"""A base class session manager. Authors: * Zach Sailer """ #----------------------------------------------------------------------------- # Copyright (C) 2013 The IPython Development Team # # Distributed under the terms of the BSD License. The full license is in # the file COPYING, distributed as part of this software. #----------------------------------------------------------------------------- #----------------------------------------------------------------------------- # Imports #----------------------------------------------------------------------------- import os import uuid import sqlite3 from tornado import web from IPython.config.configurable import LoggingConfigurable from IPython.nbformat import current from IPython.utils.traitlets import List, Dict, Unicode, TraitError #----------------------------------------------------------------------------- # Classes #----------------------------------------------------------------------------- class SessionManager(LoggingConfigurable): # Session database initialized below _cursor = None _connection = None @property def cursor(self): """Start a cursor and create a database called 'session'""" if self._cursor is None: self._cursor = self.connection.cursor() self._cursor.execute("""CREATE TABLE session (id, name, path, kernel_id, ws_url)""") return self._cursor @property def connection(self): """Start a database connection""" if self._connection is None: self._connection = sqlite3.connect(':memory:') self._connection.row_factory = sqlite3.Row return self._connection def __del__(self): """Close connection once SessionManager closes""" self.cursor.close() def session_exists(self, name, path): """Check to see if the session for the given notebook exists""" self.cursor.execute("SELECT * FROM session WHERE name=? AND path=?", (name,path)) reply = self.cursor.fetchone() if reply is None: return False else: return True def get_session_id(self): "Create a uuid for a new session" return unicode(uuid.uuid4()) def create_session(self, name=None, path=None, kernel_id=None, ws_url=None): """Creates a session and returns its model""" session_id = self.get_session_id() return self.save_session(session_id, name=name, path=path, kernel_id=kernel_id, ws_url=ws_url) def save_session(self, session_id, name=None, path=None, kernel_id=None, ws_url=None): """Saves the items for the session with the given session_id Given a session_id (and any other of the arguments), this method creates a row in the sqlite session database that holds the information for a session. Parameters ---------- session_id : str uuid for the session; this method must be given a session_id name : str the .ipynb notebook name that started the session path : str the path to the named notebook kernel_id : str a uuid for the kernel associated with this session ws_url : str the websocket url Returns ------- model : dict a dictionary of the session model """ self.cursor.execute("""INSERT INTO session VALUES (?,?,?,?,?)""", (session_id, name, path, kernel_id, ws_url)) self.connection.commit() return self.get_session(id=session_id) def get_session(self, **kwargs): """Returns the model for a particular session. Takes a keyword argument and searches for the value in the session database, then returns the rest of the session's info. Parameters ---------- **kwargs : keyword argument must be given one of the keywords and values from the session database (i.e. session_id, name, path, kernel_id, ws_url) Returns ------- model : dict returns a dictionary that includes all the information from the session described by the kwarg. """ column = kwargs.keys()[0] # uses only the first kwarg that is entered value = kwargs.values()[0] try: self.cursor.execute("SELECT * FROM session WHERE %s=?" %column, (value,)) except sqlite3.OperationalError: raise TraitError("The session database has no column: %s" %column) reply = self.cursor.fetchone() if reply is not None: model = self.reply_to_dictionary_model(reply) else: model = None return model def update_session(self, session_id, **kwargs): """Updates the values in the session database. Changes the values of the session with the given session_id with the values from the keyword arguments. Parameters ---------- session_id : str a uuid that identifies a session in the sqlite3 database **kwargs : str the key must correspond to a column title in session database, and the value replaces the current value in the session with session_id. """ column = kwargs.keys() # uses only the first kwarg that is entered value = kwargs.values() for kwarg in kwargs: try: self.cursor.execute("UPDATE session SET %s=? WHERE id=?" %kwarg, (kwargs[kwarg], session_id)) self.connection.commit() except sqlite3.OperationalError: raise TraitError("No session exists with ID: %s" %session_id) def reply_to_dictionary_model(self, reply): """Takes sqlite database session row and turns it into a dictionary""" model = {'id': reply['id'], 'notebook': {'name': reply['name'], 'path': reply['path']}, 'kernel': {'id': reply['kernel_id'], 'ws_url': reply['ws_url']}} return model def list_sessions(self): """Returns a list of dictionaries containing all the information from the session database""" session_list=[] self.cursor.execute("SELECT * FROM session") sessions = self.cursor.fetchall() for session in sessions: model = self.reply_to_dictionary_model(session) session_list.append(model) return session_list def delete_session(self, session_id): """Deletes the row in the session database with given session_id""" # Check that session exists before deleting model = self.get_session(id=session_id) if model is None: raise TraitError("The session does not exist: %s" %session_id) else: self.cursor.execute("DELETE FROM session WHERE id=?", (session_id,)) self.connection.commit()