1 /****************************************************************************
2 * RRDtool 1.0.28 Copyright Tobias Oetiker, 1997 - 2002
3 ****************************************************************************
4 * rrd_rpncalc.c RPN calculator functions
5 ****************************************************************************/
7 #include "rrd_tool.h"
8 #include "rrd_rpncalc.h"
9 #include "rrd_graph.h"
10 #include <limits.h>
12 short addop2str(enum op_en op, enum op_en op_type, char *op_str,
13 char **result_str, unsigned short *offset);
14 int tzoffset(time_t); /* used to implement LTIME */
16 short rpn_compact(rpnp_t *rpnp, rpn_cdefds_t **rpnc, short *count)
17 {
18 short i;
19 *count = 0;
20 /* count the number of rpn nodes */
21 while(rpnp[*count].op != OP_END) (*count)++;
22 if (++(*count) > DS_CDEF_MAX_RPN_NODES) {
23 rrd_set_error("Maximum %d RPN nodes permitted",
24 DS_CDEF_MAX_RPN_NODES);
25 return -1;
26 }
28 /* allocate memory */
29 *rpnc = (rpn_cdefds_t *) calloc(*count,sizeof(rpn_cdefds_t));
30 for (i = 0; rpnp[i].op != OP_END; i++)
31 {
32 (*rpnc)[i].op = (char) rpnp[i].op;
33 if (rpnp[i].op == OP_NUMBER) {
34 /* rpnp.val is a double, rpnc.val is a short */
35 double temp = floor(rpnp[i].val);
36 if (temp < SHRT_MIN || temp > SHRT_MAX) {
37 rrd_set_error(
38 "constants must be integers in the interval (%d, %d)",
39 SHRT_MIN, SHRT_MAX);
40 free(*rpnc);
41 return -1;
42 }
43 (*rpnc)[i].val = (short) temp;
44 } else if (rpnp[i].op == OP_VARIABLE ||
45 rpnp[i].op == OP_PREV_OTHER) {
46 (*rpnc)[i].val = (short) rpnp[i].ptr;
47 }
48 }
49 /* terminate the sequence */
50 (*rpnc)[(*count) - 1].op = OP_END;
51 return 0;
52 }
54 rpnp_t * rpn_expand(rpn_cdefds_t *rpnc)
55 {
56 short i;
57 rpnp_t *rpnp;
59 /* DS_CDEF_MAX_RPN_NODES is small, so at the expense of some wasted
60 * memory we avoid any reallocs */
61 rpnp = (rpnp_t *) calloc(DS_CDEF_MAX_RPN_NODES,sizeof(rpnp_t));
62 if (rpnp == NULL) return NULL;
63 for (i = 0; rpnc[i].op != OP_END; ++i)
64 {
65 rpnp[i].op = (long) rpnc[i].op;
66 if (rpnp[i].op == OP_NUMBER) {
67 rpnp[i].val = (double) rpnc[i].val;
68 } else if (rpnp[i].op == OP_VARIABLE ||
69 rpnp[i].op == OP_PREV_OTHER) {
70 rpnp[i].ptr = (long) rpnc[i].val;
71 }
72 }
73 /* terminate the sequence */
74 rpnp[i].op = OP_END;
75 return rpnp;
76 }
78 /* rpn_compact2str: convert a compact sequence of RPN operator nodes back
79 * into a CDEF string. This function is used by rrd_dump.
