/*
*
* 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,v 1.1.1.2 2017/01/10 00:25:30 christos Exp $
*/
#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