mpd/src/StateFile.cxx

143 lines
3.3 KiB
C++

// SPDX-License-Identifier: GPL-2.0-or-later
// Copyright The Music Player Daemon Project
#include "config.h"
#include "StateFile.hxx"
#include "output/State.hxx"
#include "queue/PlaylistState.hxx"
#include "io/FileLineReader.hxx"
#include "io/FileOutputStream.hxx"
#include "io/BufferedOutputStream.hxx"
#include "storage/StorageState.hxx"
#include "Partition.hxx"
#include "Instance.hxx"
#include "SongLoader.hxx"
#include "util/Domain.hxx"
#include "Log.hxx"
#include <exception>
static constexpr Domain state_file_domain("state_file");
StateFile::StateFile(StateFileConfig &&_config,
Partition &_partition, EventLoop &_loop)
:config(std::move(_config)), path_utf8(config.path.ToUTF8()),
timer_event(_loop, BIND_THIS_METHOD(OnTimeout)),
partition(_partition)
{
}
void
StateFile::RememberVersions() noexcept
{
prev_volume_version = partition.mixer_memento.GetSoftwareVolumeStateHash();
prev_output_version = audio_output_state_get_version();
prev_playlist_version = playlist_state_get_hash(partition.playlist,
partition.pc);
#ifdef ENABLE_DATABASE
prev_storage_version = storage_state_get_hash(partition.instance);
#endif
}
bool
StateFile::IsModified() const noexcept
{
return prev_volume_version != partition.mixer_memento.GetSoftwareVolumeStateHash() ||
prev_output_version != audio_output_state_get_version() ||
prev_playlist_version != playlist_state_get_hash(partition.playlist,
partition.pc)
#ifdef ENABLE_DATABASE
|| prev_storage_version != storage_state_get_hash(partition.instance)
#endif
;
}
inline void
StateFile::Write(BufferedOutputStream &os)
{
partition.mixer_memento.SaveSoftwareVolumeState(os);
audio_output_state_save(os, partition.outputs);
#ifdef ENABLE_DATABASE
storage_state_save(os, partition.instance);
#endif
playlist_state_save(os, partition.playlist, partition.pc);
}
inline void
StateFile::Write(OutputStream &os)
{
BufferedOutputStream bos(os);
Write(bos);
bos.Flush();
}
void
StateFile::Write()
{
FmtDebug(state_file_domain,
"Saving state file {}", path_utf8);
try {
FileOutputStream fos(config.path);
Write(fos);
fos.Commit();
} catch (...) {
LogError(std::current_exception());
}
RememberVersions();
}
void
StateFile::Read()
try {
bool success;
FmtDebug(state_file_domain, "Loading state file {}", path_utf8);
FileLineReader file{config.path};
#ifdef ENABLE_DATABASE
const SongLoader song_loader(partition.instance.GetDatabase(),
partition.instance.storage);
#else
const SongLoader song_loader(nullptr, nullptr);
#endif
const char *line;
while ((line = file.ReadLine()) != nullptr) {
success = partition.mixer_memento.LoadSoftwareVolumeState(line, partition.outputs) ||
audio_output_state_read(line, partition.outputs) ||
playlist_state_restore(config, line, file, song_loader,
partition.playlist,
partition.pc);
#ifdef ENABLE_DATABASE
success = success || storage_state_restore(line, file, partition.instance);
#endif
if (!success)
FmtError(state_file_domain,
"Unrecognized line in state file: {}",
line);
}
RememberVersions();
} catch (...) {
LogError(std::current_exception());
}
void
StateFile::CheckModified() noexcept
{
if (!timer_event.IsPending() && IsModified())
timer_event.Schedule(config.interval);
}
void
StateFile::OnTimeout() noexcept
{
Write();
}