gotosocial/internal/distributor/distributor.go
2021-04-20 18:14:23 +02:00

110 lines
4 KiB
Go

/*
GoToSocial
Copyright (C) 2021 GoToSocial Authors admin@gotosocial.org
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package distributor
import (
"github.com/sirupsen/logrus"
"github.com/superseriousbusiness/gotosocial/internal/db/gtsmodel"
)
// Distributor should be passed to api modules (see internal/apimodule/...). It is used for
// passing messages back and forth from the client API and the federating interface, via channels.
// It also contains logic for filtering which messages should end up where.
// It is designed to be used asynchronously: the client API and the federating API should just be able to
// fire messages into the distributor and not wait for a reply before proceeding with other work. This allows
// for clean distribution of messages without slowing down the client API and harming the user experience.
type Distributor interface {
// FromClientAPI returns a channel for accepting messages that come from the gts client API.
FromClientAPI() chan FromClientAPI
// ClientAPIOut returns a channel for putting in messages that need to go to the gts client API.
ToClientAPI() chan ToClientAPI
// Start starts the Distributor, reading from its channels and passing messages back and forth.
Start() error
// Stop stops the distributor cleanly, finishing handling any remaining messages before closing down.
Stop() error
}
// distributor just implements the Distributor interface
type distributor struct {
// federator pub.FederatingActor
fromClientAPI chan FromClientAPI
toClientAPI chan ToClientAPI
stop chan interface{}
log *logrus.Logger
}
// New returns a new Distributor that uses the given federator and logger
func New(log *logrus.Logger) Distributor {
return &distributor{
// federator: federator,
fromClientAPI: make(chan FromClientAPI, 100),
toClientAPI: make(chan ToClientAPI, 100),
stop: make(chan interface{}),
log: log,
}
}
// ClientAPIIn returns a channel for accepting messages that come from the gts client API.
func (d *distributor) FromClientAPI() chan FromClientAPI {
return d.fromClientAPI
}
// ClientAPIOut returns a channel for putting in messages that need to go to the gts client API.
func (d *distributor) ToClientAPI() chan ToClientAPI {
return d.toClientAPI
}
// Start starts the Distributor, reading from its channels and passing messages back and forth.
func (d *distributor) Start() error {
go func() {
DistLoop:
for {
select {
case clientMsg := <-d.fromClientAPI:
d.log.Infof("received message FROM client API: %+v", clientMsg)
case clientMsg := <-d.toClientAPI:
d.log.Infof("received message TO client API: %+v", clientMsg)
case <-d.stop:
break DistLoop
}
}
}()
return nil
}
// Stop stops the distributor cleanly, finishing handling any remaining messages before closing down.
// TODO: empty message buffer properly before stopping otherwise we'll lose federating messages.
func (d *distributor) Stop() error {
close(d.stop)
return nil
}
// FromClientAPI wraps a message that travels from the client API into the distributor
type FromClientAPI struct {
APObjectType gtsmodel.ActivityStreamsObject
APActivityType gtsmodel.ActivityStreamsActivity
Activity interface{}
}
// ToClientAPI wraps a message that travels from the distributor into the client API
type ToClientAPI struct {
APObjectType gtsmodel.ActivityStreamsObject
APActivityType gtsmodel.ActivityStreamsActivity
Activity interface{}
}