-#include <fcntl.h>
-#include <unistd.h>
#include <sys/select.h>
+#include <sys/stat.h>
#include <assert.h>
#include <ctype.h>
#include <errno.h>
+#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
+#include <time.h>
+#include <unistd.h>
+
+#include <X11/Xlib.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);}
+#include "bsdtimespec.h"
+#include "khatus_lib_log.h"
+#include "khatus_lib_time.h"
+
+#define usage(...) {print_usage(); fprintf(stderr, "Error:\n " __VA_ARGS__); exit(EXIT_FAILURE);}
+#define ERRMSG "ERROR"
+
+static const char errmsg[] = ERRMSG;
+static const int errlen = sizeof(ERRMSG) - 1;
char *argv0;
-typedef struct File File;
-struct File {
+/* 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. */
- File *next;
+ 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;
- File * files;
- int file_count;
+ Fifo * fifos;
+ int fifo_count;
int total_width;
+ int output_to_x_root_window;
} defaults = {
- .interval = 1,
+ .interval = 1.0,
.separator = "|",
- .files = NULL,
- .file_count = 0,
+ .fifos = NULL,
+ .fifo_count = 0,
.total_width = 0,
+ .output_to_x_root_window = 0,
+};
+
+enum read_status {
+ END_OF_FILE,
+ END_OF_MESSAGE,
+ RETRY,
+ FAILURE
};
void
-file_print_one(File *f)
+fifo_print_one(Fifo *f)
{
- debug(
- "File "
- "{"
- " 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
-file_print_all(File *head)
+fifo_print_all(Fifo *head)
{
- for (File *f = head; f; f = f->next) {
- file_print_one(f);
+ for (Fifo *f = head; f; f = f->next) {
+ fifo_print_one(f);
}
}
void
-config_print(Config *c)
+config_print(Config *cfg)
{
- debug(
- "Config "
- "{"
- " interval = %d,"
- " separator = %s,"
- " file_count = %d,"
- " total_width = %d,"
- " files = ..."
- " }\n",
- c->interval,
- c->separator,
- c->file_count,
- c->total_width
+ info(
+ "Config "
+ "{"
+ " interval = %f,"
+ " separator = %s,"
+ " fifo_count = %d,"
+ " total_width = %d,"
+ " fifos = ..."
+ " }\n",
+ cfg->interval,
+ cfg->separator,
+ cfg->fifo_count,
+ cfg->total_width
);
- file_print_all(c->files);
+ 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"
- " SEPARATOR = string\n"
- " INTERVAL = int (* (positive) number of seconds *)\n"
- "\n",
- argv0
+ 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
);
}
void
parse_opts_opt_i(Config *cfg, int argc, char *argv[], int i)
{
- if (i < argc) {
- char *param = argv[i++];
+ char *param;
- if (is_pos_num(param)) {
- cfg->interval = atoi(param);
- opts_parse_any(cfg, argc, argv, i);
- } else {
- usage("Option -i parameter is invalid: \"%s\"\n", param);
- }
- } else {
+ if (i >= argc)
usage("Option -i parameter is missing.\n");
- }
+ param = argv[i++];
+ if (!is_decimal(param))
+ usage("Option -i parameter is invalid: \"%s\"\n", param);
+ cfg->interval = atof(param);
+ opts_parse_any(cfg, argc, argv, i);
}
void
parse_opts_opt_s(Config *cfg, int argc, char *argv[], int i)
{
- if (i < argc) {
- cfg->separator = calloc((strlen(argv[i]) + 1), sizeof(char));
- strcpy(cfg->separator, argv[i]);
- opts_parse_any(cfg, argc, argv, ++i);
- } else {
+ if (i >= argc)
usage("Option -s parameter is missing.\n");
- }
+ cfg->separator = calloc((strlen(argv[i]) + 1), sizeof(char));
+ strcpy(cfg->separator, argv[i]);
+ opts_parse_any(cfg, argc, argv, ++i);
+}
+
+void
+parse_opts_opt_l(Config *cfg, int argc, char *argv[], int i)
+{
+ char *param;
+ int log_level;
+
+ if (i >= argc)
+ usage("Option -l parameter is missing.\n");
+ param = argv[i++];
+ if (!is_pos_num(param))
+ usage("Option -l parameter is invalid: \"%s\"\n", param);
+ log_level = atoi(param);
+ if (log_level > Debug)
+ usage("Option -l value (%d) exceeds maximum (%d)\n", log_level, Debug);
+ _khatus_lib_log_level = log_level;
+ opts_parse_any(cfg, argc, argv, i);
}
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 */
- default : usage("Option \"%s\" is invalid\n", argv[i]);
+ 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;
+ case 'l':
+ /* TODO: Generic set_int */
+ parse_opts_opt_l(cfg, argc, argv, ++i);
+ break;
+ default :
+ usage("Option \"%s\" is invalid\n", argv[i]);
}
}
parse_opts_spec(Config *cfg, int argc, char *argv[], int i)
{
if ((i + 3) > argc)
- usage("[spec] Parameter(s) missing for file \"%s\".\n", argv[i]);
+ usage("[spec] Parameter(s) missing for fifo \"%s\".\n", argv[i]);
char *n = 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 file \"%s\"\n", w, n);
- if (!is_pos_num(t))
- usage("[spec] Invalid TTL: \"%s\", for file \"%s\"\n", t, n);
- File *f = calloc(1, sizeof(struct File));
+ usage("[spec] Invalid width: \"%s\", for fifo \"%s\"\n", w, n);
+ 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->next = cfg->files;
-
- cfg->files = f;
+ 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;
cfg->total_width += f->width;
- cfg->file_count++;
+ cfg->fifo_count++;
