BufferedLineReader.h   [plain text]

/*
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#ifndef BufferedLineReader_h
#define BufferedLineReader_h

#include "SegmentedString.h"
#include <wtf/text/StringBuilder.h>

namespace WebCore {

// Line collection helper for the WebVTT Parser.
//
// Converts a stream of data (== a sequence of Strings) into a set of
// lines. CR, LR or CRLF are considered linebreaks. Normalizes NULs (U+0000)
// to 'REPLACEMENT CHARACTER' (U+FFFD) and does not return the linebreaks as
// part of the result.
class BufferedLineReader {
    WTF_MAKE_NONCOPYABLE(BufferedLineReader);
public:
    BufferedLineReader()
        : m_endOfStream(false)
        , m_maybeSkipLF(false) { }

    // Append data to the internal buffer.
    void append(const String& data)
    {
        ASSERT(!m_endOfStream);
        m_buffer.append(SegmentedString(data));
    }

    // Indicate that no more data will be appended. This will cause any
    // potentially "unterminated" line to be returned from getLine.
    void setEndOfStream() { m_endOfStream = true; }

    // Attempt to read a line from the internal buffer (fed via append).
    // If successful, true is returned and |line| is set to the line that was
    // read. If no line could be read false is returned.
    bool getLine(String& line);

    // Returns true if EOS has been reached proper.
    bool isAtEndOfStream() const { return m_endOfStream && m_buffer.isEmpty(); }

    void reset() { m_buffer.clear(); }

private:
    // Consume the next character the buffer if it is the character |c|.
    void scanCharacter(UChar c)
    {
        ASSERT(!m_buffer.isEmpty());
        if (m_buffer.currentChar() == c)
            m_buffer.advance();
    }

    SegmentedString m_buffer;
    StringBuilder m_lineBuffer;
    bool m_endOfStream;
    bool m_maybeSkipLF;
};

} // namespace WebCore

#endif