 }
 256
 257 /* lookup a data source name in the rrd struct and return the index,
 258  * should use ds_match() here except:
 259  * (1) need a void * pointer to the rrd
 260  * (2) error handling is left to the caller
 261  */
 262 long lookup_DS(
 263     void *rrd_vptr,
 264     char *ds_name)
 265 {
 266     unsigned int i;
 267     rrd_t    *rrd;
 268
 269     rrd = (rrd_t *) rrd_vptr;
 270
 271     for (i = 0; i < rrd->stat_head->ds_cnt; ++i) {
 272         if (strcmp(ds_name, rrd->ds_def[i].ds_nam) == 0)
 273             return i;
 274     }
 275     /* the caller handles a bad data source name in the rpn string */
 276     return -1;
 277 }
 278
 279 /* rpn_parse : parse a string and generate a rpnp array; modified
 280  * str2rpn() originally included in rrd_graph.c
 281  * arguments:
 282  * key_hash: a transparent argument passed to lookup(); conceptually this
 283  *    is a hash object for lookup of a numeric key given a variable name
 284  * expr: the string RPN expression, including variable names
 285  * lookup(): a function that retrieves a numeric key given a variable name
 286  */
 287 rpnp_t   *rpn_parse(
 288     void *key_hash,
 289     const char *const expr_const,
 290     long      (*lookup) (void *,
 291                          char *))
 292 {
 293     int       pos = 0;
 294     char     *expr;
 295     long      steps = -1;
 296     rpnp_t   *rpnp;
 297     char      vname[MAX_VNAME_LEN + 10];
 298     char     *old_locale;
 299
 300     old_locale = setlocale(LC_NUMERIC, NULL);
 301     setlocale(LC_NUMERIC, "C");
 302
 303     rpnp = NULL;
 304     expr = (char *) expr_const;
 305
 306     while (*expr) {
 307         if ((rpnp = (rpnp_t *) rrd_realloc(rpnp, (++steps + 2) *
 308                                            sizeof(rpnp_t))) == NULL) {
 309             setlocale(LC_NUMERIC, old_locale);
 310             return NULL;
 311         }
 312
 313         else if ((sscanf(expr, "%lf%n", &rpnp[steps].val, &pos) == 1)
 314                  && (expr[pos] == ',')) {
 315             rpnp[steps].op = OP_NUMBER;
 316             expr += pos;
 317         }
 318 #define match_op(VV,VVV) \
 319         else if (strncmp(expr, #VVV, strlen(#VVV))==0 && ( expr[strlen(#VVV)] == ',' || expr[strlen(#VVV)] == '\0' )){ \
 320             rpnp[steps].op = VV; \
 321             expr+=strlen(#VVV); \
 322         }
 323
 324 #define match_op_param(VV,VVV) \
 325         else if (sscanf(expr, #VVV "(" DEF_NAM_FMT ")",vname) == 1) { \
 326           int length = 0; \
 327           if ((length = strlen(#VVV)+strlen(vname)+2, \
 328               expr[length] == ',' || expr[length] == '\0') ) { \
 329              rpnp[steps].op = VV; \
 330              rpnp[steps].ptr = (*lookup)(key_hash,vname); \
 331              if (rpnp[steps].ptr < 0) { \
 332                            free(rpnp); \
 333                            return NULL; \
 334                          } else expr+=length; \
 335           } \
 336         }
 337
 338         match_op(OP_ADD, +)
 339             match_op(OP_SUB, -)
 340             match_op(OP_MUL, *)
 341             match_op(OP_DIV, /)
 342             match_op(OP_MOD, %)
 343             match_op(OP_SIN, SIN)
 344             match_op(OP_COS, COS)
 345             match_op(OP_LOG, LOG)
 346             match_op(OP_FLOOR, FLOOR)
 347             match_op(OP_CEIL, CEIL)
 348             match_op(OP_EXP, EXP)
 349             match_op(OP_DUP, DUP)
 350             match_op(OP_EXC, EXC)
 351             match_op(OP_POP, POP)
 352             match_op(OP_LTIME, LTIME)
 353             match_op(OP_LT, LT)
 354             match_op(OP_LE, LE)
 355             match_op(OP_GT, GT)
 356             match_op(OP_GE, GE)
 357             match_op(OP_EQ, EQ)
 358             match_op(OP_IF, IF)
 359             match_op(OP_MIN, MIN)
 360             match_op(OP_MAX, MAX)
 361             match_op(OP_LIMIT, LIMIT)
 362             /* order is important here ! .. match longest first */
 363             match_op(OP_UNKN, UNKN)
 364             match_op(OP_UN, UN)
