morphologyfactory: work without RemoteRepoCache

There are cases where we would not need a remote cache, so it
should be able to operate without one.

1 files changed, 18 insertions, 3 deletions

diff --git a/morphlib/morphologyfactory.py b/morphlib/morphologyfactory.py
index 5e3bf7f2..e7ee9323 100644
--- a/morphlib/morphologyfactory.py
+++ b/morphlib/morphologyfactory.py
@@ -27,10 +27,16 @@ class AutodetectError(MorphologyFactoryError):
                 "Failed to determine the build system of repo %s at "
                 "ref %s" % (repo_name, ref))
 
+class NotcachedError(MorphologyFactoryError):
+    def __init__(self, repo_name):
+        MorphologyFactoryError.__init__(self,
+                "Repository %s is not cached locally and there is no "
+                "remote cache specified" % repo_name)
+
 class MorphologyFactory(object):
     '''An way of creating morphologies which will provide a default'''
 
-    def __init__(self, local_repo_cache, remote_repo_cache):
+    def __init__(self, local_repo_cache, remote_repo_cache=None):
         self._lrc = local_repo_cache
         self._rrc = remote_repo_cache
 
@@ -45,18 +51,27 @@ class MorphologyFactory(object):
         if self._lrc.has_repo(reponame):
             repo = self._lrc.get_repo(reponame)
             return repo.cat(sha1, filename)
-        else:
+        elif self._rrc is not None:
             return self._rrc.cat_file(reponame, sha1, filename)
+        else:
+            raise NotcachedError(reponame)
 
     def _autodetect_text(self, reponame, sha1, filename):
         if self._lrc.has_repo(reponame):
             repo = self._lrc.get_repo(reponame)
             files = repo.list_files(sha1)
-        else:
+        elif self._rrc is not None:
             files = self._rrc.list_files(reponame, sha1)
+        else:
+            raise NotcachedError(reponame)
         bs = morphlib.buildsystem.detect_build_system(lambda x: x in files)
         if bs is None:
             raise AutodetectError(reponame, sha1)
+        # TODO consider changing how morphs are located to be by morph
+        #      name rather than filename, it would save creating a
+        #      filename only to strip it back to its morph name again
+        #      and would allow future changes like morphologies being
+        #      stored as git metadata instead of as a file in the repo
         assert filename.endswith('.morph')
         morph_name = filename[:-len('.morph')]
         morph_text = bs.get_morphology_text(morph_name)