forked from kentik/patricia
/
tree_node_v6.go
50 lines (41 loc) · 1.42 KB
/
tree_node_v6.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
package uint8_tree
import (
"math/bits"
"github.com/gcla/patricia"
)
const _leftmost64Bit = uint64(1 << 63)
type treeNodeV6 struct {
treeNode
Left uint // left node index: 0 for not set
Right uint // right node index: 0 for not set
prefixLeft uint64
prefixRight uint64
prefixLength uint
TagCount int
}
func (n *treeNodeV6) MatchCount(address patricia.IPv6Address) uint {
length := address.Length
if length > n.prefixLength {
length = n.prefixLength
}
matches := uint(bits.LeadingZeros64(n.prefixLeft ^ address.Left))
if matches == 64 && length > 64 {
matches += uint(bits.LeadingZeros64(n.prefixRight ^ address.Right))
}
if matches > length {
return length
}
return matches
}
// ShiftPrefix shifts the prefix by the input shiftCount
func (n *treeNodeV6) ShiftPrefix(shiftCount uint) {
n.prefixLeft, n.prefixRight, n.prefixLength = patricia.ShiftLeftIPv6(n.prefixLeft, n.prefixRight, n.prefixLength, shiftCount)
}
// IsLeftBitSet returns whether the leftmost bit is set
func (n *treeNodeV6) IsLeftBitSet() bool {
return n.prefixLeft >= _leftmost64Bit
}
// MergeFromNodes updates the prefix and prefix length from the two input nodes
func (n *treeNodeV6) MergeFromNodes(left *treeNodeV6, right *treeNodeV6) {
n.prefixLeft, n.prefixRight, n.prefixLength = patricia.MergePrefixes64(left.prefixLeft, left.prefixRight, left.prefixLength, right.prefixLeft, right.prefixRight, right.prefixLength)
}