[ 
https://issues.apache.org/jira/browse/BOOKKEEPER-312?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13565194#comment-13565194
 ] 

Mridul Muralidharan commented on BOOKKEEPER-312:
------------------------------------------------


A) About @author tags:
The author tags are from activemq testcases. Currently we do very minimal 
changes to them in the hope that we can do future merges from their codebase 
(unfortunately, this might not be posible anymore, but still ...)

$ find . -type f | xargs grep -i author | grep @
./src/test/java/org/apache/activemq/perf/NetworkedSyncTest.java: * @author 
tmielke
./src/test/java/org/apache/activemq/perf/NetworkedSyncTest.java: * @author 
tmielke
./src/test/java/org/apache/activemq/usecases/TransactionRollbackOrderTest.java: 
* @author Paul Smith
./src/test/java/org/apache/activemq/usecases/DispatchMultipleConsumersTest.java:
 * @author Rajani Chennamaneni
./src/test/java/org/apache/activemq/usecases/DiscriminatingConsumerLoadTest.java:
        * @author jlyons
./src/test/java/org/apache/activemq/usecases/DiscriminatingConsumerLoadTest.java:
        * @author jlyons
./src/test/java/org/apache/activemq/usecases/TransactionTest.java: * @author 
pragmasoft
./src/test/java/org/apache/activemq/usecases/SubscribeClosePublishThenConsumeTest.java:
 * @author Paul Smith


B) About tabs in code:
Again, this is coming from activemq codebase :
(ctrl+v, tab as grep param below)

$ find . -type f  | grep -v \.class | xargs grep '    ' | grep -v activemq
Binary file ./target/hedwig-client-jms-4.3.0-SNAPSHOT.jar matches


C) trailing spaces
There are quite a lot of cases of trailing spaces - including in generated code.
Is this mandatory to remove this ? It will be very timeconsuming to do so 
manually; and I dont have the time to try to script it.
If there is something already present, I can ofcourse run it and resubmit patch.


D) Files with lines longer than 120 characters.
There are a bunch of files with lines longer than 120 characters : mostly in 
comments and testcases.
I will try to remove them if it is a priority - unfortunately, I wont be able 
to get to these for a while due to other commitments.

$ for i in `find src -type f `; do if [ -n "`awk 'length($0) > 120' $i`" ]; 
then echo $i; fi; done | grep -v activemq | grep java$
src/test/java/org/apache/hedwig/jms/selector/BasicSelectorGrammarTest.java
src/test/java/org/apache/hedwig/jms/BasicJMSTest.java
src/test/java/org/apache/hedwig/JmsTestBase.java
src/main/java/org/apache/hedwig/jms/selector/ValueComparisonFunction.java
src/main/java/org/apache/hedwig/jms/SessionImpl.java
src/main/java/org/apache/hedwig/jms/ConnectionImpl.java
src/main/java/org/apache/hedwig/jms/spi/HedwigMessagingSessionFacade.java
src/main/java/org/apache/hedwig/jms/spi/MessageProducerImpl.java
src/main/java/org/apache/hedwig/jms/spi/TopicSubscriberImpl.java
src/main/java/org/apache/hedwig/jms/message/header/JmsHeader.java

                
> Implementation of JMS provider
> ------------------------------
>
>                 Key: BOOKKEEPER-312
>                 URL: https://issues.apache.org/jira/browse/BOOKKEEPER-312
>             Project: Bookkeeper
>          Issue Type: Sub-task
>            Reporter: Mridul Muralidharan
>            Assignee: Mridul Muralidharan
>             Fix For: 4.3.0
>
>         Attachments: hedwig-client-jms.patch, hedwig-client-jms.patch.1, 
> hedwig-client-jms.patch.10, hedwig-client-jms.patch.10, 
> hedwig-client-jms.patch.2, hedwig-client-jms.patch.3, 
> hedwig-client-jms.patch.4, hedwig-client-jms.patch.5, 
> hedwig-client-jms.patch.9, hedwig-client-jms.patch.9
>
>
> The JMS provider implementation conforming to the 1.1 spec.
> The limitations as of now are :
> 1) No support for Queue's : Hedwig currently does not have a notion of JMS 
> queue's for us to leverage.
> 2) No support for noLocal : Hedwig DOES NOT conform to JMS model of 
> connection -(n)-> session -(n)-> publisher/subscriber. Each session has a 
> hedwig connection.
> Currently I am simulating noLocal, but this IS fragile and works for the 
> duration of connection - ONLY until the message id is still in a LRUCache. As 
> mentioned before, this is a kludge, and not a good solution.
> 3) Note that everything is durable in hedwig - so we do not support 
> NON_PERSISTENT delivery mode.
> 4) Calling unsubscribe on a durable subscription will fail if it was NOT 
> created in the current session.
> In hedwig, to unsubscribe, we need the subscription id and the topic ... 
> To simulate unsubscribe(), we store the subscriberId to topicName mapping 
> when a create* api is invoked. Hence, if create* was NOT called, then we have 
> no way to infer which topic the subscription-id refers to from hedwig, and so 
> cant unsubscribe.
> The workaround is - simply create a durable subsriber just as a workaround of 
> this limitation - the topicName will be known to the user/client anyway.
> 5) Explicit session recovery is not supported.
> Reconnection of hedwig session (either explicitly or implicitly by underlying 
> client implementation) will automatically trigger redelivery of 
> un-acknowledged messages.
> 6) Because of the above, setting the JMSRedelivered flag is almost impossible 
> in a consistent way.
> Currently, we simulate it for redelivery due to provider side events : 
> rollback of txn, exception in message listener (primarily).
> At best we can simulate it with a kludge - at risk of potentially running out 
> of resources ... this is being investigated : but unlikely to have a clean 
> fix.
> 7) Hedwig only supports marking all messages until seq-id as received : while 
> JMS indicates ability to acknowledge individual messages.
> This distinction is currently unsupported.
> 8) JMS spec requires
>     "A connection's delivery of incoming messages can be temporarily stopped
> using its stop() method. It can be restarted using its start() method. When 
> the connection is stopped, delivery to all the connection’s MessageConsumers 
> is inhibited: synchronous receives block, and messages are not delivered to 
> MessageListeners."
>   We honor this for undelivered messages from server - but if stop is called 
> while there are pending messages yet to be delivered to a listener (or 
> buffered in subscriber for receive), then they will be delivered irrespective 
> of stop().

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira

Reply via email to