include: introduce bitmap API #225
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wipawel
requested changes
Nov 4, 2021
include/bitmap.h
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| int nbits; | ||
| } bitmap_t; | ||
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| static inline bitmap_t *bitmap_alloc(int nbits) { |
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I would place bitmap_alloc() and bitmap_free() into bitmap.c file and declare them as non-inline functions.
include/bitmap.h
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| if (NULL == map) | ||
| return NULL; | ||
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| map->word = kmalloc(BITS_TO_LONGS(nbits) * __SIZEOF_LONG__); |
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better would be kzmalloc(); or add explicit memset(map->word, 0, size)
include/bitmap.h
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| int nbits; | ||
| } bitmap_t; | ||
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| static inline bitmap_t *bitmap_alloc(int nbits) { |
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nit: nbits could be unsigned
include/bitmap.h
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| static inline int bitmap_find_first_clear(const bitmap_t *map) { | ||
| if (NULL == map || NULL == map->word) | ||
| return INT_MAX; | ||
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| for (int i = 0; i < BITS_TO_LONGS(map->nbits); i++) { | ||
| int ret = __builtin_ffsl(~map->word[i]); | ||
| if (0 == ret) | ||
| continue; | ||
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| return i * BITS_PER_LONG + ret - 1; | ||
| } | ||
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| return INT_MAX; | ||
| } | ||
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this one appears identical to bitmap_find_first_set()
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Author
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It is except for the negation on map->word[i]
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Right, I missed that, my bad.
Add a new bitmap_t that represents an array-based bitmap. Implement alloc/free and various functions for bitmap operations. Add div_round_up helper macro for computing the number of longs that a given bitmap should be. Signed-off-by: Connor Davis <[email protected]>
wipawel
approved these changes
Nov 15, 2021
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Add a new bitmap_t that represents an array-based bitmap.
Implement alloc/free and various functions for bitmap operations.
Add div_round_up helper macro for computing the number of longs
that a given bitmap should be.
Signed-off-by: Connor Davis [email protected]
Issue #145
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