#include <memory.h>#include "zfstream.h"gzfilebuf::gzfilebuf() :  file(NULL),  mode(0),  own_file_descriptor(0){ }gzfilebuf::~gzfilebuf() {  sync();  if ( own_file_descriptor )    close();}gzfilebuf *gzfilebuf::open( const char *name,			    int io_mode ) {  if ( is_open() )    return NULL;  char char_mode[10];  char *p;  memset(char_mode,'\0',10);  p = char_mode;  if ( io_mode & ios::in ) {    mode = ios::in;    *p++ = 'r';  } else if ( io_mode & ios::app ) {    mode = ios::app;    *p++ = 'a';  } else {    mode = ios::out;    *p++ = 'w';  }  if ( io_mode & ios::binary ) {    mode |= ios::binary;    *p++ = 'b';  }  // Hard code the compression level  if ( io_mode & (ios::out|ios::app )) {    *p++ = '9';  }  if ( (file = gzopen(name, char_mode)) == NULL )    return NULL;  own_file_descriptor = 1;  return this;}gzfilebuf *gzfilebuf::attach( int file_descriptor,			      int io_mode ) {  if ( is_open() )    return NULL;  char char_mode[10];  char *p;  memset(char_mode,'\0',10);  p = char_mode;  if ( io_mode & ios::in ) {    mode = ios::in;    *p++ = 'r';  } else if ( io_mode & ios::app ) {    mode = ios::app;    *p++ = 'a';  } else {    mode = ios::out;    *p++ = 'w';  }  if ( io_mode & ios::binary ) {    mode |= ios::binary;    *p++ = 'b';  }  // Hard code the compression level  if ( io_mode & (ios::out|ios::app )) {    *p++ = '9';  }  if ( (file = gzdopen(file_descriptor, char_mode)) == NULL )    return NULL;  own_file_descriptor = 0;  return this;}gzfilebuf *gzfilebuf::close() {  if ( is_open() ) {    sync();    gzclose( file );    file = NULL;  }  return this;}int gzfilebuf::setcompressionlevel( short comp_level ) {  return gzsetparams(file, comp_level, -2);}int gzfilebuf::setcompressionstrategy( short comp_strategy ) {  return gzsetparams(file, -2, comp_strategy);}streampos gzfilebuf::seekoff( streamoff off, ios::seek_dir dir, int which ) {  return streampos(EOF);}int gzfilebuf::underflow() {  // If the file hasn't been opened for reading, error.  if ( !is_open() || !(mode & ios::in) )    return EOF;  // if a buffer doesn't exists, allocate one.  if ( !base() ) {    if ( (allocate()) == EOF )      return EOF;    setp(0,0);  } else {    if ( in_avail() )      return (unsigned char) *gptr();    if ( out_waiting() ) {      if ( flushbuf() == EOF )	return EOF;    }  }  // Attempt to fill the buffer.  int result = fillbuf();  if ( result == EOF ) {    // disable get area    setg(0,0,0);    return EOF;  }  return (unsigned char) *gptr();}int gzfilebuf::overflow( int c ) {  if ( !is_open() || !(mode & ios::out) )    return EOF;  if ( !base() ) {    if ( allocate() == EOF )      return EOF;    setg(0,0,0);  } else {    if (in_avail()) {	return EOF;    }    if (out_waiting()) {      if (flushbuf() == EOF)	return EOF;    }  }  int bl = blen();  setp( base(), base() + bl);  if ( c != EOF ) {    *pptr() = c;    pbump(1);  }  return 0;}int gzfilebuf::sync() {  if ( !is_open() )    return EOF;  if ( out_waiting() )    return flushbuf();  return 0;}int gzfilebuf::flushbuf() {  int n;  char *q;  q = pbase();  n = pptr() - q;  if ( gzwrite( file, q, n) < n )    return EOF;  setp(0,0);  return 0;}int gzfilebuf::fillbuf() {  int required;  char *p;  p = base();  required = blen();  int t = gzread( file, p, required );  if ( t <= 0) return EOF;  setg( base(), base(), base()+t);  return t;}gzfilestream_common::gzfilestream_common() :  ios( gzfilestream_common::rdbuf() ){ }gzfilestream_common::~gzfilestream_common(){ }void gzfilestream_common::attach( int fd, int io_mode ) {  if ( !buffer.attach( fd, io_mode) )    clear( ios::failbit | ios::badbit );  else    clear();}void gzfilestream_common::open( const char *name, int io_mode ) {  if ( !buffer.open( name, io_mode ) )    clear( ios::failbit | ios::badbit );  else    clear();}void gzfilestream_common::close() {  if ( !buffer.close() )    clear( ios::failbit | ios::badbit );}gzfilebuf *gzfilestream_common::rdbuf() {  return &buffer;}     gzifstream::gzifstream() :  ios( gzfilestream_common::rdbuf() ){  clear( ios::badbit );}gzifstream::gzifstream( const char *name, int io_mode ) :  ios( gzfilestream_common::rdbuf() ){  gzfilestream_common::open( name, io_mode );}gzifstream::gzifstream( int fd, int io_mode ) :  ios( gzfilestream_common::rdbuf() ){  gzfilestream_common::attach( fd, io_mode );}gzifstream::~gzifstream() { }gzofstream::gzofstream() :  ios( gzfilestream_common::rdbuf() ){  clear( ios::badbit );}gzofstream::gzofstream( const char *name, int io_mode ) :  ios( gzfilestream_common::rdbuf() ){  gzfilestream_common::open( name, io_mode );}gzofstream::gzofstream( int fd, int io_mode ) :  ios( gzfilestream_common::rdbuf() ){  gzfilestream_common::attach( fd, io_mode );}gzofstream::~gzofstream() { }