move hashing of files to a separate function

This commit also introduces a global variable called "rehash". It will
be used to signal whether the rehashing of files needs to be done.

amprolla_update.py

@@ -73,6 +73,7 @@ def perform_update(suite, paths):
                 diffs = compare_dict(parse_release(remote_rel.text),
                                      parse_release(local_rel_text))
             if diffs:
+                globalvars.rehash = True
                 for k in diffs:
                     if k.endswith('Packages.gz') or k.endswith('Sources.gz'):
                         needsmerge[i]['mergelist'].append(k)

lib/globalvars.py

@@ -6,3 +6,6 @@ amprolla globals to pass around
 
 # state for the current suite we're in
 suite = ""
+
+# tells us if we need to recreate checksums for Release files
+rehash = True

lib/release.py

@@ -10,6 +10,7 @@ from lzma import compress as lzma_comp
 from os.path import getsize, isfile
 from subprocess import Popen
 
+import lib.globalvars as globalvars
 from lib.config import (checksums, distrolabel, gpgdir, release_aliases,
                         release_keys, signingkey)
 from lib.log import info
@@ -63,25 +64,38 @@ def write_release(oldrel, newrel, filelist, r, sign=True, rewrite=True):
         if k in rel_cont:
             new.write('%s: %s\n' % (k, rel_cont[k]))
 
+    if globalvars.rehash:
+        rehash_release(filelist, new, r)
+
+    new.close()
+
+    if sign:
+        sign_release(newrel)
+
+
+def rehash_release(_filelist, fd, r):
+    """
+    Calculates checksums of a given filelist and writes them to the given
+    file descriptor. Takes r as the third argument, which is a string to
+    remove from the path of the hashed file when writing it to a file.
+    """
+    info('Hashing checksums')
     for csum in checksums:
-        new.write('%s:\n' % csum['name'])
-        for f in filelist:
+        fd.write('%s:\n' % csum['name'])
+        for f in _filelist:
             if isfile(f):
                 cont = open(f, 'rb').read()
-                new.write(' %s %8s %s\n' % (csum['f'](cont).hexdigest(),
-                                            getsize(f), f.replace(r+'/', '')))
+                fd.write(' %s %8s %s\n' % (csum['f'](cont).hexdigest(),
+                                           getsize(f), f.replace(r+'/', '')))
             elif f.endswith('.xz') and isfile(f.replace('.xz', '.gz')):
                 xzstr = lzma_comp(open(f.replace('.xz', '.gz'), 'rb').read())
-                new.write(' %s %8s %s\n' % (csum['f'](xzstr).hexdigest(),
-                                            len(xzstr), f.replace(r+'/', '')))
+                fd.write(' %s %8s %s\n' % (csum['f'](xzstr).hexdigest(),
+                                           len(xzstr), f.replace(r+'/', '')))
             elif not f.endswith('.gz') and isfile(f+'.gz'):
                 uncomp = gzip_decomp(open(f+'.gz', 'rb').read())
-                new.write(' %s %8s %s\n' % (csum['f'](uncomp).hexdigest(),
-                                            len(uncomp), f.replace(r+'/', '')))
-    new.close()
-
-    if sign:
-        sign_release(newrel)
+                fd.write(' %s %8s %s\n' % (csum['f'](uncomp).hexdigest(),
+                                           len(uncomp), f.replace(r+'/', '')))
+    return
 
 
 def sign_release(infile):