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small textual changes to README

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Emiel Bruijntjes 2020-10-23 08:21:48 +02:00
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README.md
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@ -1066,8 +1066,8 @@ PUBLISHER CONFIRMS
RabbitMQ supports a lightweight method of confirming that broker received RabbitMQ supports a lightweight method of confirming that broker received
and processed a message. When you enable this, RabbitMQ sends back an and processed a message. When you enable this, RabbitMQ sends back an
'ack' for each publish-operation that has been handled. For this method 'ack' or 'nack' for each publish-operation. For this to work, the channel
to work, the channel needs to be put in _confirm mode_. This is done using needs to be put in _confirm mode_. This is done using the
confirmSelect() method. When the channel is successfully put in confirm mode, confirmSelect() method. When the channel is successfully put in confirm mode,
the server starts counting the received messages (starting from 1) and sends the server starts counting the received messages (starting from 1) and sends
acknowledgments for every message it processed (it can also acknowledge acknowledgments for every message it processed (it can also acknowledge
@ -1075,7 +1075,7 @@ multiple message at once).
If server is unable to process a message, it will send send negative If server is unable to process a message, it will send send negative
acknowledgments. Both positive and negative acknowledgments handling are acknowledgments. Both positive and negative acknowledgments handling are
implemented as callbacks for that should be installed on the object that passed to callbacks that you can install on the object that
is returned by the confirmSelect() method: is returned by the confirmSelect() method:
````c++ ````c++
@ -1131,7 +1131,7 @@ reliable.publish("my-exchange", "my-key", "my first message").onAck([]() {
}).onNack([]() { }).onNack([]() {
// the message has _explicitly_ been nack'ed by RabbitMQ (in your application // the message has _explicitly_ been nack'ed by RabbitMQ (in your application
// code you probably want to log handle this to avoid data-loss) // code you probably want to log or handle this to avoid data-loss)
}).onError([](const char *message) { }).onError([](const char *message) {
@ -1160,14 +1160,13 @@ API.
But it also is useful for flood prevention. RabbitMQ turns out not to be very But it also is useful for flood prevention. RabbitMQ turns out not to be very
good at handling big loads of publish-operations. If you publish messages faster good at handling big loads of publish-operations. If you publish messages faster
than RabbitMQ can handle, a server-side buffer builds up, and RabbitMQ gets slow than RabbitMQ can handle, a server-side buffer builds up, and RabbitMQ gets slow
(which causes the buffer to build up evenm further, et cetera). With publish-confirms (which causes the buffer to build up even further, et cetera). With publish-confirms
you can keep the messages in your own application, and only proceed with publishing you can keep the messages in your own application, and only proceed with publishing
them when your previous messages have been handled. With this approach you them when your previous messages have been handled. With this approach you
prevent that RabbitMQ gets overloaded. We call it throttling. prevent that RabbitMQ gets overloaded. We call it throttling.
You can build your own throttling mechanism using the confirmSelect() approach You can build your own throttling mechanism using the confirmSelect() approach
or the AMQP::Reliable class. But also here the AMQP-CPP library already has or the AMQP::Reliable class. Or you use AMQP::Throttle:
a utility class for you that you can use instead: AMQP::Throttle:
````c++ ````c++
// create a channel // create a channel
@ -1188,7 +1187,7 @@ for (size_t i = 0; i < 100000; ++i)
} }
```` ````
The AMQP::Reliable and AMQP::Throttle classes that you wrap around a channel. The AMQP::Reliable and AMQP::Throttle classes both wrap around a channel.
But what if you want to use both? You want to throttle messages, but also like But what if you want to use both? You want to throttle messages, but also like
to install your own callbacks for onAck and onLost? This is possible too: to install your own callbacks for onAck and onLost? This is possible too:
@ -1217,7 +1216,7 @@ for (size_t i = 0; i < 100000; ++i)
} }
```` ````
For more information, please see http://www.rabbitmq.com/confirms.html. For more information, see http://www.rabbitmq.com/confirms.html.
CONSUMING MESSAGES CONSUMING MESSAGES
================== ==================