1 files changed, 29 insertions, 0 deletions

diff --git a/vendor/github.com/ulikunitz/xz/internal/hash/roller.go b/vendor/github.com/ulikunitz/xz/internal/hash/roller.go
new file mode 100644
index 0000000..ab6a19c
--- /dev/null
+++ b/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
+}