platform_build_soong/shared/env.go

108 lines
2.7 KiB
Go

// Copyright 2015 Google Inc. All rights reserved.
//
// 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.
// Implements the environment JSON file handling for serializing the
// environment variables that were used in soong_build so that soong_ui can
// check whether they have changed
package shared
import (
"encoding/json"
"fmt"
"io/ioutil"
"sort"
)
type envFileEntry struct{ Key, Value string }
type envFileData []envFileEntry
// Serializes the given environment variable name/value map into JSON formatted bytes by converting
// to envFileEntry values and marshaling them.
//
// e.g. OUT_DIR = "out"
// is converted to:
// {
// "Key": "OUT_DIR",
// "Value": "out",
// },
func EnvFileContents(envDeps map[string]string) ([]byte, error) {
contents := make(envFileData, 0, len(envDeps))
for key, value := range envDeps {
contents = append(contents, envFileEntry{key, value})
}
sort.Sort(contents)
data, err := json.MarshalIndent(contents, "", " ")
if err != nil {
return nil, err
}
data = append(data, '\n')
return data, nil
}
// Reads and deserializes a Soong environment file located at the given file path to determine its
// staleness. If any environment variable values have changed, it prints them out and returns true.
// Failing to read or parse the file also causes it to return true.
func StaleEnvFile(filepath string, getenv func(string) string) (bool, error) {
data, err := ioutil.ReadFile(filepath)
if err != nil {
return true, err
}
var contents envFileData
err = json.Unmarshal(data, &contents)
if err != nil {
return true, err
}
var changed []string
for _, entry := range contents {
key := entry.Key
old := entry.Value
cur := getenv(key)
if old != cur {
changed = append(changed, fmt.Sprintf("%s (%q -> %q)", key, old, cur))
}
}
if len(changed) > 0 {
fmt.Printf("environment variables changed value:\n")
for _, s := range changed {
fmt.Printf(" %s\n", s)
}
return true, nil
}
return false, nil
}
// Implements sort.Interface so that we can use sort.Sort on envFileData arrays.
func (e envFileData) Len() int {
return len(e)
}
func (e envFileData) Less(i, j int) bool {
return e[i].Key < e[j].Key
}
func (e envFileData) Swap(i, j int) {
e[i], e[j] = e[j], e[i]
}
var _ sort.Interface = envFileData{}