nxy/bot/__init__.py
jkhsjdhjs e03f5d0a43 add auto reconnect for postgres
This only works on the second database interaction, since psycopg2 only notices that
the connection is gone, when a query is executed.

So in the common case reconnect works as follows:
- some bot method calls a cursor function like .execute(), .fetchone(), etc.
  - this raises an error if the connection is broken
  - if following code then requests a new cursor, this will also fail since psycopg2
    now knows that the connection is gone
  - the error is caught in storage.DBConn.cursor(), a new connection will be set up
    of which a new cursor is yielded
If the error happens in connection.commit() or .rollback() instead we can instantly
reconnect since these methods are wrapped.

So why not wrap the cursor methods as well?
Consider the following example:
A query is the last thing that was executed on a cursor.
The database connection is lost.
Now .fetchone() is called on the cursor.
We could wrap .fetchone() and reconnect, but we'd have to use a new cursor since
cursors are linked to connections. And on this new cursor .fetchone() wouldn't
make any sense, since we haven't executed a query on this cursor.
2020-03-16 21:51:32 +00:00

76 lines
1.8 KiB
Python

# -*- coding: utf-8 -*-
import os
import json
import logging
from collections import OrderedDict
import irc3
from dotenv import load_dotenv
MODULE = __name__
# TODO: ddg
class Bot(irc3.IrcBot):
DEV = 'BOT_DEV' in os.environ
REPO_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
CONFIG_DIR = REPO_DIR if DEV else os.path.dirname(REPO_DIR)
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.cfg_file = None
self.env_file = None
def load_config(self):
with open(self.cfg_file, 'r') as fp:
return json.load(fp, object_pairs_hook=OrderedDict)
def save_config(self, data):
with open(self.cfg_file, 'w') as fp:
json.dump(data, fp, indent=2)
@classmethod
def from_json(cls, cfg_file: str = 'config.json', env_file: str = '.env'):
cfg_file = os.path.join(cls.CONFIG_DIR, cfg_file)
env_file = os.path.join(cls.CONFIG_DIR, env_file)
load_dotenv(env_file)
with open(cfg_file, 'r') as fp:
conf = json.load(fp)
if cls.DEV:
conf['debug'] = True
bot = cls.from_config(conf)
bot.cfg_file = cfg_file
bot.env_file = env_file
return bot
@irc3.plugin
class BasePlugin:
requires = ['irc3.plugins.command']
def __init__(self, bot: Bot):
self.bot = bot
self.log = logging.getLogger('irc3.{}'.format(self.__class__.__name__.lower()))
class Plugin(BasePlugin):
@classmethod
def reload(cls, old: BasePlugin):
return cls(old.bot)
from .storage import Storage # noqa
class DatabasePlugin(Plugin):
requires = Plugin.requires + ['bot.storage']
def __init__(self, bot: Bot):
super().__init__(bot)
self.db = bot.get_plugin(Storage)
self.con = self.db.con