enhanced-discord.py/discord/shard.py

# -*- coding: utf-8 -*-

"""
The MIT License (MIT)

Copyright (c) 2015-2016 Rapptz

Permission is hereby granted, free of charge, to any person obtaining a
copy of this software and associated documentation files (the "Software"),
to deal in the Software without restriction, including without limitation
the rights to use, copy, modify, merge, publish, distribute, sublicense,
and/or sell copies of the Software, and to permit persons to whom the
Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
DEALINGS IN THE SOFTWARE.
"""

from .state import AutoShardedConnectionState
from .client import Client
from .gateway import *
from .errors import ConnectionClosed
from . import compat

import asyncio
import logging

log = logging.getLogger(__name__)

class Shard:
    def __init__(self, ws, client):
        self.ws = ws
        self._client = client
        self.loop = self._client.loop
        self._current = asyncio.Future(loop=self.loop)
        self._current.set_result(None) # we just need an already done future

    @property
    def id(self):
        return self.ws.shard_id

    @asyncio.coroutine
    def poll(self):
        try:
            yield from self.ws.poll_event()
        except (ReconnectWebSocket, ResumeWebSocket) as e:
            resume = type(e) is ResumeWebSocket
            log.info('Got ' + type(e).__name__)
            self.ws = yield from DiscordWebSocket.from_client(self._client, resume=resume,
                                                                            shard_id=self.id,
                                                                            session=self.ws.session_id,
                                                                            sequence=self.ws.sequence)
        except ConnectionClosed as e:
            yield from self._client.close()
            if e.code != 1000:
                raise

    def get_future(self):
        if self._current.done():
            self._current = compat.create_task(self.poll(), loop=self.loop)

        return self._current

class AutoShardedClient(Client):
    """A client similar to :class:`Client` except it handles the complications
    of sharding for the user into a more manageable and transparent single
    process bot.

    When using this client, you will be able to use it as-if it was a regular
    :class:`Client` with a single shard when implementation wise internally it
    is split up into multiple shards. This allows you to not have to deal with
    IPC or other complicated infrastructure.

    It is recommended to use this client only if you have surpassed at least
    1000 guilds.

    If no :attr:`shard_count` is provided, then the library will use the
    Bot Gateway endpoint call to figure out how many shards to use.
    """
    def __init__(self, *args, loop=None, **kwargs):
        kwargs.pop('shard_id', None)
        super().__init__(*args, loop=loop, **kwargs)

        self.connection = AutoShardedConnectionState(dispatch=self.dispatch, chunker=self.request_offline_members,
                                                     syncer=self._syncer, http=self.http, loop=self.loop, **kwargs)

        # instead of a single websocket, we have multiple
        # the index is the shard_id
        self.shards = []

    @asyncio.coroutine
    def request_offline_members(self, guild, *, shard_id=None):
        """|coro|

        Requests previously offline members from the guild to be filled up
        into the :attr:`Guild.members` cache. This function is usually not
        called.

        When the client logs on and connects to the websocket, Discord does
        not provide the library with offline members if the number of members
        in the guild is larger than 250. You can check if a guild is large
        if :attr:`Guild.large` is ``True``.

        Parameters
        -----------
        guild: :class:`Guild` or list
            The guild to request offline members for. If this parameter is a
            list then it is interpreted as a list of guilds to request offline
            members for.
        """

        try:
            guild_id = guild.id
            shard_id = shard_id or guild.shard_id
        except AttributeError:
            guild_id = [s.id for s in guild]

        payload = {
            'op': 8,
            'd': {
                'guild_id': guild_id,
                'query': '',
                'limit': 0
            }
        }

        ws = self.shards[shard_id].ws
        yield from ws.send_as_json(payload)

    @asyncio.coroutine
    def connect(self):
        """|coro|

        Creates a websocket connection and lets the websocket listen
        to messages from discord.

        Raises
        -------
        GatewayNotFound
            If the gateway to connect to discord is not found. Usually if this
            is thrown then there is a discord API outage.
        ConnectionClosed
            The websocket connection has been terminated.
        """
        ret = yield from DiscordWebSocket.from_sharded_client(self)
        self.shards = [Shard(ws, self) for ws in ret]

        while not self.is_closed:
            pollers = [shard.get_future() for shard in self.shards]
            yield from asyncio.wait(pollers, loop=self.loop, return_when=asyncio.FIRST_COMPLETED)

    @asyncio.coroutine
    def close(self):
        """|coro|

        Closes the connection to discord.
        """
        if self.is_closed:
            return

        for shard in self.shards:
            yield from shard.ws.close()

        yield from self.http.close()
        self._closed.set()
        self._is_ready.clear()