Files
mgmt/resources/util.go
James Shubin dacbf9b68d resources: Add resource sorting and clean tests
Resource sorting is needed for comparing resource groups.
2017-06-08 01:05:58 -04:00

80 lines
2.5 KiB
Go

// Mgmt
// Copyright (C) 2013-2017+ James Shubin and the project contributors
// Written by James Shubin <james@shubin.ca> and the project contributors
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package resources
import (
"bytes"
"encoding/base64"
"encoding/gob"
"fmt"
"sort"
errwrap "github.com/pkg/errors"
)
// ResourceSlice is a linear list of resources. It can be sorted.
type ResourceSlice []Res
func (rs ResourceSlice) Len() int { return len(rs) }
func (rs ResourceSlice) Swap(i, j int) { rs[i], rs[j] = rs[j], rs[i] }
func (rs ResourceSlice) Less(i, j int) bool { return rs[i].String() < rs[j].String() }
// Sort the list of resources and return a copy without modifying the input.
func Sort(rs []Res) []Res {
resources := []Res{}
for _, r := range rs { // copy
resources = append(resources, r)
}
sort.Sort(ResourceSlice(resources))
return resources
// sort.Sort(ResourceSlice(rs)) // this is wrong, it would modify input!
//return rs
}
// ResToB64 encodes a resource to a base64 encoded string (after serialization).
func ResToB64(res Res) (string, error) {
b := bytes.Buffer{}
e := gob.NewEncoder(&b)
err := e.Encode(&res) // pass with &
if err != nil {
return "", errwrap.Wrapf(err, "gob failed to encode")
}
return base64.StdEncoding.EncodeToString(b.Bytes()), nil
}
// B64ToRes decodes a resource from a base64 encoded string (after deserialization).
func B64ToRes(str string) (Res, error) {
var output interface{}
bb, err := base64.StdEncoding.DecodeString(str)
if err != nil {
return nil, errwrap.Wrapf(err, "base64 failed to decode")
}
b := bytes.NewBuffer(bb)
d := gob.NewDecoder(b)
err = d.Decode(&output) // pass with &
if err != nil {
return nil, errwrap.Wrapf(err, "gob failed to decode")
}
res, ok := output.(Res)
if !ok {
return nil, fmt.Errorf("output `%v` is not a Res", output)
}
return res, nil
}