/*

 *

 * Copyright (c) 1997

 * Christian Michelsen Research AS

 * Advanced Computing

 * Fantoftvegen 38, 5036 BERGEN, Norway

 * http://www.cmr.no

 *

 * Permission to use, copy, modify, distribute and sell this software

 * and its documentation for any purpose is hereby granted without fee,

 * provided that the above copyright notice appear in all copies and

 * that both that copyright notice and this permission notice appear

 * in supporting documentation.  Christian Michelsen Research AS makes no

 * representations about the suitability of this software for any

 * purpose.  It is provided "as is" without express or implied warranty.

 *

 */

#ifndef ZSTREAM__H

#define ZSTREAM__H

/*

 * zstream.h - C++ interface to the 'zlib' general purpose compression library

 * $Id: zstream.h 1.1 1997-06-25 12:00:56+02 tyge Exp tyge $

 */

#include <strstream.h>

#include <string.h>

#include <stdio.h>

#include "zlib.h"

#if defined(_WIN32)

#   include <fcntl.h>

#   include <io.h>

#   define SET_BINARY_MODE(file) setmode(fileno(file), O_BINARY)

#else

#   define SET_BINARY_MODE(file)

#endif

class zstringlen {

public:

    zstringlen(class izstream&);

    zstringlen(class ozstream&, const char*);

    size_t value() const { return val.word; }

private:

    struct Val { unsigned char byte; size_t word; } val;

};

//  ----------------------------- izstream -----------------------------

class izstream

{

    public:

        izstream() : m_fp(0) {}

        izstream(FILE* fp) : m_fp(0) { open(fp); }

        izstream(const char* name) : m_fp(0) { open(name); }

        ~izstream() { close(); }

        /* Opens a gzip (.gz) file for reading.

         * open() can be used to read a file which is not in gzip format;

         * in this case read() will directly read from the file without

         * decompression. errno can be checked to distinguish two error

         * cases (if errno is zero, the zlib error is Z_MEM_ERROR).

         */

        void open(const char* name) {

            if (m_fp) close();

            m_fp = ::gzopen(name, "rb");

        }

        void open(FILE* fp) {

            SET_BINARY_MODE(fp);

            if (m_fp) close();

            m_fp = ::gzdopen(fileno(fp), "rb");

        }

        /* Flushes all pending input if necessary, closes the compressed file

         * and deallocates all the (de)compression state. The return value is

         * the zlib error number (see function error() below).

         */

        int close() {

            int r = ::gzclose(m_fp);

            m_fp = 0; return r;

        }

        /* Binary read the given number of bytes from the compressed file.

         */

        int read(void* buf, size_t len) {

            return ::gzread(m_fp, buf, len);

        }

        /* Returns the error message for the last error which occurred on the

         * given compressed file. errnum is set to zlib error number. If an

         * error occurred in the file system and not in the compression library,

         * errnum is set to Z_ERRNO and the application may consult errno

         * to get the exact error code.

         */

        const char* error(int* errnum) {

            return ::gzerror(m_fp, errnum);

        }

        gzFile fp() { return m_fp; }

    private:

        gzFile m_fp;

};

/*

 * Binary read the given (array of) object(s) from the compressed file.

 * If the input file was not in gzip format, read() copies the objects number

 * of bytes into the buffer.

 * returns the number of uncompressed bytes actually read

 * (0 for end of file, -1 for error).

 */

template <class T, class Items>

inline int read(izstream& zs, T* x, Items items) {

    return ::gzread(zs.fp(), x, items*sizeof(T));

}

/*

 * Binary input with the '>' operator.

 */

template <class T>

inline izstream& operator>(izstream& zs, T& x) {

    ::gzread(zs.fp(), &x, sizeof(T));

    return zs;

}

inline zstringlen::zstringlen(izstream& zs) {

    zs > val.byte;

    if (val.byte == 255) zs > val.word;

    else val.word = val.byte;

}

/*

 * Read length of string + the string with the '>' operator.

 */

inline izstream& operator>(izstream& zs, char* x) {

    zstringlen len(zs);

    ::gzread(zs.fp(), x, len.value());

    x[len.value()] = '\0';

    return zs;

}

inline char* read_string(izstream& zs) {

    zstringlen len(zs);

    char* x = new char[len.value()+1];

    ::gzread(zs.fp(), x, len.value());

    x[len.value()] = '\0';

    return x;

}

// ----------------------------- ozstream -----------------------------

class ozstream

{

    public:

        ozstream() : m_fp(0), m_os(0) {

        }

        ozstream(FILE* fp, int level = Z_DEFAULT_COMPRESSION)

            : m_fp(0), m_os(0) {

            open(fp, level);

        }

        ozstream(const char* name, int level = Z_DEFAULT_COMPRESSION)

            : m_fp(0), m_os(0) {

            open(name, level);

        }

        ~ozstream() {

            close();

        }

        /* Opens a gzip (.gz) file for writing.

