#include <X11/Xlib.h>
#include "bsdtimespec.h"
+#include "khatus_lib_log.h"
+#include "khatus_lib_time.h"
-#define debug(args...) if (cfg->log_level >= Debug) {fprintf(stderr, "[debug] " args); fflush(stderr);}
-#define info( args...) if (cfg->log_level >= Info ) {fprintf(stderr, "[info] " args); fflush(stderr);}
-#define error(args...) if (cfg->log_level >= Error) {fprintf(stderr, "[error] " args); fflush(stderr);}
-#define fatal(args...) {fprintf(stderr, "[fatal] " args); exit(EXIT_FAILURE);}
-#define usage(args...) {print_usage(); fatal("[usage] " args);}
-
+#define usage(...) {print_usage(); fprintf(stderr, "Error:\n " __VA_ARGS__); exit(EXIT_FAILURE);}
#define ERRMSG "ERROR"
static const char errmsg[] = ERRMSG;
char *argv0;
-typedef enum LogLevel {
- Nothing,
- Error,
- Info,
- Debug
-} LogLevel;
-
/* TODO: Convert fifo list to fifo array. */
typedef struct Fifo Fifo;
struct Fifo {
char *name;
int fd;
int width;
- int last_read;
- int ttl;
- int pos; /* Position on the output buffer. */
+ struct timespec last_read;
+ struct timespec ttl;
+ int pos_init; /* Initial position on the output buffer. */
+ int pos_curr; /* Current position on the output buffer. */
+ int pos_final; /* Final position on the output buffer. */
Fifo *next;
};
typedef struct Config Config;
struct Config {
- int interval;
+ double interval;
char * separator;
Fifo * fifos;
int fifo_count;
int total_width;
int output_to_x_root_window;
- LogLevel log_level;
} defaults = {
- .interval = 1,
+ .interval = 1.0,
.separator = "|",
.fifos = NULL,
.fifo_count = 0,
.total_width = 0,
.output_to_x_root_window = 0,
- .log_level = Info,
+};
+
+enum read_status {
+ END_OF_FILE,
+ END_OF_MESSAGE,
+ RETRY,
+ FAILURE
};
void
-fifo_print_one(Fifo *f, Config *cfg)
+fifo_print_one(Fifo *f)
{
- info(
- "Fifo "
- "{"
- " name = %s,"
- " fd = %d,"
- " width = %d,"
- " last_read = %d,"
- " ttl = %d,"
- " pos = %d,"
- " next = %p,"
- " }\n",
- f->name,
- f->fd,
- f->width,
- f->last_read,
- f->ttl,
- f->pos,
- f->next
+ info("Fifo "
+ "{"
+ " name = %s,"
+ " fd = %d,"
+ " width = %d,"
+ " last_read = {tv_sec = %ld, tv_nsec = %ld}"
+ " ttl = {tv_sec = %ld, tv_nsec = %ld},"
+ " pos_init = %d,"
+ " pos_curr = %d,"
+ " pos_final = %d,"
+ " next = %p,"
+ " }\n",
+ f->name,
+ f->fd,
+ f->width,
+ f->last_read.tv_sec,
+ f->last_read.tv_nsec,
+ f->ttl.tv_sec,
+ f->ttl.tv_nsec,
+ f->pos_init,
+ f->pos_curr,
+ f->pos_final,
+ f->next
);
}
void
-fifo_print_all(Fifo *head, Config *cfg)
+fifo_print_all(Fifo *head)
{
for (Fifo *f = head; f; f = f->next) {
- fifo_print_one(f, cfg);
+ fifo_print_one(f);
}
}
config_print(Config *cfg)
{
info(
- "Config "
- "{"
- " interval = %d,"
- " separator = %s,"
- " fifo_count = %d,"
- " total_width = %d,"
- " log_level = %d,"
- " fifos = ..."
- " }\n",
- cfg->interval,
- cfg->separator,
- cfg->fifo_count,
- cfg->total_width,
- cfg->log_level
+ "Config "
+ "{"
+ " interval = %f,"
+ " separator = %s,"
+ " fifo_count = %d,"
+ " total_width = %d,"
+ " fifos = ..."
