mpd/src/tag/IcyMetaDataParser.hxx
2023-12-21 08:42:23 +01:00

89 lines
1.9 KiB
C++

// SPDX-License-Identifier: GPL-2.0-or-later
// Copyright The Music Player Daemon Project
#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>
#include <span>
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
* "src.size()", the caller should invoke Data().
*/
std::size_t Meta(std::span<const std::byte> src) noexcept;
/**
* Parse data and eliminate metadata.
*
* @return the number of data bytes remaining in the buffer
*/
size_t ParseInPlace(std::span<std::byte> buffer) noexcept;
std::unique_ptr<Tag> ReadTag() noexcept {
return std::exchange(tag, nullptr);
}
};
#endif