1// Copyright 2015 Google Inc. All rights reserved.
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//     http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15// env implements the environment JSON file handling for the soong_env command line tool run before
16// the builder and for the env writer in the builder.
17package env
18
19import (
20	"encoding/json"
21	"fmt"
22	"io/ioutil"
23	"os"
24	"sort"
25)
26
27type envFileEntry struct{ Key, Value string }
28type envFileData []envFileEntry
29
30func WriteEnvFile(filename string, envDeps map[string]string) error {
31	contents := make(envFileData, 0, len(envDeps))
32	for key, value := range envDeps {
33		contents = append(contents, envFileEntry{key, value})
34	}
35
36	sort.Sort(contents)
37
38	data, err := json.MarshalIndent(contents, "", "    ")
39	if err != nil {
40		return err
41	}
42
43	data = append(data, '\n')
44
45	err = ioutil.WriteFile(filename, data, 0664)
46	if err != nil {
47		return err
48	}
49
50	return nil
51}
52
53func StaleEnvFile(filename string) (bool, error) {
54	data, err := ioutil.ReadFile(filename)
55	if err != nil {
56		return true, err
57	}
58
59	var contents envFileData
60
61	err = json.Unmarshal(data, &contents)
62	if err != nil {
63		return true, err
64	}
65
66	var changed []string
67	for _, entry := range contents {
68		key := entry.Key
69		old := entry.Value
70		cur := os.Getenv(key)
71		if old != cur {
72			changed = append(changed, fmt.Sprintf("%s (%q -> %q)", key, old, cur))
73		}
74	}
75
76	if len(changed) > 0 {
77		fmt.Printf("environment variables changed value:\n")
78		for _, s := range changed {
79			fmt.Printf("   %s\n", s)
80		}
81		return true, nil
82	}
83
84	return false, nil
85}
86
87func (e envFileData) Len() int {
88	return len(e)
89}
90
91func (e envFileData) Less(i, j int) bool {
92	return e[i].Key < e[j].Key
93}
94
95func (e envFileData) Swap(i, j int) {
96	e[i], e[j] = e[j], e[i]
97}
98