// GetPendingTasks returns a slice of task.Signatures waiting in the queue
func (redisBroker *RedisBroker) GetPendingTasks(queue string) ([]*signatures.TaskSignature, error) {
conn, err := redisBroker.open()
if err != nil {
return nil, fmt.Errorf("Dial: %s", err)
}
defer conn.Close()
if queue == "" {
queue = redisBroker.config.DefaultQueue
}
bytes, err := conn.Do("LRANGE", queue, 0, 10)
if err != nil {
fmt.Printf("Error: %v\n", err)
return nil, err
}
results, err := redis.ByteSlices(bytes, err)
if err != nil {
fmt.Printf("Error: %v\n", err)
return nil, err
}
var taskSignatures []*signatures.TaskSignature
for _, result := range results {
var taskSignature signatures.TaskSignature
if err := json.Unmarshal(result, &taskSignature); err != nil {
return nil, err
}
taskSignatures = append(taskSignatures, &taskSignature)
}
return taskSignatures, nil
}
func (wp *WorkerPool) startZPolling() {
var zqstrs []string
for _, qname := range wp.queues {
zqstrs = append(zqstrs, scheduledQueue(qname))
}
for wp.running {
now := time.Now().UTC().Unix()
for _, zset := range zqstrs {
conn := wp.redisPool.Get()
res, err := redis.ByteSlices(conn.Do(zrangebyscore, zset, 0, now))
conn.Close()
if err != nil {
continue
}
for _, jsn := range res {
wp.workCh <- qj{zset, jsn}
conn := wp.redisPool.Get()
_, err := conn.Do(zremrangebyscore, zset, 0, now)
if err != nil {
// TODO -- try again
}
conn.Close()
}
}
}
}
// collectAndCallOnce collects the package, sleeps the configured duraction and
// calls the callback only once with a slice of packets, sorted by signal
// strength (strongest at index 0). This method exists since multiple gateways
// are able to receive the same packet, but the packet needs to processed
// only once.
// It is important to validate the packet before calling collectAndCallOnce
// (since the MIC is part of the storage key, make sure it is valid).
// It is safe to collect the same packet received by the same gateway twice.
// Since the underlying storage type is a set, the result will always be a
// unique set per gateway MAC and packet MIC.
func collectAndCallOnce(p *redis.Pool, rxPacket models.RXPacket, callback func(packets RXPackets) error) error {
var buf bytes.Buffer
enc := gob.NewEncoder(&buf)
if err := enc.Encode(rxPacket); err != nil {
return fmt.Errorf("encode rx packet error: %s", err)
}
c := p.Get()
defer c.Close()
// store the packet in a set with CollectAndCallOnceWait expiration
// in case the packet is received by multiple gateways, the set will contain
// each packet.
key := "collect_" + hex.EncodeToString(rxPacket.PHYPayload.MIC[:])
c.Send("MULTI")
c.Send("SADD", key, buf.Bytes())
c.Send("PEXPIRE", key, int64(CollectAndCallOnceWait*2)/int64(time.Millisecond))
_, err := c.Do("EXEC")
if err != nil {
return fmt.Errorf("add rx packet to collect set error: %s", err)
}
// acquire a lock on processing this packet
_, err = redis.String((c.Do("SET", key+"_lock", "lock", "PX", int64(CollectAndCallOnceWait*2)/int64(time.Millisecond), "NX")))
if err != nil {
if err == redis.ErrNil {
// the packet processing is already locked by an other process
// so there is nothing to do anymore :-)
return nil
}
return fmt.Errorf("acquire lock error: %s", err)
}
// wait the configured amount of time, more packets might be received
// from other gateways
time.Sleep(CollectAndCallOnceWait)
// collect all packets from the set
rxPackets := make(RXPackets, 0)
payloads, err := redis.ByteSlices(c.Do("SMEMBERS", key))
if err != nil {
return fmt.Errorf("get collect set members error: %s", err)
}
if len(payloads) == 0 {
return errors.New("zero items in collect set")
}
for _, b := range payloads {
var packet models.RXPacket
if err := gob.NewDecoder(bytes.NewReader(b)).Decode(&packet); err != nil {
return fmt.Errorf("decode rx packet error: %s", err)
}
rxPackets = append(rxPackets, packet)
}
sort.Sort(rxPackets)
return callback(rxPackets)
}
// Pull implements the `func Pull` from `Processor`. It pulls from the right-side
// of the Redis structure in a blocking-fashion, using BLPOP.
//
// If an redis.ErrNil is returned, it is silenced, and both fields are returend
// as nil. If the err is not a redis.ErrNil, but is still non-nil itself, then
// it will be returend, along with an empty []byte.
