lib/bitmap.h

   1 /*
   2  * Copyright (c) 2008, 2009 Nicira Networks.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at:
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 #ifndef BITMAP_H
  18 #define BITMAP_H 1
  19
  20 #include <limits.h>
  21 #include <stdlib.h>
  22 #include "util.h"
  23
  24 #define BITMAP_ULONG_BITS (sizeof(unsigned long) * CHAR_BIT)
  25
  26 static inline unsigned long *
  27 bitmap_unit__(const unsigned long *bitmap, size_t offset)
  28 {
  29     return (unsigned long *) &bitmap[offset / BITMAP_ULONG_BITS];
  30 }
  31
  32 static inline unsigned long
  33 bitmap_bit__(size_t offset)
  34 {
  35     return 1UL << (offset % BITMAP_ULONG_BITS);
  36 }
  37
  38 static inline unsigned long *
  39 bitmap_allocate(size_t n_bits)
  40 {
  41     size_t n_longs = DIV_ROUND_UP(n_bits, BITMAP_ULONG_BITS);
  42     return xcalloc(sizeof(unsigned long int), n_longs);
  43 }
  44
  45 static inline void
  46 bitmap_free(unsigned long *bitmap)
  47 {
  48     free(bitmap);
  49 }
  50
  51 static inline bool
  52 bitmap_is_set(const unsigned long *bitmap, size_t offset)
  53 {
  54     return (*bitmap_unit__(bitmap, offset) & bitmap_bit__(offset)) != 0;
  55 }
  56
  57 static inline void
  58 bitmap_set1(unsigned long *bitmap, size_t offset)
  59 {
  60     *bitmap_unit__(bitmap, offset) |= bitmap_bit__(offset);
  61 }
  62
  63 static inline void
  64 bitmap_set0(unsigned long *bitmap, size_t offset)
  65 {
  66     *bitmap_unit__(bitmap, offset) &= ~bitmap_bit__(offset);
  67 }
  68
  69 static inline void
  70 bitmap_set(unsigned long *bitmap, size_t offset, bool value)
  71 {
  72     if (value) {
  73         bitmap_set1(bitmap, offset);
  74     } else {
  75         bitmap_set0(bitmap, offset);
  76     }
  77 }
  78
  79 void bitmap_set_multiple(unsigned long *, size_t start, size_t count,
  80                          bool value);
  81 bool bitmap_equal(const unsigned long *, const unsigned long *, size_t n);
  82
  83 #endif /* bitmap.h */