+ " }\n",
+ cfg->interval,
+ cfg->separator,
+ cfg->fifo_count,
+ cfg->total_width
);
- fifo_print_all(cfg->fifos, cfg);
+ fifo_print_all(cfg->fifos);
}
int
return 1;
}
+int
+is_decimal(char *s)
+{
+ char c;
+ int seen = 0;
+
+ while ((c = *(s++)) != '\0')
+ if (!isdigit(c)) {
+ if (c == '.' && !seen++)
+ continue;
+ else
+ return 0;
+ }
+ return 1;
+}
+
void
print_usage()
{
assert(argv0);
fprintf(
- stderr,
- "\n"
- "Usage: %s [OPTION ...] SPEC [SPEC ...]\n"
- "\n"
- " SPEC = FILE_PATH DATA_WIDTH DATA_TTL\n"
- " FILE_PATH = string\n"
- " DATA_WIDTH = int (* (positive) number of characters *)\n"
- " DATA_TTL = int (* (positive) number of seconds *)\n"
- " OPTION = -i INTERVAL\n"
- " | -s SEPARATOR\n"
- " | -x (* Output to X root window *)\n"
- " | -l LOG_LEVEL\n"
- " SEPARATOR = string\n"
- " INTERVAL = int (* (positive) number of seconds *)\n"
- " LOG_LEVEL = int (* %d through %d *)\n"
- "\n",
- argv0,
- Nothing,
- Debug
+ stderr,
+ "\n"
+ "Usage: %s [OPTION ...] SPEC [SPEC ...]\n"
+ "\n"
+ " SPEC = FILE_PATH DATA_WIDTH DATA_TTL\n"
+ " FILE_PATH = string\n"
+ " DATA_WIDTH = int (* (positive) number of characters *)\n"
+ " DATA_TTL = float (* (positive) number of seconds *)\n"
+ " OPTION = -i INTERVAL\n"
+ " | -s SEPARATOR\n"
+ " | -x (* Output to X root window *)\n"
+ " | -l LOG_LEVEL\n"
+ " SEPARATOR = string\n"
+ " INTERVAL = float (* (positive) number of seconds *)\n"
+ " LOG_LEVEL = int (* %d through %d *)\n"
+ "\n",
+ argv0,
+ Nothing,
+ Debug
);
fprintf(
- stderr,
- "Example: %s -i 1 /dev/shm/khatus/khatus_sensor_x 4 10\n"
- "\n",
- argv0
+ stderr,
+ "Example: %s -i 1 /dev/shm/khatus/khatus_sensor_x 4 10\n"
+ "\n",
+ argv0
);
}
if (i >= argc)
usage("Option -i parameter is missing.\n");
param = argv[i++];
- if (!is_pos_num(param))
+ if (!is_decimal(param))
usage("Option -i parameter is invalid: \"%s\"\n", param);
- cfg->interval = atoi(param);
+ cfg->interval = atof(param);
opts_parse_any(cfg, argc, argv, i);
}
log_level = atoi(param);
if (log_level > Debug)
usage("Option -l value (%d) exceeds maximum (%d)\n", log_level, Debug);
- cfg->log_level = log_level;
+ _khatus_lib_log_level = log_level;
opts_parse_any(cfg, argc, argv, i);
}
char *w = argv[i++];
char *t = argv[i++];
+ struct timespec last_read;
+
if (!is_pos_num(w))
usage("[spec] Invalid width: \"%s\", for fifo \"%s\"\n", w, n);
- if (!is_pos_num(t))
+ if (!is_decimal(t))
usage("[spec] Invalid TTL: \"%s\", for fifo \"%s\"\n", t, n);
+ last_read.tv_sec = 0;
+ last_read.tv_nsec = 0;
Fifo *f = calloc(1, sizeof(struct Fifo));
if (f) {
f->name = n;
f->fd = -1;
f->width = atoi(w);
- f->ttl = atoi(t);
- f->last_read = 0;
- f->pos = cfg->total_width;
+ f->ttl = timespec_of_float(atof(t));
+ f->last_read = last_read;
+ f->pos_init = cfg->total_width;
+ f->pos_curr = f->pos_init;
+ f->pos_final = f->pos_init + f->width - 1;
f->next = cfg->fifos;
cfg->fifos = f;
}
}
+void
+fifo_expire_one(Fifo *f, struct timespec t, char *buf)
+{
+ struct timespec td;
+
+ timespecsub(&t, &(f->last_read), &td);
+ if (timespeccmp(&td, &(f->ttl), >=)) {
+ /* TODO: Maybe configurable expiry character. */
+ memset(buf + f->pos_init, '_', f->pos_final - f->pos_init);
+ warn("Data source expired: \"%s\"\n", f->name);
+ }
+}
+
+void
+fifo_expire_all(Config *cfg, struct timespec t, char *buf)
+{
+ Fifo *f;
+
+ for (f = cfg->fifos; f; f = f->next)
+ fifo_expire_one(f, t, buf);
+}
+
void
fifo_read_error(Fifo *f, char *buf)
{
char *b;
int i;
- b = buf + f->pos;
+ b = buf + f->pos_init;
/* Copy as much of the error message as possible.
