dragonfly/pkg/digest/digest_reader.go

123 lines
2.7 KiB
Go

/*
* Copyright 2022 The Dragonfly Authors
*
* 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
*
* http://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.
*/
//go:generate mockgen -destination mocks/digest_reader_mock.go -source digest_reader.go -package mocks
package digest
import (
"crypto/md5"
"crypto/sha1"
"crypto/sha256"
"crypto/sha512"
"encoding/hex"
"errors"
"fmt"
"hash"
"io"
logger "d7y.io/dragonfly/v2/internal/dflog"
)
// Reader is the interface used for reading resource.
type Reader interface {
io.Reader
Encoded() string
}
// reader reads stream with RateLimiter.
type reader struct {
r io.Reader
encoded string
hash hash.Hash
logger *logger.SugaredLoggerOnWith
}
// Option is a functional option for digest reader.
type Option func(reader *reader)
// WithLogger sets the logger for digest reader.
func WithLogger(logger *logger.SugaredLoggerOnWith) Option {
return func(reader *reader) {
reader.logger = logger
}
}
// WithEncoded sets the encoded to be verified.
func WithEncoded(encoded string) Option {
return func(reader *reader) {
reader.encoded = encoded
}
}
// NewReader creates digest reader.
func NewReader(algorithm string, r io.Reader, options ...Option) (Reader, error) {
var h hash.Hash
switch algorithm {
case AlgorithmSHA1:
h = sha1.New()
case AlgorithmSHA256:
h = sha256.New()
case AlgorithmSHA512:
h = sha512.New()
case AlgorithmMD5:
h = md5.New()
default:
return nil, fmt.Errorf("invalid algorithm: %s", algorithm)
}
reader := &reader{
r: r,
hash: h,
logger: &logger.SugaredLoggerOnWith{},
}
for _, opt := range options {
opt(reader)
}
return reader, nil
}
// Read uses to read content and validate encoded.
func (r *reader) Read(p []byte) (int, error) {
n, err := r.r.Read(p)
if err != nil && err != io.EOF {
return n, err
}
if n > 0 {
r.hash.Write(p[:n])
}
if err == io.EOF && len(r.encoded) != 0 {
encoded := r.Encoded()
if encoded != r.encoded {
r.logger.Warnf("digest encoded not match, desired: %s, actual: %s", r.encoded, encoded)
return n, errors.New("digest encoded not match")
}
r.logger.Debugf("digest encoded match: %s", encoded)
}
return n, err
}
// Encoded returns the encoded of algorithm.
func (r *reader) Encoded() string {
return hex.EncodeToString(r.hash.Sum(nil))
}