80 * arguments:
81 * rpnc: an array of compact RPN operator nodes
82 * ds_def: a pointer to the data source definition section of an RRD header
83 * for lookup of data source names by index
84 * str: out string, memory is allocated by the function, must be freed by the
85 * the caller */
86 void rpn_compact2str(rpn_cdefds_t *rpnc,ds_def_t *ds_def,char **str)
87 {
88 unsigned short i,offset = 0;
89 char buffer[7]; /* short as a string */
91 for (i = 0; rpnc[i].op != OP_END; i++)
92 {
93 if (i > 0) (*str)[offset++] = ',';
95 #define add_op(VV,VVV) \
96 if (addop2str(rpnc[i].op, VV, VVV, str, &offset) == 1) continue;
98 if (rpnc[i].op == OP_NUMBER) {
99 /* convert a short into a string */
100 #ifdef WIN32
101 _itoa(rpnc[i].val,buffer,10);
102 #else
103 sprintf(buffer,"%d",rpnc[i].val);
104 #endif
105 add_op(OP_NUMBER,buffer)
106 }
108 if (rpnc[i].op == OP_VARIABLE) {
109 char *ds_name = ds_def[rpnc[i].val].ds_nam;
110 add_op(OP_VARIABLE, ds_name)
111 }
113 if (rpnc[i].op == OP_PREV_OTHER) {
114 char *ds_name = ds_def[rpnc[i].val].ds_nam;
115 add_op(OP_VARIABLE, ds_name)
116 }
118 #undef add_op
120 #define add_op(VV,VVV) \
121 if (addop2str(rpnc[i].op, VV, #VVV, str, &offset) == 1) continue;
123 add_op(OP_ADD,+)
124 add_op(OP_SUB,-)
125 add_op(OP_MUL,*)
126 add_op(OP_DIV,/)
127 add_op(OP_MOD,%)
128 add_op(OP_SIN,SIN)
129 add_op(OP_COS,COS)
130 add_op(OP_LOG,LOG)
131 add_op(OP_FLOOR,FLOOR)
132 add_op(OP_CEIL,CEIL)
133 add_op(OP_EXP,EXP)
134 add_op(OP_DUP,DUP)
135 add_op(OP_EXC,EXC)
136 add_op(OP_POP,POP)
137 add_op(OP_LT,LT)
138 add_op(OP_LE,LE)
139 add_op(OP_GT,GT)
140 add_op(OP_GE,GE)
141 add_op(OP_EQ,EQ)
142 add_op(OP_IF,IF)
143 add_op(OP_MIN,MIN)
144 add_op(OP_MAX,MAX)
145 add_op(OP_LIMIT,LIMIT)
146 add_op(OP_UNKN,UNKN)
147 add_op(OP_UN,UN)
148 add_op(OP_NEGINF,NEGINF)
149 add_op(OP_NE,NE)
150 add_op(OP_PREV,PREV)
151 add_op(OP_INF,INF)
152 add_op(OP_ISINF,ISINF)
153 add_op(OP_NOW,NOW)
154 add_op(OP_LTIME,LTIME)
155 add_op(OP_TIME,TIME)
156 add_op(OP_ATAN,ATAN)
157 add_op(OP_SQRT,SQRT)
158 add_op(OP_SORT,SORT)
159 add_op(OP_REV,REV)
161 #undef add_op
162 }
163 (*str)[offset] = '\0';
165 }
167 short addop2str(enum op_en op, enum op_en op_type, char *op_str,
168 char **result_str, unsigned short *offset)
169 {
170 if (op == op_type) {
171 short op_len;
172 op_len = strlen(op_str);
173 *result_str = (char *) rrd_realloc(*result_str,
174 (op_len + 1 + *offset)*sizeof(char));
175 if (*result_str == NULL) {
176 rrd_set_error("failed to alloc memory in addop2str");
177 return -1;
178 }
179 strncpy(&((*result_str)[*offset]),op_str,op_len);
180 *offset += op_len;
181 return 1;
182 }
183 return 0;
184 }
186 void parseCDEF_DS(char *def,rrd_t *rrd, int ds_idx)
187 {
188 rpnp_t *rpnp = NULL;
189 rpn_cdefds_t *rpnc = NULL;
190 short count, i;
192 rpnp = rpn_parse((void*) rrd, def, &lookup_DS);
193 if (rpnp == NULL) {
194 rrd_set_error("failed to parse computed data source %s", def);
195 return;
196 }
197 /* Check for OP nodes not permitted in COMPUTE DS.
