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)
157 #undef add_op
158 }
159 (*str)[offset] = '\0';
161 }
163 short addop2str(enum op_en op, enum op_en op_type, char *op_str,
164 char **result_str, unsigned short *offset)
165 {
166 if (op == op_type) {
167 short op_len;
168 op_len = strlen(op_str);
169 *result_str = (char *) rrd_realloc(*result_str,
170 (op_len + 1 + *offset)*sizeof(char));
171 if (*result_str == NULL) {
172 rrd_set_error("failed to alloc memory in addop2str");
173 return -1;
174 }
175 strncpy(&((*result_str)[*offset]),op_str,op_len);
176 *offset += op_len;
177 return 1;
178 }
179 return 0;
180 }
182 void parseCDEF_DS(char *def,rrd_t *rrd, int ds_idx)
183 {
184 rpnp_t *rpnp = NULL;
185 rpn_cdefds_t *rpnc = NULL;
186 short count, i;
188 rpnp = rpn_parse((void*) rrd, def, &lookup_DS);
189 if (rpnp == NULL) {
190 rrd_set_error("failed to parse computed data source %s", def);
191 return;
192 }
193 /* Check for OP nodes not permitted in COMPUTE DS.
194 * Moved this check from within rpn_compact() because it really is
195 * COMPUTE DS specific. This is less efficient, but creation doesn't
196 * occur too often. */
197 for (i = 0; rpnp[i].op != OP_END; i++) {
198 if (rpnp[i].op == OP_TIME || rpnp[i].op == OP_LTIME ||
199 rpnp[i].op == OP_PREV)
200 {
201 rrd_set_error(
202 "operators time, ltime and prev not supported with DS COMPUTE");
203 free(rpnp);
204 return;
205 }
206 }
207 if (rpn_compact(rpnp,&rpnc,&count) == -1) {
208 free(rpnp);
209 return;
210 }
211 /* copy the compact rpn representation over the ds_def par array */
212 memcpy((void*) &(rrd -> ds_def[ds_idx].par[DS_cdef]),
213 (void*) rpnc, count*sizeof(rpn_cdefds_t));
214 free(rpnp);
215 free(rpnc);
216 }
218 /* lookup a data source name in the rrd struct and return the index,
219 * should use ds_match() here except:
220 * (1) need a void * pointer to the rrd
221 * (2) error handling is left to the caller
222 */
223 long lookup_DS(void *rrd_vptr,char *ds_name)
224 {
225 unsigned int i;
226 rrd_t *rrd;
228 rrd = (rrd_t *) rrd_vptr;
230 for (i = 0; i < rrd -> stat_head -> ds_cnt; ++i)
231 {
232 if(strcmp(ds_name,rrd -> ds_def[i].ds_nam) == 0)
233 return i;
234 }
235 /* the caller handles a bad data source name in the rpn string */
236 return -1;
237 }
239 /* rpn_parse : parse a string and generate a rpnp array; modified
240 * str2rpn() originally included in rrd_graph.c
241 * arguments:
242 * key_hash: a transparent argument passed to lookup(); conceptually this
243 * is a hash object for lookup of a numeric key given a variable name
244 * expr: the string RPN expression, including variable names
245 * lookup(): a function that retrieves a numeric key given a variable name
246 */
247 rpnp_t *
248 rpn_parse(void *key_hash,char *expr,long (*lookup)(void *,char*)){
249 int pos=0;
250 long steps=-1;
251 rpnp_t *rpnp;
252 char vname[30];
254 rpnp=NULL;
256 while(*expr){
257 if ((rpnp = (rpnp_t *) rrd_realloc(rpnp, (++steps + 2)*
258 sizeof(rpnp_t)))==NULL){
259 return NULL;
260 }
262 else if((sscanf(expr,"%lf%n",&rpnp[steps].val,&pos) == 1) && (expr[pos] == ',')){