 365             match_op(OP_NEGINF, NEGINF)
 366             match_op(OP_NE, NE)
 367             match_op(OP_COUNT, COUNT)
 368             match_op_param(OP_PREV_OTHER, PREV)
 369             match_op(OP_PREV, PREV)
 370             match_op(OP_INF, INF)
 371             match_op(OP_ISINF, ISINF)
 372             match_op(OP_NOW, NOW)
 373             match_op(OP_TIME, TIME)
 374             match_op(OP_ATAN2, ATAN2)
 375             match_op(OP_ATAN, ATAN)
 376             match_op(OP_SQRT, SQRT)
 377             match_op(OP_SORT, SORT)
 378             match_op(OP_REV, REV)
 379             match_op(OP_TREND, TREND)
 380             match_op(OP_TRENDNAN, TRENDNAN)
 381             match_op(OP_PREDICT, PREDICT)
 382             match_op(OP_PREDICTSIGMA, PREDICTSIGMA)
 383             match_op(OP_RAD2DEG, RAD2DEG)
 384             match_op(OP_DEG2RAD, DEG2RAD)
 385             match_op(OP_AVG, AVG)
 386             match_op(OP_ABS, ABS)
 387             match_op(OP_ADDNAN, ADDNAN)
 388 #undef match_op
 389             else if ((sscanf(expr, DEF_NAM_FMT "%n", vname, &pos) == 1)
 390                      && ((rpnp[steps].ptr = (*lookup) (key_hash, vname)) !=
 391                          -1)) {
 392             rpnp[steps].op = OP_VARIABLE;
 393             expr += pos;
 394         }
 395
 396         else {
 397             setlocale(LC_NUMERIC, old_locale);
 398             free(rpnp);
 399             return NULL;
 400         }
 401
 402         if (*expr == 0)
 403             break;
 404         if (*expr == ',')
 405             expr++;
 406         else {
 407             setlocale(LC_NUMERIC, old_locale);
 408             free(rpnp);
 409             return NULL;
 410         }
 411     }
 412     rpnp[steps + 1].op = OP_END;
 413     setlocale(LC_NUMERIC, old_locale);
 414     return rpnp;
 415 }
 416
 417 void rpnstack_init(
 418     rpnstack_t *rpnstack)
 419 {
 420     rpnstack->s = NULL;
 421     rpnstack->dc_stacksize = 0;
 422     rpnstack->dc_stackblock = 100;
 423 }
 424
 425 void rpnstack_free(
 426     rpnstack_t *rpnstack)
 427 {
 428     if (rpnstack->s != NULL)
 429         free(rpnstack->s);
 430     rpnstack->dc_stacksize = 0;
 431 }
 432
 433 static int rpn_compare_double(
 434     const void *x,
 435     const void *y)
 436 {
 437     double    diff = *((const double *) x) - *((const double *) y);
 438
 439     return (diff < 0) ? -1 : (diff > 0) ? 1 : 0;
 440 }
 441
 442 /* rpn_calc: run the RPN calculator; also performs variable substitution;
 443  * moved and modified from data_calc() originally included in rrd_graph.c
 444  * arguments:
 445  * rpnp : an array of RPN operators (including variable references)
 446  * rpnstack : the initialized stack
 447  * data_idx : when data_idx is a multiple of rpnp.step, the rpnp.data pointer
 448  *   is advanced by rpnp.ds_cnt; used only for variable substitution
 449  * output : an array of output values; OP_PREV assumes this array contains
 450  *   the "previous" value at index position output_idx-1; the definition of
 451  *   "previous" depends on the calling environment
 452  * output_idx : an index into the output array in which to store the output
 453  *   of the RPN calculator
 454  * returns: -1 if the computation failed (also calls rrd_set_error)
 455  *           0 on success
 456  */
 457 short rpn_calc(
 458     rpnp_t *rpnp,
 459     rpnstack_t *rpnstack,
 460     long data_idx,
 461     rrd_value_t *output,
 462     int output_idx)
 463 {
 464     int       rpi;
 465     long      stptr = -1;
 466
 467     /* process each op from the rpn in turn */
 468     for (rpi = 0; rpnp[rpi].op != OP_END; rpi++) {
 469         /* allocate or grow the stack */
 470         if (stptr + 5 > rpnstack->dc_stacksize) {
 471             /* could move this to a separate function */
 472             rpnstack->dc_stacksize += rpnstack->dc_stackblock;
 473             rpnstack->s = (double*)rrd_realloc(rpnstack->s,
 474                                       (rpnstack->dc_stacksize) *
 475                                       sizeof(*(rpnstack->s)));