198 * Moved this check from within rpn_compact() because it really is
199 * COMPUTE DS specific. This is less efficient, but creation doesn't
200 * occur too often. */
201 for (i = 0; rpnp[i].op != OP_END; i++) {
202 if (rpnp[i].op == OP_TIME || rpnp[i].op == OP_LTIME ||
203 rpnp[i].op == OP_PREV || rpnp[i].op == OP_COUNT)
204 {
205 rrd_set_error(
206 "operators time, ltime, prev and count not supported with DS COMPUTE");
207 free(rpnp);
208 return;
209 }
210 }
211 if (rpn_compact(rpnp,&rpnc,&count) == -1) {
212 free(rpnp);
213 return;
214 }
215 /* copy the compact rpn representation over the ds_def par array */
216 memcpy((void*) &(rrd -> ds_def[ds_idx].par[DS_cdef]),
217 (void*) rpnc, count*sizeof(rpn_cdefds_t));
218 free(rpnp);
219 free(rpnc);
220 }
222 /* lookup a data source name in the rrd struct and return the index,
223 * should use ds_match() here except:
224 * (1) need a void * pointer to the rrd
225 * (2) error handling is left to the caller
226 */
227 long lookup_DS(void *rrd_vptr,char *ds_name)
228 {
229 unsigned int i;
230 rrd_t *rrd;
232 rrd = (rrd_t *) rrd_vptr;
234 for (i = 0; i < rrd -> stat_head -> ds_cnt; ++i)
235 {
236 if(strcmp(ds_name,rrd -> ds_def[i].ds_nam) == 0)
237 return i;
238 }
239 /* the caller handles a bad data source name in the rpn string */
240 return -1;
241 }
243 /* rpn_parse : parse a string and generate a rpnp array; modified
244 * str2rpn() originally included in rrd_graph.c
245 * arguments:
246 * key_hash: a transparent argument passed to lookup(); conceptually this
247 * is a hash object for lookup of a numeric key given a variable name
248 * expr: the string RPN expression, including variable names
249 * lookup(): a function that retrieves a numeric key given a variable name
250 */
251 rpnp_t *
252 rpn_parse(void *key_hash,char *expr,long (*lookup)(void *,char*)){
253 int pos=0;
254 long steps=-1;
255 rpnp_t *rpnp;
256 char vname[30];
258 rpnp=NULL;
260 while(*expr){
261 if ((rpnp = (rpnp_t *) rrd_realloc(rpnp, (++steps + 2)*
262 sizeof(rpnp_t)))==NULL){
263 return NULL;
264 }
266 else if((sscanf(expr,"%lf%n",&rpnp[steps].val,&pos) == 1) && (expr[pos] == ',')){
267 rpnp[steps].op = OP_NUMBER;
268 expr+=pos;
269 }
271 #define match_op(VV,VVV) \
272 else if (strncmp(expr, #VVV, strlen(#VVV))==0){ \
273 rpnp[steps].op = VV; \
274 expr+=strlen(#VVV); \
275 }
278 #define match_op_param(VV,VVV) \
279 else if (sscanf(expr, #VVV "(" DEF_NAM_FMT ")",vname) == 1) { \
280 int length = 0; \
281 if ((length = strlen(#VVV)+strlen(vname)+2, \
282 expr[length] == ',' || expr[length] == '\0') ) { \
283 rpnp[steps].op = VV; \
284 rpnp[steps].ptr = (*lookup)(key_hash,vname); \
285 if (rpnp[steps].ptr < 0) { \
286 free(rpnp); \
287 return NULL; \
288 } else expr+=length; \
289 } \
290 }
292 match_op(OP_ADD,+)
293 match_op(OP_SUB,-)
294 match_op(OP_MUL,*)
295 match_op(OP_DIV,/)
296 match_op(OP_MOD,%)
297 match_op(OP_SIN,SIN)
298 match_op(OP_COS,COS)
299 match_op(OP_LOG,LOG)
