First implementation of the filesystem session store plugin

plugins/filesystem_session/__init__.py

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+from lodel.settings.validator import SettingValidator
+
+__loader__ = 'main.py'
+__confspec__ = "confspec.py"
+__author__ = "Lodel2 dev team"
+__fullname__ = "FileSystem Session Store Plugin"
+
+
+## @brief This methods allow plugin writter to write some checks
+#
+# @return True if checks are OK else returns a string with a reason
+def _activate():
+    return True

plugins/filesystem_session/confspec.py

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+# -*- coding: utf-8 -*-
+
+from lodel.settings.validator import SettingValidator
+
+CONFSPEC = {
+    'lodel2.sessions':{
+        'directory': ('/tmp/lodel2_session', SettingValidator('path')),
+        'expiration': (900, SettingValidator('int')),
+        'file_template': ('lodel2_%s.sess', SettingValidator('dummy'))
+    }
+}

plugins/filesystem_session/main.py

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+# -*- coding: utf-8 -*-
+
+import os
+from werkzeug.contrib.sessions import FilesystemSessionStore
+
+from lodel.plugin import LodelHook
+from lodel.settings import Settings
+from lodel.utils.datetime import get_utc_timestamp
+
+SESSION_FILES_BASE_DIR = Settings.sessions.directory
+SESSION_FILES_TEMPLATE = Settings.sessions.file_template
+SESSION_EXPIRATION_LIMIT = Settings.sessions.expiration
+
+session_store = FilesystemSessionStore(path=SESSION_FILES_BASE_DIR, filename_template=SESSION_FILES_TEMPLATE)
+
+
+@LodelHook('lodel_delete_old_session_files')
+def delete_old_session_files(caller, timestamp_now):
+    session_files_path = os.path.abspath(session_store.path)
+    session_files = [os.path.join(session_files_path, file_object) for file_object in os.listdir(session_files_path) if os.path.isfile(os.path.join(session_files_path, file_object))]
+
+    for session_file in session_files:
+        last_modified = os.stat(session_file).st_mtime
+        expiration_timestamp = last_modified + SESSION_EXPIRATION_LIMIT
+        if timestamp_now > expiration_timestamp:
+            os.unlink(session_file)
+
+
+def is_session_file_expired(timestamp_now, sid):
+    session_file = session_store.get_session_filename(sid)
+    expiration_timestamp = os.stat(session_file).st_mtime + SESSION_EXPIRATION_LIMIT
+    return timestamp_now >= expiration_timestamp
+
+
+## @brief starts a new session
+# @param caller *
+# @param payload dict : dictionary containing the content of the session
+@LodelHook('lodel_start_session')
+def start_session(caller, payload):
+    session = session_store.new()
+    for key, value in payload.items():
+        session[key] = value
+    session_store.save(session)
+
+
+## @brief reads the content of the session
+# @param caller *
+# @param sid str
+# @return dict
+@LodelHook('lodel_read_session')
+def read_session(caller, sid):
+    timestamp = get_utc_timestamp()
+    session = None
+    if not is_session_file_expired(timestamp, sid):
+        session = session_store.get(sid)
+
+    return session
+
+
+@LodelHook('lodel_update_session')
+def update_session(caller, timestamp_now, sid):
+    if sid is None or sid not in session_store.list():
+        session = session_store.new()
+        session['last_accessed'] = timestamp_now
+    else:
+        session = session_store.get(sid)
+        if is_session_file_expired(timestamp_now, sid):
+            session_store.delete(session)
+            session = session_store.new()
+            session['user_context'] = None
+        session['last_accessed'] = timestamp_now