[PATCH v4 03/12] ewah/bitmap: introduce bitmap_word_alloc()
- From
Christian Couder <christian.couder@gmail.com>
- Date
- Dec 18, 2019, 11:25 UTC
- Message-ID
- <20191218112547.4974-4-chriscool@tuxfamily.org>
- In-Reply-To
- <20191218112547.4974-1-chriscool@tuxfamily.org>
From: Jeff King <peff@peff.net>
In a following commit we will need to allocate a variable number of bitmap words, instead of always 32, so let's add bitmap_word_alloc() for this purpose.
Note that we have to adjust the block growth in bitmap_set(), since a caller could now use an initial size of "0" (we don't plan to do that, but it doesn't hurt to be defensive).
Helped-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Christian Couder <chriscool@tuxfamily.org> --- ewah/bitmap.c | 13 +++++++++---- ewah/ewok.h | 1 + 2 files changed, 10 insertions(+), 4 deletions(-)
diff --git a/ewah/bitmap.c b/ewah/bitmap.c index 52f1178db4..b5fed9621f 100644 --- a/ewah/bitmap.c +++ b/ewah/bitmap.c @@ -22,21 +22,26 @@ #define EWAH_MASK(x) ((eword_t)1 << (x % BITS_IN_EWORD)) #define EWAH_BLOCK(x) (x / BITS_IN_EWORD) -struct bitmap *bitmap_new(void) +struct bitmap *bitmap_word_alloc(size_t word_alloc) { struct bitmap *bitmap = xmalloc(sizeof(struct bitmap)); - bitmap->words = xcalloc(32, sizeof(eword_t)); - bitmap->word_alloc = 32; + bitmap->words = xcalloc(word_alloc, sizeof(eword_t)); + bitmap->word_alloc = word_alloc; return bitmap; } +struct bitmap *bitmap_new(void) +{ + return bitmap_word_alloc(32); +} + void bitmap_set(struct bitmap *self, size_t pos) { size_t block = EWAH_BLOCK(pos); if (block >= self->word_alloc) { size_t old_size = self->word_alloc; - self->word_alloc = block * 2; + self->word_alloc = block ? block * 2 : 1; REALLOC_ARRAY(self->words, self->word_alloc); memset(self->words + old_size, 0x0, (self->word_alloc - old_size) * sizeof(eword_t)); diff --git a/ewah/ewok.h b/ewah/ewok.h index 84b2a29faa..1b98b57c8b 100644 --- a/ewah/ewok.h +++ b/ewah/ewok.h @@ -172,6 +172,7 @@ struct bitmap { }; struct bitmap *bitmap_new(void); +struct bitmap *bitmap_word_alloc(size_t word_alloc); void bitmap_set(struct bitmap *self, size_t pos); int bitmap_get(struct bitmap *self, size_t pos); void bitmap_reset(struct bitmap *self);
-- 2.24.1.498.g561400140f