Simple yet powerful infra-structure for handling of WebSocket connections.
The server itself should be based on a common infra-structure like the one present in frameworks like node.js that should abstract the socket connection layer (select layer) on an event driven basis. The infra-structure itself should be non-blocking and asynchronous for performance and scalability.
The API layer should be provided by a simple WSGI application implemented using the Appier Framework to keep things simple and fast.
For persistence the pushi infra-structure uses the MongoDB database infra-structure to avoid any unwanted complexities and provide fast performance.
Pushi was heavily inspired by the Pusher service, and aims at providing a free alternative to it (for cost reducing).
The channel is the base object for communication and there are four types of channels so that each one has its own objectives.
Channels that may be subscribed by any connection without any sort of validation.
Authenticated channels for which the access is constrained to only server side validated connections. The validation is performed using a REST-JSON based API.
Channels that provide extra information on the situation on the channel, for instance
allow the identification of a set of connection using a single user_id
tag. Using
this approach it's possible to know when a new user connects to a channel and when
one disconnects (no more connections with the same user_id
are present). These channels
are considered private and so are subject to validation from the server side.
This channels provide the capability to aggregate a series of (personal) subscriptions
into a single channel (for simplicity). This way it's easy to aggregate a stream of
notifications that arise from a group of channels. This channel must be used together
with the publish subscribe model. A channel of this type should be named personal-<user_id>
.
Targeted at chat environment allows for the creation of automatic channels for the
various elements (users) that are subscribed to a peer channel. The activation of the
automatic peer channel configuration is archived using the peer
flag in the channel_data
structure upon the subscription of such channel. This channel type should not be created directly
but instead should be created through presence channels.
The management of these kind of channels implies that the peer
advertisement flag is set
for a channel shared among the peers, from that moment the peer is visible to all the
other peers upon subscription of that shared channel. These kind of channels should
be used together with the presence channels.
The naming of these kind of channels will always follow the structure
peer-base_channel:user_1&user_2&user_3
.
It's possible to use pushi to store messages in the server side in a publish/subscriber
way so that a user_id
may subscribe for a certain channel even when it's offline.
To be able to subscribe for a channel use the apps/<app_id>/subscribe
route with the
user_id
and the event
parameters indicating both the id and the name of the event
that should be subscribed.
To revert the subscribe operation one should call the apps/<app_id>/unsubscribe
route
with the same user_id
and the event
parameters.
When a user connects to the channel that it has subscribed the last messages are returned
as part of the channel_data
structure.
To be able to run the pushi infra-structure under a normal non encrypted connection and bind to the complete set of network interfaces in the host the following command:
APP_HOST=0.0.0.0 \
APP_PORT=8080 \
SERVER_HOST=0.0.0.0 \
SERVER_PORT=80 \
python pushi/src/pushi/base/state.py < /dev/null &> ~/pushi.log &
To be able to run in using SSL encryption additional commands must be used, please note that the SSL port used by the app is not the default one:
APP_SERVER=netius \
APP_HOST=0.0.0.0 \
APP_PORT=9090 \
APP_SSL=1 \
APP_SSL_KEY=/path/to/file.key \
APP_SSL_CER=/path/to/file.cer \
SERVER_HOST=0.0.0.0 \
SERVER_PORT=443 \
SERVER_SSL=1 \
SERVER_SSL_KEY=/path/to/file.key \
SERVER_SSL_CER=/path/to/file.cer \
python pushi/src/pushi/base/state.py < /dev/null &> ~/pushi.log &
var pushi = new Pushi("YOU_APP_KEY");
pushi.bind("message", function(event, data) {
jQuery("body").append("<div>" + data + "</div>");
});
import pushi
proxy = pushi.Pushi(
app_id = "YOU_APP_ID",
app_key = "YOU_APP_KEY",
app_secret = "YOU_APP_SECRET"
)
proxy.trigger_event(
channel = "global",
data = "hello world",
event = "message"
)
Pushi System is currently licensed under the Apache License, Version 2.0.