diff options
Diffstat (limited to 'morphlib/localartifactcache.py')
| -rw-r--r-- | morphlib/localartifactcache.py | 39 |
1 files changed, 35 insertions, 4 deletions
diff --git a/morphlib/localartifactcache.py b/morphlib/localartifactcache.py index 7ad53db0..b845cebf 100644 --- a/morphlib/localartifactcache.py +++ b/morphlib/localartifactcache.py @@ -1,4 +1,4 @@ -# Copyright (C) 2012 Codethink Limited +# Copyright (C) 2012,2013 Codethink Limited # # This program is free software; you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by @@ -20,6 +20,28 @@ import morphlib class LocalArtifactCache(object): + '''Abstraction over the local artifact cache + + It provides methods for getting a file handle to cached artifacts + so that the layout of the cache need not be known. + + It also updates modification times of artifacts so that it can track + when they were last used, so it can be requested to clean up if + disk space is low. + + Modification time is updated in both the get and has methods. + + NOTE: Parts of the build assume that every artifact of a source is + available, so all the artifacts of a source need to be removed together. + + This complication needs to be handled either during the fetch logic, by + updating the mtime of every artifact belonging to a source, or at + cleanup time by only removing an artifact if every artifact belonging to + a source is too old, and then remove them all at once. + + Since the cleanup logic will be complicated for other reasons it makes + sense to put the complication there. + ''' def __init__(self, cachedir): self.cachedir = cachedir @@ -36,28 +58,37 @@ class LocalArtifactCache(object): filename = self._source_metadata_filename(source, cachekey, name) return morphlib.savefile.SaveFile(filename, mode='w') + def _has_file(self, filename): + if os.path.exists(filename): + os.utime(filename, None) + return True + return False + def has(self, artifact): filename = self.artifact_filename(artifact) - return os.path.exists(filename) + return self._has_file(filename) def has_artifact_metadata(self, artifact, name): filename = self._artifact_metadata_filename(artifact, name) - return os.path.exists(filename) + return self._has_file(filename) def has_source_metadata(self, source, cachekey, name): filename = self._source_metadata_filename(source, cachekey, name) - return os.path.exists(filename) + return self._has_file(filename) def get(self, artifact): filename = self.artifact_filename(artifact) + os.utime(filename, None) return open(filename) def get_artifact_metadata(self, artifact, name): filename = self._artifact_metadata_filename(artifact, name) + os.utime(filename, None) return open(filename) def get_source_metadata(self, source, cachekey, name): filename = self._source_metadata_filename(source, cachekey, name) + os.utime(filename, None) return open(filename) def artifact_filename(self, artifact): |