[jbosstools-issues] [JBoss JIRA] (JBIDE-21828) OpenShift Explorer view flickers when refreshing a service

[Viacheslav Kabanovich (JIRA)]

    [ https://issues.jboss.org/browse/JBIDE-21828?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13174342#comment-13174342 ] 

Viacheslav Kabanovich commented on JBIDE-21828:
-----------------------------------------------

The first point (new substracture is created internally in a silent manner) is critical for performance in large models. Suppose, an object is added which has thousands of objects in its sub-tree. This object was not in model, adding just it one already loaded and firing only one event for it is good enough for all clients, both UI and core. If it is first added while not loaded, fired to make clients aware of it, and then is loaded firing thousands of events, then it puts high load to performance.

This can be easily reconciled with observable framework by this trick: do not add new object and do not bind it to listeners until it is loaded. Then, what if the object should be lazy to load, what then is the difference? That is where merge is important. Model knows its loaded nodes, when merging into the existing structure, the merge process will prompt new structure to 'expand' to needed level. And it is important that it will not be prompted by UI which would bounce loading between UI thread and non-UI thread, entangling them and making both performance and UI-refresh problems.

And to follow this approach, separating model from content provider is inevitable. The content provider is prompted by UI every time it gets an event, we then are at the hard choice sync/async. If model is separate, the choice is easy, it is one - just get from the model what it has at the moment and watch for next events, and process it with refresh() - whatever the order of events, that will give ui the most recent state of model. Model, when requested for children of an object which is not fully loaded yet, will start a loading job, and due to merge, clients will be notified only of exact incremental changes in known to them objects. Compare it to the approach of removing all children then adding new children and letting ui prompt them to load thus causing a lot of events and ui forgetfulness of the expanded state that should be solved on ui side.


> OpenShift Explorer view flickers when refreshing a service
> ----------------------------------------------------------
>
>                 Key: JBIDE-21828
>                 URL: https://issues.jboss.org/browse/JBIDE-21828
>             Project: Tools (JBoss Tools)
>          Issue Type: Bug
>          Components: openshift
>    Affects Versions: 4.3.1.Beta2
>            Reporter: Xavier Coulon
>         Attachments: Screenshot 2016-03-08 10.32.39.png
>
>
> When calling the "Refresh" command on a service, the tree view flickers because of too many refresh calls.
> Adding some traces revealed 25 calls to {{BaseExplorerContentProvider#refreshViewer(Object)}}, which seems way too much for a service with a single pod.
> Attachement: screenshot of the OpenShift Server view, showing 2 projects, one of which has 3 services.
> Custom/added logs in the console:
> {code}
> Refreshing viewer from org.jboss.tools.openshift.internal.ui.models.OpenShiftProjectUIModel at 431dafbc
> Refreshing viewer from org.jboss.tools.openshift.internal.ui.models.OpenShiftProjectUIModel at 431dafbc
> Refreshing viewer from org.jboss.tools.openshift.internal.ui.models.OpenShiftProjectUIModel at 431dafbc
> Refreshing viewer from org.jboss.tools.openshift.internal.ui.models.OpenShiftProjectUIModel at 431dafbc
> Refreshing viewer from org.jboss.tools.openshift.internal.ui.models.OpenShiftProjectUIModel at 431dafbc
> Refreshing viewer from org.jboss.tools.openshift.internal.ui.models.OpenShiftProjectUIModel at 431dafbc
> Refreshing viewer from sample/jee-sample
> Refreshing viewer from sample/jee-sample
> Refreshing viewer from sample/jee-sample
> Refreshing viewer from sample/jee-sample
> Refreshing viewer from sample/mongodb
> Refreshing viewer from sample/mongodb
> Refreshing viewer from sample/mongodb
> Refreshing viewer from sample/nodejs-mongodb-example
> Refreshing viewer from sample/nodejs-mongodb-example
> Refreshing viewer from sample/nodejs-mongodb-example
> Refreshing viewer from sample/nodejs-mongodb-example
> Refreshing viewer from sample/jee-sample
> Refreshing viewer from sample/jee-sample
> Refreshing viewer from sample/jee-sample
> Refreshing viewer from sample/jee-sample
> Refreshing viewer from sample/nodejs-mongodb-example
> Refreshing viewer from sample/nodejs-mongodb-example
> Refreshing viewer from org.jboss.tools.openshift.internal.ui.models.OpenShiftProjectUIModel at 431dafbc
> Refreshing viewer from org.jboss.tools.openshift.internal.ui.models.OpenShiftProjectUIModel at 431dafbc
> {code}



--
This message was sent by Atlassian JIRA
(v6.4.11#64026)