104 lines
2.3 KiB
Go
104 lines
2.3 KiB
Go
package reader
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import (
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"context"
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"sync"
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"time"
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"src.dualinventive.com/go/dinet"
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"src.dualinventive.com/go/lib/dilog"
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)
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// MessageReader reads incomming messages from a pubsub connection and send the messages to Redis
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type MessageReader struct {
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mu sync.Mutex
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logger dilog.Logger
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pubsub dinet.Conn
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r dinet.Writer
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}
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// New creates a new message reader
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func New(logger dilog.Logger, pubSubURI string, r dinet.Writer) (*MessageReader, error) {
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con, err := dinet.NewConn(dinet.TransportZmq)
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if err != nil {
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return nil, err
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}
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err = con.Connect(pubSubURI + "?type=sub")
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if err != nil {
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return nil, err
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}
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reader := &MessageReader{
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logger: logger,
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pubsub: con,
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r: r,
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}
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return reader, err
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}
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// AddConn connects to an additional ZMQ connection
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func (r *MessageReader) AddConn(pubSubURI string) error {
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return r.pubsub.Connect(pubSubURI + "?type=sub")
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}
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// Serve reads incomming messages from a pubsub connection and send the messages to Redis
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func (r *MessageReader) Serve(ctx context.Context) {
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var wg sync.WaitGroup
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// Wait until the goroutine ends
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defer wg.Wait()
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wg.Add(1)
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go func() {
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defer wg.Done()
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<-ctx.Done()
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r.mu.Lock()
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defer r.mu.Unlock()
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if err := r.pubsub.Close(); err != nil {
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r.logger.WithError(err).Error("unable to close pub sub connection")
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}
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}()
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for {
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if ctx.Err() != nil {
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r.logger.WithError(ctx.Err()).Info("reader context error")
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return
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}
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// Receive messages from the reader connection
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msg, err := r.pubsub.Recv()
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if err != nil {
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if err == dinet.ErrDisconnected {
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r.logger.WithError(err).Warning("Reconnecting due to error")
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} else {
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r.logger.WithError(err).Error("Unable to receive publish message due to")
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}
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r.reconnect(ctx)
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continue
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}
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if err := r.r.Send(msg); err != nil {
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r.logger.WithError(err).Warning("Send error")
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}
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}
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}
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func (r *MessageReader) reconnect(ctx context.Context) {
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r.mu.Lock()
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defer r.mu.Unlock()
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// Do not reconnect when the context is closed
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if ctx.Err() != nil {
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return
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}
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// Try to reconnect
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for err := r.pubsub.Reconnect(); err != nil; err = r.pubsub.Reconnect() {
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r.logger.WithError(err).Warning("Reconnect error")
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// Do not reconnect when the context is closed
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if ctx.Err() != nil {
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return
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}
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time.Sleep(100 * time.Millisecond)
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}
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}
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