[pacman-dev] [PATCH 2/2] cache terminal size, add SIGWINCH handler to reset
Dave Reisner
dreisner at archlinux.org
Tue Jun 24 16:32:32 EDT 2014
Refactoring getcols, yet again. We do the following:
1) Introduce a static global in src/pacman/util.c
2) getcols always prefers this cached value, but will derive it from
the COLUMNS environment var, the characteristics of stdout, or a sane
default (in that order).
3) Introduce a SIGWINCH signal handler to reset the cached value,
meaning we only call ioctl when we don't know the value.
On my machine, pacman -Syy goes from ~4300 ioctl calls to 3.
---
src/pacman/callback.c | 6 +++---
src/pacman/package.c | 4 ++--
src/pacman/pacman.c | 5 ++++-
src/pacman/util.c | 59 +++++++++++++++++++++++++++++++++++++--------------
src/pacman/util.h | 3 ++-
5 files changed, 54 insertions(+), 23 deletions(-)
diff --git a/src/pacman/callback.c b/src/pacman/callback.c
index 9cde1de..6be20ec 100644
--- a/src/pacman/callback.c
+++ b/src/pacman/callback.c
@@ -424,7 +424,7 @@ void cb_question(alpm_question_t *question)
"The following package cannot be upgraded due to unresolvable dependencies:\n",
"The following packages cannot be upgraded due to unresolvable dependencies:\n",
count));
- list_display(" ", namelist, getcols(fileno(stdout)));
+ list_display(" ", namelist, getcols());
printf("\n");
q->skip = noyes(_n(
"Do you want to skip the above package for this upgrade?",
@@ -494,7 +494,7 @@ void cb_progress(alpm_progress_t event, const char *pkgname, int percent,
int len, wclen, wcwid, padwid;
wchar_t *wcstr;
- const unsigned short cols = getcols(fileno(stdout));
+ const unsigned short cols = getcols();
if(config->noprogressbar || cols == 0) {
return;
@@ -664,7 +664,7 @@ void cb_dl_progress(const char *filename, off_t file_xfered, off_t file_total)
const char *rate_label, *xfered_label;
int file_percent = 0, total_percent = 0;
- const unsigned short cols = getcols(fileno(stdout));
+ const unsigned short cols = getcols();
if(config->noprogressbar || cols == 0 || file_total == -1) {
if(file_xfered == 0) {
diff --git a/src/pacman/package.c b/src/pacman/package.c
index 3be996d..1ac0fca 100644
--- a/src/pacman/package.c
+++ b/src/pacman/package.c
@@ -140,7 +140,7 @@ void dump_pkg_full(alpm_pkg_t *pkg, int extra)
optionalfor = alpm_pkg_compute_optionalfor(pkg);
}
- cols = getcols(fileno(stdout));
+ cols = getcols();
/* actual output */
if(from == ALPM_PKG_FROM_SYNCDB) {
@@ -404,7 +404,7 @@ int dump_pkg_search(alpm_db_t *db, alpm_list_t *targets, int show_status)
return 1;
}
- cols = getcols(fileno(stdout));
+ cols = getcols();
for(i = searchlist; i; i = alpm_list_next(i)) {
alpm_list_t *grp;
alpm_pkg_t *pkg = i->data;
diff --git a/src/pacman/pacman.c b/src/pacman/pacman.c
index e8c5f9e..ec200a9 100644
--- a/src/pacman/pacman.c
+++ b/src/pacman/pacman.c
@@ -312,6 +312,9 @@ static void handler(int signum)
/* a transaction is being interrupted, don't exit pacman yet. */
return;
}
+ } else if(signum == SIGWINCH) {
+ columns_cache_reset();
+ return;
}
/* SIGINT/SIGHUP: no committing transaction, release it now and then exit pacman
* SIGTERM: release no matter what */
@@ -1019,7 +1022,7 @@ int main(int argc, char *argv[])
int ret = 0;
size_t i;
struct sigaction new_action, old_action;
- const int signals[] = { SIGHUP, SIGINT, SIGTERM, SIGSEGV };
