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Diffstat (limited to 'src/trie.go')
-rw-r--r--src/trie.go40
1 files changed, 22 insertions, 18 deletions
diff --git a/src/trie.go b/src/trie.go
index 31a4d92..746c1b4 100644
--- a/src/trie.go
+++ b/src/trie.go
@@ -1,5 +1,9 @@
package main
+import (
+ "net"
+)
+
/* Binary trie
*
* Syncronization done seperatly
@@ -22,13 +26,13 @@ type Trie struct {
/* Finds length of matching prefix
* Maybe there is a faster way
*
- * Assumption: len(s1) == len(s2)
+ * Assumption: len(ip1) == len(ip2)
*/
-func commonBits(s1 []byte, s2 []byte) uint {
+func commonBits(ip1 net.IP, ip2 net.IP) uint {
var i uint
- size := uint(len(s1))
+ size := uint(len(ip1))
for i = 0; i < size; i += 1 {
- v := s1[i] ^ s2[i]
+ v := ip1[i] ^ ip2[i]
if v != 0 {
v >>= 1
if v == 0 {
@@ -93,17 +97,17 @@ func (node *Trie) RemovePeer(p *Peer) *Trie {
return node.child[0]
}
-func (node *Trie) choose(key []byte) byte {
- return (key[node.bit_at_byte] >> node.bit_at_shift) & 1
+func (node *Trie) choose(ip net.IP) byte {
+ return (ip[node.bit_at_byte] >> node.bit_at_shift) & 1
}
-func (node *Trie) Insert(key []byte, cidr uint, peer *Peer) *Trie {
+func (node *Trie) Insert(ip net.IP, cidr uint, peer *Peer) *Trie {
// At leaf
if node == nil {
return &Trie{
- bits: key,
+ bits: ip,
peer: peer,
cidr: cidr,
bit_at_byte: cidr / 8,
@@ -113,21 +117,21 @@ func (node *Trie) Insert(key []byte, cidr uint, peer *Peer) *Trie {
// Traverse deeper
- common := commonBits(node.bits, key)
+ common := commonBits(node.bits, ip)
if node.cidr <= cidr && common >= node.cidr {
if node.cidr == cidr {
node.peer = peer
return node
}
- bit := node.choose(key)
- node.child[bit] = node.child[bit].Insert(key, cidr, peer)
+ bit := node.choose(ip)
+ node.child[bit] = node.child[bit].Insert(ip, cidr, peer)
return node
}
// Split node
newNode := &Trie{
- bits: key,
+ bits: ip,
peer: peer,
cidr: cidr,
bit_at_byte: cidr / 8,
@@ -147,31 +151,31 @@ func (node *Trie) Insert(key []byte, cidr uint, peer *Peer) *Trie {
// Create new parent for node & newNode
parent := &Trie{
- bits: key,
+ bits: ip,
peer: nil,
cidr: cidr,
bit_at_byte: cidr / 8,
bit_at_shift: 7 - (cidr % 8),
}
- bit := parent.choose(key)
+ bit := parent.choose(ip)
parent.child[bit] = newNode
parent.child[bit^1] = node
return parent
}
-func (node *Trie) Lookup(key []byte) *Peer {
+func (node *Trie) Lookup(ip net.IP) *Peer {
var found *Peer
- size := uint(len(key))
- for node != nil && commonBits(node.bits, key) >= node.cidr {
+ size := uint(len(ip))
+ for node != nil && commonBits(node.bits, ip) >= node.cidr {
if node.peer != nil {
found = node.peer
}
if node.bit_at_byte == size {
break
}
- bit := node.choose(key)
+ bit := node.choose(ip)
node = node.child[bit]
}
return found