vendor

vendor/github.com/ulikunitz/xz/internal/hash/roller.go

@@ -0,0 +1,29 @@
+// Copyright 2014-2017 Ulrich Kunitz. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package hash
+
+// Roller provides an interface for rolling hashes. The hash value will become
+// valid after hash has been called Len times.
+type Roller interface {
+	Len() int
+	RollByte(x byte) uint64
+}
+
+// Hashes computes all hash values for the array p. Note that the state of the
+// roller is changed.
+func Hashes(r Roller, p []byte) []uint64 {
+	n := r.Len()
+	if len(p) < n {
+		return nil
+	}
+	h := make([]uint64, len(p)-n+1)
+	for i := 0; i < n-1; i++ {
+		r.RollByte(p[i])
+	}
+	for i := range h {
+		h[i] = r.RollByte(p[i+n-1])
+	}
+	return h
+}