[vlc-commits] en50221: avoid one memory copy (refs #12307)
Rémi Denis-Courmont
git at videolan.org
Mon Sep 29 21:01:06 CEST 2014
vlc | branch: master | Rémi Denis-Courmont <remi at remlab.net> | Mon Sep 29 21:59:47 2014 +0300| [34c1ae55153af567ee6d51f53046bbbc3ef39c0c] | committer: Rémi Denis-Courmont
en50221: avoid one memory copy (refs #12307)
> http://git.videolan.org/gitweb.cgi/vlc.git/?a=commit;h=34c1ae55153af567ee6d51f53046bbbc3ef39c0c
---
modules/access/dtv/en50221.c | 62 ++++++++++--------------------------------
1 file changed, 14 insertions(+), 48 deletions(-)
diff --git a/modules/access/dtv/en50221.c b/modules/access/dtv/en50221.c
index 4294363..81a3a75 100644
--- a/modules/access/dtv/en50221.c
+++ b/modules/access/dtv/en50221.c
@@ -34,6 +34,7 @@
#include <assert.h>
#include <sys/types.h>
#include <sys/ioctl.h>
+#include <sys/uio.h>
#include <poll.h>
#include <netinet/in.h>
@@ -243,64 +244,29 @@ static void Dump( bool b_outgoing, uint8_t *p_data, int i_size )
* TPDUSend
*****************************************************************************/
static int TPDUSend( cam_t * p_cam, uint8_t i_slot, uint8_t i_tag,
- const uint8_t *p_content, int i_length )
+ const uint8_t *p_content, size_t i_length )
{
- uint8_t i_tcid = i_slot + 1;
- uint8_t p_data[MAX_TPDU_SIZE];
- int i_size;
-
- i_size = 0;
- p_data[0] = i_slot;
- p_data[1] = i_tcid;
- p_data[2] = i_tag;
-
- switch ( i_tag )
- {
- case T_RCV:
- case T_CREATE_TC:
- case T_CTC_REPLY:
- case T_DELETE_TC:
- case T_DTC_REPLY:
- case T_REQUEST_TC:
- p_data[3] = 1; /* length */
- p_data[4] = i_tcid;
- i_size = 5;
- break;
-
- case T_NEW_TC:
- case T_TC_ERROR:
- p_data[3] = 2; /* length */
- p_data[4] = i_tcid;
- p_data[5] = p_content[0];
- i_size = 6;
- break;
+ uint8_t p_data[9], *p = p_data;
- case T_DATA_LAST:
- case T_DATA_MORE:
- {
- /* i_length <= MAX_TPDU_DATA */
- uint8_t *p = p_data + 3;
- p = SetLength( p, i_length + 1 );
- *p++ = i_tcid;
+ *(p++) = i_slot;
+ *(p++) = i_slot + 1; /* TCID */
+ *(p++) = i_tag;
+ p = SetLength( p, i_length + 1 );
- if ( i_length )
- memcpy( p, p_content, i_length );
- i_size = i_length + (p - p_data);
- break;
- }
+ *(p++) = i_slot + 1;
+ Dump( true, p_data, p - p_data );
- default:
- break;
- }
- Dump( true, p_data, i_size );
+ const struct iovec iov[2] = {
+ { p_data, p - p_data },
+ { (void *)p_content, i_length },
+ };
- if ( write( p_cam->fd, p_data, i_size ) != i_size )
+ if ( writev( p_cam->fd, iov, 2 ) <= 0 )
{
msg_Err( p_cam->obj, "cannot write to CAM device: %s",
vlc_strerror_c(errno) );
return VLC_EGENERIC;
}
-
return VLC_SUCCESS;
}
More information about the vlc-commits
mailing list