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Diffstat (limited to 'morphlib/systemmetadatadir.py')
-rw-r--r-- | morphlib/systemmetadatadir.py | 87 |
1 files changed, 0 insertions, 87 deletions
diff --git a/morphlib/systemmetadatadir.py b/morphlib/systemmetadatadir.py deleted file mode 100644 index 573d8a20..00000000 --- a/morphlib/systemmetadatadir.py +++ /dev/null @@ -1,87 +0,0 @@ -# Copyright (C) 2013-2015 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 -# the Free Software Foundation; version 2 of the License. -# -# 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, see <http://www.gnu.org/licenses/>. -# -# =*= License: GPL-2 =*= - - -import collections -import glob -import json -import os - - -class SystemMetadataDir(collections.MutableMapping): - - '''An abstraction over the /baserock metadata directory. - - This allows methods of iterating over it, and accessing it like - a dict. - - The /baserock metadata directory contains information about all of - the chunks in a built system. It exists to provide traceability from - the input sources to the output. - - If you create the object with smd = SystemMetadataDir('/baserock') - data = smd['key'] will read /baserock/key.meta and return its JSON - encoded contents as native python objects. - - smd['key'] = data will write data to /baserock/key.meta as JSON - - The key may not have '\0' characters in it since the underlying - system calls don't support embedded NUL bytes. - - The key may not have '/' characters in it since we do not support - morphologies with slashes in their names. - - ''' - - def __init__(self, metadata_path): - collections.MutableMapping.__init__(self) - self._metadata_path = metadata_path - - def _join_path(self, *args): - return os.path.join(self._metadata_path, *args) - - def _raw_path_iter(self): - return glob.iglob(self._join_path('*.meta')) - - @staticmethod - def _check_key(key): - if any(c in key for c in "\0/"): - raise KeyError(key) - - def __getitem__(self, key): - self._check_key(key) - try: - with open(self._join_path('%s.meta' % key), 'r') as f: - return json.load(f, encoding='unicode-escape') - except IOError: - raise KeyError(key) - - def __setitem__(self, key, value): - self._check_key(key) - with open(self._join_path('%s.meta' % key), 'w') as f: - json.dump(value, f, indent=4, sort_keys=True, - encoding='unicode-escape') - - def __delitem__(self, key): - self._check_key(key) - os.unlink(self._join_path('%s.meta' % key)) - - def __iter__(self): - return (os.path.basename(fn)[:-len('.meta')] - for fn in self._raw_path_iter()) - - def __len__(self): - return len(list(self._raw_path_iter())) |