// AtomicAction performs an action 'atomically' by keeping track of successfully
// completed actions in the supplied completion log and re-running them if they
// are not successfully logged therein after deleting the entire contents of the
// dir parameter. Consequently it does not make sense to apply AtomicAction to
// the same directory in sequence.
func AtomicAction(jirix *jiri.X, installFn func() error, dir, message string) error {
atomicFn := func() error {
completionLogPath := filepath.Join(dir, ".complete")
s := jirix.NewSeq()
if dir != "" {
if exists, _ := s.IsDir(dir); exists {
// If the dir exists but the completionLogPath doesn't, then it
// means the previous action didn't finish.
// Remove the dir so we can perform the action again.
if exists, _ := s.IsFile(completionLogPath); !exists {
s.RemoveAll(dir).Done()
} else {
if jirix.Verbose() {
fmt.Fprintf(jirix.Stdout(), "AtomicAction: %s already completed in %s\n", message, dir)
}
return nil
}
}
}
if err := installFn(); err != nil {
if dir != "" {
s.RemoveAll(dir).Done()
}
return err
}
return s.WriteFile(completionLogPath, []byte("completed"), DefaultFilePerm).Done()
}
return jirix.NewSeq().Call(atomicFn, message).Done()
}
// ensureAction ensures that the requested profile and target
// is installed/uninstalled, installing/uninstalling it if and only if necessary.
func ensureAction(jirix *jiri.X, pdb *profiles.DB, action profiles.Action, installer, profile string, root jiri.RelPath, target profiles.Target) error {
verb := ""
switch action {
case profiles.Install:
verb = "install"
case profiles.Uninstall:
verb = "uninstall"
default:
return fmt.Errorf("unrecognised action %v", action)
}
if jirix.Verbose() {
fmt.Fprintf(jirix.Stdout(), "%s %v %s\n", verb, action, target)
}
if t := pdb.LookupProfileTarget(installer, profile, target); t != nil {
if jirix.Verbose() {
fmt.Fprintf(jirix.Stdout(), "%v %v is already %sed as %v\n", profile, target, verb, t)
}
return nil
}
mgr := LookupManager(profiles.QualifiedProfileName(installer, profile))
if mgr == nil {
return fmt.Errorf("profile %v is not supported", profile)
}
version, err := mgr.VersionInfo().Select(target.Version())
if err != nil {
return err
}
target.SetVersion(version)
if jirix.Verbose() {
fmt.Fprintf(jirix.Stdout(), "%s %s %s\n", verb, profile, target.DebugString())
}
if action == profiles.Install {
return mgr.Install(jirix, pdb, root, target)
}
return mgr.Uninstall(jirix, pdb, root, target)
}