workbench/libs/iffparse/openiff.c

   1 /*
   2     Copyright © 1995-2007, The AROS Development Team. All rights reserved.
   3     $Id$
   4 */
   5
   6 #define DEBUG 0
   7 #include <aros/debug.h>
   8 #include "iffparse_intern.h"
   9
  10 /* NOTE: Original iffparse.library doesn't have this check here. - Piru */
  11 #define USE_IFFVALIDITYCHECK    1
  12
  13 /*****************************************************************************
  14
  15     NAME */
  16 #include <proto/iffparse.h>
  17
  18         AROS_LH2(LONG, OpenIFF,
  19
  20 /*  SYNOPSIS */
  21         AROS_LHA(struct IFFHandle *, iff, A0),
  22         AROS_LHA(LONG              , rwMode, D0),
  23
  24 /*  LOCATION */
  25         struct Library *, IFFParseBase, 6, IFFParse)
  26
  27 /*  FUNCTION
  28         Initializes an IFFHandle struct for a new session of reading or
  29         writing. The direction of the I/O is determined by the rwMode flags
  30         supplied (IFFF_READ or IFFF_WRITE).
  31
  32     INPUTS
  33         iff - pointer to IFFHandle struct.
  34         ewMode - IFFF_READ or IFFF_WRITE
  35
  36
  37     RESULT
  38         error -  0 if successfull, IFFERR_#? elsewise.
  39
  40     NOTES
  41          This function tells the custom stream handler to initialize
  42         by sending it a IFFCMD_INIT IFFStreamCmd.
  43
  44     EXAMPLE
  45
  46     BUGS
  47
  48     SEE ALSO
  49         CloseIFF(), InitIFF()
  50
  51     INTERNALS
  52
  53 *****************************************************************************/
  54 {
  55     AROS_LIBFUNC_INIT
  56     LONG  err;
  57     struct IFFStreamCmd cmd;
  58
  59     if (iff == NULL)
  60     {
  61         D(bug("openiff error: IFFERR_NOMEM\n"));
  62         return (IFFERR_NOMEM);
  63     }
  64
  65     /* Check that a valid StreamHandler Hook has been supplied */
  66     if (!( GetIntIH(iff)->iff_StreamHandler) )
  67     {
  68         D(bug("openiff error: IFFERR_NOHOOK\n"));
  69         return (IFFERR_NOHOOK);
  70     }
  71
  72     /* Tell the custom stream to initialize itself */
  73
  74     cmd.sc_Command = IFFCMD_INIT;
  75     err = CallHookPkt (GetIntIH(iff)->iff_StreamHandler, iff, &cmd);
  76
  77     if (!err)
  78     {
  79 #if USE_IFFVALIDITYCHECK
  80         /* If we are opend in read mode we should test if we have a valid IFF-File */
  81         if (rwMode == IFFF_READ && iff->iff_Stream)
  82         {
  83             struct ContextNode *cn;
  84
  85             D(bug("testing if it's a valid IFF file\n"));
  86             /* Get header of iff-stream */
  87             err = GetChunkHeader(iff, IPB(IFFParseBase));
  88
  89             /* Valid IFF header ? */
  90             if (!err)
  91             {
  92                 /* We have now entried the chunk */
  93                 D(bug("entered the chunk\n"));
  94                 GetIntIH(iff)->iff_CurrentState = IFFSTATE_COMPOSITE;
  95
  96                 cn = TopChunk(iff);
  97
  98                 /* We must see if we have a IFF header ("FORM", "CAT" or "LIST") */
  99                 if (GetIntCN(cn)->cn_Composite)
 100                 {
 101                     D(bug("an iff header\n"));
 102                     /* Everything went OK */
 103                     /* Set the acess mode, and mark the stream as opened */
 104                     iff->iff_Flags &= ~IFFF_RWBITS;
 105                     iff->iff_Flags |= (rwMode | IFFF_OPEN | IFFF_NEWFILE);
 106
 107                     err = 0L;
 108                 }
 109                 else
 110                 {
 111                     err = IFFERR_NOTIFF;
 112                     D(bug("OpenIFF: not an IFF header, pop the context node\n"));
 113
 114                     /* Pop the contextnode */
 115                     PopContextNode(iff, IPB(IFFParseBase));
 116                 }
 117             }
 118             else
 119             {
 120                 if (err  == IFFERR_MANGLED)
 121                 {
 122                     err = IFFERR_NOTIFF;
 123                     D(bug("openiff error: IFFERR_MANGLED\n"));
 124                 }
 125
 126                 /* Fail. We should send CLEANUP to the stream */
 127                 cmd.sc_Command = IFFCMD_CLEANUP;
 128                 err = CallHookPkt
 129                 (
 130                     GetIntIH(iff)->iff_StreamHandler,
 131                     iff,
 132                     &cmd
 133                 );
 134             }
 135         } /* IFFF_READ */
 136         else
 137 #endif /* USE_IFFVALIDITYCHECK */
 138         {
 139             iff->iff_Flags &= ~IFFF_RWBITS;
 140             iff->iff_Flags |= (rwMode | IFFF_OPEN | IFFF_NEWFILE);
 141             err = 0L;
 142         }
 143
 144     } /* if (!err) */
 145
 146     D(bug("openiff: return %d\n", err));
 147     return (err);
 148     AROS_LIBFUNC_EXIT
 149 } /* OpenIFF */