Add variant of Ref::update_ref() to update with custom Hasher instance

1 files changed, 7 insertions, 3 deletions

diff --git a/libimagref/src/reference.rs b/libimagref/src/reference.rs
index 571312bf..e1d0f02a 100644
--- a/libimagref/src/reference.rs
+++ b/libimagref/src/reference.rs
@@ -353,6 +353,12 @@ impl<'a> Ref<'a> {
     /// Update the Ref by re-checking the file from FS
     /// This errors if the file is not present or cannot be read()
     pub fn update_ref(&mut self) -> Result<()> {
+        self.update_ref_with_hasher(&DefaultHasher::new())
+    }
+
+    /// Update the Ref by re-checking the file from FS using the passed Hasher instance
+    /// This errors if the file is not present or cannot be read()
+    pub fn update_ref_with_hasher<H: Hasher>(&mut self, h: &H) -> Result<()> {
         let current_hash = try!(self.get_current_hash()); // uses the default hasher
         let current_perm = try!(self.get_current_permissions());
 
@@ -363,11 +369,9 @@ impl<'a> Ref<'a> {
             .map_err(|e| REK::StoreWriteError.into_error_with_cause(e))
         );
 
-        let hasher_name  = DefaultHasher::new().hash_name();
-
         try!(self.0
             .get_header_mut()
-            .set(&format!("ref.content_hash.{}", hasher_name)[..], Value::String(current_hash))
+            .set(&format!("ref.content_hash.{}", h.hash_name())[..], Value::String(current_hash))
             .map_err(Box::new)
             .map_err(|e| REK::StoreWriteError.into_error_with_cause(e))
         );