300 match_op(OP_FLOOR,FLOOR)
301 match_op(OP_CEIL,CEIL)
302 match_op(OP_EXP,EXP)
303 match_op(OP_DUP,DUP)
304 match_op(OP_EXC,EXC)
305 match_op(OP_POP,POP)
306 match_op(OP_LTIME,LTIME)
307 match_op(OP_LT,LT)
308 match_op(OP_LE,LE)
309 match_op(OP_GT,GT)
310 match_op(OP_GE,GE)
311 match_op(OP_EQ,EQ)
312 match_op(OP_IF,IF)
313 match_op(OP_MIN,MIN)
314 match_op(OP_MAX,MAX)
315 match_op(OP_LIMIT,LIMIT)
316 /* order is important here ! .. match longest first */
317 match_op(OP_UNKN,UNKN)
318 match_op(OP_UN,UN)
319 match_op(OP_NEGINF,NEGINF)
320 match_op(OP_NE,NE)
321 match_op(OP_COUNT,COUNT)
322 match_op_param(OP_PREV_OTHER,PREV)
323 match_op(OP_PREV,PREV)
324 match_op(OP_INF,INF)
325 match_op(OP_ISINF,ISINF)
326 match_op(OP_NOW,NOW)
327 match_op(OP_TIME,TIME)
328 match_op(OP_ATAN,ATAN)
329 match_op(OP_SQRT,SQRT)
330 match_op(OP_SORT,SORT)
331 match_op(OP_REV,REV)
332 #undef match_op
335 else if ((sscanf(expr, DEF_NAM_FMT "%n",
336 vname,&pos) == 1)
337 && ((rpnp[steps].ptr = (*lookup)(key_hash,vname)) != -1)){
338 rpnp[steps].op = OP_VARIABLE;
339 expr+=pos;
340 }
342 else {
343 free(rpnp);
344 return NULL;
345 }
346 if (*expr == 0)
347 break;
348 if (*expr == ',')
349 expr++;
350 else {
351 free(rpnp);
352 return NULL;
353 }
354 }
355 rpnp[steps+1].op = OP_END;
356 return rpnp;
357 }
359 void
360 rpnstack_init(rpnstack_t *rpnstack)
361 {
362 rpnstack -> s = NULL;
363 rpnstack -> dc_stacksize = 0;
364 rpnstack -> dc_stackblock = 100;
365 }
367 void
368 rpnstack_free(rpnstack_t *rpnstack)
369 {
370 if (rpnstack -> s != NULL)
371 free(rpnstack -> s);
372 rpnstack -> dc_stacksize = 0;
373 }
375 static int
376 rpn_compare_double(const void *x, const void *y)
377 {
378 double diff = *((const double *)x) - *((const double *)y);
380 return (diff < 0) ? -1 : (diff > 0) ? 1 : 0;
381 }
383 /* rpn_calc: run the RPN calculator; also performs variable substitution;
384 * moved and modified from data_calc() originally included in rrd_graph.c
385 * arguments:
386 * rpnp : an array of RPN operators (including variable references)
387 * rpnstack : the initialized stack
388 * data_idx : when data_idx is a multiple of rpnp.step, the rpnp.data pointer
389 * is advanced by rpnp.ds_cnt; used only for variable substitution
390 * output : an array of output values; OP_PREV assumes this array contains
391 * the "previous" value at index position output_idx-1; the definition of
392 * "previous" depends on the calling environment
393 * output_idx : an index into the output array in which to store the output
394 * of the RPN calculator
395 * returns: -1 if the computation failed (also calls rrd_set_error)
396 * 0 on success
397 */
398 short
399 rpn_calc(rpnp_t *rpnp, rpnstack_t *rpnstack, long data_idx,
400 rrd_value_t *output, int output_idx)
401 {
402 int rpi;
403 long stptr = -1;
405 /* process each op from the rpn in turn */
406 for (rpi=0; rpnp[rpi].op != OP_END; rpi++){
407 /* allocate or grow the stack */
408 if (stptr + 5 > rpnstack -> dc_stacksize){
