MatrixSynapse/synapse/replication/tcp/__init__.py

# Copyright 2017 Vector Creations Ltd
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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"""This module implements the TCP replication protocol used by synapse to
communicate between the master process and its workers (when they're enabled).

Further details can be found in docs/tcp_replication.rst


Structure of the module:
 * handler.py  - the classes used to handle sending/receiving commands to
                 replication
 * command.py  - the definitions of all the valid commands
 * protocol.py - the TCP protocol classes
 * resource.py - handles streaming stream updates to replications
 * streams/    - the definitions of all the valid streams


The general interaction of the classes are:

        +---------------------+
        | ReplicationStreamer |
        +---------------------+
                    |
                    v
        +---------------------------+     +----------------------+
        | ReplicationCommandHandler |---->|ReplicationDataHandler|
        +---------------------------+     +----------------------+
                    | ^
                    v |
            +-------------+
            | Protocols   |
            | (TCP/redis) |
            +-------------+

Where the ReplicationDataHandler (or subclasses) handles incoming stream
updates.
"""