src/gallium/auxiliary/util/u_bitmask.h

   1 /**************************************************************************
   2  *
   3  * Copyright 2009 VMware, Inc.
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sub license, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  21  * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
  22  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  23  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  **************************************************************************/
  27
  28 /**
  29  * @file
  30  * Generic bitmask.
  31  *
  32  * @author Jose Fonseca <jfonseca@vmware.com>
  33  */
  34
  35 #ifndef U_HANDLE_BITMASK_H_
  36 #define U_HANDLE_BITMASK_H_
  37
  38
  39 #include "pipe/p_compiler.h"
  40
  41
  42 #ifdef __cplusplus
  43 extern "C" {
  44 #endif
  45
  46
  47 #define UTIL_BITMASK_INVALID_INDEX (~0U)
  48
  49
  50 /**
  51  * Abstract data type to represent arbitrary set of bits.
  52  */
  53 struct util_bitmask;
  54
  55
  56 struct util_bitmask *
  57 util_bitmask_create(void);
  58
  59
  60 /**
  61  * Search a cleared bit and set it.
  62  *
  63  * It searches for the first cleared bit.
  64  *
  65  * Returns the bit index on success, or UTIL_BITMASK_INVALID_INDEX on out of
  66  * memory growing the bitmask.
  67  */
  68 unsigned
  69 util_bitmask_add(struct util_bitmask *bm);
  70
  71 /**
  72  * Set a bit.
  73  *
  74  * Returns the input index on success, or UTIL_BITMASK_INVALID_INDEX on out of
  75  * memory growing the bitmask.
  76  */
  77 unsigned
  78 util_bitmask_set(struct util_bitmask *bm,
  79                  unsigned index);
  80
  81 void
  82 util_bitmask_clear(struct util_bitmask *bm,
  83                    unsigned index);
  84
  85 boolean
  86 util_bitmask_get(struct util_bitmask *bm,
  87                  unsigned index);
  88
  89
  90 void
  91 util_bitmask_destroy(struct util_bitmask *bm);
  92
  93
  94 /**
  95  * Search for the first set bit.
  96  *
  97  * Returns UTIL_BITMASK_INVALID_INDEX if a set bit cannot be found.
  98  */
  99 unsigned
 100 util_bitmask_get_first_index(struct util_bitmask *bm);
 101
 102
 103 /**
 104  * Search for the first set bit, starting from the giving index.
 105  *
 106  * Returns UTIL_BITMASK_INVALID_INDEX if a set bit cannot be found.
 107  */
 108 unsigned
 109 util_bitmask_get_next_index(struct util_bitmask *bm,
 110                             unsigned index);
 111
 112
 113 #ifdef __cplusplus
 114 }
 115 #endif
 116
 117 #endif /* U_HANDLE_BITMASK_H_ */