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 EnvFileContents(envDeps map[string]string) ([]byte, 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 nil, err
41	}
42
43	data = append(data, '\n')
44
45	return data, nil
46}
47
48func StaleEnvFile(filename string) (bool, error) {
49	data, err := ioutil.ReadFile(filename)
50	if err != nil {
51		return true, err
52	}
53
54	var contents envFileData
55
56	err = json.Unmarshal(data, &contents)
57	if err != nil {
58		return true, err
59	}
60
61	var changed []string
62	for _, entry := range contents {
63		key := entry.Key
64		old := entry.Value
65		cur := os.Getenv(key)
66		if old != cur {
67			changed = append(changed, fmt.Sprintf("%s (%q -> %q)", key, old, cur))
68		}
69	}
70
71	if len(changed) > 0 {
72		fmt.Printf("environment variables changed value:\n")
73		for _, s := range changed {
74			fmt.Printf("   %s\n", s)
75		}
76		return true, nil
77	}
78
79	return false, nil
80}
81
82func (e envFileData) Len() int {
83	return len(e)
84}
85
86func (e envFileData) Less(i, j int) bool {
87	return e[i].Key < e[j].Key
88}
89
90func (e envFileData) Swap(i, j int) {
91	e[i], e[j] = e[j], e[i]
92}
93