Documentation
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Overview ¶
Package subscriber provides the functionalities to consume messages from an AWS SQS queue. For more information about to AWS SQS go to https://aws.amazon.com/sqs/
AWS SQS Subscriber ¶
Subscriber is a high throughput golang AWS SQS client that can create multiple consumers that concurrently receive messages from AWS SQS and push them into a single channel for consumption.
Worker ¶
Worker is the service implementation of a Subscriber.
Index ¶
Constants ¶
This section is empty.
Variables ¶
var ErrWorkerClosed = errors.New("worker closed")
ErrWorkerClosed is returned by the Worker 'Start' method after a call to 'Stop'.
Functions ¶
This section is empty.
Types ¶
type Config ¶
type Config struct {
// AWS session
AWSSession *session.Session
// SQS queue from which the subscriber is going to consume from
SqsQueueURL string
// number of messages the subscriber will attempt to fetch on each receive.
MaxMessagesPerBatch *int64
// the duration (in seconds) for which the call waits for a message to arrive
// in the queue before returning. If a message is available, the call returns
// sooner than TimeSeconds. If no messages are available and the wait time
// expires, the call returns successfully with an empty list of messages.
TimeoutSeconds *int64
// The duration (in seconds) that the received messages are hidden from subsequent
// retrieve requests after being retrieved by a ReceiveMessage request.
// VisibilityTimeout should be < time needed to process a message
VisibilityTimeout *int64
// number of consumers per subscriber
NumConsumers int
// subscriber logger
Logger Logger
}
Config holds the info required to work with Amazon SQS
type Logger ¶
type Logger interface {
Printf(string, ...interface{})
}
Logger interface allows to use other loggers than standard log.Logger
type SQSMessage ¶
type SQSMessage struct {
// contains filtered or unexported fields
}
SQSMessage is the implementation of a SQS message
func (*SQSMessage) ChangeMessageVisibility ¶
func (m *SQSMessage) ChangeMessageVisibility(newVisibilityTimeout *int64) error
ChangeMessageVisibility modifies current message visibility timeout to the one specified in the parameters. This is normally useful when the message processing is taking more time than the default visibility timeout
func (*SQSMessage) Message ¶
func (m *SQSMessage) Message() []byte
Message returns the body of the SQS message in bytes
func (*SQSMessage) MessageAttributes ¶
func (m *SQSMessage) MessageAttributes() map[string]*sqs.MessageAttributeValue
MessageAttributes returns the message attributes
type Subscriber ¶
type Subscriber struct {
// contains filtered or unexported fields
}
Subscriber is an SQS client that allows a user to consume messages from AWS SQS. Once Stop has been called on subscriber, it might not be reused; future calls to methods such as Consume or Stop will return an error.
func (*Subscriber) Consume ¶
func (s *Subscriber) Consume() (<-chan *SQSMessage, <-chan error, error)
Consume starts consuming messages from the SQS queue. Returns a channel of SubscriberMessage to consume them and a channel of errors
func (*Subscriber) Stop ¶
func (s *Subscriber) Stop() error
Stop stop gracefully the Subscriber. Blocks until all consumers from the subscriber are gracefully stopped
type Worker ¶
type Worker struct {
// contains filtered or unexported fields
}
Worker represents a SQS worker service
func NewWorker ¶
func NewWorker(conf WorkerConfig) *Worker
NewWorker creates a new Worker based on the given configuration that process messages from AWS SQS
func (*Worker) Config ¶
func (w *Worker) Config() *WorkerConfig
Config returns current configuration
type WorkerConfig ¶
type WorkerConfig struct {
// SQS subscriber
Subscriber *Subscriber
// SQS Message Handler
MessageHandler func(context.Context, *Worker, *SQSMessage)
// SQS Error Handler
ErrorHandler func(context.Context, *Worker, error)
}
WorkerConfig is the worker startup config
Source Files