X-Git-Url: http://git.vrable.net/?a=blobdiff_plain;f=python%2Fcumulus%2Fstore%2F__init__.py;h=6c8c8eec0a884b9a4b151b5b59209aeddad71c5e;hb=ac2119cf623ab1c2ea2a4e46005c2eee94a85ec0;hp=7c43b695b232bf4eb4e87dbfa27a26713f08c0bc;hpb=c519cb09affc7e3235a7d75c349ef4cdddc778e0;p=cumulus.git diff --git a/python/cumulus/store/__init__.py b/python/cumulus/store/__init__.py index 7c43b69..6c8c8ee 100644 --- a/python/cumulus/store/__init__.py +++ b/python/cumulus/store/__init__.py @@ -11,32 +11,64 @@ class NotFoundError(exceptions.KeyError): pass -class Store: +class Store (object): """Base class for all cumulus storage backends.""" + def __new__ (cls, url, **kw): + """ Return the correct sub-class depending on url, + pass parsed url parameters to object + """ + if cls != Store: + return super(Store, cls).__new__(cls, url, **kw) + (scheme, netloc, path, params, query, fragment) \ + = urlparse.urlparse(url) + + try: + cumulus = __import__('cumulus.store.%s' % scheme, globals()) + subcls = getattr (cumulus.store, scheme).Store + obj = super(Store, cls).__new__(subcls, url, **kw) + obj.scheme = scheme + obj.netloc = netloc + obj.path = path + obj.params = params + obj.query = query + obj.fragment = fragment + return obj + except ImportError: + raise NotImplementedError, "Scheme %s not implemented" % scheme + def list(self, type): - raise NotImplementedException + raise NotImplementedError def get(self, type, name): - raise NotImplementedException + raise NotImplementedError def put(self, type, name, fp): - raise NotImplementedException + raise NotImplementedError def delete(self, type, name): - raise NotImplementedException + raise NotImplementedError + + def stat(self, type, name): + raise NotImplementedError + + def scan(self): + """Cache file information stored in this backend. + + This might make subsequent list or stat calls more efficient, but this + function is intended purely as a performance optimization.""" + + pass + + def close(self): + """Tier down the connection explicitly if needed + + Currently needed for sftp to be able to end the program.""" + + pass + + def __del__(self): + self.close() def open(url): - (scheme, netloc, path, params, query, fragment) \ - = urlparse.urlparse(url) - - if scheme == "file": - import cumulus.store.file - return cumulus.store.file.FileStore(path) - elif scheme == "s3": - import cumulus.store.s3 - while path.startswith("/"): path = path[1:] - (bucket, path) = path.split("/", 1) - return cumulus.store.s3.S3Store(bucket, path) - else: - raise NotImplementedException + return Store(url)