 476             if (rpnstack->s == NULL) {
 477                 rrd_set_error("RPN stack overflow");
 478                 return -1;
 479             }
 480         }
 481 #define stackunderflow(MINSIZE)                         \
 482         if(stptr<MINSIZE){                              \
 483             rrd_set_error("RPN stack underflow");       \
 484             return -1;                                  \
 485         }
 486
 487         switch (rpnp[rpi].op) {
 488         case OP_NUMBER:
 489             rpnstack->s[++stptr] = rpnp[rpi].val;
 490             break;
 491         case OP_VARIABLE:
 492         case OP_PREV_OTHER:
 493             /* Sanity check: VDEFs shouldn't make it here */
 494             if (rpnp[rpi].ds_cnt == 0) {
 495                 rrd_set_error("VDEF made it into rpn_calc... aborting");
 496                 return -1;
 497             } else {
 498                 /* make sure we pull the correct value from
 499                  * the *.data array. Adjust the pointer into
 500                  * the array acordingly. Advance the ptr one
 501                  * row in the rra (skip over non-relevant
 502                  * data sources)
 503                  */
 504                 if (rpnp[rpi].op == OP_VARIABLE) {
 505                     rpnstack->s[++stptr] = *(rpnp[rpi].data);
 506                 } else {
 507                     if ((output_idx) <= 0) {
 508                         rpnstack->s[++stptr] = DNAN;
 509                     } else {
 510                         rpnstack->s[++stptr] =
 511                             *(rpnp[rpi].data - rpnp[rpi].ds_cnt);
 512                     }
 513
 514                 }
 515                 if (data_idx % rpnp[rpi].step == 0) {
 516                     rpnp[rpi].data += rpnp[rpi].ds_cnt;
 517                 }
 518             }
 519             break;
 520         case OP_COUNT:
 521             rpnstack->s[++stptr] = (output_idx + 1);    /* Note: Counter starts at 1 */
 522             break;
 523         case OP_PREV:
 524             if ((output_idx) <= 0) {
 525                 rpnstack->s[++stptr] = DNAN;
 526             } else {
 527                 rpnstack->s[++stptr] = output[output_idx - 1];
 528             }
 529             break;
 530         case OP_UNKN:
 531             rpnstack->s[++stptr] = DNAN;
 532             break;
 533         case OP_INF:
 534             rpnstack->s[++stptr] = DINF;
 535             break;
 536         case OP_NEGINF:
 537             rpnstack->s[++stptr] = -DINF;
 538             break;
 539         case OP_NOW:
 540             rpnstack->s[++stptr] = (double) time(NULL);
 541             break;
 542         case OP_TIME:
 543             /* HACK: this relies on the data_idx being the time,
 544              ** which the within-function scope is unaware of */
 545             rpnstack->s[++stptr] = (double) data_idx;
 546             break;
 547         case OP_LTIME:
 548             rpnstack->s[++stptr] =
 549                 (double) tzoffset(data_idx) + (double) data_idx;
 550             break;
 551         case OP_ADD:
 552             stackunderflow(1);
 553             rpnstack->s[stptr - 1] = rpnstack->s[stptr - 1]
 554                 + rpnstack->s[stptr];
 555             stptr--;
 556             break;
 557         case OP_ADDNAN:
 558             stackunderflow(1);
 559             if (isnan(rpnstack->s[stptr - 1])) {
 560                 rpnstack->s[stptr - 1] = rpnstack->s[stptr];
 561             } else if (isnan(rpnstack->s[stptr])) {
 562                 /* NOOP */
 563                 /* rpnstack->s[stptr - 1] = rpnstack->s[stptr - 1]; */
 564             } else {
 565                 rpnstack->s[stptr - 1] = rpnstack->s[stptr - 1]
 566                     + rpnstack->s[stptr];
 567             }
 568
 569             stptr--;
 570             break;
 571         case OP_SUB:
 572             stackunderflow(1);
 573             rpnstack->s[stptr - 1] = rpnstack->s[stptr - 1]
 574                 - rpnstack->s[stptr];
 575             stptr--;
 576             break;
