Zipios++
zipinputstreambuf.cpp
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00001 
00002 #include "zipios++/zipios-config.h"
00003 
00004 #include <algorithm>
00005 #include "zipios++/meta-iostreams.h"
00006 
00007 #include <zlib.h>
00008 
00009 #include "zipios++/zipinputstreambuf.h"
00010 #include "zipios_common.h"
00011 
00012 namespace zipios {
00013 
00014 using std::ios ;
00015 using std::cerr ;
00016 using std::endl ;
00017 
00018 ZipInputStreambuf::ZipInputStreambuf( streambuf *inbuf, int s_pos, bool del_inbuf ) 
00019   : InflateInputStreambuf( inbuf, s_pos, del_inbuf ),
00020     _open_entry( false                   ) 
00021 {}
00022 
00023 void ZipInputStreambuf::closeEntry() {
00024   if ( ! _open_entry )
00025     return ;
00026   
00027   // check if we're positioned correctly, otherwise position us correctly
00028   int position = _inbuf->pubseekoff(0, ios::cur, 
00029                                     ios::in);
00030   if ( position != _data_start + static_cast< int >( _curr_entry.getCompressedSize() ) )
00031     _inbuf->pubseekoff(_data_start + _curr_entry.getCompressedSize(), 
00032                        ios::beg, ios::in) ;
00033 
00034 }
00035 
00036 void ZipInputStreambuf::close() {
00037 }
00038 
00039 ConstEntryPointer ZipInputStreambuf::getNextEntry() {
00040   if ( _open_entry )
00041     closeEntry() ;
00042 
00043   // read the zip local header
00044   istream is( _inbuf ) ; // istream does not destroy the streambuf.
00045   is.exceptions( ios::eofbit | ios::failbit | ios::badbit );
00046 
00047   try {
00048     is >> _curr_entry ;
00049     if ( _curr_entry.isValid() ) {
00050       _data_start = _inbuf->pubseekoff(0, ios::cur, ios::in);
00051       if ( _curr_entry.getMethod() == DEFLATED ) {
00052         _open_entry = true ;
00053         reset() ; // reset inflatestream data structures 
00054         // cerr << "deflated" << endl ;
00055       } else if ( _curr_entry.getMethod() == STORED ) {
00056         _open_entry = true ;
00057         _remain = _curr_entry.getSize() ;
00058         // Force underflow on first read:
00059         setg( &( _outvec[ 0 ] ),
00060               &( _outvec[ 0 ] ) + _outvecsize,
00061               &( _outvec[ 0 ] ) + _outvecsize );
00062         // cerr << "stored" << endl ;
00063       } else {
00064         _open_entry = false ; // Unsupported compression format.
00065         throw FCollException( "Unsupported compression format" ) ;
00066       }
00067     }
00068   } catch (...) {
00069     _open_entry = false ;
00070   }
00071 
00072   if ( _curr_entry.isValid() && _curr_entry.trailingDataDescriptor() )
00073     throw FCollException( "Trailing data descriptor in zip file not supported" ) ; 
00074   return new ZipLocalEntry( _curr_entry ) ;
00075 }
00076 
00077 
00078 ZipInputStreambuf::~ZipInputStreambuf() {
00079 }
00080 
00081 
00082 int ZipInputStreambuf::underflow() {
00083   if ( ! _open_entry )
00084     return EOF ; // traits_type::eof() 
00085   if ( _curr_entry.getMethod() == DEFLATED )
00086     return InflateInputStreambuf::underflow() ;
00087 
00088   // Ok, we're are stored, so we handle it ourselves.
00089   int num_b = min( _remain, _outvecsize ) ;
00090   int g = _inbuf->sgetn( &(_outvec[ 0 ] ) , num_b ) ;
00091   setg( &( _outvec[ 0 ] ),
00092         &( _outvec[ 0 ] ),
00093         &( _outvec[ 0 ] ) + g ) ;
00094   _remain -= g ;
00095   if ( g > 0 )
00096     return static_cast< unsigned char >( *gptr() ) ;
00097   else
00098     return EOF ; // traits_type::eof() 
00099 }
00100 
00101 
00102 // FIXME: We need to check somew
00103 //  
00104 //    // gp_bitfield bit 3 is one, if the length of the zip entry
00105 //    // is stored in a trailer.
00106 //    if ( is->good  && ( _curr_entry.gp_bitfield & 4 ) != 1 )
00107 //      return true ;
00108 //    else {
00109 //      is->clear() ;
00110 //      return false ;
00111 //    }
00112 
00113 
00114 } // namespace
00115 
00120 /*
00121   Zipios++ - a small C++ library that provides easy access to .zip files.
00122   Copyright (C) 2000  Thomas Søndergaard
00123   
00124   This library is free software; you can redistribute it and/or
00125   modify it under the terms of the GNU Lesser General Public
00126   License as published by the Free Software Foundation; either
00127   version 2 of the License, or (at your option) any later version.
00128   
00129   This library is distributed in the hope that it will be useful,
00130   but WITHOUT ANY WARRANTY; without even the implied warranty of
00131   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00132   Lesser General Public License for more details.
00133   
00134   You should have received a copy of the GNU Lesser General Public
00135   License along with this library; if not, write to the Free Software
00136   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307  USA
00137 */