mirror of
https://github.com/featurebasedb/featurebase.git
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3c832591df
This commit moves the index package to the root. Because pilosa is an index at its core, it's redundant to have an index subpackage. It also provides better naming such as `pilosa.Bitmap` instead of `index.Bitmap`.
53 lines
1,020 B
Go
53 lines
1,020 B
Go
package pilosa
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// bit population count, take from
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// https://code.google.com/p/go/issues/detail?id=4988#c11
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// credit: https://code.google.com/u/arnehormann/
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func popcount(x uint64) (n uint64) {
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x -= (x >> 1) & 0x5555555555555555
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x = (x>>2)&0x3333333333333333 + x&0x3333333333333333
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x += x >> 4
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x &= 0x0f0f0f0f0f0f0f0f
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x *= 0x0101010101010101
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return x >> 56
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}
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func popcntSliceGo(s []uint64) uint64 {
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cnt := uint64(0)
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for _, x := range s {
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cnt += popcount(x)
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}
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return cnt
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}
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func popcntMaskSliceGo(s, m []uint64) uint64 {
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cnt := uint64(0)
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for i := range s {
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cnt += popcount(s[i] &^ m[i])
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}
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return cnt
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}
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func popcntAndSliceGo(s, m []uint64) uint64 {
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cnt := uint64(0)
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for i := range s {
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cnt += popcount(s[i] & m[i])
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}
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return cnt
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}
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func popcntOrSliceGo(s, m []uint64) uint64 {
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cnt := uint64(0)
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for i := range s {
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cnt += popcount(s[i] | m[i])
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}
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return cnt
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}
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func popcntXorSliceGo(s, m []uint64) uint64 {
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cnt := uint64(0)
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for i := range s {
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cnt += popcount(s[i] ^ m[i])
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}
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return cnt
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}
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