 577         case OP_MUL:
 578             stackunderflow(1);
 579             rpnstack->s[stptr - 1] = (rpnstack->s[stptr - 1])
 580                 * (rpnstack->s[stptr]);
 581             stptr--;
 582             break;
 583         case OP_DIV:
 584             stackunderflow(1);
 585             rpnstack->s[stptr - 1] = rpnstack->s[stptr - 1]
 586                 / rpnstack->s[stptr];
 587             stptr--;
 588             break;
 589         case OP_MOD:
 590             stackunderflow(1);
 591             rpnstack->s[stptr - 1] = fmod(rpnstack->s[stptr - 1]
 592                                           , rpnstack->s[stptr]);
 593             stptr--;
 594             break;
 595         case OP_SIN:
 596             stackunderflow(0);
 597             rpnstack->s[stptr] = sin(rpnstack->s[stptr]);
 598             break;
 599         case OP_ATAN:
 600             stackunderflow(0);
 601             rpnstack->s[stptr] = atan(rpnstack->s[stptr]);
 602             break;
 603         case OP_RAD2DEG:
 604             stackunderflow(0);
 605             rpnstack->s[stptr] = 57.29577951 * rpnstack->s[stptr];
 606             break;
 607         case OP_DEG2RAD:
 608             stackunderflow(0);
 609             rpnstack->s[stptr] = 0.0174532952 * rpnstack->s[stptr];
 610             break;
 611         case OP_ATAN2:
 612             stackunderflow(1);
 613             rpnstack->s[stptr - 1] = atan2(rpnstack->s[stptr - 1],
 614                                            rpnstack->s[stptr]);
 615             stptr--;
 616             break;
 617         case OP_COS:
 618             stackunderflow(0);
 619             rpnstack->s[stptr] = cos(rpnstack->s[stptr]);
 620             break;
 621         case OP_CEIL:
 622             stackunderflow(0);
 623             rpnstack->s[stptr] = ceil(rpnstack->s[stptr]);
 624             break;
 625         case OP_FLOOR:
 626             stackunderflow(0);
 627             rpnstack->s[stptr] = floor(rpnstack->s[stptr]);
 628             break;
 629         case OP_LOG:
 630             stackunderflow(0);
 631             rpnstack->s[stptr] = log(rpnstack->s[stptr]);
 632             break;
 633         case OP_DUP:
 634             stackunderflow(0);
 635             rpnstack->s[stptr + 1] = rpnstack->s[stptr];
 636             stptr++;
 637             break;
 638         case OP_POP:
 639             stackunderflow(0);
 640             stptr--;
 641             break;
 642         case OP_EXC:
 643             stackunderflow(1);
 644             {
 645                 double    dummy;
 646
 647                 dummy = rpnstack->s[stptr];
 648                 rpnstack->s[stptr] = rpnstack->s[stptr - 1];
 649                 rpnstack->s[stptr - 1] = dummy;
 650             }
 651             break;
 652         case OP_EXP:
 653             stackunderflow(0);
 654             rpnstack->s[stptr] = exp(rpnstack->s[stptr]);
 655             break;
 656         case OP_LT:
 657             stackunderflow(1);
 658             if (isnan(rpnstack->s[stptr - 1]));
 659             else if (isnan(rpnstack->s[stptr]))
 660                 rpnstack->s[stptr - 1] = rpnstack->s[stptr];
 661             else
 662                 rpnstack->s[stptr - 1] = rpnstack->s[stptr - 1] <
 663                     rpnstack->s[stptr] ? 1.0 : 0.0;
 664             stptr--;
 665             break;
 666         case OP_LE:
 667             stackunderflow(1);
 668             if (isnan(rpnstack->s[stptr - 1]));
 669             else if (isnan(rpnstack->s[stptr]))
 670                 rpnstack->s[stptr - 1] = rpnstack->s[stptr];
 671             else
 672                 rpnstack->s[stptr - 1] = rpnstack->s[stptr - 1] <=
 673                     rpnstack->s[stptr] ? 1.0 : 0.0;
 674             stptr--;
 675             break;
 676         case OP_GT:
 677             stackunderflow(1);
 678             if (isnan(rpnstack->s[stptr - 1]));
 679             else if (isnan(rpnstack->s[stptr]))
 680                 rpnstack->s[stptr - 1] = rpnstack->s[stptr];
 681             else
