CachedMd5Comparer

1 files changed, 32 insertions, 0 deletions

diff --git a/util.go b/util.go
index d40d33e..041daed 100644
--- a/util.go
+++ b/util.go
@@ -4,7 +4,10 @@ import (
     "runtime"
     "path/filepath"
     "fmt"
+    "encoding/json"
     "os"
+    "io"
+    "crypto/md5"
 )
 
 func GetDefaultConfigDir() string {
@@ -56,3 +59,32 @@ func checkErr(err error) {
         os.Exit(1)
     }
 }
+
+func writeJson(path string, data interface{}) error {
+    tmpFile := path + ".tmp"
+    f, err := os.Create(tmpFile)
+    if err != nil {
+        return err
+    }
+
+    err = json.NewEncoder(f).Encode(data)
+    f.Close()
+    if err != nil {
+        os.Remove(tmpFile)
+        return err
+    }
+
+    return os.Rename(tmpFile, path)
+}
+
+func md5sum(path string) string {
+    h := md5.New()
+    f, err := os.Open(path)
+    if err != nil {
+        return ""
+    }
+    defer f.Close()
+
+    io.Copy(h, f)
+    return fmt.Sprintf("%x", h.Sum(nil))
+}