InputByteStream.h

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/* This file is part of dvi2bitmap; see README for copyrights and licence */

#ifndef INPUT_BYTE_STREAM_HEADER_READ
#define INPUT_BYTE_STREAM_HEADER_READ 1

#include <Byte.h>
#include <DviError.h>
#include <verbosity.h>

#include <string>

class InputByteStreamError : public DviError {
 public:
    InputByteStreamError(string s) : DviError(s) { }
};

class InputByteStream {

 public:
    InputByteStream(int fileno)
            throw (InputByteStreamError);
    InputByteStream(string srcspec)
            throw (InputByteStreamError);
    ~InputByteStream();

    bool eof();
    virtual void close();
    Byte getByte(void)
            throw (InputByteStreamError);
    const Byte *getBlock(unsigned int length)
            throw (InputByteStreamError);
    void skip (unsigned int)
            throw (InputByteStreamError);

    signed int getSIU(int)
            throw (InputByteStreamError);
    signed int getSIS(int)
            throw (InputByteStreamError);
    unsigned int getUIU(int)
            throw (InputByteStreamError);
    /*
     * static getUIU reads from an array, rather than the file (ie,
     * it's really nothing to do with InputByteStream, but it's here
     * for consistency.
     */
    static unsigned int getUIU(int, const Byte *)
            throw (InputByteStreamError);
    static void setDefaultBufferSize(unsigned int length);
    static inline void verbosity (const verbosities level) {
        verbosity_ = level;
    }
    static verbosities getVerbosity(void) { return verbosity_; };

 protected:
    InputByteStream();
    bool bindToFileDescriptor(int fileno,
                              string filename="",
                              int bufsize=0,
                              bool fillBufferAndClose=false,
                              bool assertIsSeekable=false)
            throw (InputByteStreamError);
    int openSourceSpec(string srcspec)
            throw (InputByteStreamError);
    int getFD(void) const { return fd_; }
    void bufferSeek(unsigned int pos)
            throw (InputByteStreamError);
    void reloadBuffer(void);

 private:
    int fd_;                    /* file descriptor of handled file/pipe */
    int mappedfd_;              /* saved file descriptor of mapped file */
    string fname_;              /* name of file, or string rep'n of fd */
    Byte *buf_;                 /* buffer */
    size_t buflen_;             /* size of buffer */
    Byte *p_;                   /* current position in buffer */
    Byte *eob_;                 /* end of buffer */
    bool eof_;                  /* true on end of file (note this is from
                                   the client's point of view, not the class's:
                                   if we have `preloaded' a file, the
                                   underlying file will be closed, but there
                                   will still be more to read from the 
                                   stream) */
    void read_buf_(void)
            throw (InputByteStreamError);
    size_t certainly_read_(int fd, Byte *b, size_t len)
            throw (InputByteStreamError);

    static verbosities verbosity_;
    static unsigned int default_buffer_length_;
};

#endif /* INPUT_BYTE_STREAM_HEADER_READ */