[
https://issues.apache.org/jira/browse/IGNITE-15166?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Ivan Bessonov reassigned IGNITE-15166:
--------------------------------------
Assignee: Ivan Bessonov
> Support renaming in named list configuration elements
> -----------------------------------------------------
>
> Key: IGNITE-15166
> URL: https://issues.apache.org/jira/browse/IGNITE-15166
> Project: Ignite
> Issue Type: Improvement
> Affects Versions: 3.0.0-alpha2
> Reporter: Ivan Bessonov
> Assignee: Ivan Bessonov
> Priority: Major
> Labels: iep-55, ignite-3
>
> h3. Motivation
> Current NamedListChange API does not allow you to perform rename operation.
> Best that you can do is to manually copy the required element and then delete
> the original. This is bad for several reasons:
> * inconvenient both in Java API and CLI tool;
> * results in "onDelete" and "onCreate" events, which is probably not what
> people want.
> There must be a way to rename elements in Java API at least so that "ALTER
> ..." DDL command could be properly implemented.
> h3. Java API
> {{NamedListChange}} is a right place to add "rename" method. It should have
> two parameters and following restrictions:
> * "old" and "new" names are not null;
> * element with "old" name must exist;
> * element with "new" name must not exist.
> New method must be added {{to ConfigurationNamedListListener}}, named
> "onRename". It should have "onUpdate" semantics, but with two new parameters:
> "oldKey" and "newKey". Names are a subject to change.
> h3. CLI
> -This is a little less obvious since HOCON/JSON describe data, not
> operations. We already have specific syntax for "delete" operation. I suggest
> making "rename" look similar:-
> {code:java}
> root.namedList {
> oldName = newName
> }{code}
> -In short, now we can assign 3 things to the element:-
> * -regular composite object with its inner values;-
> * -"null" for deletion;-
> * -"String" for renaming.-
> HOCON/JSON format will have no alterations for this feature. DDL commands are
> to be used for these operations instead.
> h3. Implementation hints
> This will be similar to how we store ordering of named list elements. But
> this time we have to assign each element a unique identifier. This can be a
> String or a number. Laziest solution is to use UUID with hyphens removed from
> it. That'll do it.
> NamedListNode object will store these ids. In short, following algorithms
> will have to be altered:
> * conversion of update tree to the flat map - this one should be easy;
> * applying the flat map to the tree - a bit trickier. Matching from ids to
> keys will be required, we have to make sure that it won't cost too much;
> * matching old list with a new one to properly invoke listeners - should be
> partially solved by the code from the issue above, but still, might be tricky
> as well.
> -HOCON / JSON "parsers" will have to be altered as well to support "rename"
> operation. That should be easy.-
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