 682                 rpnstack->s[stptr - 1] = rpnstack->s[stptr - 1] >
 683                     rpnstack->s[stptr] ? 1.0 : 0.0;
 684             stptr--;
 685             break;
 686         case OP_GE:
 687             stackunderflow(1);
 688             if (isnan(rpnstack->s[stptr - 1]));
 689             else if (isnan(rpnstack->s[stptr]))
 690                 rpnstack->s[stptr - 1] = rpnstack->s[stptr];
 691             else
 692                 rpnstack->s[stptr - 1] = rpnstack->s[stptr - 1] >=
 693                     rpnstack->s[stptr] ? 1.0 : 0.0;
 694             stptr--;
 695             break;
 696         case OP_NE:
 697             stackunderflow(1);
 698             if (isnan(rpnstack->s[stptr - 1]));
 699             else if (isnan(rpnstack->s[stptr]))
 700                 rpnstack->s[stptr - 1] = rpnstack->s[stptr];
 701             else
 702                 rpnstack->s[stptr - 1] = rpnstack->s[stptr - 1] ==
 703                     rpnstack->s[stptr] ? 0.0 : 1.0;
 704             stptr--;
 705             break;
 706         case OP_EQ:
 707             stackunderflow(1);
 708             if (isnan(rpnstack->s[stptr - 1]));
 709             else if (isnan(rpnstack->s[stptr]))
 710                 rpnstack->s[stptr - 1] = rpnstack->s[stptr];
 711             else
 712                 rpnstack->s[stptr - 1] = rpnstack->s[stptr - 1] ==
 713                     rpnstack->s[stptr] ? 1.0 : 0.0;
 714             stptr--;
 715             break;
 716         case OP_IF:
 717             stackunderflow(2);
 718             rpnstack->s[stptr - 2] = (isnan(rpnstack->s[stptr - 2])
 719                                       || rpnstack->s[stptr - 2] ==
 720                                       0.0) ? rpnstack->s[stptr] : rpnstack->
 721                 s[stptr - 1];
 722             stptr--;
 723             stptr--;
 724             break;
 725         case OP_MIN:
 726             stackunderflow(1);
 727             if (isnan(rpnstack->s[stptr - 1]));
 728             else if (isnan(rpnstack->s[stptr]))
 729                 rpnstack->s[stptr - 1] = rpnstack->s[stptr];
 730             else if (rpnstack->s[stptr - 1] > rpnstack->s[stptr])
 731                 rpnstack->s[stptr - 1] = rpnstack->s[stptr];
 732             stptr--;
 733             break;
 734         case OP_MAX:
 735             stackunderflow(1);
 736             if (isnan(rpnstack->s[stptr - 1]));
 737             else if (isnan(rpnstack->s[stptr]))
 738                 rpnstack->s[stptr - 1] = rpnstack->s[stptr];
 739             else if (rpnstack->s[stptr - 1] < rpnstack->s[stptr])
 740                 rpnstack->s[stptr - 1] = rpnstack->s[stptr];
 741             stptr--;
 742             break;
 743         case OP_LIMIT:
 744             stackunderflow(2);
 745             if (isnan(rpnstack->s[stptr - 2]));
 746             else if (isnan(rpnstack->s[stptr - 1]))
 747                 rpnstack->s[stptr - 2] = rpnstack->s[stptr - 1];
 748             else if (isnan(rpnstack->s[stptr]))
 749                 rpnstack->s[stptr - 2] = rpnstack->s[stptr];
 750             else if (rpnstack->s[stptr - 2] < rpnstack->s[stptr - 1])
 751                 rpnstack->s[stptr - 2] = DNAN;
 752             else if (rpnstack->s[stptr - 2] > rpnstack->s[stptr])
 753                 rpnstack->s[stptr - 2] = DNAN;
 754             stptr -= 2;
 755             break;
 756         case OP_UN:
 757             stackunderflow(0);
 758             rpnstack->s[stptr] = isnan(rpnstack->s[stptr]) ? 1.0 : 0.0;
 759             break;
 760         case OP_ISINF:
 761             stackunderflow(0);
 762             rpnstack->s[stptr] = isinf(rpnstack->s[stptr]) ? 1.0 : 0.0;
 763             break;
 764         case OP_SQRT:
 765             stackunderflow(0);
 766             rpnstack->s[stptr] = sqrt(rpnstack->s[stptr]);
 767             break;
 768         case OP_SORT:
 769             stackunderflow(0);
 770             {
 771                 int       spn = (int) rpnstack->s[stptr--];
 772
 773                 stackunderflow(spn - 1);
 774                 qsort(rpnstack->s + stptr - spn + 1, spn, sizeof(double),
