lib/bitmap.h

   1 /*
   2  * Copyright (c) 2008, 2009, 2010, 2011, 2012 Nicira, Inc.
   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 CONST_CAST(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 unsigned long *bitmap_allocate1(size_t n_bits);
  57
  58 static inline unsigned long *
  59 bitmap_clone(const unsigned long *bitmap, size_t n_bits)
  60 {
  61     return xmemdup(bitmap, bitmap_n_bytes(n_bits));
  62 }
  63
  64 static inline void
  65 bitmap_free(unsigned long *bitmap)
  66 {
  67     free(bitmap);
  68 }
  69
  70 static inline bool
  71 bitmap_is_set(const unsigned long *bitmap, size_t offset)
  72 {
  73     return (*bitmap_unit__(bitmap, offset) & bitmap_bit__(offset)) != 0;
  74 }
  75
  76 static inline void
  77 bitmap_set1(unsigned long *bitmap, size_t offset)
  78 {
  79     *bitmap_unit__(bitmap, offset) |= bitmap_bit__(offset);
  80 }
  81
  82 static inline void
  83 bitmap_set0(unsigned long *bitmap, size_t offset)
  84 {
  85     *bitmap_unit__(bitmap, offset) &= ~bitmap_bit__(offset);
  86 }
  87
  88 static inline void
  89 bitmap_set(unsigned long *bitmap, size_t offset, bool value)
  90 {
  91     if (value) {
  92         bitmap_set1(bitmap, offset);
  93     } else {
  94         bitmap_set0(bitmap, offset);
  95     }
  96 }
  97
  98 void bitmap_set_multiple(unsigned long *, size_t start, size_t count,
  99                          bool value);
 100 bool bitmap_equal(const unsigned long *, const unsigned long *, size_t n);
 101 size_t bitmap_scan(const unsigned long int *, size_t start, size_t end);
 102
 103 #define BITMAP_FOR_EACH_1(IDX, SIZE, BITMAP) \
 104     for ((IDX) = bitmap_scan(BITMAP, 0, SIZE); (IDX) < (SIZE); \
 105          (IDX) = bitmap_scan(BITMAP, (IDX) + 1, SIZE))
 106
 107 #endif /* bitmap.h */