mpd/src/db/update/InotifyQueue.cxx
2017-01-03 20:48:59 +01:00

92 lines
2.3 KiB
C++

/*
* Copyright 2003-2017 The Music Player Daemon Project
* http://www.musicpd.org
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "config.h"
#include "InotifyQueue.hxx"
#include "InotifyDomain.hxx"
#include "Service.hxx"
#include "Log.hxx"
#include "util/StringCompare.hxx"
/**
* Wait this long after the last change before calling
* update_enqueue(). This increases the probability that updates can
* be bundled.
*/
static constexpr std::chrono::steady_clock::duration INOTIFY_UPDATE_DELAY =
std::chrono::seconds(5);
void
InotifyQueue::OnTimeout()
{
unsigned id;
while (!queue.empty()) {
const char *uri_utf8 = queue.front().c_str();
id = update.Enqueue(uri_utf8, false);
if (id == 0) {
/* retry later */
Schedule(INOTIFY_UPDATE_DELAY);
return;
}
FormatDebug(inotify_domain, "updating '%s' job=%u",
uri_utf8, id);
queue.pop_front();
}
}
gcc_pure
static bool
path_in(const char *path, const char *possible_parent)
{
if (StringIsEmpty(path))
return true;
auto rest = StringAfterPrefix(path, possible_parent);
return rest != nullptr &&
(StringIsEmpty(rest) || rest[0] == '/');
}
void
InotifyQueue::Enqueue(const char *uri_utf8)
{
Schedule(INOTIFY_UPDATE_DELAY);
for (auto i = queue.begin(), end = queue.end(); i != end;) {
const char *current_uri = i->c_str();
if (path_in(uri_utf8, current_uri))
/* already enqueued */
return;
if (path_in(current_uri, uri_utf8))
/* existing path is a sub-path of the new
path; we can dequeue the existing path and
update the new path instead */
i = queue.erase(i);
else
++i;
}
queue.emplace_back(uri_utf8);
}