diff options
author | Max Kellermann <max@musicpd.org> | 2018-01-29 12:02:14 +0100 |
---|---|---|
committer | Max Kellermann <max@musicpd.org> | 2018-01-30 00:05:57 +0100 |
commit | ce2b6dc84d2e62cb4686b052613af383c8f620e1 (patch) | |
tree | de2b924d2a671074bb3448baffde6fa57b3e8324 /src/RemoteTagCache.cxx | |
parent | 7d16d8c8871b628244c5110103c7220940092462 (diff) |
RemoteTagCache: new glue class for integrating RemoteTagScanner
This commit also puts an instance of RemoteTagScanner into the
Instance class, and hooks it into the "add" and "addid" commands.
Diffstat (limited to 'src/RemoteTagCache.cxx')
-rw-r--r-- | src/RemoteTagCache.cxx | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/src/RemoteTagCache.cxx b/src/RemoteTagCache.cxx new file mode 100644 index 000000000..ec0c5d0ba --- /dev/null +++ b/src/RemoteTagCache.cxx @@ -0,0 +1,140 @@ +/* + * Copyright 2003-2018 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 "RemoteTagCache.hxx" +#include "RemoteTagCacheHandler.hxx" +#include "input/ScanTags.hxx" +#include "util/DeleteDisposer.hxx" +#include "Log.hxx" + +RemoteTagCache::RemoteTagCache(EventLoop &event_loop, + RemoteTagCacheHandler &_handler) noexcept + :handler(_handler), + defer_invoke_handler(event_loop, BIND_THIS_METHOD(InvokeHandlers)), + map(typename KeyMap::bucket_traits(&buckets.front(), buckets.size())) +{ +} + +RemoteTagCache::~RemoteTagCache() noexcept +{ + map.clear_and_dispose(DeleteDisposer()); +} + +void +RemoteTagCache::Lookup(const std::string &uri) noexcept +{ + std::unique_lock<Mutex> lock(mutex); + + KeyMap::insert_commit_data hint; + auto result = map.insert_check(uri, Item::Hash(), Item::Equal(), hint); + if (result.second) { + auto *item = new Item(*this, uri); + map.insert_commit(*item, hint); + waiting_list.push_back(*item); + lock.unlock(); + + try { + item->scanner = InputScanTags(uri.c_str(), *item); + if (!item->scanner) { + /* unsupported */ + lock.lock(); + ItemResolved(*item); + return; + } + + item->scanner->Start(); + } catch (...) { + FormatError(std::current_exception(), + "Failed to scan tags of '%s'", + uri.c_str()); + + item->scanner.reset(); + + lock.lock(); + ItemResolved(*item); + return; + } + } else if (result.first->scanner) { + /* already scanning this one - no-op */ + } else { + /* already finished: re-invoke the handler */ + + auto &item = *result.first; + + idle_list.erase(waiting_list.iterator_to(item)); + invoke_list.push_back(item); + + ScheduleInvokeHandlers(); + } +} + +void +RemoteTagCache::ItemResolved(Item &item) noexcept +{ + waiting_list.erase(waiting_list.iterator_to(item)); + invoke_list.push_back(item); + + ScheduleInvokeHandlers(); +} + +void +RemoteTagCache::InvokeHandlers() noexcept +{ + const std::lock_guard<Mutex> lock(mutex); + + while (!invoke_list.empty()) { + auto &item = invoke_list.front(); + invoke_list.pop_front(); + idle_list.push_back(item); + + const ScopeUnlock unlock(mutex); + handler.OnRemoteTag(item.uri.c_str(), item.tag); + } + + /* evict items if there are too many */ + while (map.size() > MAX_SIZE && !idle_list.empty()) { + auto *item = &idle_list.front(); + idle_list.pop_front(); + map.erase(map.iterator_to(*item)); + delete item; + } +} + +void +RemoteTagCache::Item::OnRemoteTag(Tag &&_tag) noexcept +{ + tag = std::move(_tag); + + scanner.reset(); + + const std::lock_guard<Mutex> lock(parent.mutex); + parent.ItemResolved(*this); +} + +void +RemoteTagCache::Item::OnRemoteTagError(std::exception_ptr e) noexcept +{ + FormatError(e, "Failed to scan tags of '%s'", uri.c_str()); + + scanner.reset(); + + const std::lock_guard<Mutex> lock(parent.mutex); + parent.ItemResolved(*this); +} |