Changed the filesystem session handler's main module's methods

plugins/filesystem_session/main.py

@@ -1,44 +1,150 @@
 # -*- coding: utf-8 -*-
 
-from lodel.plugin import LodelHook
+import binascii
+import copy
+import datetime
+import os
+import pickle
+import re
+import time
 
-from .filesystem_session_store import FileSystemSession
+from lodel import logger
+from lodel.settings import Settings
+from lodel.auth.exceptions import ClientAuthenticationFailure
 
-## @brief starts a new session and returns its sid
-# @param caller *
-# @param payload dict
+from .filesystem_session import FileSystemSession
+
+## @brief lists the active sessions in a dict
+# Its keys are the session tokens and its values are the file paths of session 
+# files.
+__sessions = dict()
+
+# ====== UTILS ====== # 
+
+## @brief Generates a session token
+# @return str
+def __generate_token():
+    new_token = binascii.hexlify(os.urandom(Settings.sessions.tokensize//2))
+    if new_token in __sessions.keys():
+        new_token = __generate_token()
+    return new_token
+
+## @brief Checks if a token is valid and matchs with a registered session
+# @param token str
+# @raise ClientAuthenticationFailure for invalid or not found session token
+def _check_token(token):
+    # Bad length
+    if len(token) != Settings.sessions.tokensize:
+        raise ClientAuthenticationFailure("Malformed session token")
+    # Not found
+    if token not in __sessions:
+        raise ClientAuthenticationFailure("No session found with this token")
+
+
+## @brief Lists all the session files' paths
+# @return list
+def _list_all_sessions():
+    session_files_directory = os.abspath(Settings.sessions.directory)
+    return [file_path for file_path in os.listdir(session_files_directory) if os.path.isfile(os.path.join(session_files_directory, file_path))]
+
+
+## @brief Returns the token from a session file's name
+# @param filename str
+# @return str
+def _get_token_from_session_filename(filename):
+    token_regex = re.compile(Settings.sessions.file_template % '(?P<token>.*)')
+    token_searching_result = token_regex.match(filename)
+    if token_searching_result is not None:
+        return token_searching_result.groupdict()['token']
+    return None
+
+
+## @brief Defines a session file name from a token
+# @param token str
+# @return str
+def _generate_filename_from_token(token):
+    return Settings.sessions.file_template % token
+
+
+## @brief Defines a session file path from a token
+# @param token str
+# @return str
+def _generate_filepath_from_token(token):
+    return os.path.join(Settings.sessions.directory, Settings.sessions.file_template) % token
+
+
+## @brief Returns the session's last modification timestamp
+# @param token str
+# @return float
+def _get_session_last_modified(token):
+    if token in __sessions.keys():
+        return os.stat(__sessions[token]).st_mtime
+    else:
+        raise ValueError("The given token %s doesn't match with an existing session")
+
+# ====== SESSION MANAGEMENT ====== #
+## @brief Registers the session in the active sessions' list
+# @param session LodelSession
+def _register_session(token):
+    __sessions[token] = os.path.join(Settings.sessions.directory, _generate_filename_from_token(token))
+    
+    
+## @brief Session store's garbage collector
+def gc():
+    # unregistered files in the session directory
+    sessions_dir_files = _list_all_sessions()
+    for sessions_dir_file in sessions_dir_files:
+        token = _get_token_from_session_filename(sessions_dir_file)
+        if token is None or token not in __sessions.keys():
+            os.unlink(sessions_dir_file)
+    
+    # expired registered sessions
+    for token in __sessions.keys():
+        if os.path.isfile(__sessions[token]):
+            now_timestamp = time.mktime(datetime.datetime.now().timetuple())
+            if now_timestamp - _get_session_last_modified(token) > Settings.sessions.expiration:
+                destroy_session(token)
+
+
+## @brief starts a new session and returns its token
 # @return str
 def start_session():
-    new_session = FileSystemSession()
-    return new_session.sid
-
-## @brief destroys a session
-# @param caller *
-# @param sid str : session id
-def destroy_session(sid):
-    FileSystemSession.destroy(sid)
-
-## @brief reads a session content
-# @param caller *
-# @param sid str: session id
+    new_token = __generate_token()
+    new_session = FileSystemSession(new_token)
+    new_session.save()
+    _register_session(new_token)
+    _check_token(new_token)
+    logger.debug("New session created")
+    return new_token
+
+
+## @brief destroys a session defined by its token
+# @param token str
+def destroy_session(token):
+    _check_token(token)
+    if os.path.isfile(__sessions[token]):
+        os.unlink(__sessions[token])
+    del(__sessions[token])
+    logger.debug("Session %s destroyed" % token)
+
+
+## @brief restores a session's content
+# @param token str
 # @return FileSystemSession
-def restore_session(sid):
-    return FileSystemSession.load(sid)
-
-##@brief Set a session value
-#@param name str : session variable name
-#@param value mixed : session variable value
-def set_value(name, value):
-    pass
-
-##@brief Get a session value
-#@param name str : the session variable name
-#@return the value
-def get_value(name):
-    pass
-
-##@brief Delete a session value
-#@param name str : the session variable name
-def del_value(name):
-    pass
-    
+def restore_session(token):
+    _check_token(token)
+    logger.debug("Restoring session : %s" % token)
+    if os.path.isfile(__sessions[token]):
+        with open(__sessions[token], 'rb') as session_file:
+            session = pickle.load(session_file)
+        return session
+    return None
+
+
+def save_session(token, datas=None):
+    _check_token(token)
+    session = restore_session(token)
+    session.datas = copy.copy(datas)
+    with open(__sessions[token], 'wb') as session_file:
+        pickle.dump(session, session_file)
+    logger.debug("Session %s saved" % token)