263 rpnp[steps].op = OP_NUMBER;
264 expr+=pos;
265 }
267 #define match_op(VV,VVV) \
268 else if (strncmp(expr, #VVV, strlen(#VVV))==0){ \
269 rpnp[steps].op = VV; \
270 expr+=strlen(#VVV); \
271 }
274 #define match_op_param(VV,VVV) \
275 else if (sscanf(expr, #VVV "(" DEF_NAM_FMT ")",vname) == 1) { \
276 int length = 0; \
277 if ((length = strlen(#VVV)+strlen(vname)+2, \
278 expr[length] == ',' || expr[length] == '\0') ) { \
279 rpnp[steps].op = VV; \
280 rpnp[steps].ptr = (*lookup)(key_hash,vname); \
281 if (rpnp[steps].ptr < 0) { \
282 free(rpnp); \
283 return NULL; \
284 } else expr+=length; \
285 } \
286 }
288 match_op(OP_ADD,+)
289 match_op(OP_SUB,-)
290 match_op(OP_MUL,*)
291 match_op(OP_DIV,/)
292 match_op(OP_MOD,%)
293 match_op(OP_SIN,SIN)
294 match_op(OP_COS,COS)
295 match_op(OP_LOG,LOG)
296 match_op(OP_FLOOR,FLOOR)
297 match_op(OP_CEIL,CEIL)
298 match_op(OP_EXP,EXP)
299 match_op(OP_DUP,DUP)
300 match_op(OP_EXC,EXC)
301 match_op(OP_POP,POP)
302 match_op(OP_LT,LT)
303 match_op(OP_LE,LE)
304 match_op(OP_GT,GT)
305 match_op(OP_GE,GE)
306 match_op(OP_EQ,EQ)
307 match_op(OP_IF,IF)
308 match_op(OP_MIN,MIN)
309 match_op(OP_MAX,MAX)
310 match_op(OP_LIMIT,LIMIT)
311 /* order is important here ! .. match longest first */
312 match_op(OP_UNKN,UNKN)
313 match_op(OP_UN,UN)
314 match_op(OP_NEGINF,NEGINF)
315 match_op(OP_NE,NE)
316 match_op_param(OP_PREV_OTHER,PREV)
317 match_op(OP_PREV,PREV)
318 match_op(OP_INF,INF)
319 match_op(OP_ISINF,ISINF)
320 match_op(OP_NOW,NOW)
321 match_op(OP_LTIME,LTIME)
322 match_op(OP_TIME,TIME)
324 #undef match_op
327 else if ((sscanf(expr, DEF_NAM_FMT "%n",
328 vname,&pos) == 1)
329 && ((rpnp[steps].ptr = (*lookup)(key_hash,vname)) != -1)){
330 rpnp[steps].op = OP_VARIABLE;
331 expr+=pos;
332 }
334 else {
335 free(rpnp);
336 return NULL;
337 }
338 if (*expr == 0)
339 break;
340 if (*expr == ',')
341 expr++;
342 else {
343 free(rpnp);
344 return NULL;
345 }
346 }
347 rpnp[steps+1].op = OP_END;
348 return rpnp;
349 }
351 void
352 rpnstack_init(rpnstack_t *rpnstack)
353 {
354 rpnstack -> s = NULL;
355 rpnstack -> dc_stacksize = 0;
356 rpnstack -> dc_stackblock = 100;
357 }
359 void
360 rpnstack_free(rpnstack_t *rpnstack)
361 {
362 if (rpnstack -> s != NULL)
363 free(rpnstack -> s);
364 rpnstack -> dc_stacksize = 0;
365 }
367 /* rpn_calc: run the RPN calculator; also performs variable substitution;
368 * moved and modified from data_calc() originally included in rrd_graph.c
369 * arguments:
370 * rpnp : an array of RPN operators (including variable references)
371 * rpnstack : the initialized stack
372 * data_idx : when data_idx is a multiple of rpnp.step, the rpnp.data pointer
373 * is advanced by rpnp.ds_cnt; used only for variable substitution
374 * output : an array of output values; OP_PREV assumes this array contains
375 * the "previous" value at index position output_idx-1; the definition of
376 * "previous" depends on the calling environment
377 * output_idx : an index into the output array in which to store the output
378 * of the RPN calculator