+ const int signals[] = { SIGHUP, SIGINT, SIGTERM, SIGSEGV, SIGWINCH };
uid_t myuid = getuid();
/* Set signal handlers */
diff --git a/src/pacman/util.c b/src/pacman/util.c
index ebf15db..9244870 100644
--- a/src/pacman/util.c
+++ b/src/pacman/util.c
@@ -46,6 +46,7 @@
#include "conf.h"
#include "callback.h"
+static int cached_columns = 0;
struct table_cell_t {
char *label;
@@ -155,29 +156,55 @@ static int flush_term_input(int fd)
return 0;
}
-/* gets the current screen column width */
-unsigned short getcols(int fd)
-{
- const unsigned short default_tty = 80;
- const unsigned short default_notty = 0;
- unsigned short termwidth = 0;
+void columns_cache_reset() {
+ cached_columns = 0;
+}
- if(!isatty(fd)) {
- return default_notty;
- }
+static int getcols_fd(int fd) {
+ int width = -1;
#if defined(TIOCGSIZE)
struct ttysize win;
if(ioctl(fd, TIOCGSIZE, &win) == 0) {
- termwidth = win.ts_cols;
+ width = win.ts_cols;
}
#elif defined(TIOCGWINSZ)
struct winsize win;
if(ioctl(fd, TIOCGWINSZ, &win) == 0) {
- termwidth = win.ws_col;
+ width = win.ws_col;
}
#endif
- return termwidth == 0 ? default_tty : termwidth;
+
+ if(width <= 0) {
+ return -EIO;
+ }
+
+ return width;
+}
+
+unsigned short getcols(void) {
+ const char *e;
+ int c = 0;
+
+ if(cached_columns > 0) {
+ return cached_columns;
+ }
+
+ e = getenv("COLUMNS");
+ if(e) {
+ c = strtol(e, NULL, 10);
+ }
+
+ if(c <= 0) {
+ c = getcols_fd(STDOUT_FILENO);
+ }
+
+ if(c <= 0) {
+ c = 80;
+ }
+
+ cached_columns = c;
+ return c;
}
/* does the same thing as 'rm -rf' */
@@ -892,7 +919,7 @@ static void _display_targets(alpm_list_t *targets, int verbose)
pm_asprintf(&str, "%s (%zd)", _("Packages"), alpm_list_count(targets));
printf("\n");
- cols = getcols(fileno(stdout));
+ cols = getcols();
if(verbose) {
header = create_verbose_header(alpm_list_count(targets));
if(table_display(header, rows, cols) != 0) {
@@ -1196,7 +1223,7 @@ void display_new_optdepends(alpm_pkg_t *oldpkg, alpm_pkg_t *newpkg)
if(optstrings) {
printf(_("New optional dependencies for %s\n"), alpm_pkg_get_name(newpkg));
- unsigned short cols = getcols(fileno(stdout));
+ unsigned short cols = getcols();
list_display_linebreak(" ", optstrings, cols);
}
@@ -1218,7 +1245,7 @@ void display_optdepends(alpm_pkg_t *pkg)
if(optstrings) {
printf(_("Optional dependencies for %s\n"), alpm_pkg_get_name(pkg));
- unsigned short cols = getcols(fileno(stdout));
+ unsigned short cols = getcols();
list_display_linebreak(" ", optstrings, cols);
}
@@ -1241,7 +1268,7 @@ void select_display(const alpm_list_t *pkglist)
alpm_list_t *list = NULL;
char *string = NULL;
const char *dbname = NULL;
- unsigned short cols = getcols(fileno(stdout));
+ unsigned short cols = getcols();
for(i = pkglist; i; i = i->next) {
alpm_pkg_t *pkg = i->data;
diff --git a/src/pacman/util.h b/src/pacman/util.h
index 4a31e89..b591fba 100644
--- a/src/pacman/util.h
+++ b/src/pacman/util.h
@@ -49,7 +49,8 @@ int trans_init(alpm_transflag_t flags, int check_valid);
int trans_release(void);
int needs_root(void);
int check_syncdbs(size_t need_repos, int check_valid);
-unsigned short getcols(int fd);
+unsigned short getcols(void);
+void columns_cache_reset(void);
int rmrf(const char *path);
void indentprint(const char *str, unsigned short indent, unsigned short cols);
size_t strtrim(char *str);
--
2.0.0
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