src/add-ons/media/plugins/matroska/libMatroskaParser/StreamIO.cpp

   1 /*
   2  * Copyright (c) 2004, Marcus Overhagen
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without modification,
   6  * are permitted provided that the following conditions are met:
   7  *
   8  *  * Redistributions of source code must retain the above copyright notice,
   9  *    this list of conditions and the following disclaimer.
  10  *  * Redistributions in binary form must reproduce the above copyright notice,
  11  *    this list of conditions and the following disclaimer in the documentation
  12  *    and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  16  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  17  * IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
  18  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
  19  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  21  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
  22  * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  23  * OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25 #include <stdio.h>
  26 #include <malloc.h>
  27
  28 #include "StreamIO.h"
  29
  30 struct StreamIO {
  31         InputStream filecache;
  32         BPositionIO *source;
  33 };
  34
  35 static int
  36 stream_read(struct InputStream *cc, ulonglong pos, void *buffer, int count)
  37 {
  38         return reinterpret_cast<StreamIO *>(cc)->source->ReadAt(pos, buffer, count);
  39 }
  40
  41 // Only needed if resync required.
  42 static longlong
  43 stream_scan(struct InputStream *cc, ulonglong start, unsigned signature)
  44 {
  45         return -1;
  46 }
  47
  48 //static void
  49 //stream_close(struct InputStream *cc)
  50 //{
  51 //}
  52
  53 // Size of a buffer
  54 // we might want to test against bytes remaining in file.
  55 static unsigned
  56 stream_getsize(struct InputStream *cc)
  57 {
  58         return 524288;
  59 }
  60
  61 static const char *
  62 stream_geterror(struct InputStream *cc)
  63 {
  64         return "";
  65 }
  66
  67 /* memory allocation */
  68 static void     *
  69 stream_memalloc(struct InputStream *cc, size_t size)
  70 {
  71         return malloc(size);
  72 }
  73
  74 static void     *
  75 stream_memrealloc(struct InputStream *cc,void *mem,size_t newsize)
  76 {
  77         return realloc(mem,newsize);
  78 }
  79
  80 static void
  81 stream_memfree(struct InputStream *cc, void *mem)
  82 {
  83         free(mem);
  84 }
  85
  86 // zero return causes parser to abort open
  87 static int
  88 stream_progress(struct InputStream *cc, ulonglong cur, ulonglong max)
  89 {
  90 // no idea what this function is supposed to do.
  91         return max-cur;
  92 }
  93
  94 InputStream *
  95 CreateFileCache(BDataIO *dataio)
  96 {
  97         BPositionIO *posio;
  98         posio = dynamic_cast<BPositionIO *>(dataio);
  99         if (!posio)
 100                 return NULL;
 101
 102         StreamIO *io;
 103         io = (StreamIO *)malloc(sizeof(StreamIO));
 104         if (!io)
 105                 return NULL;
 106
 107         io->filecache.read = &stream_read;
 108         io->filecache.scan = &stream_scan;
 109 //      io->filecache.close = &stream_close;
 110         io->filecache.getcachesize = &stream_getsize;
 111         io->filecache.geterror = &stream_geterror;
 112         io->filecache.memalloc = &stream_memalloc;
 113         io->filecache.memrealloc = &stream_memrealloc;
 114         io->filecache.memfree = &stream_memfree;
 115         io->filecache.progress = &stream_progress;
 116         io->source = posio;
 117
 118         return reinterpret_cast<InputStream *>(io);
 119 }
 120