X-Git-Url: https://git.xandkar.net/?p=khatus.git;a=blobdiff_plain;f=x5%2Fkhatus.c;h=4dd42da54409bc9d19eb712982c535ec1ac85ccd;hp=faef5b1799edde6923396a0ba6f5f8ee514e0a64;hb=16e0239d76a7de132b20a564cc2c14ff2358ecf2;hpb=bec93767e683bb3f5de385d250d61ac06d436c29 diff --git a/x5/khatus.c b/x5/khatus.c index faef5b1..4dd42da 100644 --- a/x5/khatus.c +++ b/x5/khatus.c @@ -1,100 +1,120 @@ - -#include -#include #include #include #include #include #include +#include #include #include #include +#include +#include + +#include + +#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" -#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);} +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; -} defaults = { - .interval = 1, - .separator = "|", - .files = NULL, - .file_count = 0, - .total_width = 0, + int output_to_x_root_window; +}; + +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 @@ -106,72 +126,126 @@ is_pos_num(char *s) 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 opts_parse_any(Config *, int, char *[], int); /* For mutually-recursive calls. */ +/* For mutually-recursive calls. */ +void opts_parse_any(Config *, int, char *[], int); 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]); } } @@ -179,29 +253,38 @@ void 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."); } @@ -213,142 +296,325 @@ 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); } } } 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(Fifo *f, struct timespec t, char *buf) { - ssize_t n; - char *b; + struct timespec td; - b = buf + f->pos; - memset(b, ' ', f->width); - /* TODO: Read upto \n or 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_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. */ - 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. */ + /* + * TODO Define max after which we stop reading. + * To ensure that a rogue large message + * doesn't trap us here. + */ + } + break; + default: + assert(0); + } + } } void -read_all(Config *cfg, char *buf) +fifo_read_all(Config *cfg, struct timespec *ti, char *buf) { fd_set fds; - int maxfd; - int ready; + int maxfd = -1; + int ready = 0; struct stat st; + struct timespec t; FD_ZERO(&fds); - - /* TODO: Check TTL */ - for (File *f = cfg->files; f; f = f->next) { + 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); - debug("opening: %s\n", f->name); - if (f->fd < 0) + 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("selecting...\n"); - ready = select(maxfd + 1, &fds, NULL, NULL, NULL); + ready = pselect(maxfd + 1, &fds, NULL, NULL, ti, NULL); debug("ready: %d\n", ready); - assert(ready != 0); - if (ready < 0) - 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); + clock_gettime(CLOCK_MONOTONIC, &t); + if (ready == -1) { + switch (errno) { + case EINTR: + error("pselect temp failure: %d, errno: %d, msg: %s\n", + ready, errno, strerror(errno)); + /* TODO: Reconsider what to do here. */ + return; + default: + fatal("pselect failed: %d, errno: %d, msg: %s\n", + ready, errno, strerror(errno)); } } + /* At-least-once ensures that expiries are still checked on timeouts. */ + do { + 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); + } + } else { + fifo_expire(f, t, buf); + } + } + } while (ready); + assert(ready == 0); } int main(int argc, char *argv[]) { - int width; - int nfiles = 0; - int seplen; + Config cfg = { + .interval = 1.0, + .separator = "|", + .fifos = NULL, + .fifo_count = 0, + .total_width = 0, + .output_to_x_root_window = 0, + }; + + int width = 0; + int nfifos = 0; + int seplen = 0; int prefix = 0; + int errors = 0; char *buf; - Config *cfg = &defaults; + Display *d = 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"); + config_print(&cfg); + + 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 given file paths. See log.\n"); - width = cfg->total_width; - seplen = strlen(cfg->separator); + 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 && !(d = XOpenDisplay(NULL))) + fatal("XOpenDisplay failed with: %p\n", d); + /* TODO: Handle signals */ for (;;) { - read_all(cfg, buf); - printf("%s\n", buf); + clock_gettime(CLOCK_MONOTONIC, &t0); // FIXME: check errors + fifo_read_all(&cfg, &ti, buf); + if (cfg.output_to_x_root_window) { + if (XStoreName(d, DefaultRootWindow(d), buf) < 0) + fatal("XStoreName failed.\n"); + XFlush(d); + } else { + 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; }