def clear(self): """Remove all entries from the database. This operation can be undone using the :meth:`undo` method. """ cmds = CompositeOperation() for entry in self: for tag in entry.tags: cmds.add(commands.RemoveTag(self.session, entry, tag)) # TODO: also remove all FITS header entries and all FITS header # comments from each entry before removing the entry itself! # remove all entries from all helper tables database_tables = [ tables.JSONDump, tables.Tag, tables.FitsHeaderEntry, tables.FitsKeyComment ] for table in database_tables: for entry in self.session.query(table): cmds.add(commands.RemoveEntry(self.session, entry)) for entry in self: cmds.add(commands.RemoveEntry(self.session, entry)) del self._cache[entry.id] if self._enable_history: self._command_manager.do(cmds) else: cmds()
def set_cache_size(self, cache_size): """Set a new value for the maximum number of database entries in the cache. Use the value ``float('inf')`` to disable caching. If the new cache is smaller than the previous one and cannot contain all the entries anymore, entries are removed from the cache until the number of entries equals the cache size. Which entries are removed depends on the implementation of the cache (e.g. :class:`sunpy.database.caching.LRUCache`, :class:`sunpy.database.caching.LFUCache`). """ cmds = CompositeOperation() # remove items from the cache if the given argument is lower than the # current cache size while cache_size < self.cache_size: # remove items from the cache until cache_size == maxsize of the # cache entry_id, entry = self._cache.to_be_removed cmd = commands.RemoveEntry(self.session, entry) if self._enable_history: cmds.add(cmd) else: cmd() del self._cache[entry_id] self._cache.maxsize = cache_size if cmds: self._command_manager.do(cmds)
def remove(self, database_entry): """Remove the given database entry from the database table.""" remove_entry_cmd = commands.RemoveEntry(self.session, database_entry) if self._enable_history: self._command_manager.do(remove_entry_cmd) else: remove_entry_cmd() try: del self._cache[database_entry.id] except KeyError: # entry cannot be removed because it was already removed or never # existed in the database. This can be safely ignored, the user # doesn't even know there's a cache here pass
def remove_many(self, database_entries): """Remove a row of database entries "at once". If this method is used, only one entry is saved in the undo history. Parameters ---------- database_entries : iterable of sunpy.database.tables.DatabaseEntry The database entries that will be removed from the database. """ cmds = CompositeOperation() for database_entry in database_entries: cmd = commands.RemoveEntry(self.session, database_entry) if self._enable_history: cmds.add(cmd) else: cmd() try: del self._cache[database_entry.id] except KeyError: pass if cmds: self._command_manager.do(cmds)
def remove_tag(self, database_entry, tag_name): """Remove the given tag from the database entry. If the tag is not connected to any entry after this operation, the tag itself is removed from the database as well. Raises ------ sunpy.database.NoSuchTagError If the tag is not connected to the given entry. """ tag = self.get_tag(tag_name) cmds = CompositeOperation() remove_tag_cmd = commands.RemoveTag(self.session, database_entry, tag) remove_tag_cmd() if self._enable_history: cmds.add(remove_tag_cmd) if not tag.data: remove_entry_cmd = commands.RemoveEntry(self.session, tag) remove_entry_cmd() if self._enable_history: cmds.add(remove_entry_cmd) if self._enable_history: self._command_manager.push_undo_command(cmds)