Network.AWS.SQS.ReceiveMessage

Retrieves one or more messages, with a maximum limit of 10 messages, from the specified queue. Long poll support is enabled by using the WaitTimeSeconds parameter. For more information, see Amazon SQS Long Poll in the Amazon SQSDeveloper Guide.

Short poll is the default behavior where a weighted random set of machines is sampled on a ReceiveMessage call. This means only the messages on the sampled machines are returned. If the number of messages in the queue is small (less than 1000), it is likely you will get fewer messages than you requested per ReceiveMessage call. If the number of messages in the queue is extremely small, you might not receive any messages in a particular ReceiveMessage response; in which case you should repeat the request.

For each message returned, the response includes the following:

Message body

MD5 digest of the message body. For information about MD5, go to http://www.faqs.org/rfcs/rfc1321.html.

Message ID you received when you sent the message to the queue.

Receipt handle.

Message attributes.

MD5 digest of the message attributes.

The receipt handle is the identifier you must provide when deleting the message. For more information, see Queue and Message Identifiers in the Amazon SQS Developer Guide.

You can provide the VisibilityTimeout parameter in your request, which will be applied to the messages that Amazon SQS returns in the response. If you do not include the parameter, the overall visibility timeout for the queue is used for the returned messages. For more information, see Visibility Timeout in the Amazon SQS Developer Guide.

http://docs.aws.amazon.com/AWSSimpleQueueService/latest/APIReference/API_ReceiveMessage.html

Request

data ReceiveMessage

Instances

Eq ReceiveMessage

Show ReceiveMessage

AWSRequest ReceiveMessage

ToQuery ReceiveMessage

ToHeaders ReceiveMessage

ToPath ReceiveMessage

type Rs ReceiveMessage = ReceiveMessageResponse

type Sv ReceiveMessage = SQS

Request constructor

receiveMessage

Arguments

:: Text

rmQueueUrl

-> ReceiveMessage

ReceiveMessage constructor.

The fields accessible through corresponding lenses are:

• rmAttributeNames :: [Text]
• rmMaxNumberOfMessages :: Maybe Int
• rmMessageAttributeNames :: [Text]
• rmQueueUrl :: Text
• rmVisibilityTimeout :: Maybe Int
• rmWaitTimeSeconds :: Maybe Int

Request lenses

rmAttributeNames :: Lens' ReceiveMessage [Text]

A list of attributes that need to be returned along with each message.

The following lists the names and descriptions of the attributes that can be returned:

All - returns all values. ApproximateFirstReceiveTimestamp - returns the time when the message was first received (epoch time in milliseconds). ApproximateReceiveCount - returns the number of times a message has been received but not deleted. SenderId - returns the AWS account number (or the IP address, if anonymous access is allowed) of the sender. SentTimestamp - returns the time when the message was sent (epoch time in milliseconds).

rmMaxNumberOfMessages :: Lens' ReceiveMessage (Maybe Int)

The maximum number of messages to return. Amazon SQS never returns more messages than this value but may return fewer. Values can be from 1 to 10. Default is 1.

All of the messages are not necessarily returned.

rmMessageAttributeNames :: Lens' ReceiveMessage [Text]

The message attribute Name can contain the following characters: A-Z, a-z, 0-9, underscore(_), hyphen(-), and period (.). The message attribute name must not start or end with a period, and it should not have successive periods. The message attribute name is case sensitive and must be unique among all attribute names for the message. The message attribute name can be up to 256 characters long. Attribute names cannot start with "AWS." or "Amazon." because these prefixes are reserved for use by Amazon Web Services.

rmQueueUrl :: Lens' ReceiveMessage Text

The URL of the Amazon SQS queue to take action on.

rmVisibilityTimeout :: Lens' ReceiveMessage (Maybe Int)

The duration (in seconds) that the received messages are hidden from subsequent retrieve requests after being retrieved by a ReceiveMessage request.

rmWaitTimeSeconds :: Lens' ReceiveMessage (Maybe Int)

The duration (in seconds) for which the call will wait for a message to arrive in the queue before returning. If a message is available, the call will return sooner than WaitTimeSeconds.

Response

data ReceiveMessageResponse

Instances

Eq ReceiveMessageResponse

Show ReceiveMessageResponse

Monoid ReceiveMessageResponse

FromXML ReceiveMessageResponse

Semigroup ReceiveMessageResponse

Response constructor

receiveMessageResponse :: ReceiveMessageResponse

ReceiveMessageResponse constructor.

The fields accessible through corresponding lenses are:

• rmrMessages :: [Message]

Response lenses

rmrMessages :: Lens' ReceiveMessageResponse [Message]

A list of messages.