409 /* could move this to a separate function */
410 rpnstack -> dc_stacksize += rpnstack -> dc_stackblock;
411 rpnstack -> s = rrd_realloc(rpnstack -> s,
412 (rpnstack -> dc_stacksize)*sizeof(*(rpnstack -> s)));
413 if (rpnstack -> s == NULL){
414 rrd_set_error("RPN stack overflow");
415 return -1;
416 }
417 }
419 #define stackunderflow(MINSIZE) \
420 if(stptr<MINSIZE){ \
421 rrd_set_error("RPN stack underflow"); \
422 return -1; \
423 }
425 switch (rpnp[rpi].op){
426 case OP_NUMBER:
427 rpnstack -> s[++stptr] = rpnp[rpi].val;
428 break;
429 case OP_VARIABLE:
430 /* Sanity check: VDEFs shouldn't make it here */
431 if (rpnp[rpi].ds_cnt == 0) {
432 rrd_set_error("VDEF made it into rpn_calc... aborting");
433 return -1;
434 } else {
435 /* make sure we pull the correct value from
436 * the *.data array. Adjust the pointer into
437 * the array acordingly. Advance the ptr one
438 * row in the rra (skip over non-relevant
439 * data sources)
440 */
441 rpnstack -> s[++stptr] = *(rpnp[rpi].data);
442 if (data_idx % rpnp[rpi].step == 0){
443 rpnp[rpi].data += rpnp[rpi].ds_cnt;
444 }
445 }
446 break;
447 case OP_COUNT:
448 rpnstack -> s[++stptr] = (output_idx+1); /* Note: Counter starts at 1 */
449 break;
450 case OP_PREV:
451 if ((output_idx) <= 0) {
452 rpnstack -> s[++stptr] = DNAN;
453 } else {
454 rpnstack -> s[++stptr] = output[output_idx-1];
455 }
456 break;
457 case OP_PREV_OTHER:
458 if ((output_idx) <= 0) {
459 rpnstack -> s[++stptr] = DNAN;
460 } else {
461 rpnstack -> s[++stptr] = rpnp[rpnp[rpi].ptr].data[output_idx-1];
462 }
463 break;
464 case OP_UNKN:
465 rpnstack -> s[++stptr] = DNAN;
466 break;
467 case OP_INF:
468 rpnstack -> s[++stptr] = DINF;
469 break;
470 case OP_NEGINF:
471 rpnstack -> s[++stptr] = -DINF;
472 break;
473 case OP_NOW:
474 rpnstack -> s[++stptr] = (double)time(NULL);
475 break;
476 case OP_TIME:
477 /* HACK: this relies on the data_idx being the time,
478 ** which the within-function scope is unaware of */
479 rpnstack -> s[++stptr] = (double) data_idx;
480 break;
481 case OP_LTIME:
482 rpnstack -> s[++stptr] =
483 (double) tzoffset(data_idx) + (double)data_idx;
484 break;
485 case OP_ADD:
486 stackunderflow(1);
487 rpnstack -> s[stptr-1] = rpnstack -> s[stptr-1]
488 + rpnstack -> s[stptr];
489 stptr--;
490 break;
491 case OP_SUB:
492 stackunderflow(1);
493 rpnstack -> s[stptr-1] = rpnstack -> s[stptr-1]
494 - rpnstack -> s[stptr];
495 stptr--;
496 break;
497 case OP_MUL:
498 stackunderflow(1);
499 rpnstack -> s[stptr-1] = (rpnstack -> s[stptr-1])
500 * (rpnstack -> s[stptr]);
501 stptr--;
502 break;
503 case OP_DIV:
504 stackunderflow(1);
505 rpnstack -> s[stptr-1] = rpnstack -> s[stptr-1]
506 / rpnstack -> s[stptr];
507 stptr--;
508 break;
509 case OP_MOD:
510 stackunderflow(1);
511 rpnstack -> s[stptr-1]= fmod( rpnstack -> s[stptr-1]
512 ,rpnstack -> s[stptr]);
513 stptr--;
514 break;
515 case OP_SIN:
516 stackunderflow(0);
517 rpnstack -> s[stptr] = sin(rpnstack -> s[stptr]);
