Improve Sheet model

src/utils/filehash.go

@@ -0,0 +1,32 @@
+package utils
+
+import (
+	"hash/fnv"
+	"io"
+	"mime/multipart"
+	"os"
+)
+
+func FileHashFromUpload(file multipart.File) (uint64, error) {
+	h := fnv.New64a()
+	if _, err := io.Copy(h, file); err != nil {
+		return 0, err
+	}
+
+	return h.Sum64(), nil
+}
+
+func FileHash(path string) (uint64, error) {
+	f, err := os.Open(path)
+	if err != nil {
+		return 0, err
+	}
+	defer f.Close()
+
+	h := fnv.New64a()
+	if _, err := io.Copy(h, f); err != nil {
+		return 0, err
+	}
+
+	return h.Sum64(), nil
+}