379 * returns: -1 if the computation failed (also calls rrd_set_error)
380 * 0 on success
381 */
382 short
383 rpn_calc(rpnp_t *rpnp, rpnstack_t *rpnstack, long data_idx,
384 rrd_value_t *output, int output_idx)
385 {
386 int rpi;
387 long stptr = -1;
389 /* process each op from the rpn in turn */
390 for (rpi=0; rpnp[rpi].op != OP_END; rpi++){
391 /* allocate or grow the stack */
392 if (stptr + 5 > rpnstack -> dc_stacksize){
393 /* could move this to a separate function */
394 rpnstack -> dc_stacksize += rpnstack -> dc_stackblock;
395 rpnstack -> s = rrd_realloc(rpnstack -> s,
396 (rpnstack -> dc_stacksize)*sizeof(*(rpnstack -> s)));
397 if (rpnstack -> s == NULL){
398 rrd_set_error("RPN stack overflow");
399 return -1;
400 }
401 }
403 #define stackunderflow(MINSIZE) \
404 if(stptr<MINSIZE){ \
405 rrd_set_error("RPN stack underflow"); \
406 return -1; \
407 }
409 switch (rpnp[rpi].op){
410 case OP_NUMBER:
411 rpnstack -> s[++stptr] = rpnp[rpi].val;
412 break;
413 case OP_VARIABLE:
414 /* Sanity check: VDEFs shouldn't make it here */
415 if (rpnp[rpi].ds_cnt == 0) {
416 rrd_set_error("VDEF made it into rpn_calc... aborting");
417 return -1;
418 } else {
419 /* make sure we pull the correct value from
420 * the *.data array. Adjust the pointer into
421 * the array acordingly. Advance the ptr one
422 * row in the rra (skip over non-relevant
423 * data sources)
424 */
425 rpnstack -> s[++stptr] = *(rpnp[rpi].data);
426 if (data_idx % rpnp[rpi].step == 0){
427 rpnp[rpi].data += rpnp[rpi].ds_cnt;
428 }
429 }
430 break;
431 case OP_PREV:
432 if ((output_idx-1) <= 0) {
433 rpnstack -> s[++stptr] = DNAN;
434 } else {
435 rpnstack -> s[++stptr] = output[output_idx-1];
436 }
437 break;
438 case OP_PREV_OTHER:
439 if ((output_idx-1) <= 0) {
440 rpnstack -> s[++stptr] = DNAN;
441 } else {
442 rpnstack -> s[++stptr] = rpnp[rpnp[rpi].ptr].data[output_idx-1];
443 }
444 break;
445 case OP_UNKN:
446 rpnstack -> s[++stptr] = DNAN;
447 break;
448 case OP_INF:
449 rpnstack -> s[++stptr] = DINF;
450 break;
451 case OP_NEGINF:
452 rpnstack -> s[++stptr] = -DINF;
453 break;
454 case OP_NOW:
455 rpnstack -> s[++stptr] = (double)time(NULL);
456 break;
457 case OP_TIME:
458 /* HACK: this relies on the data_idx being the time,
459 ** which the within-function scope is unaware of */
460 rpnstack -> s[++stptr] = (double) data_idx;
461 break;
462 case OP_LTIME:
463 rpnstack -> s[++stptr] =
464 (double) tzoffset(data_idx) + (double)data_idx;
465 break;
466 case OP_ADD:
467 stackunderflow(1);
468 rpnstack -> s[stptr-1] = rpnstack -> s[stptr-1]
469 + rpnstack -> s[stptr];
470 stptr--;
471 break;
472 case OP_SUB:
473 stackunderflow(1);
474 rpnstack -> s[stptr-1] = rpnstack -> s[stptr-1]
475 - rpnstack -> s[stptr];
476 stptr--;
477 break;
478 case OP_MUL:
479 stackunderflow(1);
480 rpnstack -> s[stptr-1] = (rpnstack -> s[stptr-1])
481 * (rpnstack -> s[stptr]);
482 stptr--;
483 break;
484 case OP_DIV:
485 stackunderflow(1);
486 rpnstack -> s[stptr-1] = rpnstack -> s[stptr-1]
487 / rpnstack -> s[stptr];
488 stptr--;
489 break;
490 case OP_MOD:
