diff options
| author | Marcus Müller <marcus@hostalia.de> | 2018-09-21 00:00:57 +0200 |
|---|---|---|
| committer | Marcus Müller <marcus@hostalia.de> | 2018-09-21 00:00:57 +0200 |
| commit | 267d669eb21c514c18a6ee979f5cf247d251f1ad (patch) | |
| tree | c6120f5993f82daf13894e8bf905c4169493152e /grc/core/cache.py | |
| parent | 896d1c9da31963ecf5b0d90942c2af51ca998a69 (diff) | |
| parent | 7b20b28a9e5aa4e32ee37e89e7f80d74485344e8 (diff) | |
Merge branch 'merge_next' (which merges next)
This has been in the making far too long.
We finally merge the next branch into master, in preparation of
releasing GNU Radio 3.8.
There will be breakage.
There will be awesomeness.
There will be progress in the greatest SDR framework to ever grace the
surface of the earth.
Hold tight for now.
Diffstat (limited to 'grc/core/cache.py')
| -rw-r--r-- | grc/core/cache.py | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/grc/core/cache.py b/grc/core/cache.py new file mode 100644 index 0000000000..dd85bf9806 --- /dev/null +++ b/grc/core/cache.py @@ -0,0 +1,100 @@ +# Copyright 2017 Free Software Foundation, Inc. +# This file is part of GNU Radio +# +# GNU Radio Companion 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. +# +# GNU Radio Companion 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 absolute_import, print_function, unicode_literals + +from io import open +import json +import logging +import os + +import six + +from .io import yaml + +logger = logging.getLogger(__name__) + + +class Cache(object): + + def __init__(self, filename): + self.cache_file = filename + self.cache = {} + self.need_cache_write = True + self._accessed_items = set() + try: + os.makedirs(os.path.dirname(filename)) + except OSError: + pass + try: + self._converter_mtime = os.path.getmtime(filename) + except OSError: + self._converter_mtime = -1 + + def load(self): + try: + logger.debug("Loading block cache from: {}".format(self.cache_file)) + with open(self.cache_file, encoding='utf-8') as cache_file: + self.cache = json.load(cache_file) + self.need_cache_write = False + except (IOError, ValueError): + self.need_cache_write = True + + def get_or_load(self, filename): + self._accessed_items.add(filename) + if os.path.getmtime(filename) <= self._converter_mtime: + try: + return self.cache[filename] + except KeyError: + pass + + with open(filename, encoding='utf-8') as fp: + data = yaml.safe_load(fp) + self.cache[filename] = data + self.need_cache_write = True + return data + + def save(self): + if not self.need_cache_write: + return + + logger.info('Saving %d entries to json cache', len(self.cache)) + # Dumping to binary file is only supported for Python3 >= 3.6 + with open(self.cache_file, 'w', encoding='utf8') as cache_file: + cache_file.write(json.dumps(self.cache, ensure_ascii=False)) + + def prune(self): + for filename in (set(self.cache) - self._accessed_items): + del self.cache[filename] + + def __enter__(self): + self.load() + return self + + def __exit__(self, exc_type, exc_val, exc_tb): + self.save() + + +def byteify(data): + if isinstance(data, dict): + return {byteify(key): byteify(value) for key, value in six.iteritems(data)} + elif isinstance(data, list): + return [byteify(element) for element in data] + elif isinstance(data, six.text_type) and six.PY2: + return data.encode('utf-8') + else: + return data |