diff options
| -rw-r--r-- | apt/cache.py | 66 |
1 files changed, 39 insertions, 27 deletions
diff --git a/apt/cache.py b/apt/cache.py index faad8523..1ba262aa 100644 --- a/apt/cache.py +++ b/apt/cache.py @@ -689,6 +689,38 @@ class MarkedChangesFilter(Filter): return False +class _FilteredCacheHelper(object): + """Helper class for FilteredCache to break a reference cycle.""" + + def __init__(self, cache): + # Do not keep a reference to the cache, or you have a cycle! + + self._filtered = {} + self._filters = {} + cache.connect2("cache_post_change", self.filter_cache_post_change) + cache.connect2("cache_post_open", self.filter_cache_post_change) + + def _reapply_filter(self, cache): + " internal helper to refilter " + # Do not keep a reference to the cache, or you have a cycle! + self._filtered = {} + for pkg in cache: + for f in self._filters: + if f.apply(pkg): + self._filtered[pkg.name] = 1 + break + + def set_filter(self, filter): + """Set the current active filter.""" + self._filters = [] + self._filters.append(filter) + + def filter_cache_post_change(self, cache): + """Called internally if the cache changes, emit a signal then.""" + # Do not keep a reference to the cache, or you have a cycle! + self._reapply_filter(cache) + + class FilteredCache(object): """ A package cache that is filtered. @@ -700,23 +732,20 @@ class FilteredCache(object): self.cache = Cache(progress) else: self.cache = cache - self.cache.connect("cache_post_change", self.filter_cache_post_change) - self.cache.connect("cache_post_open", self.filter_cache_post_change) - self._filtered = {} - self._filters = [] + self._helper = _FilteredCacheHelper(self.cache) def __len__(self): - return len(self._filtered) + return len(self._helper._filtered) def __getitem__(self, key): return self.cache[key] def __iter__(self): - for pkgname in self._filtered: + for pkgname in self._helper._filtered: yield self.cache[pkgname] def keys(self): - return self._filtered.keys() + return self._helper._filtered.keys() def has_key(self, key): return key in self @@ -724,38 +753,21 @@ class FilteredCache(object): def __contains__(self, key): try: # Normalize package name for multi arch - return self.cache[key].name in self._filtered + return self.cache[key].name in self._helper._filtered except KeyError: return False - def _reapply_filter(self): - " internal helper to refilter " - self._filtered = {} - for pkg in self.cache: - for f in self._filters: - if f.apply(pkg): - self._filtered[pkg.name] = 1 - break - def set_filter(self, filter): """Set the current active filter.""" - self._filters = [] - self._filters.append(filter) - #self._reapplyFilter() - # force a cache-change event that will result in a refiltering + self._helper.set_filter(filter) self.cache.cache_post_change() def filter_cache_post_change(self): """Called internally if the cache changes, emit a signal then.""" - #print "filterCachePostChange()" - self._reapply_filter() - -# def connect(self, name, callback): -# self.cache.connect(name, callback) + self._helper.filter_cache_post_change(self.cache) def __getattr__(self, key): """we try to look exactly like a real cache.""" - #print "getattr: %s " % key return getattr(self.cache, key) |