518 break;
519 case OP_ATAN:
520 stackunderflow(0);
521 rpnstack -> s[stptr] = atan(rpnstack -> s[stptr]);
522 break;
523 case OP_COS:
524 stackunderflow(0);
525 rpnstack -> s[stptr] = cos(rpnstack -> s[stptr]);
526 break;
527 case OP_CEIL:
528 stackunderflow(0);
529 rpnstack -> s[stptr] = ceil(rpnstack -> s[stptr]);
530 break;
531 case OP_FLOOR:
532 stackunderflow(0);
533 rpnstack -> s[stptr] = floor(rpnstack -> s[stptr]);
534 break;
535 case OP_LOG:
536 stackunderflow(0);
537 rpnstack -> s[stptr] = log(rpnstack -> s[stptr]);
538 break;
539 case OP_DUP:
540 stackunderflow(0);
541 rpnstack -> s[stptr+1] = rpnstack -> s[stptr];
542 stptr++;
543 break;
544 case OP_POP:
545 stackunderflow(0);
546 stptr--;
547 break;
548 case OP_EXC:
549 stackunderflow(1);
550 {
551 double dummy;
552 dummy = rpnstack -> s[stptr] ;
553 rpnstack -> s[stptr] = rpnstack -> s[stptr-1];
554 rpnstack -> s[stptr-1] = dummy;
555 }
556 break;
557 case OP_EXP:
558 stackunderflow(0);
559 rpnstack -> s[stptr] = exp(rpnstack -> s[stptr]);
560 break;
561 case OP_LT:
562 stackunderflow(1);
563 if (isnan(rpnstack -> s[stptr-1]))
564 ;
565 else if (isnan(rpnstack -> s[stptr]))
566 rpnstack -> s[stptr-1] = rpnstack -> s[stptr];
567 else
568 rpnstack -> s[stptr-1] = rpnstack -> s[stptr-1] <
569 rpnstack -> s[stptr] ? 1.0 : 0.0;
570 stptr--;
571 break;
572 case OP_LE:
573 stackunderflow(1);
574 if (isnan(rpnstack -> s[stptr-1]))
575 ;
576 else if (isnan(rpnstack -> s[stptr]))
577 rpnstack -> s[stptr-1] = rpnstack -> s[stptr];
578 else
579 rpnstack -> s[stptr-1] = rpnstack -> s[stptr-1] <=
580 rpnstack -> s[stptr] ? 1.0 : 0.0;
581 stptr--;
582 break;
583 case OP_GT:
584 stackunderflow(1);
585 if (isnan(rpnstack -> s[stptr-1]))
586 ;
587 else if (isnan(rpnstack -> s[stptr]))
588 rpnstack -> s[stptr-1] = rpnstack -> s[stptr];
589 else
590 rpnstack -> s[stptr-1] = rpnstack -> s[stptr-1] >
591 rpnstack -> s[stptr] ? 1.0 : 0.0;
592 stptr--;
593 break;
594 case OP_GE:
595 stackunderflow(1);
596 if (isnan(rpnstack -> s[stptr-1]))
597 ;
598 else if (isnan(rpnstack -> s[stptr]))
599 rpnstack -> s[stptr-1] = rpnstack -> s[stptr];
600 else
601 rpnstack -> s[stptr-1] = rpnstack -> s[stptr-1] >=
602 rpnstack -> s[stptr] ? 1.0 : 0.0;
603 stptr--;
604 break;
605 case OP_NE:
606 stackunderflow(1);
607 if (isnan(rpnstack -> s[stptr-1]))
608 ;
609 else if (isnan(rpnstack -> s[stptr]))
610 rpnstack -> s[stptr-1] = rpnstack -> s[stptr];
611 else
612 rpnstack -> s[stptr-1] = rpnstack -> s[stptr-1] ==
613 rpnstack -> s[stptr] ? 0.0 : 1.0;
614 stptr--;
615 break;
616 case OP_EQ:
617 stackunderflow(1);
618 if (isnan(rpnstack -> s[stptr-1]))
619 ;
620 else if (isnan(rpnstack -> s[stptr]))
621 rpnstack -> s[stptr-1] = rpnstack -> s[stptr];
622 else
623 rpnstack -> s[stptr-1] = rpnstack -> s[stptr-1] ==
624 rpnstack -> s[stptr] ? 1.0 : 0.0;
625 stptr--;
626 break;
627 case OP_IF:
628 stackunderflow(2);
629 rpnstack->s[stptr-2] = rpnstack->s[stptr-2] != 0.0 ?
