mpd/src/IcyMetaDataParser.hxx

104 lines
2.6 KiB
C++

/*
* Copyright 2003-2021 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.
*/
#ifndef MPD_ICY_META_DATA_PARSER_HXX
#define MPD_ICY_META_DATA_PARSER_HXX
#include "lib/icu/Converter.hxx"
#include "tag/Tag.hxx"
#include "config.h"
#include <cstddef>
#include <memory>
class IcyMetaDataParser {
size_t data_size = 0, data_rest;
size_t meta_size, meta_position;
char *meta_data;
#ifdef HAVE_ICU_CONVERTER
std::unique_ptr<IcuConverter> icu_converter;
#endif
std::unique_ptr<Tag> tag;
public:
~IcyMetaDataParser() noexcept {
Reset();
}
#ifdef HAVE_ICU_CONVERTER
/**
* Throws on error.
*/
void SetCharset(const char *charset);
#endif
/**
* Initialize an enabled icy_metadata object with the specified
* data_size (from the icy-metaint HTTP response header).
*/
void Start(size_t _data_size) noexcept {
data_size = data_rest = _data_size;
meta_size = 0;
tag = nullptr;
}
/**
* Resets the icy_metadata. Call this after rewinding the stream.
*/
void Reset() noexcept;
/**
* Checks whether the icy_metadata object is enabled.
*/
bool IsDefined() const noexcept {
return data_size > 0;
}
/**
* Evaluates data. Returns the number of bytes of normal data which
* can be read by the caller, but not more than "length". If the
* return value is smaller than "length", the caller should invoke
* icy_meta().
*/
size_t Data(size_t length) noexcept;
/**
* Reads metadata from the stream. Returns the number of bytes
* consumed. If the return value is smaller than "length", the caller
* should invoke icy_data().
*/
size_t Meta(const void *data, size_t length) noexcept;
/**
* Parse data and eliminate metadata.
*
* @return the number of data bytes remaining in the buffer
*/
size_t ParseInPlace(void *data, size_t length) noexcept;
std::unique_ptr<Tag> ReadTag() noexcept {
return std::exchange(tag, nullptr);
}
};
#endif