| // Copyright 2015 CoreOS, 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 |
| // |
| // 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 unit |
| |
| import ( |
| "bytes" |
| "io" |
| ) |
| |
| // Serialize encodes all of the given UnitOption objects into a |
| // unit file. When serialized the options are sorted in their |
| // supplied order but grouped by section. |
| func Serialize(opts []*UnitOption) io.Reader { |
| var buf bytes.Buffer |
| |
| if len(opts) == 0 { |
| return &buf |
| } |
| |
| // Index of sections -> ordered options |
| idx := map[string][]*UnitOption{} |
| // Separately preserve order in which sections were seen |
| sections := []string{} |
| for _, opt := range opts { |
| sec := opt.Section |
| if _, ok := idx[sec]; !ok { |
| sections = append(sections, sec) |
| } |
| idx[sec] = append(idx[sec], opt) |
| } |
| |
| for i, sect := range sections { |
| writeSectionHeader(&buf, sect) |
| writeNewline(&buf) |
| |
| opts := idx[sect] |
| for _, opt := range opts { |
| writeOption(&buf, opt) |
| writeNewline(&buf) |
| } |
| if i < len(sections)-1 { |
| writeNewline(&buf) |
| } |
| } |
| |
| return &buf |
| } |
| |
| func writeNewline(buf *bytes.Buffer) { |
| buf.WriteRune('\n') |
| } |
| |
| func writeSectionHeader(buf *bytes.Buffer, section string) { |
| buf.WriteRune('[') |
| buf.WriteString(section) |
| buf.WriteRune(']') |
| } |
| |
| func writeOption(buf *bytes.Buffer, opt *UnitOption) { |
| buf.WriteString(opt.Name) |
| buf.WriteRune('=') |
| buf.WriteString(opt.Value) |
| } |