630 rpnstack->s[stptr-1] : rpnstack->s[stptr];
631 stptr--;
632 stptr--;
633 break;
634 case OP_MIN:
635 stackunderflow(1);
636 if (isnan(rpnstack->s[stptr-1]))
637 ;
638 else if (isnan(rpnstack->s[stptr]))
639 rpnstack->s[stptr-1] = rpnstack->s[stptr];
640 else if (rpnstack->s[stptr-1] > rpnstack->s[stptr])
641 rpnstack->s[stptr-1] = rpnstack->s[stptr];
642 stptr--;
643 break;
644 case OP_MAX:
645 stackunderflow(1);
646 if (isnan(rpnstack->s[stptr-1]))
647 ;
648 else if (isnan(rpnstack->s[stptr]))
649 rpnstack->s[stptr-1] = rpnstack->s[stptr];
650 else if (rpnstack->s[stptr-1] < rpnstack->s[stptr])
651 rpnstack->s[stptr-1] = rpnstack->s[stptr];
652 stptr--;
653 break;
654 case OP_LIMIT:
655 stackunderflow(2);
656 if (isnan(rpnstack->s[stptr-2]))
657 ;
658 else if (isnan(rpnstack->s[stptr-1]))
659 rpnstack->s[stptr-2] = rpnstack->s[stptr-1];
660 else if (isnan(rpnstack->s[stptr]))
661 rpnstack->s[stptr-2] = rpnstack->s[stptr];
662 else if (rpnstack->s[stptr-2] < rpnstack->s[stptr-1])
663 rpnstack->s[stptr-2] = DNAN;
664 else if (rpnstack->s[stptr-2] > rpnstack->s[stptr])
665 rpnstack->s[stptr-2] = DNAN;
666 stptr-=2;
667 break;
668 case OP_UN:
669 stackunderflow(0);
670 rpnstack->s[stptr] = isnan(rpnstack->s[stptr]) ? 1.0 : 0.0;
671 break;
672 case OP_ISINF:
673 stackunderflow(0);
674 rpnstack->s[stptr] = isinf(rpnstack->s[stptr]) ? 1.0 : 0.0;
675 break;
676 case OP_SQRT:
677 stackunderflow(0);
678 rpnstack -> s[stptr] = sqrt(rpnstack -> s[stptr]);
679 break;
680 case OP_SORT:
681 stackunderflow(0);
682 {
683 int spn = (int)rpnstack -> s[stptr--];
685 stackunderflow(spn-1);
686 qsort(rpnstack -> s + stptr-spn+1, spn, sizeof(double),
687 rpn_compare_double);
688 }
689 break;
690 case OP_REV:
691 stackunderflow(0);
692 {
693 int spn = (int)rpnstack -> s[stptr--];
694 double *p, *q;
696 stackunderflow(spn-1);
698 p = rpnstack -> s + stptr-spn+1;
699 q = rpnstack -> s + stptr;
700 while (p < q) {
701 double x = *q;
703 *q-- = *p;
704 *p++ = x;
705 }
706 }
707 break;
708 case OP_END:
709 break;
710 }
711 #undef stackunderflow
712 }
713 if(stptr!=0){
714 rrd_set_error("RPN final stack size != 1");
715 return -1;
716 }
718 output[output_idx] = rpnstack->s[0];
719 return 0;
720 }
722 /* figure out what the local timezone offset for any point in
723 time was. Return it in seconds */
724 int
725 tzoffset( time_t now ){
726 int gm_sec, gm_min, gm_hour, gm_yday, gm_year,
727 l_sec, l_min, l_hour, l_yday, l_year;
728 struct tm t;
729 int off;
730 gmtime_r(&now, &t);
731 gm_sec = t.tm_sec;
732 gm_min = t.tm_min;
733 gm_hour = t.tm_hour;
734 gm_yday = t.tm_yday;
735 gm_year = t.tm_year;
736 localtime_r(&now, &t);
737 l_sec = t.tm_sec;
738 l_min = t.tm_min;
739 l_hour = t.tm_hour;
740 l_yday = t.tm_yday;
741 l_year = t.tm_year;
742 off = (l_sec-gm_sec)+(l_min-gm_min)*60+(l_hour-gm_hour)*3600;
743 if ( l_yday > gm_yday || l_year > gm_year){
744 off += 24*3600;
745 } else if ( l_yday < gm_yday || l_year < gm_year){
746 off -= 24*3600;
747 }
748 return off;
749 }