RabbitMQ Java client dependency has been updated to 3.1.3.
clj-http dependency has been updated to 0.7.4.
Cheshire dependency has been updated to 5.2.0.
In its early days, Langohr has been using QueueingConsumer for langohr.queue/subscribe.
It was later replaced by a DefaultConsumer implementation.
The key difference between the two is that
QueueingConsumerblocks the caller- with
QueueingConsumer, deliveries are typically processed in the same thread
This implementation has pros and cons. As such, an implementation on top of
QueueingConsumer is back with langohr.consumers/blocking-subscribe which is
identical to langohr.consumers/subscribe in the signature but blocks the caller.
In addition, langohr.consumers/ack-unless-exception is a new convenience function
that takes a delivery handler fn and will return a new function
that explicitly acks deliveries unless an exception was raised by the original handler:
(require '[langohr.consumers :as lc])
(require '[langohr.basic :as lb])
(let [f (fn [metadata payload]
(comment "Message delivery handler"))
f' (lc/ack-unless-exception f)]
(lb/consume ch q (lc/create-default :handle-delivery-fn f'))Contributed by Ian Eure.
Several new functions in langohr.shutdown aid with shutdown signals:
langohr.shutdown/initiated-by-application?langohr.shutdown/initiated-by-broker?langohr.shutdown/reason-oflangohr.shutdown/channel-oflangohr.shutdown/connection-of
Langohr now depends on org.clojure/clojure version 1.5.0. It is
still compatible with Clojure 1.3 and if your project.clj depends on
a different version, it will be used, but 1.5 is the default now.
We encourage all users to upgrade to 1.5, it is a drop-in replacement for the majority of projects out there.
1.0.0-beta13 has BREAKING CHANGES:
The options langohr.consumers/subscribe takes now have consistent naming:
:handle-consume-okbecomes:handle-consume-ok-fn:handle-cancelbecomes:handle-cancel-fn:handle-cancel-okbecomes:handle-cancel-ok-fn:handle-shutdown-signal-okbecomes:handle-shutdown-signal-ok-fn:handle-recover-okbecomes:handle-recover-ok-fn:handle-delivery-fndoes not change
This makes handler argument names consistent across the board.
Previous options (:handle-cancel, etc) are still supported
for backwards compatibility but will eventually be removed.
Previously functions such as langohr.queue/declare returned the underlying
RabbitMQ Java client responses. In case a piece of information from the
response was needed (e.g. to get the queue name that was generated by
RabbitMQ), the only way to obtain it was via the Java interop.
This means developers had to learn about how the Java client works. Such responses are also needlessly unconvenient when inspecting them in the REPL.
Langohr 1.0.0-beta12 makes this much better by returning a data structure
that behaves like a regular immutable Clojure map but also provides the same
Java interoperability methods for backwards compatibility.
For example, langohr.queue/declare now returns a value that is a map
but also provides the same .getQueue method you previously had to use.
Since the responses implement all the Clojure map interfaces, it is possible to use destructuring on them:
(require '[langohr.core :as lhc])
(require '[langohr.queue :as lhq])
(let [conn (lhc/connect)
channel (lhc/create-channel conn)
{:keys [queue] :as declare-ok} (lhq/declare channel "" :exclusive true)]
(println "Response: " declare-ok)
(println (format "Declared a queue named %s" queue)))will output
Response: {:queue amq.gen-G9bmz19UjHLBjyxhanOG3Q, :consumer-count 0, :message_count 0, :consumer_count 0, :message-count 0}
Declared a queue named amq.gen-G9bmz19UjHLBjyxhanOG3Q
langohr.confirm/add-listener now returns the channel instead of the listener. This way
it is more useful with the threading macro (->) that threads channels (a much more
common use case).
langohr.exchage/unbind was missing in earlier releases and now added.
langohr.core/closed? is a new function that complements langohr.core/open?.
langohr.queue/declare-server-named is a new convenience function
that declares a server-named queue and returns the name RabbitMQ
generated:
(require '[langohr.core :as lhc])
(require '[langohr.queue :as lhq])
(let [conn (lhc/connect)
channel (lhc/create-channel conn)
queue (lhq/declare-server-named channel)]
(println (format "Declared a queue named %s" queue))Langohr will now correct the port to TLS/SSL if provided :port is
5672 (default non-TLS port) and :ssl is set to true.
Langohr 1.0.0-beta11 features initial bits of RabbitMQ HTTP API client
under langohr.http.
Langohr will now automatically enable TLS/SSL if provided :port is
5671.
