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Commit | Line | Data |
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064af421 | 1 | /* |
7cc48aed | 2 | * Copyright (c) 2008, 2009 Nicira Networks. |
064af421 | 3 | * |
a14bc59f BP |
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: | |
064af421 | 7 | * |
a14bc59f BP |
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. | |
064af421 BP |
15 | */ |
16 | ||
17 | #include <config.h> | |
18 | #include "bitmap.h" | |
19 | #include <string.h> | |
20 | ||
21 | /* Sets 'count' consecutive bits in 'bitmap', starting at bit offset 'start', | |
22 | * to 'value'. */ | |
23 | void | |
24 | bitmap_set_multiple(unsigned long *bitmap, size_t start, size_t count, | |
25 | bool value) | |
26 | { | |
27 | for (; count && start % BITMAP_ULONG_BITS; count--) { | |
28 | bitmap_set(bitmap, start++, value); | |
29 | } | |
30 | for (; count >= BITMAP_ULONG_BITS; count -= BITMAP_ULONG_BITS) { | |
31 | *bitmap_unit__(bitmap, start) = -(unsigned long) value; | |
32 | start += BITMAP_ULONG_BITS; | |
33 | } | |
34 | for (; count; count--) { | |
35 | bitmap_set(bitmap, start++, value); | |
36 | } | |
37 | } | |
38 | ||
39 | /* Compares the 'n' bits in bitmaps 'a' and 'b'. Returns true if all bits are | |
40 | * equal, false otherwise. */ | |
41 | bool | |
42 | bitmap_equal(const unsigned long *a, const unsigned long *b, size_t n) | |
43 | { | |
44 | size_t i; | |
45 | ||
46 | if (memcmp(a, b, n / BITMAP_ULONG_BITS * sizeof(unsigned long))) { | |
47 | return false; | |
48 | } | |
49 | for (i = ROUND_DOWN(n, BITMAP_ULONG_BITS); i < n; i++) { | |
50 | if (bitmap_is_set(a, i) != bitmap_is_set(b, i)) { | |
51 | return false; | |
52 | } | |
53 | } | |
54 | return true; | |
55 | } | |
7cc48aed BP |
56 | |
57 | /* Scans 'bitmap' from bit offset 'start' to 'end', excluding 'end' itself. | |
58 | * Returns the bit offset of the lowest-numbered bit set to 1, or 'end' if | |
59 | * all of the bits are set to 0. */ | |
60 | size_t | |
61 | bitmap_scan(const unsigned long int *bitmap, size_t start, size_t end) | |
62 | { | |
63 | /* XXX slow */ | |
64 | size_t i; | |
65 | ||
66 | for (i = start; i < end; i++) { | |
67 | if (bitmap_is_set(bitmap, i)) { | |
68 | break; | |
69 | } | |
70 | } | |
71 | return i; | |
72 | } |