wings/server/state.go

89 lines
1.7 KiB
Go

package server
import (
"encoding/json"
"github.com/pkg/errors"
"io/ioutil"
"os"
"sync"
)
var (
statesLock sync.Mutex
statesFile = "data/states.json"
)
// DoesStatesFileExist .
func DoesStatesFileExist() (bool, error) {
statesLock.Lock()
defer statesLock.Unlock()
if _, err := os.Stat(statesFile); err != nil {
if !os.IsNotExist(err) {
return false, errors.WithStack(err)
}
return false, nil
}
return true, nil
}
// FetchServerStates .
func FetchServerStates() (map[string]string, error) {
// Check if the states file exists.
exists, err := DoesStatesFileExist()
if err != nil {
return nil, errors.WithStack(err)
}
// Request a lock after we check if the file exists.
statesLock.Lock()
defer statesLock.Unlock()
// Return an empty map if the file does not exist.
if !exists {
return map[string]string{}, nil
}
// Open the states file.
f, err := os.Open(statesFile)
if err != nil {
return nil, errors.WithStack(err)
}
defer f.Close()
// Convert the json object to a map.
states := map[string]string{}
if err := json.NewDecoder(f).Decode(&states); err != nil {
return nil, errors.WithStack(err)
}
return states, nil
}
// SaveServerStates .
func SaveServerStates() error {
// Get the states of all servers on the daemon.
states := map[string]string{}
for _, s := range GetServers().All() {
states[s.Uuid] = s.State
}
// Convert the map to a json object.
data, err := json.Marshal(states)
if err != nil {
return errors.WithStack(err)
}
statesLock.Lock()
defer statesLock.Unlock()
// Write the data to the file
if err := ioutil.WriteFile(statesFile, data, 0644); err != nil {
return errors.WithStack(err)
}
return nil
}