You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
29 lines
706 B
29 lines
706 B
// 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
|
|
}
|
|
|