src/common/zipstream.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        zipstream.cpp
   3 // Purpose:     input stream for ZIP archive access
   4 // Author:      Vaclav Slavik
   5 // Copyright:   (c) 1999 Vaclav Slavik
   6 // Licence:     wxWindows Licence
   7 /////////////////////////////////////////////////////////////////////////////
   8
   9 #ifdef __GNUG__
  10 #pragma implementation
  11 #endif
  12
  13 #include <wx/wxprec.h>
  14
  15 #ifdef __BORDLANDC__
  16 #pragma hdrstop
  17 #endif
  18
  19 #ifndef WXPRECOMP
  20 #include <wx/wx.h>
  21 #endif
  22
  23 #include <wx/stream.h>
  24 #include <wx/wfstream.h>
  25 #include <wx/zipstream.h>
  26 #include "unzip.h"
  27
  28
  29
  30
  31 wxZipInputStream::wxZipInputStream(const wxString& archive, const wxString& file) : wxInputStream()
  32 {
  33     unz_file_info zinfo;
  34
  35     m_Pos = 0;
  36     m_Size = 0;
  37     m_Archive = (void*) unzOpen(archive);
  38     if (m_Archive == NULL) {
  39         m_lasterror = wxStream_READ_ERR;
  40         return;
  41     }
  42     if (unzLocateFile((unzFile)m_Archive, file, 0) != UNZ_OK) {
  43         m_lasterror = wxStream_READ_ERR;
  44         return;
  45     }
  46     unzGetCurrentFileInfo((unzFile)m_Archive, &zinfo, NULL, 0, NULL, 0, NULL, 0);
  47
  48     if (unzOpenCurrentFile((unzFile)m_Archive) != UNZ_OK) {
  49         m_lasterror = wxStream_READ_ERR;
  50         return;
  51     }
  52     m_Size = zinfo.uncompressed_size;
  53 }
  54
  55
  56
  57 wxZipInputStream::~wxZipInputStream()
  58 {
  59     if (m_Archive) {
  60         if (m_Size != 0)
  61             unzCloseCurrentFile((unzFile)m_Archive);
  62         unzClose((unzFile)m_Archive);
  63     }
  64 }
  65
  66
  67
  68 size_t wxZipInputStream::OnSysRead(void *buffer, size_t bufsize)
  69 {
  70     if (m_Pos + bufsize > m_Size) bufsize = m_Size - m_Pos;
  71     unzReadCurrentFile((unzFile)m_Archive, buffer, bufsize);
  72     m_Pos += bufsize;
  73     return bufsize;
  74 }
  75
  76
  77
  78 off_t wxZipInputStream::OnSysSeek(off_t seek, wxSeekMode mode)
  79 {
  80     off_t nextpos;
  81     void *buf;
  82
  83     switch (mode) {
  84         case wxFromCurrent : nextpos = seek + m_Pos; break;
  85         case wxFromStart : nextpos = seek; break;
  86         case wxFromEnd : nextpos = m_Size - 1 + seek; break;
  87         default : nextpos = m_Pos; break; /* just to fool compiler, never happens */
  88     }
  89
  90     // cheated seeking :
  91     if (nextpos > m_Pos) {
  92         buf = malloc(nextpos - m_Pos);
  93         unzReadCurrentFile((unzFile)m_Archive, buf, nextpos -  m_Pos);
  94         free(buf);
  95     }
  96     else if (nextpos < m_Pos) {
  97         unzCloseCurrentFile((unzFile)m_Archive);
  98         if (unzOpenCurrentFile((unzFile)m_Archive) != UNZ_OK) {
  99             m_lasterror = wxStream_READ_ERR;
 100             return m_Pos;
 101         }
 102         buf = malloc(nextpos);
 103         unzReadCurrentFile((unzFile)m_Archive, buf, nextpos);
 104         free(buf);
 105     }
 106
 107     m_Pos = nextpos;
 108     return m_Pos;
 109 }
 110