         * The compression level parameter should be in 0..9

         * errno can be checked to distinguish two error cases

         * (if errno is zero, the zlib error is Z_MEM_ERROR).

         */

        void open(const char* name, int level = Z_DEFAULT_COMPRESSION) {

            char mode[4] = "wb\0";

            if (level != Z_DEFAULT_COMPRESSION) mode[2] = '0'+level;

            if (m_fp) close();

            m_fp = ::gzopen(name, mode);

        }

        /* open from a FILE pointer.

         */

        void open(FILE* fp, int level = Z_DEFAULT_COMPRESSION) {

            SET_BINARY_MODE(fp);

            char mode[4] = "wb\0";

            if (level != Z_DEFAULT_COMPRESSION) mode[2] = '0'+level;

            if (m_fp) close();

            m_fp = ::gzdopen(fileno(fp), mode);

        }

        /* Flushes all pending output if necessary, closes the compressed file

         * and deallocates all the (de)compression state. The return value is

         * the zlib error number (see function error() below).

         */

        int close() {

            if (m_os) {

                ::gzwrite(m_fp, m_os->str(), m_os->pcount());

                delete[] m_os->str(); delete m_os; m_os = 0;

            }

            int r = ::gzclose(m_fp); m_fp = 0; return r;

        }

        /* Binary write the given number of bytes into the compressed file.

         */

        int write(const void* buf, size_t len) {

            return ::gzwrite(m_fp, (voidp) buf, len);

        }

        /* Flushes all pending output into the compressed file. The parameter

         * _flush is as in the deflate() function. The return value is the zlib

         * error number (see function gzerror below). flush() returns Z_OK if

         * the flush_ parameter is Z_FINISH and all output could be flushed.

         * flush() should be called only when strictly necessary because it can

         * degrade compression.

         */

        int flush(int _flush) {

            os_flush();

            return ::gzflush(m_fp, _flush);

        }

        /* Returns the error message for the last error which occurred on the

         * given compressed file. errnum is set to zlib error number. If an

         * error occurred in the file system and not in the compression library,

         * errnum is set to Z_ERRNO and the application may consult errno

         * to get the exact error code.

         */

        const char* error(int* errnum) {

            return ::gzerror(m_fp, errnum);

        }

        gzFile fp() { return m_fp; }

        ostream& os() {

            if (m_os == 0) m_os = new ostrstream;

            return *m_os;

        }

        void os_flush() {

            if (m_os && m_os->pcount()>0) {

                ostrstream* oss = new ostrstream;

                oss->fill(m_os->fill());

                oss->flags(m_os->flags());

                oss->precision(m_os->precision());

                oss->width(m_os->width());

                ::gzwrite(m_fp, m_os->str(), m_os->pcount());

                delete[] m_os->str(); delete m_os; m_os = oss;

            }

        }

    private:

        gzFile m_fp;

        ostrstream* m_os;

};

/*

 * Binary write the given (array of) object(s) into the compressed file.

 * returns the number of uncompressed bytes actually written

 * (0 in case of error).

 */

template <class T, class Items>

inline int write(ozstream& zs, const T* x, Items items) {

    return ::gzwrite(zs.fp(), (voidp) x, items*sizeof(T));

}

/*

 * Binary output with the '<' operator.

 */

template <class T>

inline ozstream& operator<(ozstream& zs, const T& x) {

    ::gzwrite(zs.fp(), (voidp) &x, sizeof(T));

    return zs;

}

inline zstringlen::zstringlen(ozstream& zs, const char* x) {

    val.byte = 255;  val.word = ::strlen(x);

    if (val.word < 255) zs < (val.byte = val.word);

    else zs < val;

}

/*

 * Write length of string + the string with the '<' operator.

 */

inline ozstream& operator<(ozstream& zs, const char* x) {

    zstringlen len(zs, x);

    ::gzwrite(zs.fp(), (voidp) x, len.value());

    return zs;

}

#ifdef _MSC_VER

inline ozstream& operator<(ozstream& zs, char* const& x) {

    return zs < (const char*) x;

}

#endif

/*

 * Ascii write with the << operator;

 */

template <class T>

inline ostream& operator<<(ozstream& zs, const T& x) {

    zs.os_flush();

    return zs.os() << x;

}

#endif