Refactor things so that checksumming happens in one place only.

DRY.

1 files changed, 13 insertions, 23 deletions

diff --git a/summainlib.py b/summainlib.py
index 347d525..3cc92d5 100644
--- a/summainlib.py
+++ b/summainlib.py
@@ -208,12 +208,10 @@ class FilesystemObject(object):
         return self.lookup_group(self._stat_result.st_gid)
 
     def _compute_md5(self):
-        if stat.S_ISREG(self._stat_result.st_mode):
-            return self.compute_md5(self._filename, self._md5)
+        return self.compute_checksum(self._filename, self._md5)
 
     def _compute_sha1(self):
-        if stat.S_ISREG(self._stat_result.st_mode):
-            return self.compute_sha1(self._filename, self._sha1)
+        return self.compute_checksum(self._filename, self._sha1)
 
     def _compute_target(self):
         if stat.S_ISLNK(self._stat_result.st_mode):
@@ -232,25 +230,17 @@ class FilesystemObject(object):
     def lookup_group(self, gid):
         return grp.getgrgid(gid).gr_name
 
-    def compute_md5(self, filename, md5):
-        f = self.open_file(filename)
-        while True:
-            data = f.read(64*1024) # 64 KiB seems reasonable.
-            if not data:
-                break
-            md5.update(data)
-        f.close()
-        return md5.hexdigest()
-
-    def compute_sha1(self, filename, sha1):
-        f = self.open_file(filename)
-        while True:
-            data = f.read(64*1024) # 64 KiB seems reasonable.
-            if not data:
-                break
-            sha1.update(data)
-        f.close()
-        return sha1.hexdigest()
+    def compute_checksum(self, filename, checksummer):
+        if stat.S_ISREG(self._stat_result.st_mode):
+            with self.open_file(filename) as f:
+                while True:
+                    data = f.read(64*1024) # 64 KiB seems reasonable.
+                    if not data:
+                        break
+                    checksummer.update(data)
+            return checksummer.hexdigest()
+        else:
+            return ''
 
     def _normalize_key(self, key):
         key = key.lower()