} else {
fatal("[memory] Allocation failure.");
}
{
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);
}
}
}
void
-opts_parse(Config *cfg, int argc, char *argv[], int i)
+opts_parse(Config *cfg, int argc, char *argv[])
{
opts_parse_any(cfg, argc, argv, 1);
- File *last = cfg->files;
- cfg->files = NULL;
- for (File *f = last; f; ) {
- File *next = f->next;
- f->next = cfg->files;
- cfg->files = f;
+ Fifo *last = cfg->fifos;
+ cfg->fifos = NULL;
+ for (Fifo *f = last; f; ) {
+ Fifo *next = f->next;
+ f->next = cfg->fifos;
+ cfg->fifos = f;
f = next;
}
}
void
-read_one(File *f, char *buf)
+fifo_expire_one(Fifo *f, struct timespec t, char *buf)
{
- ssize_t n;
- char *b;
+ struct timespec td;
- b = buf + f->pos;
- memset(b, ' ', f->width);
- while ((n = read(f->fd, b, f->width)) > 0) {
- b += n;
- debug("read %zd from %s\n", n, f->name);
+ 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);
}
+}
- if (n > -1) {
- if (*(b - 1) == '\n')
- *(b - 1) = ' ';
- } else {
- error(
- "Failed to read: \"%s\". Error: %s\n",
- f->name,
- strerror(errno)
- );
- }
+void
+fifo_expire_all(Config *cfg, struct timespec t, char *buf)
+{
+ Fifo *f;
- close(f->fd);
- f->fd = -1;
+ for (f = cfg->fifos; f; f = f->next)
+ fifo_expire_one(f, t, buf);
}
void
-read_all(Config *cfg, char *buf)
+fifo_read_error(Fifo *f, char *buf)
+{
+ char *b;
+ int i;
+
+ b = buf + f->pos_init;
+ /* Copy as much of the error message as possible.
+ * EXCLUDING the terminating \0. */
+ for (i = 0; i < errlen && i < f->width; i++)
+ b[i] = errmsg[i];
+ /* Any remaining slots: */
+ for (; i < f->width; i++)
+ b[i] = '_';
+}
+
+enum read_status
+fifo_read_one(Fifo *f, struct timespec t, char *buf)
+{
+ char c; /* Character read. */
+ int r; /* Remaining unused slots in buffer range. */
+
+ 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, struct timespec t, char *buf)
{
fd_set fds;
- int maxfd;
- int ready;
+ int maxfd = -1;
+ int ready = 0;
+ struct stat st;
FD_ZERO(&fds);
-
- /* TODO: stat then check TTL */
- for (File *f = cfg->files; f; f = f->next) {
- debug("opening: %s\n", f->name);
- if (f->fd < 0)
+ 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) {
+ 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;
+ }
+ if (f->fd < 0) {
+ debug("%s: closed. opening. fd: %d\n", f->name, f->fd);
f->fd = open(f->name, O_RDONLY | O_NONBLOCK);
- if (f->fd == -1)
- /* TODO: Consider backing off retries for failed files. */
- fatal("Failed to open \"%s\"\n", f->name);
+ } 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 (File *f = cfg->files; f; f = f->next) {
- if (FD_ISSET(f->fd, &fds)) {
- debug("reading: %s\n", f->name);
- read_one(f, buf);
+ 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
main(int argc, char *argv[])
{
- int width;
- int nfiles = 0;
- int seplen;
+ int width = 0;
+ int nfifos = 0;
+ int seplen = 0;
int prefix = 0;
+ int errors = 0;
char *buf;
- Config *cfg = &defaults;
+ 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, 1);
+ opts_parse(cfg, argc, argv);
debug("argv0 = %s\n", argv0);
config_print(cfg);
- if (cfg->files == NULL)
- usage("No file specs were given!\n");
+
+ ti = timespec_of_float(cfg->interval);
+
+ 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 */
- for (File *f = cfg->files; f; f = f->next) {
- f->pos += prefix;
+ /* 2nd pass to make space for separators */
+ for (Fifo *f = cfg->fifos; f; f = f->next) {
+ f->pos_init += prefix;
+ f->pos_final += prefix;
+ f->pos_curr = f->pos_init;
prefix += seplen;
- nfiles++;
+ nfifos++;
}
- width += (seplen * (nfiles - 1));
+ width += (seplen * (nfifos - 1));
buf = calloc(1, width + 1);
if (buf == NULL)
fatal("[memory] Failed to allocate buffer of %d bytes", width);
memset(buf, ' ', width);
buf[width] = '\0';
- /* 2nd pass to set the separators */
- for (File *f = cfg->files; f; f = f->next) {
- if (f->pos) { /* Skip the first, left-most */
+ /* 3rd pass to set the separators */
+ for (Fifo *f = cfg->fifos; f; f = f->next) {
+ 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);
}
}
- printf("%s\n", buf);
- /* TODO: nanosleep and nano time diff */
+ if (cfg->output_to_x_root_window && !(display = XOpenDisplay(NULL)))
+ fatal("XOpenDisplay failed with: %p\n", display);
+ /* TODO: Handle signals */
for (;;) {
- read_all(cfg, buf);
- printf("%s\n", buf);
+ clock_gettime(CLOCK_MONOTONIC, &t0); // FIXME: check errors
+ /* 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, t0, buf);
+ if (cfg->output_to_x_root_window) {
+ if (XStoreName(display, DefaultRootWindow(display), buf) < 0)
+ fatal("XStoreName failed.\n");
+ XFlush(display);
+ } else {
+ 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);
+ 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;
}
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