FirstOne returns the first set bit from the range [start, )
(start uint32)
| 101 | |
| 102 | // FirstOne returns the first set bit from the range [start, ) |
| 103 | func (b *Bitmap) FirstOne(start uint32) (bit uint32, err error) { |
| 104 | i, nbit := int(start/64), start%64 |
| 105 | n := len(b.bitBlock) |
| 106 | if i >= n { |
| 107 | return MaxBitEntryLimit, fmt.Errorf("given start of range exceeds bitmap size") |
| 108 | } |
| 109 | w := b.bitBlock[i] & (math.MaxUint64 << nbit) |
| 110 | for { |
| 111 | if w != uint64(0) { |
| 112 | r := bits.TrailingZeros64(w) |
| 113 | return uint32(r + i*64), nil |
| 114 | } |
| 115 | i++ |
| 116 | if i == n { |
| 117 | break |
| 118 | } |
| 119 | w = b.bitBlock[i] |
| 120 | } |
| 121 | return MaxBitEntryLimit, fmt.Errorf("bitmap has no set bits") |
| 122 | } |
| 123 | |
| 124 | // Maximum return the largest value in the Bitmap. |
| 125 | func (b *Bitmap) Maximum() uint32 { |