1 #include <sys/select.h>
16 #include "bsdtimespec.h"
17 #include "khatus_lib_log.h"
18 #include "khatus_lib_time.h"
20 #define usage(...) {print_usage(); fprintf(stderr, "Error:\n " __VA_ARGS__); exit(EXIT_FAILURE);}
21 #define ERRMSG "ERROR"
23 static const char errmsg
[] = ERRMSG
;
24 static const int errlen
= sizeof(ERRMSG
) - 1;
28 /* TODO: Convert fifo list to fifo array. */
29 typedef struct Fifo Fifo
;
34 struct timespec last_read
;
36 int pos_init
; /* Initial position on the output buffer. */
37 int pos_curr
; /* Current position on the output buffer. */
38 int pos_final
; /* Final position on the output buffer. */
42 typedef struct Config Config
;
49 int output_to_x_root_window
;
56 .output_to_x_root_window
= 0,
67 fifo_print_one(Fifo
*f
)
74 " last_read = {tv_sec = %ld, tv_nsec = %ld}"
75 " ttl = {tv_sec = %ld, tv_nsec = %ld},"
96 fifo_print_all(Fifo
*head
)
98 for (Fifo
*f
= head
; f
; f
= f
->next
) {
104 config_print(Config
*cfg
)
120 fifo_print_all(cfg
->fifos
);
127 if (!isdigit(*(s
++)))
138 while ((c
= *(s
++)) != '\0')
140 if (c
== '.' && !seen
++)
155 "Usage: %s [OPTION ...] SPEC [SPEC ...]\n"
157 " SPEC = FILE_PATH DATA_WIDTH DATA_TTL\n"
158 " FILE_PATH = string\n"
159 " DATA_WIDTH = int (* (positive) number of characters *)\n"
160 " DATA_TTL = float (* (positive) number of seconds *)\n"
161 " OPTION = -i INTERVAL\n"
163 " | -x (* Output to X root window *)\n"
165 " SEPARATOR = string\n"
166 " INTERVAL = float (* (positive) number of seconds *)\n"
167 " LOG_LEVEL = int (* %d through %d *)\n"
175 "Example: %s -i 1 /dev/shm/khatus/khatus_sensor_x 4 10\n"
181 void opts_parse_any(Config
*, int, char *[], int); /* For mutually-recursive calls. */
184 parse_opts_opt_i(Config
*cfg
, int argc
, char *argv
[], int i
)
189 usage("Option -i parameter is missing.\n");
191 if (!is_decimal(param
))
192 usage("Option -i parameter is invalid: \"%s\"\n", param
);
193 cfg
->interval
= atof(param
);
194 opts_parse_any(cfg
, argc
, argv
, i
);
198 parse_opts_opt_s(Config
*cfg
, int argc
, char *argv
[], int i
)
201 usage("Option -s parameter is missing.\n");
202 cfg
->separator
= calloc((strlen(argv
[i
]) + 1), sizeof(char));
203 strcpy(cfg
->separator
, argv
[i
]);
204 opts_parse_any(cfg
, argc
, argv
, ++i
);
208 parse_opts_opt_l(Config
*cfg
, int argc
, char *argv
[], int i
)
214 usage("Option -l parameter is missing.\n");
216 if (!is_pos_num(param
))
217 usage("Option -l parameter is invalid: \"%s\"\n", param
);
218 log_level
= atoi(param
);
219 if (log_level
> Debug
)
220 usage("Option -l value (%d) exceeds maximum (%d)\n", log_level
, Debug
);
221 _khatus_lib_log_level
= log_level
;
222 opts_parse_any(cfg
, argc
, argv
, i
);
226 parse_opts_opt(Config
*cfg
, int argc
, char *argv
[], int i
)
228 switch (argv
[i
][1]) {
230 /* TODO: Generic set_int */
231 parse_opts_opt_i(cfg
, argc
, argv
, ++i
);
234 /* TODO: Generic set_str */
235 parse_opts_opt_s(cfg
, argc
, argv
, ++i
);
238 cfg
->output_to_x_root_window
= 1;
239 opts_parse_any(cfg
, argc
, argv
, ++i
);
242 /* TODO: Generic set_int */
243 parse_opts_opt_l(cfg
, argc
, argv
, ++i
);
246 usage("Option \"%s\" is invalid\n", argv
[i
]);
251 parse_opts_spec(Config
*cfg
, int argc
, char *argv
[], int i
)
254 usage("[spec] Parameter(s) missing for fifo \"%s\".\n", argv
[i
]);
260 struct timespec last_read
;
263 usage("[spec] Invalid width: \"%s\", for fifo \"%s\"\n", w
, n
);
265 usage("[spec] Invalid TTL: \"%s\", for fifo \"%s\"\n", t
, n
);
266 last_read
.tv_sec
= 0;
267 last_read
.tv_nsec
= 0;
268 Fifo
*f
= calloc(1, sizeof(struct Fifo
));
273 f
->ttl
= timespec_of_float(atof(t
));
274 f
->last_read
= last_read
;
275 f
->pos_init
= cfg
->total_width
;
276 f
