bitmap: add bitmap_unset() function
We've never needed to unset an individual bit in a bitmap until now. Typically they start with all bits unset and we bitmap_set() them, or we are applying another bitmap as a mask. But the easiest way to apply an object filter to a bitmap result will be to unset the individual bits. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jeff King committed
Feb 14, 2020 at 13:22 UTC
cc4aa28506e079e0c17cfbe78743530795803ea8
2 files changed
+9
ewah/bitmap.c
+8
@@ -45,6 +45,14 @@ void bitmap_set(struct bitmap *self, size_t pos)
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self->words[block] |= EWAH_MASK(pos);
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}
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+void bitmap_unset(struct bitmap *self, size_t pos)
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+{
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+ size_t block = EWAH_BLOCK(pos);
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+
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+ if (block < self->word_alloc)
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+ self->words[block] &= ~EWAH_MASK(pos);
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+}
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+
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int bitmap_get(struct bitmap *self, size_t pos)
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{
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size_t block = EWAH_BLOCK(pos);
ewah/ewok.h
+1
@@ -173,6 +173,7 @@ struct bitmap {
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struct bitmap *bitmap_new(void);
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void bitmap_set(struct bitmap *self, size_t pos);
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+void bitmap_unset(struct bitmap *self, size_t pos);
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int bitmap_get(struct bitmap *self, size_t pos);
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void bitmap_reset(struct bitmap *self);
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void bitmap_free(struct bitmap *self);