- * EXCLUDING the reminating \0. */
+ * EXCLUDING the terminating \0. */
for (i = 0; i < errlen && i < f->width; i++)
b[i] = errmsg[i];
/* Any remaining slots: */
b[i] = '_';
}
-void
-fifo_read_one(Fifo *f, char *buf, Config *cfg)
+enum read_status
+fifo_read_one(Fifo *f, struct timespec t, char *buf)
{
- ssize_t current;
- ssize_t total;
- char *b;
- char c;
+ char c; /* Character read. */
+ int r; /* Remaining unused slots in buffer range. */
- current = 0;
- total = 0;
- c = '\0';
- b = buf + f->pos;
- while ((current = read(f->fd, &c, 1)) && c != '\n' && c != '\0' && total++ < f->width)
- *b++ = c;
- if (current == -1) {
- error("Failed to read: \"%s\". Error: %s\n", f->name, strerror(errno));
- fifo_read_error(f, buf);
- } else
- while (total++ < f->width)
- *b++ = ' ';
- /* TODO Record timestamp read */
- close(f->fd);
- f->fd = -1;
+ for (;;) {
+ switch (read(f->fd, &c, 1)) {
+ case -1:
+ error("Failed to read: \"%s\". errno: %d, msg: %s\n",
+ f->name, errno, strerror(errno));
+ switch (errno) {
+ case EINTR:
+ case EAGAIN:
+ return RETRY;
+ default:
+ return FAILURE;
+ }
+ case 0:
+ debug("%s: End of FILE\n", f->name);
+ f->pos_curr = f->pos_init;
+ return END_OF_FILE;
+ case 1:
+ /* TODO: Consider making msg term char a CLI option */
+ if (c == '\n' || c == '\0') {
+ r = f->pos_final - f->pos_curr;
+ if (r > 0)
+ memset(buf + f->pos_curr, ' ', r);
+ f->pos_curr = f->pos_init;
+ f->last_read = t;
+ return END_OF_MESSAGE;
+ } else {
+ if (f->pos_curr <= f->pos_final)
+ buf[f->pos_curr++] = c;
+ /* Drop beyond available range. */
+ }
+ break;
+ default:
+ assert(0);
+ }
+ }
}
void
-fifo_read_all(Config *cfg, char *buf)
+fifo_read_all(Config *cfg, struct timespec t, char *buf)
{
fd_set fds;
int maxfd = -1;
- int ready;
+ int ready = 0;
struct stat st;
FD_ZERO(&fds);
fifo_read_error(f, buf);
continue;
}
- debug("opening: %s\n", f->name);
- if (f->fd < 0)
+ if (f->fd < 0) {
+ debug("%s: closed. opening. fd: %d\n", f->name, f->fd);
f->fd = open(f->name, O_RDONLY | O_NONBLOCK);
+ } else {
+ debug("%s: already openned. fd: %d\n", f->name, f->fd);
+ }
if (f->fd == -1) {
/* TODO: Consider backing off retries for failed fifos. */
error("Failed to open \"%s\"\n", f->name);
fifo_read_error(f, buf);
continue;
}
+ debug("%s: open. fd: %d\n", f->name, f->fd);
if (f->fd > maxfd)
maxfd = f->fd;
FD_SET(f->fd, &fds);
debug("ready: %d\n", ready);
assert(ready != 0);
if (ready < 0)
+ /* TODO: Do we really want to fail here? */
fatal("%s", strerror(errno));
- for (Fifo *f = cfg->fifos; f; f = f->next) {
- if (FD_ISSET(f->fd, &fds)) {
- debug("reading: %s\n", f->name);
- fifo_read_one(f, buf, cfg);
- }
- }
-}
-
-void
-snooze(struct timespec *t, Config *cfg)
-{
- struct timespec remainder;
- int result;
-
- result = nanosleep(t, &remainder);
-
- if (result < 0) {
- if (errno == EINTR) {
- info(
- "nanosleep interrupted. Remainder: "
- "{ tv_sec = %ld, tv_nsec = %ld }",
- remainder.tv_sec, remainder.tv_nsec);
- /* No big deal if we occasionally sleep less,
- * so not attempting to correct after an interruption.
