1                 : /******************************************************************************
       2                 :  *
       3                 :  * Purpose:  Implementation of the Open() function.
       4                 :  * 
       5                 :  ******************************************************************************
       6                 :  * Copyright (c) 2009
       7                 :  * PCI Geomatics, 50 West Wilmot Street, Richmond Hill, Ont, Canada
       8                 :  *
       9                 :  * Permission is hereby granted, free of charge, to any person obtaining a
      10                 :  * copy of this software and associated documentation files (the "Software"),
      11                 :  * to deal in the Software without restriction, including without limitation
      12                 :  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
      13                 :  * and/or sell copies of the Software, and to permit persons to whom the
      14                 :  * Software is furnished to do so, subject to the following conditions:
      15                 :  *
      16                 :  * The above copyright notice and this permission notice shall be included
      17                 :  * in all copies or substantial portions of the Software.
      18                 :  *
      19                 :  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
      20                 :  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
      21                 :  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
      22                 :  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
      23                 :  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
      24                 :  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
      25                 :  * DEALINGS IN THE SOFTWARE.
      26                 :  ****************************************************************************/
      27                 : #include "pcidsk.h"
      28                 : #include "pcidsk_config.h"
      29                 : #include "pcidsk_types.h"
      30                 : #include "pcidsk_file.h"
      31                 : #include "pcidsk_interfaces.h"
      32                 : #include "core/cpcidskfile.h"
      33                 : #include <string>
      34                 : #include <cstring>
      35                 : #include <cassert>
      36                 : 
      37                 : using namespace PCIDSK;
      38                 : 
      39                 : /************************************************************************/
      40                 : /*                                Open()                                */
      41                 : /************************************************************************/
      42                 : 
      43                 : /**
      44                 :  * Open a PCIDSK (.pix) file. 
      45                 :  *
      46                 :  * This function attempts to open the named file, with the indicated
      47                 :  * access and the provided set of system interface methods.
      48                 :  *
      49                 :  * @param filename the name of the PCIDSK file to access.
      50                 :  * @param access either "r" for read-only, or "r+" for read-write access.
      51                 :  * @param interfaces Either NULL to use default interfaces, or a pointer
      52                 :  * to a populated interfaces object. 
      53                 :  *
      54                 :  * @return a pointer to a file object for accessing the PCIDSK file. 
      55                 :  */
      56                 : 
      57             110 : PCIDSKFile *PCIDSK::Open( std::string filename, std::string access,
      58                 :                           const PCIDSKInterfaces *interfaces )
      59                 : 
      60                 : {
      61                 : /* -------------------------------------------------------------------- */
      62                 : /*      Use default interfaces if none are passed in.                   */
      63                 : /* -------------------------------------------------------------------- */
      64             110 :     PCIDSKInterfaces default_interfaces;
      65             110 :     if( interfaces == NULL )
      66               0 :         interfaces = &default_interfaces;
      67                 : 
      68                 : /* -------------------------------------------------------------------- */
      69                 : /*      First open the file, and confirm that it is PCIDSK before       */
      70                 : /*      going further.                                                  */
      71                 : /* -------------------------------------------------------------------- */
      72             110 :     void *io_handle = interfaces->io->Open( filename, access );
      73                 : 
      74             110 :     assert( io_handle != NULL );
      75                 : 
      76                 :     char header_check[6];
      77                 : 
      78             110 :     if( interfaces->io->Read( header_check, 1, 6, io_handle ) != 6 
      79                 :         || memcmp(header_check,"PCIDSK",6) != 0 )
      80                 :     {
      81               0 :         interfaces->io->Close( io_handle );
      82                 :         ThrowPCIDSKException( "File %s does not appear to be PCIDSK format.",
      83               0 :                               filename.c_str() );
      84                 :     }
      85                 : 
      86                 : /* -------------------------------------------------------------------- */
      87                 : /*      Create the PCIDSKFile object.                                   */
      88                 : /* -------------------------------------------------------------------- */
      89                 : 
      90             110 :     CPCIDSKFile *file = new CPCIDSKFile( filename );
      91                 :     
      92             110 :     file->interfaces = *interfaces;
      93             110 :     file->io_handle = io_handle;
      94             110 :     file->io_mutex = interfaces->CreateMutex();
      95                 : 
      96             110 :     if( strstr(access.c_str(),"+") != NULL )
      97              59 :         file->updatable = true;
      98                 : 
      99                 : /* -------------------------------------------------------------------- */
     100                 : /*      Initialize it from the header.                                  */
     101                 : /* -------------------------------------------------------------------- */
     102                 :     try
     103                 :     {
     104             110 :         file->InitializeFromHeader();
     105                 :     }
     106               0 :     catch(...)
     107                 :     {
     108               0 :         delete file;
     109               0 :         throw;
     110                 :     }
     111                 : 
     112             110 :     return file;
     113                 : }