->pos_curr
= f
->pos_init
;
277 f
->pos_final
= f
->pos_init
+ f
->width
- 1;
278 f
->next
= cfg
->fifos
;
281 cfg
->total_width
+= f
->width
;
284 fatal("[memory] Allocation failure.");
286 opts_parse_any(cfg
, argc
, argv
, i
);
290 opts_parse_any(Config
*cfg
, int argc
, char *argv
[], int i
)
293 switch (argv
[i
][0]) {
295 parse_opts_opt(cfg
, argc
, argv
, i
);
298 parse_opts_spec(cfg
, argc
, argv
, i
);
304 opts_parse(Config
*cfg
, int argc
, char *argv
[])
306 opts_parse_any(cfg
, argc
, argv
, 1);
308 Fifo
*last
= cfg
->fifos
;
310 for (Fifo
*f
= last
; f
; ) {
311 Fifo
*next
= f
->next
;
312 f
->next
= cfg
->fifos
;
319 fifo_expire_one(Fifo
*f
, struct timespec t
, char *buf
)
323 timespecsub(&t
, &(f
->last_read
), &td
);
324 if (timespeccmp(&td
, &(f
->ttl
), >=)) {
325 /* TODO: Maybe configurable expiry character. */
326 memset(buf
+ f
->pos_init
, '_', f
->pos_final
- f
->pos_init
);
327 warn("Data source expired: \"%s\"\n", f
->name
);
332 fifo_expire_all(Config
*cfg
, struct timespec t
, char *buf
)
336 for (f
= cfg
->fifos
; f
; f
= f
->next
)
337 fifo_expire_one(f
, t
, buf
);
341 fifo_read_error(Fifo
*f
, char *buf
)
346 b
= buf
+ f
->pos_init
;
347 /* Copy as much of the error message as possible.
348 * EXCLUDING the reminating \0. */
349 for (i
= 0; i
< errlen
&& i
< f
->width
; i
++)
351 /* Any remaining slots: */
352 for (; i
< f
->width
; i
++)
357 fifo_read_one(Fifo
*f
, struct timespec t
, char *buf
)
359 char c
; /* Character read. */
360 int r
; /* Remaining unused slots in buffer range. */
363 switch (read(f
->fd
, &c
, 1)) {
365 error("Failed to read: \"%s\". errno: %d, msg: %s\n",
366 f
->name
, errno
, strerror(errno
));
375 debug("%s: End of FILE\n", f
->name
);
376 f
->pos_curr
= f
->pos_init
;
379 /* TODO: Consider making msg term char a CLI option */
380 if (c
== '\n' || c
== '\0') {
381 r
= f
->pos_final
- f
->pos_curr
;
383 memset(buf
+ f
->pos_curr
, ' ', r
);
384 f
->pos_curr
= f
->pos_init
;
386 return END_OF_MESSAGE
;
388 if (f
->pos_curr
<= f
->pos_final
)
389 buf
[f
->pos_curr
++] = c
;
390 /* Drop beyond available range. */
400 fifo_read_all(Config
*cfg
, struct timespec t
, char *buf
)
408 for (Fifo
*f
= cfg
->fifos
; f
; f
= f
->next
) {
409 /* TODO: Create the FIFO if it doesn't already exist. */
410 if (lstat(f
->name
, &st
) < 0) {
411 error("Cannot stat \"%s\". Error: %s\n", f
->name
, strerror(errno
));
412 fifo_read_error(f
, buf
);
415 if (!(st
.st_mode
& S_IFIFO
)) {
416 error("\"%s\" is not a FIFO\n", f
->name
);
417 fifo_read_error(f
, buf
);
421 debug("%s: closed. opening. fd: %d\n", f
->name
, f
->fd
);
422 f
->fd
= open(f
->name
, O_RDONLY
| O_NONBLOCK
);
424 debug("%s: already openned. fd: %d\n", f
->name
, f
->fd
);
427 /* TODO: Consider backing off retries for failed fifos. */
428 error("Failed to open \"%s\"\n", f
->name
);
429 fifo_read_error(f
, buf
);
432 debug("%s: open. fd: %d\n", f
->name
, f
->fd
);
437 debug("selecting...\n");
438 ready
= select(maxfd
+ 1, &fds
, NULL
, NULL
, NULL
);
439 debug("ready: %d\n", ready
);
442 /* TODO: Do we really want to fail here? */
443 fatal("%s", strerror(errno
));
445 for (Fifo
*f
= cfg
->fifos
; f
; f
= f
->next
) {
446 if (FD_ISSET(f
->fd
, &fds
)) {
447 debug("reading: %s\n", f
->name
);
448 switch (fifo_read_one(f
, t
, buf
)) {
450 * ### MESSAGE LOSS ###
451 * is introduced by closing at EOM in addition
452 * to EOF, since there may be unread messages
453 * remaining in the pipe. However,
455 * ### INTER-MESSAGE PUSHBACK ###
456 * is also gained, since pipes block at the
459 * This is an acceptable trade-off because we
460 * are a stateless reporter of a _most-recent_
461 * status, not a stateful accumulator.
