X-Git-Url: https://git.xandkar.net/?a=blobdiff_plain;f=x5%2Fkhatus.c;h=cc28cba53b212177532b7a366484fa4cb9f583e7;hb=b7487ec5a6f62c0c57836fff6cbaa52b116f0831;hp=c5da07333549457d7817f6eca9037a467c939430;hpb=a6d4c9c3b8d4dc85415c572e2182ce0225962f83;p=khatus.git diff --git a/x5/khatus.c b/x5/khatus.c index c5da073..cc28cba 100644 --- a/x5/khatus.c +++ b/x5/khatus.c @@ -8,16 +8,24 @@ #include #include #include +#include #include #include +#include "bsdtimespec.h" + #define debug(args...) {fprintf(stderr, "[debug] " args);} #define info( args...) {fprintf(stderr, "[info] " args);} #define error(args...) {fprintf(stderr, "[error] " args);} #define fatal(args...) {fprintf(stderr, "[fatal] " args); exit(EXIT_FAILURE);} #define usage(args...) {print_usage(); fatal("[usage] " args);} +#define ERRMSG "ERROR" + +static const char errmsg[] = ERRMSG; +static const int errlen = sizeof(ERRMSG) - 1; + char *argv0; /* TODO: Convert fifo list to fifo array. */ @@ -173,14 +181,20 @@ void parse_opts_opt(Config *cfg, int argc, char *argv[], int i) { switch (argv[i][1]) { - case 'i': parse_opts_opt_i(cfg, argc, argv, ++i); break; /* TODO: Generic set_int */ - case 's': parse_opts_opt_s(cfg, argc, argv, ++i); break; /* TODO: Generic set_str */ - case 'x': { + case 'i': + /* TODO: Generic set_int */ + parse_opts_opt_i(cfg, argc, argv, ++i); + break; + case 's': + /* TODO: Generic set_str */ + parse_opts_opt_s(cfg, argc, argv, ++i); + break; + case 'x': cfg->output_to_x_root_window = 1; opts_parse_any(cfg, argc, argv, ++i); break; - } - default : usage("Option \"%s\" is invalid\n", argv[i]); + default : + usage("Option \"%s\" is invalid\n", argv[i]); } } @@ -222,8 +236,11 @@ opts_parse_any(Config *cfg, int argc, char *argv[], int i) { if (i < argc) { switch (argv[i][0]) { - case '-': parse_opts_opt(cfg, argc, argv, i); break; - default : parse_opts_spec(cfg, argc, argv, i); + case '-': + parse_opts_opt(cfg, argc, argv, i); + break; + default : + parse_opts_spec(cfg, argc, argv, i); } } } @@ -244,7 +261,23 @@ opts_parse(Config *cfg, int argc, char *argv[]) } void -read_one(Fifo *f, char *buf) +fifo_read_error(Fifo *f, char *buf) +{ + char *b; + int i; + + b = buf + f->pos; + /* Copy as much of the error message as possible. + * EXCLUDING the reminating \0. */ + for (i = 0; i < errlen && i < f->width; i++) + b[i] = errmsg[i]; + /* Any remaining slots: */ + for (; i < f->width; i++) + b[i] = '_'; +} + +void +fifo_read_one(Fifo *f, char *buf) { ssize_t current; ssize_t total; @@ -255,18 +288,21 @@ read_one(Fifo *f, char *buf) total = 0; c = '\0'; b = buf + f->pos; - memset(b, ' ', f->width); while ((current = read(f->fd, &c, 1)) && c != '\n' && c != '\0' && total++ < f->width) *b++ = c; - if (current == -1) + 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; } void -read_all(Config *cfg, char *buf) +fifo_read_all(Config *cfg, char *buf) { fd_set fds; int maxfd = -1; @@ -274,19 +310,27 @@ read_all(Config *cfg, char *buf) struct stat st; FD_ZERO(&fds); - /* TODO: Check TTL */ for (Fifo *f = cfg->fifos; f; f = f->next) { /* TODO: Create the FIFO if it doesn't already exist. */ - if (lstat(f->name, &st) < 0) - fatal("Cannot stat \"%s\". Error: %s\n", f->name, strerror(errno)); - if (!(st.st_mode & S_IFIFO)) - fatal("\"%s\" is not a FIFO\n", f->name); + if (lstat(f->name, &st) < 0) { + error("Cannot stat \"%s\". Error: %s\n", f->name, strerror(errno)); + fifo_read_error(f, buf); + continue; + } + if (!