//
// If an item can sucessfully be removed from the keyspace, it is returned
// without error.
func (f *fifoProcessor) Pull(cnx redis.Conn, src string,
timeout time.Duration) ([]byte, error) {
slices, err := redis.ByteSlices(cnx.Do("BRPOP", src, block(timeout)))
if err != nil {
return nil, err
}
return slices[1], nil
}
func RedisDoGetMultiByteSlice(cmd string, args ...interface{}) (data [][]byte, err error) {
c := RedisPool.Get()
defer c.Close()
// data_origin, err := c.Do("keys", "channel:*")
data, err = redis.ByteSlices(c.Do(cmd, args...))
if err != nil {
fmt.Println(err)
}
return
}
func (wp *WorkerPool) startPolling() {
qstr := strings.Join(wp.queues, " ")
for {
conn := wp.redisPool.Get()
res, err := redis.ByteSlices(conn.Do("BLPOP", qstr, wp.timeout.Seconds()))
conn.Close()
if err != nil {
continue
}
wp.workCh <- qj{string(res[0]), res[1]}
}
}
func TestExpectSlice(t *testing.T) {
connection := NewConn()
field1 := []byte("hello")
connection.Command("HMGET", "key", "field1", "field2").ExpectSlice(field1, nil)
if len(connection.commands) != 1 {
t.Fatalf("Did not registered the command. Expected '1' and got '%d'", len(connection.commands))
}
reply, err := redis.ByteSlices(connection.Do("HMGET", "key", "field1", "field2"))
if err != nil {
t.Fatal(err)
}
if string(reply[0]) != string(field1) {
t.Fatalf("reply[0] not hello but %s", string(reply[0]))
}
if reply[1] != nil {
t.Fatal("reply[1] not nil")
}
}
// StartConsuming enters a loop and waits for incoming messages
func (redisBroker *RedisBroker) StartConsuming(consumerTag string, taskProcessor TaskProcessor) (bool, error) {
if redisBroker.retryFunc == nil {
redisBroker.retryFunc = utils.RetryClosure()
}
redisBroker.pool = redisBroker.newPool()
defer redisBroker.pool.Close()
_, err := redisBroker.pool.Get().Do("PING")
if err != nil {
redisBroker.retryFunc()
return redisBroker.retry, err // retry true
}
redisBroker.retryFunc = utils.RetryClosure()
redisBroker.stopChan = make(chan int)
redisBroker.stopReceivingChan = make(chan int)
redisBroker.errorsChan = make(chan error)
deliveries := make(chan []byte)
redisBroker.wg.Add(1)
go func() {
defer redisBroker.wg.Done()
log.Print("[*] Waiting for messages. To exit press CTRL+C")
conn := redisBroker.pool.Get()
for {
select {
// A way to stop this goroutine from redisBroker.StopConsuming
case <-redisBroker.stopReceivingChan:
return
default:
itemBytes, err := conn.Do("BLPOP", redisBroker.config.DefaultQueue, "1")
if err != nil {
redisBroker.errorsChan <- err
return
}
// Unline BLPOP, LPOP is non blocking so nil means we can keep iterating
if itemBytes == nil {
continue
}
items, err := redis.ByteSlices(itemBytes, nil)
if err != nil {
redisBroker.errorsChan <- err
return
}
if len(items) != 2 {
log.Println("Got unexpected amount of byte arrays, ignoring")
continue
}
// items[0] - queue name (key), items[1] - value
item := items[1]
signature := new(signatures.TaskSignature)
if err := json.Unmarshal(item, signature); err != nil {
redisBroker.errorsChan <- err
return
}
// If the task is not registered, we requeue it,
// there might be different workers for processing specific tasks
if !redisBroker.IsTaskRegistered(signature.Name) {
_, err := conn.Do("RPUSH", redisBroker.config.DefaultQueue, item)
if err != nil {
redisBroker.errorsChan <- err
return
}
continue
}
deliveries <- item
}
}
}()
if err := redisBroker.consume(deliveries, taskProcessor); err != nil {
return redisBroker.retry, err // retry true
}
return redisBroker.retry, nil
}
func (*RedisStore) Byteses(reply interface{}, err error) ([][]byte, error) {
return redis.ByteSlices(reply, err)
}
ve(redis.Ints(nil, nil)),
ve([]int(nil), redis.ErrNil),
},
{
"strings([v1, v2])",
ve(redis.Strings([]interface{}{[]byte("v1"), []byte("v2")}, nil)),
ve([]string{"v1", "v2"}, nil),
},
{
"strings(nil)",
ve(redis.Strings(nil, nil)),
ve([]string(nil), redis.ErrNil),
},
{
"byteslices([v1, v2])",
ve(redis.ByteSlices([]interface{}{[]byte("v1"), []byte("v2")}, nil)),
ve([][]byte{[]byte("v1"), []byte("v2")}, nil),
},
{
"byteslices(nil)",
ve(redis.ByteSlices(nil, nil)),
ve([][]byte(nil), redis.ErrNil),
},
{
"values([v1, v2])",
ve(redis.Values([]interface{}{[]byte("v1"), []byte("v2")}, nil)),
ve([]interface{}{[]byte("v1"), []byte("v2")}, nil),
},
{
"values(nil)",
ve(redis.Values(nil, nil)),