- */
- } else {
- fatal("nanosleep: %s\n", strerror(errno));
+ while (ready) {
+ for (Fifo *f = cfg->fifos; f; f = f->next) {
+ if (FD_ISSET(f->fd, &fds)) {
+ debug("reading: %s\n", f->name);
+ switch (fifo_read_one(f, t, buf)) {
+ /*
+ * ### MESSAGE LOSS ###
+ * is introduced by closing at EOM in addition
+ * to EOF, since there may be unread messages
+ * remaining in the pipe. However,
+ *
+ * ### INTER-MESSAGE PUSHBACK ###
+ * is also gained, since pipes block at the
+ * "open" call.
+ *
+ * This is an acceptable trade-off because we
+ * are a stateless reporter of a _most-recent_
+ * status, not a stateful accumulator.
+ */
+ case END_OF_MESSAGE:
+ case END_OF_FILE:
+ case FAILURE:
+ close(f->fd);
+ f->fd = -1;
+ ready--;
+ break;
+ case RETRY:
+ break;
+ default:
+ assert(0);
+ }
+ }
}
}
+ assert(ready == 0);
}
int
debug("argv0 = %s\n", argv0);
config_print(cfg);
- /* TODO: Support interval < 1. i.e. implement timespec_of_float */
- ti.tv_sec = cfg->interval;
- ti.tv_nsec = 0;
+ ti = timespec_of_float(cfg->interval);
if (cfg->fifos == NULL)
usage("No fifo specs were given!\n");
/* 2nd pass to make space for separators */
for (Fifo *f = cfg->fifos; f; f = f->next) {
- f->pos += prefix;
+ f->pos_init += prefix;
+ f->pos_final += prefix;
+ f->pos_curr = f->pos_init;
prefix += seplen;
nfifos++;
}
buf[width] = '\0';
/* 3rd pass to set the separators */
for (Fifo *f = cfg->fifos; f; f = f->next) {
- if (f->pos) { /* Skip the first, left-most */
+ if (f->pos_init) { /* Skip the first, left-most */
/* Copying only seplen ensures we omit the '\0' byte. */
- strncpy(buf + (f->pos - seplen), cfg->separator, seplen);
+ strncpy(buf + (f->pos_init - seplen), cfg->separator, seplen);
}
}
/* TODO: Handle signals */
for (;;) {
clock_gettime(CLOCK_MONOTONIC, &t0); // FIXME: check errors
- /* TODO: Cache expiration. i.e. use the TTL */
- /* TODO: How to trigger TTL check? On select? Alarm signal? */
/* TODO: Set timeout on fifo_read_all based on diff of last time of
- * fifo_read_all and desired time of next TTL check.
+ * fifo_read_all and desired time of next TTL check?
*/
/* TODO: How long to wait on IO? Max TTL? */
- fifo_read_all(cfg, buf);
+ fifo_read_all(cfg, t0, buf);
if (cfg->output_to_x_root_window) {
if (XStoreName(display, DefaultRootWindow(display), buf) < 0)
fatal("XStoreName failed.\n");
puts(buf);
fflush(stdout);
}
+
+ /*
+ * This is a good place for expiry check, since we're about to
+ * sleep anyway and the time taken by the check will be
+ * subtracted from the sleep period.
+ */
+ fifo_expire_all(cfg, t0, buf);
+
clock_gettime(CLOCK_MONOTONIC, &t1); // FIXME: check errors
timespecsub(&t1, &t0, &td);
debug("td {tv_sec = %ld, tv_nsec = %ld}\n", td.tv_sec, td.tv_nsec);
*/
timespecsub(&ti, &td, &tc);
debug("snooze YES\n");
- snooze(&tc, cfg);
- } else
+ snooze(&tc);
+ } else {
debug("snooze NO\n");
+ }
}
return EXIT_SUCCESS;