oggpage.h

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#ifndef TAG_PARSER_OGGPAGE_H
#define TAG_PARSER_OGGPAGE_H
 
#include "../global.h"
 
#include <cstdint>
#include <iosfwd>
#include <numeric>
#include <vector>
 
namespace TagParser {
 
class TAG_PARSER_EXPORT OggPage {
public:
    OggPage();
    OggPage(std::istream &stream, std::uint64_t startOffset, std::int32_t maxSize);
 
    void parseHeader(std::istream &stream, std::uint64_t startOffset, std::int32_t maxSize);
    static std::uint32_t computeChecksum(std::istream &stream, std::uint64_t startOffset);
    static void updateChecksum(std::iostream &stream, std::uint64_t startOffset);
 
    std::uint64_t startOffset() const;
    std::uint8_t streamStructureVersion() const;
    std::uint8_t headerTypeFlag() const;
    bool isContinued() const;
    bool isFirstpage() const;
    bool isLastPage() const;
    bool isLastSegmentUnconcluded() const;
    std::uint64_t absoluteGranulePosition() const;
    std::uint32_t streamSerialNumber() const;
    bool matchesStreamSerialNumber(std::uint32_t streamSerialNumber) const;
    std::uint32_t sequenceNumber() const;
    std::uint32_t checksum() const;
    std::uint8_t segmentTableSize() const;
    const std::vector<std::uint32_t> &segmentSizes() const;
    std::uint32_t headerSize() const;
    std::uint32_t dataSize() const;
    std::uint32_t totalSize() const;
    std::uint64_t dataOffset(std::vector<std::uint32_t>::size_type segmentIndex = 0) const;
    static std::uint32_t makeSegmentSizeDenotation(std::ostream &stream, std::uint32_t size);
 
private:
    std::uint64_t m_startOffset;
    std::uint8_t m_streamStructureVersion;
    std::uint8_t m_headerTypeFlag;
    std::uint64_t m_absoluteGranulePosition;
    std::uint32_t m_streamSerialNumber;
    std::uint32_t m_sequenceNumber;
    std::uint32_t m_checksum;
    std::uint8_t m_segmentCount;
    bool m_lastSegmentUnconcluded;
    std::vector<std::uint32_t> m_segmentSizes;
};
 
inline OggPage::OggPage()
    : m_startOffset(0)
    , m_streamStructureVersion(0)
    , m_headerTypeFlag(0)
    , m_absoluteGranulePosition(0)
    , m_streamSerialNumber(0)
    , m_sequenceNumber(0)
    , m_checksum(0)
    , m_segmentCount(0)
    , m_lastSegmentUnconcluded(false)
{
}
 
inline OggPage::OggPage(std::istream &stream, std::uint64_t startOffset, std::int32_t maxSize)
    : OggPage()
{
    parseHeader(stream, startOffset, maxSize);
}
 
inline std::uint64_t OggPage::startOffset() const
{
    return m_startOffset;
}
 
inline std::uint8_t OggPage::streamStructureVersion() const
{
    return m_streamStructureVersion;
}
 
inline std::uint8_t OggPage::headerTypeFlag() const
{
    return m_headerTypeFlag & 0xF; // last 4 bits are used internally
}
 
inline bool OggPage::isContinued() const
{
    return m_headerTypeFlag & 0x01;
}
 
inline bool OggPage::isFirstpage() const
{
    return m_headerTypeFlag & 0x02;
}
 
inline bool OggPage::isLastPage() const
{
    return m_headerTypeFlag & 0x04;
}
 
inline bool OggPage::isLastSegmentUnconcluded() const
{
    return m_lastSegmentUnconcluded;
}
 
inline std::uint64_t OggPage::absoluteGranulePosition() const
{
    return m_absoluteGranulePosition;
}
 
inline std::uint32_t OggPage::streamSerialNumber() const
{
    return m_streamSerialNumber;
}
 
inline bool OggPage::matchesStreamSerialNumber(std::uint32_t streamSerialNumber) const
{
    return m_streamSerialNumber == streamSerialNumber;
}
 
inline std::uint32_t OggPage::sequenceNumber() const
{
    return m_sequenceNumber;
}
 
inline std::uint32_t OggPage::checksum() const
{
    return m_checksum;
}
 
inline std::uint8_t OggPage::segmentTableSize() const
{
    return m_segmentCount;
}
 
inline const std::vector<std::uint32_t> &OggPage::segmentSizes() const
{
    return m_segmentSizes;
}
 
inline std::uint32_t OggPage::headerSize() const
{
    return 27 + m_segmentCount;
}
 
inline std::uint32_t OggPage::dataSize() const
{
    return std::accumulate(m_segmentSizes.cbegin(), m_segmentSizes.cend(), 0u);
}
 
inline std::uint32_t OggPage::totalSize() const
{
    return headerSize() + dataSize();
}
 
inline std::uint64_t OggPage::dataOffset(std::vector<std::uint32_t>::size_type segmentIndex) const
{
    return startOffset() + headerSize()
        + std::accumulate<decltype(m_segmentSizes)::const_iterator, std::uint64_t>(
            m_segmentSizes.cbegin(), m_segmentSizes.cbegin() + static_cast<decltype(m_segmentSizes)::difference_type>(segmentIndex), 0u);
}
 
} // namespace TagParser
 
#endif // TAG_PARSER_OGGPAGE_H