Update vendor

vendor/github.com/cockroachdb/cmux/patricia.go

@@ -0,0 +1,173 @@
+package cmux
+
+import (
+	"bytes"
+	"io"
+)
+
+// patriciaTree is a simple patricia tree that handles []byte instead of string
+// and cannot be changed after instantiation.
+type patriciaTree struct {
+	root *ptNode
+}
+
+func newPatriciaTree(b ...[]byte) *patriciaTree {
+	return &patriciaTree{
+		root: newNode(b),
+	}
+}
+
+func newPatriciaTreeString(strs ...string) *patriciaTree {
+	b := make([][]byte, len(strs))
+	for i, s := range strs {
+		b[i] = []byte(s)
+	}
+	return &patriciaTree{
+		root: newNode(b),
+	}
+}
+
+func (t *patriciaTree) matchPrefix(r io.Reader) bool {
+	return t.root.match(r, true)
+}
+
+func (t *patriciaTree) match(r io.Reader) bool {
+	return t.root.match(r, false)
+}
+
+type ptNode struct {
+	prefix   []byte
+	next     map[byte]*ptNode
+	terminal bool
+}
+
+func newNode(strs [][]byte) *ptNode {
+	if len(strs) == 0 {
+		return &ptNode{
+			prefix:   []byte{},
+			terminal: true,
+		}
+	}
+
+	if len(strs) == 1 {
+		return &ptNode{
+			prefix:   strs[0],
+			terminal: true,
+		}
+	}
+
+	p, strs := splitPrefix(strs)
+	n := &ptNode{
+		prefix: p,
+	}
+
+	nexts := make(map[byte][][]byte)
+	for _, s := range strs {
+		if len(s) == 0 {
+			n.terminal = true
+			continue
+		}
+		nexts[s[0]] = append(nexts[s[0]], s[1:])
+	}
+
+	n.next = make(map[byte]*ptNode)
+	for first, rests := range nexts {
+		n.next[first] = newNode(rests)
+	}
+
+	return n
+}
+
+func splitPrefix(bss [][]byte) (prefix []byte, rest [][]byte) {
+	if len(bss) == 0 || len(bss[0]) == 0 {
+		return prefix, bss
+	}
+
+	if len(bss) == 1 {
+		return bss[0], [][]byte{{}}
+	}
+
+	for i := 0; ; i++ {
+		var cur byte
+		eq := true
+		for j, b := range bss {
+			if len(b) <= i {
+				eq = false
+				break
+			}
+
+			if j == 0 {
+				cur = b[i]
+				continue
+			}
+
+			if cur != b[i] {
+				eq = false
+				break
+			}
+		}
+
+		if !eq {
+			break
+		}
+
+		prefix = append(prefix, cur)
+	}
+
+	rest = make([][]byte, 0, len(bss))
+	for _, b := range bss {
+		rest = append(rest, b[len(prefix):])
+	}
+
+	return prefix, rest
+}
+
+func readBytes(r io.Reader, n int) (b []byte, err error) {
+	b = make([]byte, n)
+	o := 0
+	for o < n {
+		nr, err := r.Read(b[o:])
+		if err != nil && err != io.EOF {
+			return b, err
+		}
+
+		o += nr
+
+		if err == io.EOF {
+			break
+		}
+	}
+	return b[:o], nil
+}
+
+func (n *ptNode) match(r io.Reader, prefix bool) bool {
+	if l := len(n.prefix); l > 0 {
+		b, err := readBytes(r, l)
+		if err != nil || len(b) != l || !bytes.Equal(b, n.prefix) {
+			return false
+		}
+	}
+
+	if prefix && n.terminal {
+		return true
+	}
+
+	b := make([]byte, 1)
+	for {
+		nr, err := r.Read(b)
+		if nr != 0 {
+			break
+		}
+
+		if err == io.EOF {
+			return n.terminal
+		}
+
+		if err != nil {
+			return false
+		}
+	}
+
+	nextN, ok := n.next[b[0]]
+	return ok && nextN.match(r, prefix)
+}