 775                       rpn_compare_double);
 776             }
 777             break;
 778         case OP_REV:
 779             stackunderflow(0);
 780             {
 781                 int       spn = (int) rpnstack->s[stptr--];
 782                 double   *p, *q;
 783
 784                 stackunderflow(spn - 1);
 785
 786                 p = rpnstack->s + stptr - spn + 1;
 787                 q = rpnstack->s + stptr;
 788                 while (p < q) {
 789                     double    x = *q;
 790
 791                     *q-- = *p;
 792                     *p++ = x;
 793                 }
 794             }
 795             break;
 796         case OP_PREDICT:
 797         case OP_PREDICTSIGMA:
 798             stackunderflow(2);
 799             {
 800                 /* the local averaging window (similar to trend, but better here, as we get better statistics thru numbers)*/
 801                 int   locstepsize = rpnstack->s[--stptr];
 802                 /* the number of shifts and range-checking*/
 803                 int     shifts = rpnstack->s[--stptr];
 804                 stackunderflow(shifts);
 805                 // handle negative shifts special
 806                 if (shifts<0) {
 807                     stptr--;
 808                 } else {
 809                     stptr-=shifts;
 810                 }
 811                 /* the real calculation */
 812                 double val=DNAN;
 813                 /* the info on the datasource */
 814                 time_t  dsstep = (time_t) rpnp[rpi - 1].step;
 815                 int    dscount = rpnp[rpi - 1].ds_cnt;
 816                 int   locstep = (int)ceil((float)locstepsize/(float)dsstep);
 817
 818                 /* the sums */
 819                 double    sum = 0;
 820                 double    sum2 = 0;
 821                 int       count = 0;
 822                 /* now loop for each position */
 823                 int doshifts=shifts;
 824                 if (shifts<0) { doshifts=-shifts; }
 825                 for(int loop=0;loop<doshifts;loop++) {
 826                     /* calculate shift step */
 827                     int shiftstep=1;
 828                     if (shifts<0) {
 829                         shiftstep = loop*rpnstack->s[stptr];
 830                     } else {
 831                         shiftstep = rpnstack->s[stptr+loop];
 832                     }
 833                     if(shiftstep <0) {
 834                         rrd_set_error("negative shift step not allowed: %i",shiftstep);
 835                         return -1;
 836                     }
 837                     shiftstep=(int)ceil((float)shiftstep/(float)dsstep);
 838                     /* loop all local shifts */
 839                     for(int i=0;i<=locstep;i++) {
 840                         /* now calculate offset into data-array - relative to output_idx*/
 841                         int offset=shiftstep+i;
 842                         /* and process if we have index 0 of above */
 843                         if ((offset>=0)&&(offset<output_idx)) {
 844                             /* get the value */
 845                             val =rpnp[rpi - 1].data[-dscount * offset];
 846                             /* and handle the non NAN case only*/
 847                             if (! isnan(val)) {
 848                                 sum+=val;
 849                                 sum2+=val*val;
 850                                 count++;
 851                             }
 852                         }
 853                     }
 854                 }
 855                 /* do the final calculations */
 856                 val=DNAN;
 857                 if (rpnp[rpi].op == OP_PREDICT) {  /* the average */
 858                     if (count>0) {
 859                         val = sum/(double)count;
 860                     }
 861                 } else {
 862                     if (count>1) { /* the sigma case */
 863                         val=count*sum2-sum*sum;
 864                         if (val<0) {
