mpd/src/TagFile.cxx

116 lines
2.8 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 "TagFile.hxx"
#include "tag/Generic.hxx"
#include "tag/Handler.hxx"
#include "tag/Builder.hxx"
#include "fs/Path.hxx"
#include "decoder/DecoderList.hxx"
#include "decoder/DecoderPlugin.hxx"
#include "input/InputStream.hxx"
#include "input/LocalOpen.hxx"
#include <exception>
#include <assert.h>
class TagFileScan {
const Path path_fs;
const char *const suffix;
TagHandler &handler;
Mutex mutex;
InputStreamPtr is;
public:
TagFileScan(Path _path_fs, const char *_suffix,
TagHandler &_handler) noexcept
:path_fs(_path_fs), suffix(_suffix),
handler(_handler),
is(nullptr) {}
bool ScanFile(const DecoderPlugin &plugin) noexcept {
return plugin.ScanFile(path_fs, handler);
}
bool ScanStream(const DecoderPlugin &plugin) noexcept {
if (plugin.scan_stream == nullptr)
return false;
/* open the InputStream (if not already open) */
if (is == nullptr) {
try {
is = OpenLocalInputStream(path_fs, mutex);
} catch (...) {
return false;
}
} else {
try {
is->LockRewind();
} catch (...) {
}
}
/* now try the stream_tag() method */
return plugin.ScanStream(*is, handler);
}
bool Scan(const DecoderPlugin &plugin) noexcept {
return plugin.SupportsSuffix(suffix) &&
(ScanFile(plugin) || ScanStream(plugin));
}
};
bool
ScanFileTagsNoGeneric(Path path_fs, TagHandler &handler) noexcept
{
assert(!path_fs.IsNull());
/* check if there's a suffix and a plugin */
const auto *suffix = path_fs.GetSuffix();
if (suffix == nullptr)
return false;
const auto suffix_utf8 = Path::FromFS(suffix).ToUTF8();
TagFileScan tfs(path_fs, suffix_utf8.c_str(), handler);
return decoder_plugins_try([&](const DecoderPlugin &plugin){
return tfs.Scan(plugin);
});
}
bool
ScanFileTagsWithGeneric(Path path, TagBuilder &builder,
AudioFormat *audio_format) noexcept
{
FullTagHandler h(builder, audio_format);
if (!ScanFileTagsNoGeneric(path, h))
return false;
if (builder.empty())
ScanGenericTags(path, h);
return true;
}