X-Git-Url: http://git.vrable.net/?a=blobdiff_plain;f=python%2Fcumulus%2Fstore%2F__init__.py;h=a59c21741072df0a9c47f3d500d845410b00ca0c;hb=fae5b159f9526d9903121fea3d5da7ba4b4ba73b;hp=84ca119238b9f6ee0d7e1b87830a51c4caf4211f;hpb=a44f5f73e7b43ff152f8b515a74bb9e0b1b48cc6;p=cumulus.git diff --git a/python/cumulus/store/__init__.py b/python/cumulus/store/__init__.py index 84ca119..a59c217 100644 --- a/python/cumulus/store/__init__.py +++ b/python/cumulus/store/__init__.py @@ -1,58 +1,75 @@ -import exceptions, re, urlparse +# Cumulus: Efficient Filesystem Backup to the Cloud +# Copyright (C) 2008-2010 The Cumulus Developers +# See the AUTHORS file for a list of contributors. +# +# 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 +# the Free Software Foundation; either version 2 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License along +# with this program; if not, write to the Free Software Foundation, Inc., +# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + +from __future__ import division, print_function, unicode_literals + +import importlib +import re +try: + # Python 3 + from urllib import parse as urlparse + from urllib.parse import quote, unquote +except ImportError: + # Python 2 + from urllib import quote, unquote + import urlparse type_patterns = { 'checksums': re.compile(r"^snapshot-(.*)\.(\w+)sums$"), 'segments': re.compile(r"^([0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12})(\.\S+)?$"), - 'snapshots': re.compile(r"^snapshot-(.*)\.lbs$") + 'snapshots': re.compile(r"^snapshot-(.*)\.(cumulus|lbs)$") } -class NotFoundError(exceptions.KeyError): +class NotFoundError(KeyError): """Exception thrown when a file is not found in a repository.""" pass -class Store (object): +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 + def __init__(self, url): + """Initializes a new storage backend. + + Params: + url: The parsed (by urlsplit) URL that specifies the storage + location. """ - 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 + pass - def list(self, type): + # TODO: Implement context manager. + + def list(self, path): raise NotImplementedError - def get(self, type, name): + def get(self, path): raise NotImplementedError - def put(self, type, name, fp): + def put(self, path, fp): raise NotImplementedError - def delete(self, type, name): + def delete(self, path): raise NotImplementedError - def stat(self, type, name): + def stat(self, path): raise NotImplementedError - def scan(self): + def scan(self, path): """Cache file information stored in this backend. This might make subsequent list or stat calls more efficient, but this @@ -61,11 +78,33 @@ class Store (object): pass def close(self): - """Tier down the connection explicitly if needed + """Tear down the connection explicitly if needed - Currently needed for sftp to be able to end the program.""" + Currently needed for sftp to be able to end the program.""" - pass + pass + + def __del__(self): + self.close() def open(url): - return Store(url) + """Parse a storage url, then locate and initialize a backend for it.""" + parsed_url = urlparse.urlsplit(url) + + # If there is no scheme, fall back to treating the string as local path and + # construct a file:/// URL. + if not parsed_url.scheme: + parsed_url = urlparse.SplitResult("file", "", quote(url), "", "") + + try: + # TODO: Support a registry for schemes that don't map to a module. + if re.match(r"^\w+$", parsed_url.scheme): + handler = importlib.import_module("cumulus.store.%s" % + parsed_url.scheme) + obj = handler.Store(parsed_url) + return obj + except ImportError: + # Fall through to error below + pass + + raise NotImplementedError("Scheme %s not implemented" % scheme)