"""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 uuid import sqlite3 from tornado import web from IPython.config.configurable import LoggingConfigurable from IPython.utils.py3compat import unicode_type #----------------------------------------------------------------------------- # Classes #----------------------------------------------------------------------------- class SessionManager(LoggingConfigurable): # Session database initialized below _cursor = None _connection = None _columns = {'session_id', 'name', 'path', 'kernel_id', 'ws_url'} @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 (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 = self.row_factory 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 a 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 new_session_id(self): "Create a uuid for a new session" return unicode_type(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.new_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) ) return self.get_session(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. """ if not kwargs: raise TypeError("must specify a column to query") conditions = [] for column in kwargs.keys(): if column not in self._columns: raise TypeError("No such column: %r", column) conditions.append("%s=?" % column) query = "SELECT * FROM session WHERE %s" % (' AND '.join(conditions)) self.cursor.execute(query, list(kwargs.values())) model = self.cursor.fetchone() if model is None: q = [] for key, value in kwargs.items(): q.append("%s=%r" % (key, value)) raise web.HTTPError(404, u'Session not found: %s' % (', '.join(q))) 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. """ self.get_session(session_id=session_id) if not kwargs: # no changes return sets = [] for column in kwargs.keys(): if column not in self._columns: raise TypeError("No such column: %r" % column) sets.append("%s=?" % column) query = "UPDATE session SET %s WHERE session_id=?" % (', '.join(sets)) self.cursor.execute(query, list(kwargs.values()) + [session_id]) @staticmethod def row_factory(cursor, row): """Takes sqlite database session row and turns it into a dictionary""" row = sqlite3.Row(cursor, row) model = { 'id': row['session_id'], 'notebook': { 'name': row['name'], 'path': row['path'] }, 'kernel': { 'id': row['kernel_id'], 'ws_url': row['ws_url'] } } return model def list_sessions(self): """Returns a list of dictionaries containing all the information from the session database""" c = self.cursor.execute("SELECT * FROM session") return list(c.fetchall()) def delete_session(self, session_id): """Deletes the row in the session database with given session_id""" # Check that session exists before deleting self.get_session(session_id=session_id) self.cursor.execute("DELETE FROM session WHERE session_id=?", (session_id,))