From: Siraaj Khandkar <siraaj@khandkar.net>
Date: Thu, 26 Mar 2020 19:48:30 +0000 (-0400)
Subject: Co-locate all slot functions
X-Git-Url: https://git.xandkar.net/?a=commitdiff_plain;h=4bfac488ba99787df53cf6b8627b0192921309cf;p=khatus.git

Co-locate all slot functions
---

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[])
 {