(st.st_mode & S_IFIFO)) { + error("\"%s\" is not a FIFO\n", f->name); + fifo_read_error(f, buf); + continue; + } debug("opening: %s\n", f->name); if (f->fd < 0) f->fd = open(f->name, O_RDONLY | O_NONBLOCK); - if (f->fd == -1) + if (f->fd == -1) { /* TODO: Consider backing off retries for failed fifos. */ - fatal("Failed to open \"%s\"\n", f->name); + error("Failed to open \"%s\"\n", f->name); + fifo_read_error(f, buf); + continue; + } if (f->fd > maxfd) maxfd = f->fd; FD_SET(f->fd, &fds); @@ -300,7 +344,30 @@ read_all(Config *cfg, char *buf) for (Fifo *f = cfg->fifos; f; f = f->next) { if (FD_ISSET(f->fd, &fds)) { debug("reading: %s\n", f->name); - read_one(f, buf); + fifo_read_one(f, buf); + } + } +} + +void +snooze(struct timespec *t) +{ + 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)); } } } @@ -308,27 +375,56 @@ read_all(Config *cfg, char *buf) int main(int argc, char *argv[]) { - int width; + int width = 0; int nfifos = 0; - int seplen; + int seplen = 0; int prefix = 0; + int errors = 0; char *buf; Config cfg0 = defaults; Config *cfg = &cfg0; Display *display = NULL; + struct stat st; + struct timespec + t0, /* time stamp. before reading fifos */ + t1, /* time stamp. after reading fifos */ + ti, /* time interval desired (t1 - t0) */ + td, /* time interval measured (t1 - t0) */ + tc; /* time interval correction (ti - td) when td < ti */ argv0 = argv[0]; opts_parse(cfg, argc, argv); 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; + if (cfg->fifos == NULL) usage("No fifo specs were given!\n"); + /* 1st pass to check file existence and type */ + for (Fifo *f = cfg->fifos; f; f = f->next) { + if (lstat(f->name, &st) < 0) { + error("Cannot stat \"%s\". Error: %s\n", f->name, strerror(errno)); + errors++; + continue; + } + if (!(st.st_mode & S_IFIFO)) { + error("\"%s\" is not a FIFO\n", f->name); + errors++; + continue; + } + } + if (errors) + fatal("Encountered errors with the given file paths. See log.\n"); + width = cfg->total_width; seplen = strlen(cfg->separator); - /* 1st pass to make space for separators */ + /* 2nd pass to make space for separators */ for (Fifo *f = cfg->fifos; f; f = f->next) { f->pos += prefix; prefix += seplen; @@ -340,7 +436,7 @@ main(int argc, char *argv[]) fatal("[memory] Failed to allocate buffer of %d bytes", width); memset(buf, ' ', width); buf[width] = '\0'; - /* 2nd pass to set the separators */ + /* 3rd pass to set the separators */ for (Fifo *f = cfg->fifos; f; f = f->next) { if (f->pos) { /* Skip the first, left-most */ /* Copying only seplen ensures we omit the '\0' byte. */ @@ -350,14 +446,16 @@ main(int argc, char *argv[]) if (cfg->output_to_x_root_window && !(display = XOpenDisplay(NULL))) fatal("XOpenDisplay failed with: %p\n", display); - /* TODO: nanosleep and nano time diff */ + /* TODO: Handle signals */ for (;;) { - /* TODO: Check TTL and maybe blank-out */ + 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 read_all based on diff of last time of - * read_all and desired time of next TTL check. - * */ - read_all(cfg, buf); + /* TODO: Set timeout on fifo_read_all based on diff of last time of + * fifo_read_all and desired time of next TTL check. + */ + /* TODO: How long to wait on IO? Max TTL? */ + fifo_read_all(cfg, buf); if (cfg->output_to_x_root_window) { if (XStoreName(display, DefaultRootWindow(display), buf) < 0) fatal("XStoreName failed.\n"); @@ -366,6 +464,18 @@ main(int argc, char *argv[]) puts(buf); fflush(stdout); } + 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); + if (timespeccmp(&td, &ti, <)) { + /* Pushback on data producers by refusing to read the + * pipe more frequently than the interval. + */ + timespecsub(&ti, &td, &tc); + debug("snooze YES\n"); + snooze(&tc); + } else + debug("snooze NO\n"); } return EXIT_SUCCESS;