libust/buffer.h

   1 /* Copyright (C) 2005-2009  Mathieu Desnoyers
   2  *
   3  * This library is free software; you can redistribute it and/or
   4  * modify it under the terms of the GNU Lesser General Public
   5  * License as published by the Free Software Foundation; either
   6  * version 2.1 of the License, or (at your option) any later version.
   7  *
   8  * This library is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * Lesser General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU Lesser General Public
  14  * License along with this library; if not, write to the Free Software
  15  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
  16  */
  17
  18 #ifndef UST_BUFFER_H
  19 #define UST_BUFFER_H
  20
  21 /* Buffer offset macros */
  22
  23 /*
  24  * BUFFER_TRUNC zeroes the subbuffer offset and the subbuffer number parts of
  25  * the offset, which leaves only the buffer number.
  26  */
  27 #define BUFFER_TRUNC(offset, chan) \
  28         ((offset) & (~((chan)->alloc_size-1)))
  29 #define BUFFER_OFFSET(offset, chan) ((offset) & ((chan)->alloc_size - 1))
  30 #define SUBBUF_OFFSET(offset, chan) ((offset) & ((chan)->subbuf_size - 1))
  31 #define SUBBUF_ALIGN(offset, chan) \
  32         (((offset) + (chan)->subbuf_size) & (~((chan)->subbuf_size - 1)))
  33 #define SUBBUF_TRUNC(offset, chan) \
  34         ((offset) & (~((chan)->subbuf_size - 1)))
  35 #define SUBBUF_INDEX(offset, chan) \
  36         (BUFFER_OFFSET((offset), chan) >> (chan)->subbuf_size_order)
  37
  38
  39 #endif /* UST_BUFFER_H */