/
compressor.go
83 lines (70 loc) · 2 KB
/
compressor.go
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// Copyright 2020 Northern.tech AS
//
// 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.
package artifact
import (
"io"
"sort"
"strings"
"github.com/pkg/errors"
)
var compressors = make(map[string]Compressor)
type Compressor interface {
GetFileExtension() string
NewReader(r io.Reader) (io.ReadCloser, error)
NewWriter(w io.Writer) (io.WriteCloser, error)
}
func RegisterCompressor(id string, compressor Compressor) {
compressors[id] = compressor
}
func NewCompressorFromFileName(name string) (Compressor, error) {
for _, compressor := range compressors {
extension := compressor.GetFileExtension()
if extension != "" && strings.HasSuffix(name, extension) {
return compressor, nil
}
}
return NewCompressorNone(), nil
}
func NewCompressorFromId(id string) (Compressor, error) {
compressor, ok := compressors[id]
if !ok {
return nil, errors.Errorf("invalid compressor id: %v", id)
}
return compressor, nil
}
type compressorIdSort []string
func (s compressorIdSort) Len() int {
return len(s)
}
func (s compressorIdSort) Swap(i, j int) {
s[i], s[j] = s[j], s[i]
}
func (s compressorIdSort) Less(i, j int) bool {
if s[i] == "none" {
return true
} else if s[j] == "none" {
return false
} else {
return s[i] < s[j]
}
}
func GetRegisteredCompressorIds() []string {
ids := make([]string, 0, len(compressors))
for id := range compressors {
ids = append(ids, id)
}
// Sort 'none' at the front and alphabetically thereafter
sort.Sort(compressorIdSort(ids))
return ids
}