lib/bitmap.h

   1 /*
   2  * Copyright (c) 2008, 2009, 2010, 2011 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 size_t
  39 bitmap_n_longs(size_t n_bits)
  40 {
  41     return DIV_ROUND_UP(n_bits, BITMAP_ULONG_BITS);
  42 }
  43
  44 static inline size_t
  45 bitmap_n_bytes(size_t n_bits)
  46 {
  47     return bitmap_n_longs(n_bits) * sizeof(unsigned long int);
  48 }
  49
  50 static inline unsigned long *
  51 bitmap_allocate(size_t n_bits)
  52 {
  53     return xzalloc(bitmap_n_bytes(n_bits));
  54 }
  55
  56 static inline unsigned long *
  57 bitmap_clone(const unsigned long *bitmap, size_t n_bits)
  58 {
  59     return xmemdup(bitmap, bitmap_n_bytes(n_bits));
  60 }
  61
  62 static inline void
  63 bitmap_free(unsigned long *bitmap)
  64 {
  65     free(bitmap);
  66 }
  67
  68 static inline bool
  69 bitmap_is_set(const unsigned long *bitmap, size_t offset)
  70 {
  71     return (*bitmap_unit__(bitmap, offset) & bitmap_bit__(offset)) != 0;
  72 }
  73
  74 static inline void
  75 bitmap_set1(unsigned long *bitmap, size_t offset)
  76 {
  77     *bitmap_unit__(bitmap, offset) |= bitmap_bit__(offset);
  78 }
  79
  80 static inline void
  81 bitmap_set0(unsigned long *bitmap, size_t offset)
  82 {
  83     *bitmap_unit__(bitmap, offset) &= ~bitmap_bit__(offset);
  84 }
  85
  86 static inline void
  87 bitmap_set(unsigned long *bitmap, size_t offset, bool value)
  88 {
  89     if (value) {
  90         bitmap_set1(bitmap, offset);
  91     } else {
  92         bitmap_set0(bitmap, offset);
  93     }
  94 }
  95
  96 void bitmap_set_multiple(unsigned long *, size_t start, size_t count,
  97                          bool value);
  98 bool bitmap_equal(const unsigned long *, const unsigned long *, size_t n);
  99 size_t bitmap_scan(const unsigned long int *, size_t start, size_t end);
 100
 101 #define BITMAP_FOR_EACH_1(IDX, SIZE, BITMAP) \
 102     for ((IDX) = bitmap_scan(BITMAP, 0, SIZE); (IDX) < (SIZE); \
 103          (IDX) = bitmap_scan(BITMAP, (IDX) + 1, SIZE))
 104
 105 #endif /* bitmap.h */