libgo/go/hash/hash.go

   1 // Copyright 2009 The Go Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style
   3 // license that can be found in the LICENSE file.
   4
   5 // Package hash provides interfaces for hash functions.
   6 package hash
   7
   8 import "io"
   9
  10 // Hash is the common interface implemented by all hash functions.
  11 type Hash interface {
  12         // Write adds more data to the running hash.
  13         // It never returns an error.
  14         io.Writer
  15
  16         // Sum appends the current hash to b and returns the resulting slice.
  17         // It does not change the underlying hash state.
  18         Sum(b []byte) []byte
  19
  20         // Reset resets the hash to one with zero bytes written.
  21         Reset()
  22
  23         // Size returns the number of bytes Sum will return.
  24         Size() int
  25
  26         // BlockSize returns the hash's underlying block size.
  27         // The Write method must be able to accept any amount
  28         // of data, but it may operate more efficiently if all writes
  29         // are a multiple of the block size.
  30         BlockSize() int
  31 }
  32
  33 // Hash32 is the common interface implemented by all 32-bit hash functions.
  34 type Hash32 interface {
  35         Hash
  36         Sum32() uint32
  37 }
  38
  39 // Hash64 is the common interface implemented by all 64-bit hash functions.
  40 type Hash64 interface {
  41         Hash
  42         Sum64() uint64
  43 }