Slightly optimize very large directories

Cumulatively 10% of user time, give or take.

These are mainly pointless multibyte to wide string conversions.

The hit to source code readibility is minimal.
This commit is contained in:
Přemysl Eric Janouch 2021-10-05 20:15:52 +02:00
parent 0d10ae06e6
commit 536aa57761
Signed by: p
GPG Key ID: A0420B94F92B9493
1 changed files with 17 additions and 16 deletions

33
sdn.cpp
View File

@ -318,9 +318,9 @@ fun invert (cchar_t &ch) {
}
fun apply_attrs (const wstring &w, attr_t attrs) -> ncstring {
ncstring res;
for (auto c : w)
res += cchar (attrs, c);
ncstring res (w.size (), cchar_t {});
for (size_t i = 0; i < w.size (); i++)
res[i] = cchar (attrs, w[i]);
return res;
}
@ -557,8 +557,8 @@ static struct {
// Refreshed by reload():
map<uid_t, string> unames; ///< User names by UID
map<gid_t, string> gnames; ///< Group names by GID
map<uid_t, wstring> unames; ///< User names by UID
map<gid_t, wstring> gnames; ///< Group names by GID
struct tm now; ///< Current local time for display
} g;
@ -674,12 +674,12 @@ fun make_entry (const struct dirent *f) -> entry {
auto usr = g.unames.find (info.st_uid);
e.cols[entry::USER] = (usr != g.unames.end ())
? apply_attrs (to_wide (usr->second), 0)
? apply_attrs (usr->second, 0)
: apply_attrs (to_wstring (info.st_uid), 0);
auto grp = g.gnames.find (info.st_gid);
e.cols[entry::GROUP] = (grp != g.gnames.end ())
? apply_attrs (to_wide (grp->second), 0)
? apply_attrs (grp->second, 0)
: apply_attrs (to_wstring (info.st_gid), 0);
auto size = to_wstring (info.st_size);
@ -689,16 +689,16 @@ fun make_entry (const struct dirent *f) -> entry {
else if (info.st_size >> 10) size = to_wstring (info.st_size >> 10) + L"K";
e.cols[entry::SIZE] = apply_attrs (size, 0);
char buf[32] = "";
wchar_t buf[32] = L"";
auto tm = localtime (&info.st_mtime);
strftime (buf, sizeof buf,
(tm->tm_year == g.now.tm_year) ? "%b %e %H:%M" : "%b %e %Y", tm);
e.cols[entry::MTIME] = apply_attrs (to_wide (buf), 0);
wcsftime (buf, sizeof buf / sizeof *buf,
(tm->tm_year == g.now.tm_year) ? L"%b %e %H:%M" : L"%b %e %Y", tm);
e.cols[entry::MTIME] = apply_attrs (buf, 0);
auto &fn = e.cols[entry::FILENAME] =
apply_attrs (to_wide (e.filename), ls_format (e, false));
if (!e.target_path.empty ()) {
fn.append (apply_attrs (to_wide (" -> "), 0));
fn.append (apply_attrs (L" -> ", 0));
fn.append (apply_attrs (to_wide (e.target_path), ls_format (e, true)));
}
return e;
@ -784,9 +784,10 @@ fun update () {
}
fun operator< (const entry &e1, const entry &e2) -> bool {
auto t1 = make_tuple (e1.filename != "..",
static string dotdot {".."};
auto t1 = make_tuple (e1.filename != dotdot,
!S_ISDIR (e1.info.st_mode) && !S_ISDIR (e1.target_info.st_mode));
auto t2 = make_tuple (e2.filename != "..",
auto t2 = make_tuple (e2.filename != dotdot,
!S_ISDIR (e2.info.st_mode) && !S_ISDIR (e2.target_info.st_mode));
if (t1 != t2)
return t1 < t2;
@ -835,12 +836,12 @@ fun resort (const string anchor = at_cursor ().filename) {
fun reload (bool keep_anchor) {
g.unames.clear();
while (auto *ent = getpwent ())
g.unames.emplace (ent->pw_uid, ent->pw_name);
g.unames.emplace (ent->pw_uid, to_wide (ent->pw_name));
endpwent();
g.gnames.clear();
while (auto *ent = getgrent ())
g.gnames.emplace (ent->gr_gid, ent->gr_name);
g.gnames.emplace (ent->gr_gid, to_wide (ent->gr_name));
endgrent();
string anchor;