RabbitMQ Java Client has been upgraded to version 3.0.2.
langohr.exchange/declare-passive is a new function that performs passive
exchange declaration (checks if an exchange exists).
An example to demonstrate:
(require '[langohr.channel :as lch])
(require '[langohr.exchange :as le])
(let [ch (lch/open conn)]
(le/declare-passive ch "an.exchange"))If the exchange does exist, the function has no effect. If not,
an exception (com.rabbitmq.client.ShutdownSignalException, java.io.IOException) will be thrown.
langohr.basic/reject now correctly uses basic.reject AMQP method
and not basic.ack.
Contributed by @natedev.
1.0.0-beta9 has BREAKING CHANGES:
Langohr no longer instantiates a string from the message body before passing it to return listeners. The body will be passed as is, as an array of bytes.
1.0.0-beta8 has BREAKING CHANGES:
langohr.basic/get now returns a pair of [metadata payload] to be consistent with what
delivery handler functions accept:
(require '[langohr.basic :as lhb])
(let [[metadata payload] (lhb/get channel queue)]
(println metadata)
(println (String. ^bytes payload)))1.0.0-beta7 has BREAKING CHANGES:
The options langohr.consumers/create-default takes now have consistent naming:
:consume-ok-fnbecomes:handle-consume-ok-fn:cancel-fnbecomes:handle-cancel-fn:cancel-ok-fnbecomes:handle-cancel-ok-fn:shutdown-signal-ok-fnbecomes:handle-shutdown-signal-ok-fn:recover-ok-fnbecomes:handle-recover-ok-fn:handle-delivery-fndoes not change
This makes handler argument names consistent across the board.
1.0.0-beta6 has BREAKING CHANGES:
langohr.consumers/create-default's :handle-delivery-fn signature is now consistent with
that of langohr.basic/subscribe:
(fn [^Channel ch metadata ^bytes payload]
)This makes delivery handler signatures consistent across the board.
langohr.core/connect now supports several more options:
:ssl(true or false): when true, Langohr will use the default SSL protocol (SSLv3) and the default (trusting) trust manager:ssl-context(javax.net.ssl.SSLContext): SSL context to use to create connection factory:sasl-config(com.rabbitmq.client.SaslConfig): use if you need to use a custom SASL config:socket-factory(javax.net.SocketFactory): use if you need to use a custom socket factory
Langohr now provides its capabilities to the broker so it's possible to tell the difference between Langohr and the RabbitMQ Java client in the RabbitMQ Management UI connection information.
langohr.core/capabilities-of is a new function that returns broker capabilities as an immutable map,
e.g.
{:exchange_exchange_bindings true
:consumer_cancel_notify true
:basic.nack true
:publisher_confirms true}Langohr now depends on org.clojure/clojure version 1.4.0. It is still compatible with Clojure 1.3 and if your project.clj depends
on 1.3, it will be used, but 1.4 is the default now.
We encourage all users to upgrade to 1.4, it is a drop-in replacement for the majority of projects out there.
langohr.basic/publish no longer assumes the payload is always a string. It can be anything the langohr.conversion/BytePayload
protocol is implemented for, by default byte arrays and strings.
langohr.queue/declare now uses default value for the :exclusive parameter as false. The reason for
this is that exclusive queues are deleted when connection that created them is closed. This caused
confusion w.r.t. non-auto-deleted queues being deleted in such cases.
langohr.core/settings-from is a new public API function that parses AMQP and AMQPS connection URIs
and returns an immutable map of individual arguments. URI parsing is now delegated to the Java client
for consistency.
RabbitMQ Java Client has been upgraded to version 2.8.6.
Previously message handlers registered via langohr.consumers/subscribe had the following
signature:
(fn [^QueueingConsumer$Delivery delivery ^AMQP$BasicProperties properties payload] ...)starting with beta2, it has changed to be more Clojure friendly
(fn [^Channel ch metadata payload] ...)All message metadata (both envelope and message properties) are now passed in as a single Clojure map that you can use destructuring on:
(fn [^Channel ch {:keys [type content-type message-id correlation-id] :as metadata} payload] ...)In addition, in explicit acknowledgement mode, ack-ing and nack-ing messages got easier because consumer channel is now passed in.
It is important to remember that sharing channels between threads that publish messages is dangerous and should be avoided. Ack-ing, nack-ing and consuming messages with shared channels is usually acceptable.
RabbitMQ Java Client which Langohr is based on has been upgraded to version 2.8.1.
Langohr now uses Leiningen 2.