diff options
Diffstat (limited to 'src/bar.c')
-rw-r--r-- | src/bar.c | 193 |
1 files changed, 93 insertions, 100 deletions
@@ -1,37 +1,48 @@ // Copyright © Tavian Barnes <tavianator@tavianator.com> // SPDX-License-Identifier: 0BSD -#include "prelude.h" #include "bar.h" + +#include "alloc.h" #include "atomic.h" +#include "bfs.h" #include "bfstd.h" #include "bit.h" #include "dstring.h" +#include "sighook.h" + #include <errno.h> #include <fcntl.h> #include <signal.h> #include <stdarg.h> #include <stdio.h> +#include <stdlib.h> #include <string.h> #include <sys/ioctl.h> +#include <termios.h> +#include <unistd.h> struct bfs_bar { int fd; atomic unsigned int width; atomic unsigned int height; -}; -/** The global status bar instance. */ -static struct bfs_bar the_bar = { - .fd = -1, + struct sighook *exit_hook; + struct sighook *winch_hook; }; /** Get the terminal size, if possible. */ static int bfs_bar_getsize(struct bfs_bar *bar) { -#ifdef TIOCGWINSZ +#if BFS_HAS_TCGETWINSIZE || defined(TIOCGWINSZ) struct winsize ws; - if (ioctl(bar->fd, TIOCGWINSZ, &ws) != 0) { - return -1; + +# if BFS_HAS_TCGETWINSIZE + int ret = tcgetwinsize(bar->fd, &ws); +# else + int ret = ioctl(bar->fd, TIOCGWINSZ, &ws); +# endif + if (ret != 0) { + return ret; } store(&bar->width, ws.ws_col, relaxed); @@ -43,10 +54,14 @@ static int bfs_bar_getsize(struct bfs_bar *bar) { #endif } -/** Async Signal Safe puts(). */ -static int ass_puts(int fd, const char *str) { - size_t len = strlen(str); - return xwrite(fd, str, len) == len ? 0 : -1; +/** Write a string to the status bar (async-signal-safe). */ +static int bfs_bar_write(struct bfs_bar *bar, const char *str, size_t len) { + return xwrite(bar->fd, str, len) == len ? 0 : -1; +} + +/** Write a string to the status bar (async-signal-safe). */ +static int bfs_bar_puts(struct bfs_bar *bar, const char *str) { + return bfs_bar_write(bar, str, strlen(str)); } /** Number of decimal digits needed for terminal sizes. */ @@ -68,66 +83,63 @@ static char *ass_itoa(char *str, unsigned int n) { return str + len; } +/** Reset the scrollable region and hide the bar. */ +static int bfs_bar_reset(struct bfs_bar *bar) { + return bfs_bar_puts(bar, + "\0337" // DECSC: Save cursor + "\033[r" // DECSTBM: Reset scrollable region + "\0338" // DECRC: Restore cursor + "\033[J" // ED: Erase display from cursor to end + ); +} + +/** Hide the bar if the terminal is shorter than this. */ +#define BFS_BAR_MIN_HEIGHT 3 + /** Update the size of the scrollable region. */ static int bfs_bar_resize(struct bfs_bar *bar) { - char esc_seq[12 + ITOA_DIGITS] = + unsigned int height = load(&bar->height, relaxed); + if (height < BFS_BAR_MIN_HEIGHT) { + return bfs_bar_reset(bar); + } + + static const char PREFIX[] = + "\033D" // IND: Line feed, possibly scrolling + "\033[1A" // CUU: Move cursor up 1 row "\0337" // DECSC: Save cursor "\033[;"; // DECSTBM: Set scrollable region + static const char SUFFIX[] = + "r" // (end of DECSTBM) + "\0338" // DECRC: Restore the cursor + "\033[J"; // ED: Erase display from cursor to end - // DECSTBM takes the height as the second argument - unsigned int height = load(&bar->height, relaxed); - char *ptr = esc_seq + strlen(esc_seq); - ptr = ass_itoa(ptr, height - 1); + char esc_seq[sizeof(PREFIX) + ITOA_DIGITS + sizeof(SUFFIX)]; - strcpy(ptr, - "r" // DECSTBM - "\0338" // DECRC: Restore the cursor - "\033[J" // ED: Erase display from cursor to end - ); + // DECSTBM takes the height as the second argument + char *cur = stpcpy(esc_seq, PREFIX); + cur = ass_itoa(cur, height - 1); + cur = stpcpy(cur, SUFFIX); - return ass_puts(bar->fd, esc_seq); + return bfs_bar_write(bar, esc_seq, cur - esc_seq); } #ifdef SIGWINCH /** SIGWINCH handler. */ -static void sighand_winch(int sig) { - int error = errno; - - bfs_bar_getsize(&the_bar); - bfs_bar_resize(&the_bar); - - errno = error; +static void bfs_bar_sigwinch(int sig, siginfo_t *info, void *arg) { + struct bfs_bar *bar = arg; + bfs_bar_getsize(bar); + bfs_bar_resize(bar); } #endif -/** Reset the scrollable region and hide the bar. */ -static int bfs_bar_reset(struct bfs_bar *bar) { - return ass_puts(bar->fd, - "\0337" // DECSC: Save cursor - "\033[r" // DECSTBM: Reset scrollable region - "\0338" // DECRC: Restore cursor - "\033[J" // ED: Erase display from cursor to end - ); -} - /** Signal handler for process-terminating signals. */ -static void sighand_reset(int sig) { - bfs_bar_reset(&the_bar); - raise(sig); -} - -/** Register sighand_reset() for a signal. */ -static void reset_before_death_by(int sig) { - struct sigaction sa = { - .sa_handler = sighand_reset, - .sa_flags = SA_RESETHAND, - }; - sigemptyset(&sa.sa_mask); - sigaction(sig, &sa, NULL); +static void bfs_bar_sigexit(int sig, siginfo_t *info, void *arg) { + struct bfs_bar *bar = arg; + bfs_bar_reset(bar); } /** printf() to the status bar with a single write(). */ -attr(printf(2, 3)) +_printf(2, 3) static int bfs_bar_printf(struct bfs_bar *bar, const char *format, ...) { va_list args; va_start(args, format); @@ -138,64 +150,47 @@ static int bfs_bar_printf(struct bfs_bar *bar, const char *format, ...) { return -1; } - int ret = ass_puts(bar->fd, str); + int ret = bfs_bar_write(bar, str, dstrlen(str)); dstrfree(str); return ret; } struct bfs_bar *bfs_bar_show(void) { - if (the_bar.fd >= 0) { - errno = EBUSY; - goto fail; + struct bfs_bar *bar = ALLOC(struct bfs_bar); + if (!bar) { + return NULL; } - char term[L_ctermid]; - ctermid(term); - if (strlen(term) == 0) { - errno = ENOTTY; + bar->fd = open_cterm(O_RDWR | O_CLOEXEC); + if (bar->fd < 0) { goto fail; } - the_bar.fd = open(term, O_RDWR | O_CLOEXEC); - if (the_bar.fd < 0) { - goto fail; + if (bfs_bar_getsize(bar) != 0) { + goto fail_close; } - if (bfs_bar_getsize(&the_bar) != 0) { + bar->exit_hook = atsigexit(bfs_bar_sigexit, bar); + if (!bar->exit_hook) { goto fail_close; } - reset_before_death_by(SIGABRT); - reset_before_death_by(SIGINT); - reset_before_death_by(SIGPIPE); - reset_before_death_by(SIGQUIT); - reset_before_death_by(SIGTERM); - #ifdef SIGWINCH - struct sigaction sa = { - .sa_handler = sighand_winch, - .sa_flags = SA_RESTART, - }; - sigemptyset(&sa.sa_mask); - sigaction(SIGWINCH, &sa, NULL); + bar->winch_hook = sighook(SIGWINCH, bfs_bar_sigwinch, bar, 0); + if (!bar->winch_hook) { + goto fail_hook; + } #endif - unsigned int height = load(&the_bar.height, relaxed); - bfs_bar_printf(&the_bar, - "\n" // Make space for the bar - "\0337" // DECSC: Save cursor - "\033[;%ur" // DECSTBM: Set scrollable region - "\0338" // DECRC: Restore cursor - "\033[1A", // CUU: Move cursor up 1 row - height - 1 - ); - - return &the_bar; + bfs_bar_resize(bar); + return bar; +fail_hook: + sigunhook(bar->exit_hook); fail_close: - close_quietly(the_bar.fd); - the_bar.fd = -1; + close_quietly(bar->fd); fail: + free(bar); return NULL; } @@ -205,6 +200,10 @@ unsigned int bfs_bar_width(const struct bfs_bar *bar) { int bfs_bar_update(struct bfs_bar *bar, const char *str) { unsigned int height = load(&bar->height, relaxed); + if (height < BFS_BAR_MIN_HEIGHT) { + return 0; + } + return bfs_bar_printf(bar, "\0337" // DECSC: Save cursor "\033[%u;0f" // HVP: Move cursor to row, column @@ -223,17 +222,11 @@ void bfs_bar_hide(struct bfs_bar *bar) { return; } - signal(SIGABRT, SIG_DFL); - signal(SIGINT, SIG_DFL); - signal(SIGPIPE, SIG_DFL); - signal(SIGQUIT, SIG_DFL); - signal(SIGTERM, SIG_DFL); -#ifdef SIGWINCH - signal(SIGWINCH, SIG_DFL); -#endif + sigunhook(bar->winch_hook); + sigunhook(bar->exit_hook); bfs_bar_reset(bar); xclose(bar->fd); - bar->fd = -1; + free(bar); } |