/
subscriptions_manager.go
151 lines (138 loc) · 4.45 KB
/
subscriptions_manager.go
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// SPDX-License-Identifier: AGPL-3.0-or-later
// DMRHub - Run a DMR network server in a single binary
// Copyright (C) 2023-2024 Jacob McSwain
//
// 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 <https://www.gnu.org/licenses/>.
//
// The source code is available at <https://github.com/USA-RedDragon/DMRHub>
package openbridge
import (
"context"
"sync"
"github.com/USA-RedDragon/DMRHub/internal/config"
"github.com/USA-RedDragon/DMRHub/internal/db/models"
"github.com/USA-RedDragon/DMRHub/internal/logging"
"github.com/redis/go-redis/v9"
"go.opentelemetry.io/otel"
)
var subscriptionManager *SubscriptionManager //nolint:golint,gochecknoglobals
type SubscriptionManager struct {
subscriptions map[uint]context.CancelFunc
subscriptionsMutex *sync.RWMutex
subscriptionCancelMutex map[uint]*sync.RWMutex
}
func GetSubscriptionManager() *SubscriptionManager {
if subscriptionManager == nil {
subscriptionManager = &SubscriptionManager{
subscriptions: make(map[uint]context.CancelFunc),
subscriptionsMutex: &sync.RWMutex{},
subscriptionCancelMutex: make(map[uint]*sync.RWMutex),
}
}
return subscriptionManager
}
func (m *SubscriptionManager) CancelSubscription(p models.Peer) {
m.subscriptionsMutex.RLock()
m.subscriptionCancelMutex[p.ID].RLock()
cancel, ok := m.subscriptions[p.ID]
m.subscriptionCancelMutex[p.ID].RUnlock()
m.subscriptionsMutex.RUnlock()
if ok {
m.subscriptionsMutex.Lock()
m.subscriptionCancelMutex[p.ID].Lock()
delete(m.subscriptions, p.ID)
m.subscriptionCancelMutex[p.ID].Unlock()
delete(m.subscriptionCancelMutex, p.ID)
m.subscriptionsMutex.Unlock()
cancel()
}
}
func (m *SubscriptionManager) Subscribe(ctx context.Context, redis *redis.Client, p models.Peer) {
_, span := otel.Tracer("DMRHub").Start(ctx, "Server.handlePacket")
defer span.End()
if !p.Ingress {
return
}
m.subscriptionsMutex.RLock()
_, ok := m.subscriptions[p.ID]
m.subscriptionsMutex.RUnlock()
if !ok {
newCtx, cancel := context.WithCancel(context.Background())
m.subscriptionsMutex.Lock()
_, ok = m.subscriptionCancelMutex[p.ID]
if !ok {
m.subscriptionCancelMutex[p.ID] = &sync.RWMutex{}
}
m.subscriptionCancelMutex[p.ID].Lock()
m.subscriptions[p.ID] = cancel
m.subscriptionCancelMutex[p.ID].Unlock()
m.subscriptionsMutex.Unlock()
go m.subscribe(newCtx, redis, p) //nolint:golint,contextcheck
}
}
func (m *SubscriptionManager) subscribe(ctx context.Context, redis *redis.Client, p models.Peer) {
if config.GetConfig().Debug {
logging.Logf("Listening for calls on peer %d", p.ID)
}
pubsub := redis.Subscribe(ctx, "openbridge:packets")
defer func() {
err := pubsub.Unsubscribe(ctx, "openbridge:packets")
if err != nil {
logging.Errorf("Error unsubscribing from openbridge:packets: %s", err)
}
err = pubsub.Close()
if err != nil {
logging.Errorf("Error closing pubsub connection: %s", err)
}
}()
pubsubChannel := pubsub.Channel()
for {
select {
case <-ctx.Done():
if config.GetConfig().Debug {
logging.Log("Context canceled, stopping subscription to openbridge:packets")
}
m.subscriptionsMutex.Lock()
_, ok := m.subscriptionCancelMutex[p.ID]
if ok {
m.subscriptionCancelMutex[p.ID].Lock()
}
delete(m.subscriptions, p.ID)
if ok {
m.subscriptionCancelMutex[p.ID].Unlock()
delete(m.subscriptionCancelMutex, p.ID)
}
m.subscriptionsMutex.Unlock()
return
case msg := <-pubsubChannel:
rawPacket := models.RawDMRPacket{}
_, err := rawPacket.UnmarshalMsg([]byte(msg.Payload))
if err != nil {
logging.Errorf("Failed to unmarshal raw packet: %s", err)
continue
}
packet, ok := models.UnpackPacket(rawPacket.Data)
if !ok {
logging.Errorf("Failed to unpack packet: %s", err)
continue
}
if packet.Repeater == p.ID {
continue
}
packet.Repeater = p.ID
packet.Slot = false
redis.Publish(ctx, "openbridge:outgoing", packet.Encode())
}
}
}