17 lines
527 B
Go
17 lines
527 B
Go
package torrent
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import (
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"github.com/anacrolix/torrent/typed-roaring"
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)
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// Return the number of bits set in the range. To do this we need the rank of the item before the
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// first, and the rank of the last item. An off-by-one minefield. Hopefully I haven't missed
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// something in roaring's API that provides this.
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func roaringBitmapRangeCardinality[T typedRoaring.BitConstraint](bm interface{ Rank(T) uint64 }, start, end T) (card uint64) {
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card = bm.Rank(end - 1)
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if start != 0 {
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card -= bm.Rank(start - 1)
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}
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return
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}
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