gotosocial/internal/processing/streaming/openstream.go
2021-12-20 18:42:19 +01:00

121 lines
3.9 KiB
Go

/*
GoToSocial
Copyright (C) 2021-2022 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 streaming
import (
"context"
"errors"
"fmt"
"github.com/sirupsen/logrus"
"github.com/superseriousbusiness/gotosocial/internal/gtserror"
"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
"github.com/superseriousbusiness/gotosocial/internal/id"
"github.com/superseriousbusiness/gotosocial/internal/stream"
)
func (p *processor) OpenStreamForAccount(ctx context.Context, account *gtsmodel.Account, streamTimeline string) (*stream.Stream, gtserror.WithCode) {
l := logrus.WithFields(logrus.Fields{
"func": "OpenStreamForAccount",
"account": account.ID,
"streamType": streamTimeline,
})
l.Debug("received open stream request")
// each stream needs a unique ID so we know to close it
streamID, err := id.NewRandomULID()
if err != nil {
return nil, gtserror.NewErrorInternalError(fmt.Errorf("error generating stream id: %s", err))
}
thisStream := &stream.Stream{
ID: streamID,
Timeline: streamTimeline,
Messages: make(chan *stream.Message, 100),
Hangup: make(chan interface{}, 1),
Connected: true,
}
go p.waitToCloseStream(account, thisStream)
v, ok := p.streamMap.Load(account.ID)
if !ok || v == nil {
// there is no entry in the streamMap for this account yet, so make one and store it
streamsForAccount := &stream.StreamsForAccount{
Streams: []*stream.Stream{
thisStream,
},
}
p.streamMap.Store(account.ID, streamsForAccount)
} else {
// there is an entry in the streamMap for this account
// parse the interface as a streamsForAccount
streamsForAccount, ok := v.(*stream.StreamsForAccount)
if !ok {
return nil, gtserror.NewErrorInternalError(errors.New("stream map error"))
}
// append this stream to it
streamsForAccount.Lock()
streamsForAccount.Streams = append(streamsForAccount.Streams, thisStream)
streamsForAccount.Unlock()
}
return thisStream, nil
}
// waitToCloseStream waits until the hangup channel is closed for the given stream.
// It then iterates through the map of streams stored by the processor, removes the stream from it,
// and then closes the messages channel of the stream to indicate that the channel should no longer be read from.
func (p *processor) waitToCloseStream(account *gtsmodel.Account, thisStream *stream.Stream) {
<-thisStream.Hangup // wait for a hangup message
// lock the stream to prevent more messages being put in it while we work
thisStream.Lock()
defer thisStream.Unlock()
// indicate the stream is no longer connected
thisStream.Connected = false
// load and parse the entry for this account from the stream map
v, ok := p.streamMap.Load(account.ID)
if !ok || v == nil {
return
}
streamsForAccount, ok := v.(*stream.StreamsForAccount)
if !ok {
return
}
// lock the streams for account while we remove this stream from its slice
streamsForAccount.Lock()
defer streamsForAccount.Unlock()
// put everything into modified streams *except* the stream we're removing
modifiedStreams := []*stream.Stream{}
for _, s := range streamsForAccount.Streams {
if s.ID != thisStream.ID {
modifiedStreams = append(modifiedStreams, s)
}
}
streamsForAccount.Streams = modifiedStreams
// finally close the messages channel so no more messages can be read from it
close(thisStream.Messages)
}