From 4bfac488ba99787df53cf6b8627b0192921309cf Mon Sep 17 00:00:00 2001 From: Siraaj Khandkar Date: Thu, 26 Mar 2020 15:48:30 -0400 Subject: [PATCH] Co-locate all slot functions --- x5/khatus.c | 394 ++++++++++++++++++++++++++-------------------------- 1 file changed, 197 insertions(+), 197 deletions(-) diff --git a/x5/khatus.c b/x5/khatus.c index c2430d0..5caae33 100644 --- a/x5/khatus.c +++ b/x5/khatus.c @@ -113,6 +113,203 @@ slots_print(Slot *head) } } +void +slot_expire(Slot *s, struct timespec t, char *buf) +{ + struct timespec td; + + timespecsub(&t, &(s->in_last_read), &td); + if (timespeccmp(&td, &(s->out_ttl), >=)) { + /* TODO: Maybe configurable expiry character. */ + memset(buf + s->out_pos_lo, '_', s->out_pos_hi - s->out_pos_lo); + khlib_warn("Slot expired: \"%s\"\n", s->in_fifo); + } +} + +void +slot_read_error(Slot *s, char *buf) +{ + char *b; + int i; + + b = buf + s->out_pos_lo; + /* Copy as much of the error message as possible. + * EXCLUDING the terminating \0. */ + for (i = 0; i < errlen && i < s->out_width; i++) + b[i] = errmsg[i]; + /* Any remaining positions: */ + for (; i < s->out_width; i++) + b[i] = '_'; +} + +enum read_status +slot_read(Slot *s, struct timespec t, char *buf) +{ + char c; /* Character read. */ + int r; /* Remaining unused positions in buffer range. */ + + for (;;) { + switch (read(s->in_fd, &c, 1)) { + case -1: + khlib_error( + "Failed to read: \"%s\". errno: %d, msg: %s\n", + s->in_fifo, + errno, + strerror(errno) + ); + switch (errno) { + case EINTR: + case EAGAIN: + return RETRY; + default: + return FAILURE; + } + case 0: + khlib_debug("%s: End of FILE\n", s->in_fifo); + s->out_pos_cur = s->out_pos_lo; + return END_OF_FILE; + case 1: + /* TODO: Consider making msg term char a CLI option */ + if (c == '\n' || c == '\0') { + r = s->out_pos_hi - s->out_pos_cur; + if (r > 0) + memset(buf + s->out_pos_cur, ' ', r); + s->out_pos_cur = s->out_pos_lo; + s->in_last_read = t; + return END_OF_MESSAGE; + } else { + if (s->out_pos_cur <= s->out_pos_hi) + buf[s->out_pos_cur++] = 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 +slots_read(Config *cfg, struct timespec *ti, char *buf) +{ + fd_set fds; + int maxfd = -1; + int ready = 0; + struct stat st; + struct timespec t; + Slot *s; + + FD_ZERO(&fds); + for (s = cfg->slots; s; s = s->next) { + /* TODO: Create the FIFO if it doesn't already exist. */ + if (lstat(s->in_fifo, &st) < 0) { + khlib_error( + "Cannot stat \"%s\". Error: %s\n", + s->in_fifo, + strerror(errno) + ); + slot_read_error(s, buf); + continue; + } + if (!(st.st_mode & S_IFIFO)) { + khlib_error("\"%s\" is not a FIFO\n", s->in_fifo); + slot_read_error(s, buf); + continue; + } + if (s->in_fd < 0) { + khlib_debug( + "%s: closed. opening. in_fd: %d\n", + s->in_fifo, + s->in_fd + ); + s->in_fd = open(s->in_fifo, O_RDONLY | O_NONBLOCK); + } else { + khlib_debug( + "%s: already openned. in_fd: %d\n", + s->in_fifo, + s->in_fd + ); + } + if (s->in_fd == -1) { + /* TODO Consider backing off retries for failed slots */ + khlib_error("Failed to open \"%s\"\n", s->in_fifo); + slot_read_error(s, buf); + continue; + } + khlib_debug("%s: open. in_fd: %d\n", s->in_fifo, s->in_fd); + if (s->in_fd > maxfd) + maxfd = s->in_fd; + FD_SET(s->in_fd, &fds); + } + khlib_debug("selecting...\n"); + ready = pselect(maxfd + 1, &fds, NULL, NULL, ti, NULL); + khlib_debug("ready: %d\n", ready); + clock_gettime(CLOCK_MONOTONIC, &t); + if (ready == -1) { + switch (errno) { + case EINTR: + khlib_error( + "pselect temp failure: %d, errno: %d, msg: %s\n", + ready, + errno, + strerror(errno) + ); + /* TODO: Reconsider what to do here. */ + return; + default: + khlib_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 (s = cfg->slots; s; s = s->next) { + if (FD_ISSET(s->in_fd, &fds)) { + khlib_debug("reading: %s\n", s->in_fifo); + switch (slot_read(s, 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(s->in_fd); + s->in_fd = -1; + ready--; + break; + case