protoio: I/O helpers for protobuf messages

internal/protoio/protoio.go

@@ -0,0 +1,48 @@
+// Package protoio contains I/O functions for protocol buffers.
+package protoio
+
+import (
+	"io/ioutil"
+	"os"
+
+	"blitiri.com.ar/go/chasquid/internal/safeio"
+
+	"github.com/golang/protobuf/proto"
+)
+
+// ReadMessage reads a protocol buffer message from fname, and unmarshalls it
+// into pb.
+func ReadMessage(fname string, pb proto.Message) error {
+	in, err := ioutil.ReadFile(fname)
+	if err != nil {
+		return err
+	}
+	return proto.Unmarshal(in, pb)
+}
+
+// ReadTextMessage reads a text format protocol buffer message from fname, and
+// unmarshalls it into pb.
+func ReadTextMessage(fname string, pb proto.Message) error {
+	in, err := ioutil.ReadFile(fname)
+	if err != nil {
+		return err
+	}
+	return proto.UnmarshalText(string(in), pb)
+}
+
+// WriteMessage marshals pb and atomically writes it into fname.
+func WriteMessage(fname string, pb proto.Message, perm os.FileMode) error {
+	out, err := proto.Marshal(pb)
+	if err != nil {
+		return err
+	}
+
+	return safeio.WriteFile(fname, out, perm)
+}
+
+// WriteTextMessage marshals pb in text format and atomically writes it into
+// fname.
+func WriteTextMessage(fname string, pb proto.Message, perm os.FileMode) error {
+	out := proto.MarshalTextString(pb)
+	return safeio.WriteFile(fname, []byte(out), perm)
+}