diff options
| -rw-r--r-- | morphlib/__init__.py | 1 | ||||
| -rw-r--r-- | morphlib/systemmetadatadir.py | 87 | ||||
| -rw-r--r-- | morphlib/systemmetadatadir_tests.py | 75 |
3 files changed, 163 insertions, 0 deletions
diff --git a/morphlib/__init__.py b/morphlib/__init__.py index b1e3c7c3..7eb3f975 100644 --- a/morphlib/__init__.py +++ b/morphlib/__init__.py @@ -78,6 +78,7 @@ import sourcepool import stagingarea import stopwatch import sysbranchdir +import systemmetadatadir import tempdir import util import workspace diff --git a/morphlib/systemmetadatadir.py b/morphlib/systemmetadatadir.py new file mode 100644 index 00000000..eac5b446 --- /dev/null +++ b/morphlib/systemmetadatadir.py @@ -0,0 +1,87 @@ +# Copyright (C) 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 +# 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, write to the Free Software Foundation, Inc., +# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. +# +# =*= 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) + 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) + + 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())) diff --git a/morphlib/systemmetadatadir_tests.py b/morphlib/systemmetadatadir_tests.py new file mode 100644 index 00000000..0126f862 --- /dev/null +++ b/morphlib/systemmetadatadir_tests.py @@ -0,0 +1,75 @@ +# Copyright (C) 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 +# 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, write to the Free Software Foundation, Inc., +# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. +# +# =*= License: GPL-2 =*= + + +import operator +import os +import shutil +import tempfile +import unittest + +import morphlib + + +class SystemMetadataDirTests(unittest.TestCase): + + def setUp(self): + self.tempdir = tempfile.mkdtemp() + self.metadatadir = os.path.join(self.tempdir, 'baserock') + os.mkdir(self.metadatadir) + self.smd = morphlib.systemmetadatadir.SystemMetadataDir( + self.metadatadir) + + def tearDown(self): + shutil.rmtree(self.tempdir) + + def test_add_new(self): + self.smd['key'] = {'foo': 'bar'} + self.assertEqual(self.smd['key']['foo'], 'bar') + + def test_replace(self): + self.smd['key'] = {'foo': 'bar'} + self.smd['key'] = {'foo': 'baz'} + self.assertEqual(self.smd['key']['foo'], 'baz') + + def test_remove(self): + self.smd['key'] = {'foo': 'bar'} + del self.smd['key'] + self.assertTrue('key' not in self.smd) + + def test_iterate(self): + self.smd['build-essential'] = "Some data" + self.smd['core'] = "More data" + self.smd['foundation'] = "Yet more data" + self.assertEqual(sorted(self.smd.keys()), + ['build-essential', 'core', 'foundation']) + self.assertEqual(dict(self.smd.iteritems()), + { + 'build-essential': "Some data", + 'core': "More data", + 'foundation': "Yet more data", + }) + + def test_raises_KeyError(self): + self.assertRaises(KeyError, operator.getitem, self.smd, 'key') + + def test_validates_keys(self): + for key in ('foo/bar', 'baz\0quux'): + self.assertRaises(KeyError, operator.getitem, self.smd, key) + self.assertRaises(KeyError, operator.setitem, + self.smd, key, 'value') + self.assertRaises(KeyError, operator.delitem, self.smd, key) |