src.dualinventive.com/go/influxdb-logger/internal/reader/reader.go

102 lines
2.0 KiB
Go

package reader
import (
"context"
"sync"
"time"
"github.com/sirupsen/logrus"
"src.dualinventive.com/go/dinet"
)
// MessageReader reads incomming messages from a pubsub connection and send the messages to Influx
type MessageReader struct {
mu sync.Mutex
pubsub dinet.Conn
w dinet.Writer
}
// New creates a new message reader
func New(pubSubURI string, w dinet.Writer) (*MessageReader, error) {
con, err := dinet.NewConn(dinet.TransportZmq)
if err != nil {
return nil, err
}
err = con.Connect(pubSubURI + "?type=sub")
if err != nil {
return nil, err
}
reader := &MessageReader{}
reader.pubsub = con
reader.w = w
return reader, err
}
// Serve reads incomming messages from a pubsub connection and send the messages to Redis
func (r *MessageReader) Serve(ctx context.Context) {
var wg sync.WaitGroup
// Wait until the goroutine ends
defer wg.Wait()
wg.Add(1)
go func() {
defer wg.Done()
<-ctx.Done()
r.mu.Lock()
defer r.mu.Unlock()
if err := r.pubsub.Close(); err != nil {
logrus.Error("Unable to close pub sub connection:", err)
}
}()
for {
if ctx.Err() != nil {
logrus.Infof("reader context error: %v", ctx.Err())
return
}
// Receive messages from the reader connection
msg, err := r.pubsub.Recv()
if err != nil {
if err == dinet.ErrDisconnected {
logrus.Warn("Reconnecting due to error:", err)
} else {
logrus.Error("Unable to receive publish message due to:", err)
}
r.reconnect(ctx)
continue
}
if err := r.w.Send(msg); err != nil {
logrus.Warn("Send error: ", err)
}
}
}
func (r *MessageReader) reconnect(ctx context.Context) {
select {
case <-ctx.Done():
// Do not reconnect when the context is closed
return
default:
}
r.mu.Lock()
defer r.mu.Unlock()
// Try to reconnect
for err := r.pubsub.Reconnect(); err != nil; err = r.pubsub.Reconnect() {
select {
case <-ctx.Done():
// Do not reconnect when the context is closed
return
default:
}
logrus.Warn("Reconnect error: ", err)
time.Sleep(100 * time.Millisecond)
}
}