[MPlayer-cvslog] r33120 - trunk/stream/cache2.c

[reimar]

Author: reimar
Date: Sat Mar 26 21:04:47 2011
New Revision: 33120

Log:
Ensure we always pass a buffer of at least sector size to the read function.
This is never an issue with streams that have actual sectors, the reads
will always return a multiple of sector size and the cache is always used
in blocks of sector size.
However the rtp protocol misuses this so it can just assume it always has
a sufficiently large buffer available and thus fails without this extra hack.

Modified:
   trunk/stream/cache2.c

Modified: trunk/stream/cache2.c
==============================================================================
--- trunk/stream/cache2.c	Sat Mar 26 19:37:05 2011	(r33119)
+++ trunk/stream/cache2.c	Sat Mar 26 21:04:47 2011	(r33120)
@@ -168,6 +168,7 @@ static int cache_fill(cache_vars_t *s)
   int back,back2,newb,space,len,pos;
   off_t read=s->read_filepos;
   int read_chunk;
+  int wraparound_copy = 0;
 
   if(read<s->min_filepos || read>s->max_filepos){
       // seek...
@@ -209,8 +210,16 @@ static int cache_fill(cache_vars_t *s)
 
 //  printf("### read=0x%X  back=%d  newb=%d  space=%d  pos=%d\n",read,back,newb,space,pos);
 
-  // reduce space if needed:
-  if(space>s->buffer_size-pos) space=s->buffer_size-pos;
+  // try to avoid wrap-around. If not possible due to sector size
+  // do an extra copy.
+  if(space>s->buffer_size-pos) {
+    if (s->buffer_size-pos >= s->sector_size) {
+      space=s->buffer_size-pos;
+    } else {
+      space = s->sector_size;
+      wraparound_copy = 1;
+    }
+  }
 
   // limit one-time block size
   read_chunk = s->stream->read_chunk;
@@ -225,6 +234,13 @@ static int cache_fill(cache_vars_t *s)
   s->min_filepos=read-back; // avoid seeking-back to temp area...
 #endif
 
+  if (wraparound_copy) {
+    int to_copy;
+    len = stream_read_internal(s->stream, s->stream->buffer, space);
+    to_copy = FFMIN(len, s->buffer_size-pos);
+    memcpy(s->buffer + pos, s->stream->buffer, to_copy);
+    memcpy(s->buffer, s->stream->buffer + to_copy, len - to_copy);
+  } else
   len = stream_read_internal(s->stream, &s->buffer[pos], space);
   s->eof= !len;