491 stackunderflow(1);
492 rpnstack -> s[stptr-1]= fmod( rpnstack -> s[stptr-1]
493 ,rpnstack -> s[stptr]);
494 stptr--;
495 break;
496 case OP_SIN:
497 stackunderflow(0);
498 rpnstack -> s[stptr] = sin(rpnstack -> s[stptr]);
499 break;
500 case OP_COS:
501 stackunderflow(0);
502 rpnstack -> s[stptr] = cos(rpnstack -> s[stptr]);
503 break;
504 case OP_CEIL:
505 stackunderflow(0);
506 rpnstack -> s[stptr] = ceil(rpnstack -> s[stptr]);
507 break;
508 case OP_FLOOR:
509 stackunderflow(0);
510 rpnstack -> s[stptr] = floor(rpnstack -> s[stptr]);
511 break;
512 case OP_LOG:
513 stackunderflow(0);
514 rpnstack -> s[stptr] = log(rpnstack -> s[stptr]);
515 break;
516 case OP_DUP:
517 stackunderflow(0);
518 rpnstack -> s[stptr+1] = rpnstack -> s[stptr];
519 stptr++;
520 break;
521 case OP_POP:
522 stackunderflow(0);
523 stptr--;
524 break;
525 case OP_EXC:
526 stackunderflow(1);
527 {
528 double dummy;
529 dummy = rpnstack -> s[stptr] ;
530 rpnstack -> s[stptr] = rpnstack -> s[stptr-1];
531 rpnstack -> s[stptr-1] = dummy;
532 }
533 break;
534 case OP_EXP:
535 stackunderflow(0);
536 rpnstack -> s[stptr] = exp(rpnstack -> s[stptr]);
537 break;
538 case OP_LT:
539 stackunderflow(1);
540 if (isnan(rpnstack -> s[stptr-1]))
541 ;
542 else if (isnan(rpnstack -> s[stptr]))
543 rpnstack -> s[stptr-1] = rpnstack -> s[stptr];
544 else
545 rpnstack -> s[stptr-1] = rpnstack -> s[stptr-1] <
546 rpnstack -> s[stptr] ? 1.0 : 0.0;
547 stptr--;
548 break;
549 case OP_LE:
550 stackunderflow(1);
551 if (isnan(rpnstack -> s[stptr-1]))
552 ;
553 else if (isnan(rpnstack -> s[stptr]))
554 rpnstack -> s[stptr-1] = rpnstack -> s[stptr];
555 else
556 rpnstack -> s[stptr-1] = rpnstack -> s[stptr-1] <=
557 rpnstack -> s[stptr] ? 1.0 : 0.0;
558 stptr--;
559 break;
560 case OP_GT:
561 stackunderflow(1);
562 if (isnan(rpnstack -> s[stptr-1]))
563 ;
564 else if (isnan(rpnstack -> s[stptr]))
565 rpnstack -> s[stptr-1] = rpnstack -> s[stptr];
566 else
567 rpnstack -> s[stptr-1] = rpnstack -> s[stptr-1] >
568 rpnstack -> s[stptr] ? 1.0 : 0.0;
569 stptr--;
570 break;
571 case OP_GE:
572 stackunderflow(1);
573 if (isnan(rpnstack -> s[stptr-1]))
574 ;
575 else if (isnan(rpnstack -> s[stptr]))
576 rpnstack -> s[stptr-1] = rpnstack -> s[stptr];
577 else
578 rpnstack -> s[stptr-1] = rpnstack -> s[stptr-1] >=
579 rpnstack -> s[stptr] ? 1.0 : 0.0;
580 stptr--;
581 break;
582 case OP_NE:
583 stackunderflow(1);
584 if (isnan(rpnstack -> s[stptr-1]))
585 ;
586 else if (isnan(rpnstack -> s[stptr]))
587 rpnstack -> s[stptr-1] = rpnstack -> s[stptr];
588 else
589 rpnstack -> s[stptr-1] = rpnstack -> s[stptr-1] ==
590 rpnstack -> s[stptr] ? 0.0 : 1.0;
591 stptr--;
592 break;
593 case OP_EQ:
594 stackunderflow(1);
595 if (isnan(rpnstack -> s[stptr-1]))
596 ;
597 else if (isnan(rpnstack -> s[stptr]))
598 rpnstack -> s[stptr-1] = rpnstack -> s[stptr];
599 else
600 rpnstack -> s[stptr-1] = rpnstack -> s[stptr-1] ==
601 rpnstack -> s[stptr] ? 1.0 : 0.0;
602 stptr--;
603 break;
604 case OP_IF:
605 stackunderflow(2);
606 rpnstack->s[stptr-2] = rpnstack->s[stptr-2] != 0.0 ?