482 main(int argc
, char *argv
[])
490 Config cfg0
= defaults
;
492 Display
*display
= NULL
;
495 t0
, /* time stamp. before reading fifos */
496 t1
, /* time stamp. after reading fifos */
497 ti
, /* time interval desired (t1 - t0) */
498 td
, /* time interval measured (t1 - t0) */
499 tc
; /* time interval correction (ti - td) when td < ti */
503 opts_parse(cfg
, argc
, argv
);
504 debug("argv0 = %s\n", argv0
);
507 ti
= timespec_of_float(cfg
->interval
);
509 if (cfg
->fifos
== NULL
)
510 usage("No fifo specs were given!\n");
512 /* 1st pass to check file existence and type */
513 for (Fifo
*f
= cfg
->fifos
; f
; f
= f
->next
) {
514 if (lstat(f
->name
, &st
) < 0) {
515 error("Cannot stat \"%s\". Error: %s\n", f
->name
, strerror(errno
));
519 if (!(st
.st_mode
& S_IFIFO
)) {
520 error("\"%s\" is not a FIFO\n", f
->name
);
526 fatal("Encountered errors with the given file paths. See log.\n");
528 width
= cfg
->total_width
;
529 seplen
= strlen(cfg
->separator
);
531 /* 2nd pass to make space for separators */
532 for (Fifo
*f
= cfg
->fifos
; f
; f
= f
->next
) {
533 f
->pos_init
+= prefix
;
534 f
->pos_final
+= prefix
;
535 f
->pos_curr
= f
->pos_init
;
539 width
+= (seplen
* (nfifos
- 1));
540 buf
= calloc(1, width
+ 1);
542 fatal("[memory] Failed to allocate buffer of %d bytes", width
);
543 memset(buf
, ' ', width
);
545 /* 3rd pass to set the separators */
546 for (Fifo
*f
= cfg
->fifos
; f
; f
= f
->next
) {
547 if (f
->pos_init
) { /* Skip the first, left-most */
548 /* Copying only seplen ensures we omit the '\0' byte. */
549 strncpy(buf
+ (f
->pos_init
- seplen
), cfg
->separator
, seplen
);
553 if (cfg
->output_to_x_root_window
&& !(display
= XOpenDisplay(NULL
)))
554 fatal("XOpenDisplay failed with: %p\n", display
);
555 /* TODO: Handle signals */
557 clock_gettime(CLOCK_MONOTONIC
, &t0
); // FIXME: check errors
558 /* TODO: Set timeout on fifo_read_all based on diff of last time of
559 * fifo_read_all and desired time of next TTL check?
561 /* TODO: How long to wait on IO? Max TTL? */
562 fifo_read_all(cfg
, t0
, buf
);
563 if (cfg
->output_to_x_root_window
) {
564 if (XStoreName(display
, DefaultRootWindow(display
), buf
) < 0)
565 fatal("XStoreName failed.\n");
573 * This is a good place for expiry check, since we're about to
574 * sleep anyway and the time taken by the check will be
575 * subtracted from the sleep period.
577 fifo_expire_all(cfg
, t0
, buf
);
579 clock_gettime(CLOCK_MONOTONIC
, &t1
); // FIXME: check errors
580 timespecsub(&t1
, &t0
, &td
);
581 debug("td {tv_sec = %ld, tv_nsec = %ld}\n", td
.tv_sec
, td
.tv_nsec
);
582 if (timespeccmp(&td
, &ti
, <)) {
583 /* Pushback on data producers by refusing to read the
584 * pipe more frequently than the interval.
586 timespecsub(&ti
, &td
, &tc
);
587 debug("snooze YES\n");
590 debug("snooze NO\n");
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