RETRY: + break; + default: + assert(0); + } + } else { + slot_expire(s, t, buf); + } + } + } while (ready); + assert(ready == 0); +} + void config_print(Config *cfg) { @@ -334,203 +531,6 @@ opts_parse(Config *cfg, int argc, char *argv[]) cfg->slots = slots_rev(cfg->slots); } -void -slot_expire(Slot *s, struct timespec t, char *buf) -{ - struct timespec td; - - timespecsub(&t, &(s->in_last_read), &td); - if (timespeccmp(&td, &(s->out_ttl), >=)) { - /* TODO: Maybe configurable expiry character. */ - memset(buf + s->out_pos_lo, '_', s->out_pos_hi - s->out_pos_lo); - khlib_warn("Slot expired: \"%s\"\n", s->in_fifo); - } -} - -void -slot_read_error(Slot *s, char *buf) -{ - char *b; - int i; - - b = buf + s->out_pos_lo; - /* Copy as much of the error message as possible. - * EXCLUDING the terminating \0. */ - for (i = 0; i < errlen && i < s->out_width; i++) - b[i] = errmsg[i]; - /* Any remaining positions: */ - for (; i < s->out_width; i++) - b[i] = '_'; -} - -enum read_status -slot_read(Slot *s, struct timespec t, char *buf) -{ - char c; /* Character read. */ - int r; /* Remaining unused positions in buffer range. */ - - for (;;) { - switch (read(s->in_fd, &c, 1)) { - case -1: - khlib_error( - "Failed to read: \"%s\". errno: %d, msg: %s\n", - s->in_fifo, - errno, - strerror(errno) - ); - switch (errno) { - case EINTR: - case EAGAIN: - return RETRY; - default: - return FAILURE; - } - case 0: - khlib_debug("%s: End of FILE\n", s->in_fifo); - s->out_pos_cur = s->out_pos_lo; - return END_OF_FILE; - case 1: - /* TODO: Consider making msg term char a CLI option */ - if (c == '\n' || c == '\0') { - r = s->out_pos_hi - s->out_pos_cur; - if (r > 0) - memset(buf + s->out_pos_cur, ' ', r); - s->out_pos_cur = s->out_pos_lo; - s->in_last_read = t; - return END_OF_MESSAGE; - } else { - if (s->out_pos_cur <= s->out_pos_hi) - buf[s->out_pos_cur++] = 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 -slots_read(Config *cfg, struct timespec *ti, char *buf) -{ - fd_set fds; - int maxfd = -1; - int ready = 0; - struct stat st; - struct timespec t; - Slot *s; - - FD_ZERO(&fds); - for (s = cfg->slots; s; s = s->next) { - /* TODO: Create the FIFO if it doesn't already exist. */ - if (lstat(s->in_fifo, &st) < 0) { - khlib_error( - "Cannot stat \"%s\". Error: %s\n", - s->in_fifo, - strerror(errno) - ); - slot_read_error(s, buf); - continue; - } - if (!(st.st_mode & S_IFIFO)) { - khlib_error("\"%s\" is not a FIFO\n", s->in_fifo); - slot_read_error(s, buf); - continue; - } - if (s->in_fd < 0) { - khlib_debug( - "%s: closed. opening. in_fd: %d\n", - s->in_fifo, - s->in_fd - ); - s->in_fd = open(s->in_fifo, O_RDONLY | O_NONBLOCK); - } else { - khlib_debug( - "%s: already openned. in_fd: %d\n", - s->in_fifo, - s->in_fd - ); - } - if (s->in_fd == -1) { - /* TODO Consider backing off retries for failed slots */ - khlib_error("Failed to open \"%s\"\n", s->in_fifo); - slot_read_error(s, buf); - continue; - } - khlib_debug("%s: open. in_fd: %d\n", s->in_fifo, s->in_fd); - if (s->in_fd > maxfd) - maxfd = s->in_fd; - FD_SET(s->in_fd, &fds); - } - khlib_debug("selecting...\n"); - ready = pselect(maxfd + 1, &fds, NULL, NULL, ti, NULL); - khlib_debug("ready: %d\n", ready); - clock_gettime(CLOCK_MONOTONIC, &t); - if (ready == -1) { - switch (errno) { - case EINTR: - khlib_error( - "pselect temp failure: %d, errno: %d, msg: %s\n", - ready, - errno, - strerror(errno) - ); - /* TODO: Reconsider what to do here. */ - return; - default: - khlib_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 (s = cfg->slots; s; s = s->next) { - if (FD_ISSET(s->in_fd, &fds)) { - khlib_debug("reading: %s\n", s->in_fifo); - switch (slot_read(s, 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(s->in_fd); - s->in_fd = -1; - ready--; - break; - case RETRY: - break; - default: - assert(0); - } - } else { - slot_expire(s, t, buf); - } - } - } while (ready); - assert(ready == 0); -} - int main(int argc, char *argv[]) { -- 2.20.1