607 rpnstack->s[stptr-1] : rpnstack->s[stptr];
608 stptr--;
609 stptr--;
610 break;
611 case OP_MIN:
612 stackunderflow(1);
613 if (isnan(rpnstack->s[stptr-1]))
614 ;
615 else if (isnan(rpnstack->s[stptr]))
616 rpnstack->s[stptr-1] = rpnstack->s[stptr];
617 else if (rpnstack->s[stptr-1] > rpnstack->s[stptr])
618 rpnstack->s[stptr-1] = rpnstack->s[stptr];
619 stptr--;
620 break;
621 case OP_MAX:
622 stackunderflow(1);
623 if (isnan(rpnstack->s[stptr-1]))
624 ;
625 else if (isnan(rpnstack->s[stptr]))
626 rpnstack->s[stptr-1] = rpnstack->s[stptr];
627 else if (rpnstack->s[stptr-1] < rpnstack->s[stptr])
628 rpnstack->s[stptr-1] = rpnstack->s[stptr];
629 stptr--;
630 break;
631 case OP_LIMIT:
632 stackunderflow(2);
633 if (isnan(rpnstack->s[stptr-2]))
634 ;
635 else if (isnan(rpnstack->s[stptr-1]))
636 rpnstack->s[stptr-2] = rpnstack->s[stptr-1];
637 else if (isnan(rpnstack->s[stptr]))
638 rpnstack->s[stptr-2] = rpnstack->s[stptr];
639 else if (rpnstack->s[stptr-2] < rpnstack->s[stptr-1])
640 rpnstack->s[stptr-2] = DNAN;
641 else if (rpnstack->s[stptr-2] > rpnstack->s[stptr])
642 rpnstack->s[stptr-2] = DNAN;
643 stptr-=2;
644 break;
645 case OP_UN:
646 stackunderflow(0);
647 rpnstack->s[stptr] = isnan(rpnstack->s[stptr]) ? 1.0 : 0.0;
648 break;
649 case OP_ISINF:
650 stackunderflow(0);
651 rpnstack->s[stptr] = isinf(rpnstack->s[stptr]) ? 1.0 : 0.0;
652 break;
653 case OP_END:
654 break;
655 }
656 #undef stackunderflow
657 }
658 if(stptr!=0){
659 rrd_set_error("RPN final stack size != 1");
660 return -1;
661 }
663 output[output_idx] = rpnstack->s[0];
664 return 0;
665 }
667 /* figure out what the local timezone offset for any point in
668 time was. Return it in seconds */
669 int
670 tzoffset( time_t now ){
671 int gm_sec, gm_min, gm_hour, gm_yday, gm_year,
672 l_sec, l_min, l_hour, l_yday, l_year;
673 struct tm t;
674 int off;
675 gmtime_r(&now, &t);
676 gm_sec = t.tm_sec;
677 gm_min = t.tm_min;
678 gm_hour = t.tm_hour;
679 gm_yday = t.tm_yday;
680 gm_year = t.tm_year;
681 localtime_r(&now, &t);
682 l_sec = t.tm_sec;
683 l_min = t.tm_min;
684 l_hour = t.tm_hour;
685 l_yday = t.tm_yday;
686 l_year = t.tm_year;
687 off = (l_sec-gm_sec)+(l_min-gm_min)*60+(l_hour-gm_hour)*3600;
688 if ( l_yday > gm_yday || l_year > gm_year){
689 off += 24*3600;
690 } else if ( l_yday < gm_yday || l_year < gm_year){
691 off -= 24*3600;
692 }
693 return off;
694 }