Merge pull request #71 from auyer/master

Cleaning lock files on Interruption

2 files changed, 99 insertions, 0 deletions

diff --git a/util/interrupt/cleaner.go b/util/interrupt/cleaner.go
new file mode 100644
index 00000000..76c9d04d
--- /dev/null
+++ b/util/interrupt/cleaner.go
@@ -0,0 +1,49 @@
+package interrupt
+
+import (
+	"fmt"
+	"os"
+	"os/signal"
+	"syscall"
+)
+
+// Cleaner type referes to a function with no inputs that returns an error
+type Cleaner func() error
+
+var cleaners []Cleaner
+var active = false
+
+// RegisterCleaner is responsible for regisreting a cleaner function. When a function is registered, the Signal watcher is started in a goroutine.
+func RegisterCleaner(f ...Cleaner) {
+	for _, fn := range f {
+		cleaners = append([]Cleaner{fn}, cleaners...)
+		if !active {
+			active = true
+			go func() {
+				ch := make(chan os.Signal, 1)
+				signal.Notify(ch, syscall.SIGINT, syscall.SIGTERM, os.Interrupt)
+				<-ch
+				// Prevent un-terminated ^C character in terminal
+				fmt.Println()
+				fmt.Println("Cleaning")
+				errl := Clean()
+				for _, err := range errl {
+					fmt.Println(err)
+				}
+				os.Exit(1)
+			}()
+		}
+	}
+}
+
+// Clean invokes all registered cleanup functions, and returns a list of errors, if they exist.
+func Clean() (errorlist []error) {
+	for _, f := range cleaners {
+		err := f()
+		if err != nil {
+			errorlist = append(errorlist, err)
+		}
+	}
+	cleaners = []Cleaner{}
+	return
+}
diff --git a/util/interrupt/cleaner_test.go b/util/interrupt/cleaner_test.go
new file mode 100644
index 00000000..c4e5c9b3
--- /dev/null
+++ b/util/interrupt/cleaner_test.go
@@ -0,0 +1,50 @@
+package interrupt
+
+import (
+	"errors"
+	"testing"
+)
+
+// TestRegisterAndErrorAtCleaning tests if the registered order was kept by checking the returned errors
+func TestRegisterAndErrorAtCleaning(t *testing.T) {
+	active = true // this prevents goroutine from being started during the tests
+
+	f := func() error {
+		return errors.New("X")
+	}
+	f2 := func() error {
+		return errors.New("Y")
+	}
+	f3 := func() error {
+		return nil
+	}
+	RegisterCleaner(f)
+	RegisterCleaner(f2, f3)
+	// count := 0
+
+	errl := Clean()
+	if len(errl) != 2 {
+		t.Fatalf("unexpected error count")
+	}
+	if errl[0].Error() != "Y" && errl[1].Error() != "X" {
+		t.Fatalf("unexpected error order")
+
+	}
+}
+
+func TestRegisterAndClean(t *testing.T) {
+	active = true // this prevents goroutine from being started during the tests
+
+	f := func() error {
+		return nil
+	}
+	f2 := func() error {
+		return nil
+	}
+	RegisterCleaner(f, f2)
+
+	errl := Clean()
+	if len(errl) != 0 {
+		t.Fatalf("unexpected error count")
+	}
+}