| // Copyright 2017 Docker, Inc. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // https://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| package digest |
| |
| import "hash" |
| |
| // Digester calculates the digest of written data. Writes should go directly |
| // to the return value of Hash, while calling Digest will return the current |
| // value of the digest. |
| type Digester interface { |
| Hash() hash.Hash // provides direct access to underlying hash instance. |
| Digest() Digest |
| } |
| |
| // digester provides a simple digester definition that embeds a hasher. |
| type digester struct { |
| alg Algorithm |
| hash hash.Hash |
| } |
| |
| func (d *digester) Hash() hash.Hash { |
| return d.hash |
| } |
| |
| func (d *digester) Digest() Digest { |
| return NewDigest(d.alg, d.hash) |
| } |