 865                             val=DNAN;
 866                         } else {
 867                             val=sqrt(val/((float)count*((float)count-1.0)));
 868                         }
 869                     }
 870                 }
 871                 rpnstack->s[stptr] = val;
 872             }
 873             break;
 874         case OP_TREND:
 875         case OP_TRENDNAN:
 876             stackunderflow(1);
 877             if ((rpi < 2) || (rpnp[rpi - 2].op != OP_VARIABLE)) {
 878                 rrd_set_error("malformed trend arguments");
 879                 return -1;
 880             } else {
 881                 time_t    dur = (time_t) rpnstack->s[stptr];
 882                 time_t    step = (time_t) rpnp[rpi - 2].step;
 883
 884                 if (output_idx > (int) ceil((float) dur / (float) step)) {
 885                     int       ignorenan = (rpnp[rpi].op == OP_TREND);
 886                     double    accum = 0.0;
 887                     int       i = 0;
 888                     int       count = 0;
 889
 890                     do {
 891                         double    val =
 892                             rpnp[rpi - 2].data[rpnp[rpi - 2].ds_cnt * i--];
 893                         if (ignorenan || !isnan(val)) {
 894                             accum += val;
 895                             ++count;
 896                         }
 897
 898                         dur -= step;
 899                     } while (dur > 0);
 900
 901                     rpnstack->s[--stptr] =
 902                         (count == 0) ? DNAN : (accum / count);
 903                 } else
 904                     rpnstack->s[--stptr] = DNAN;
 905             }
 906             break;
 907         case OP_AVG:
 908             stackunderflow(0);
 909             {
 910                 int       i = (int) rpnstack->s[stptr--];
 911                 double    sum = 0;
 912                 int       count = 0;
 913
 914                 stackunderflow(i - 1);
 915                 while (i > 0) {
 916                     double    val = rpnstack->s[stptr--];
 917
 918                     i--;
 919                     if (isnan(val)) {
 920                         continue;
 921                     }
 922                     count++;
 923                     sum += val;
 924                 }
 925                 /* now push the result back on stack */
 926                 if (count > 0) {
 927                     rpnstack->s[++stptr] = sum / count;
 928                 } else {
 929                     rpnstack->s[++stptr] = DNAN;
 930                 }
 931             }
 932             break;
 933         case OP_ABS:
 934             stackunderflow(0);
 935             rpnstack->s[stptr] = fabs(rpnstack->s[stptr]);
 936             break;
 937         case OP_END:
 938             break;
 939         }
 940 #undef stackunderflow
 941     }
 942     if (stptr != 0) {
 943         rrd_set_error("RPN final stack size != 1");
 944         return -1;
 945     }
 946
 947     output[output_idx] = rpnstack->s[0];
 948     return 0;
 949 }
 950
 951 /* figure out what the local timezone offset for any point in
 952    time was. Return it in seconds */
 953 int tzoffset(
 954     time_t now)
 955 {
 956     int       gm_sec, gm_min, gm_hour, gm_yday, gm_year,
 957         l_sec, l_min, l_hour, l_yday, l_year;
 958     struct tm t;
 959     int       off;
 960
 961     gmtime_r(&now, &t);
 962     gm_sec = t.tm_sec;
 963     gm_min = t.tm_min;
 964     gm_hour = t.tm_hour;
 965     gm_yday = t.tm_yday;
 966     gm_year = t.tm_year;
 967     localtime_r(&now, &t);
 968     l_sec = t.tm_sec;
 969     l_min = t.tm_min;
 970     l_hour = t.tm_hour;
 971     l_yday = t.tm_yday;
 972     l_year = t.tm_year;
 973     off =
 974         (l_sec - gm_sec) + (l_min - gm_min) * 60 + (l_hour - gm_hour) * 3600;
 975     if (l_yday > gm_yday || l_year > gm_year) {
 976         off += 24 * 3600;
 977     } else if (l_yday < gm_yday || l_year < gm_year) {
 978         off -= 24 * 3600;
 979     }
 980     return off;
 981 }