106 lines
4.5 KiB
ReStructuredText
106 lines
4.5 KiB
ReStructuredText
Storage Engines
|
|
===============
|
|
|
|
Every time you login to Telegram, some personal piece of data are created and held by both parties (the client, Pyrogram
|
|
and the server, Telegram). This session data is uniquely bound to your own account, indefinitely (until you logout or
|
|
decide to manually terminate it) and is used to authorize a client to execute API calls on behalf of your identity.
|
|
|
|
.. contents:: Contents
|
|
:backlinks: none
|
|
:local:
|
|
|
|
-----
|
|
|
|
Persisting Sessions
|
|
-------------------
|
|
|
|
In order to make a client reconnect successfully between restarts, that is, without having to start a new
|
|
authorization process from scratch each time, Pyrogram needs to store the generated session data somewhere.
|
|
|
|
Other useful data being stored is peers' cache. In short, peers are all those entities you can chat with, such as users
|
|
or bots, basic groups, but also channels and supergroups. Because of how Telegram works, a unique pair of **id** and
|
|
**access_hash** is needed to contact a peer. This, plus other useful info such as the peer type, is what is stored
|
|
inside a session storage.
|
|
|
|
So, if you ever wondered how is Pyrogram able to contact peers just by asking for their ids, it's because of this very
|
|
reason: the peer *id* is looked up in the internal database and the available *access_hash* is retrieved, which is then
|
|
used to correctly invoke API methods.
|
|
|
|
Different Storage Engines
|
|
-------------------------
|
|
|
|
Let's now talk about how Pyrogram actually stores all the relevant data. Pyrogram offers two different types of storage
|
|
engines: a **File Storage** and a **Memory Storage**. These engines are well integrated in the library and require a
|
|
minimal effort to set up. Here's how they work:
|
|
|
|
File Storage
|
|
^^^^^^^^^^^^
|
|
|
|
This is the most common storage engine. It is implemented by using **SQLite**, which will store the session and peers
|
|
details. The database will be saved to disk as a single portable file and is designed to efficiently store and retrieve
|
|
peers whenever they are needed.
|
|
|
|
To use this type of engine, simply pass any name of your choice to the ``session_name`` parameter of the
|
|
:obj:`~pyrogram.Client` constructor, as usual:
|
|
|
|
.. code-block:: python
|
|
|
|
from pyrogram import Client
|
|
|
|
with Client("my_account") as app:
|
|
print(app.get_me())
|
|
|
|
Once you successfully log in (either with a user or a bot identity), a session file will be created and saved to disk as
|
|
``my_account.session``. Any subsequent client restart will make Pyrogram search for a file named that way and the
|
|
session database will be automatically loaded.
|
|
|
|
Memory Storage
|
|
^^^^^^^^^^^^^^
|
|
|
|
In case you don't want to have any session file saved to disk, you can use an in-memory storage by passing the special
|
|
session name "**:memory:**" to the ``session_name`` parameter of the :obj:`~pyrogram.Client` constructor:
|
|
|
|
.. code-block:: python
|
|
|
|
from pyrogram import Client
|
|
|
|
with Client(":memory:") as app:
|
|
print(app.get_me())
|
|
|
|
This storage engine is still backed by SQLite, but the database exists purely in memory. This means that, once you stop a
|
|
client, the entire database is discarded and the session details used for logging in again will be lost forever.
|
|
|
|
Session Strings
|
|
---------------
|
|
|
|
In case you want to use an in-memory storage, but also want to keep access to the session you created, call
|
|
:meth:`~pyrogram.Client.export_session_string` anytime before stopping the client...
|
|
|
|
.. code-block:: python
|
|
|
|
from pyrogram import Client
|
|
|
|
with Client(":memory:") as app:
|
|
print(app.export_session_string())
|
|
|
|
...and save the resulting (quite long) string somewhere. You can use this string as session name the next time you want
|
|
to login using the same session; the storage used will still be completely in-memory:
|
|
|
|
.. code-block:: python
|
|
|
|
from pyrogram import Client
|
|
|
|
session_string = "...ZnUIFD8jsjXTb8g_vpxx48k1zkov9sapD-tzjz-S4WZv70M..."
|
|
|
|
with Client(session_string) as app:
|
|
print(app.get_me())
|
|
|
|
Session strings are useful when you want to run authorized Pyrogram clients on platforms like
|
|
`Heroku <https://www.heroku.com/>`_, where their ephemeral filesystems makes it much harder for a file-based storage
|
|
engine to properly work as intended.
|
|
|
|
But, why is the session string so long? Can't it be shorter? No, it can't. The session string already packs the bare
|
|
minimum data Pyrogram needs to successfully reconnect to an authorized session, and the 2048-bits auth key is the major
|
|
contributor to the overall length. Needless to say that this string, as well as any other session storage, represent
|
|
strictly personal data. Keep them safe.
|