3
0
corteza/sam/websocket/event_queue.go

121 lines
2.6 KiB
Go

package websocket
import (
"context"
"encoding/json"
"github.com/titpetric/factory"
"github.com/crusttech/crust/internal/payload"
"github.com/crusttech/crust/internal/payload/outgoing"
"github.com/crusttech/crust/sam/repository"
"github.com/crusttech/crust/sam/types"
)
type (
eventQueueWalker interface {
Walk(func(session *Session))
}
eventQueue struct {
origin uint64
queue chan *types.EventQueueItem
}
)
const (
eventQueueBacklog = 512
)
var eq *eventQueue
func init() {
eq = EventQueue(factory.Sonyflake.NextID())
}
func EventQueue(origin uint64) *eventQueue {
return &eventQueue{
origin: origin,
queue: make(chan *types.EventQueueItem, eventQueueBacklog),
}
}
// @todo: retire this function, use Events().Push(ctx, item) directly.
func (eq *eventQueue) store(ctx context.Context, qp repository.EventsRepository) {
go func() {
for {
select {
case <-ctx.Done():
case eqi := <-eq.queue:
qp.Push(ctx, eqi)
}
}
}()
}
func (eq *eventQueue) feedSessions(ctx context.Context, config *repository.Flags, qp repository.EventsRepository, store eventQueueWalker) error {
for {
item, err := qp.Pull(ctx)
if err != nil {
return err
}
if item.SubType == types.EventQueueItemSubTypeUser {
p := &outgoing.Payload{}
if err := json.Unmarshal(item.Payload, p); err != nil {
return err
}
if p.ChannelJoin != nil {
// Handle subscribing
// This store.Walk handler does not send to subscribed sessions but
// subscribes all sessions that belong to the same user
store.Walk(func(s *Session) {
if payload.Uint64toa(s.user.Identity()) == p.ChannelJoin.UserID {
s.subs.Add(p.ChannelJoin.ID)
}
})
} else if p.ChannelPart != nil {
// Handle un-subscribing
// This store.Walk handler does not send to subscribed sessions but
// subscribes all sessions that belong to the same user
store.Walk(func(s *Session) {
if payload.Uint64toa(s.user.Identity()) == p.ChannelPart.UserID {
s.subs.Delete(p.ChannelPart.ID)
}
})
} else {
// No other payload types we can handle at the moment.
return nil
}
} else if item.Subscriber == "" {
// Distribute payload to all connected sessions
store.Walk(func(s *Session) {
s.sendBytes(item.Payload)
})
} else {
// Distribute payload to specific subscribers
store.Walk(func(s *Session) {
if s.subs.Get(item.Subscriber) != nil {
s.sendBytes(item.Payload)
}
})
}
}
}
// Adds origin to the event and puts it into queue.
func (eq *eventQueue) push(ctx context.Context, eqi *types.EventQueueItem) {
eqi.Origin = eq.origin
select {
case <-ctx.Done():
case eq.queue <- eqi:
}
}