qqu0127 opened a new pull request, #2325: URL: https://github.com/apache/helix/pull/2325
### Issues - [ ] My PR addresses the following Helix issues and references them in the PR description: N.A. ### Description - [X] Here are some details about my PR, including screenshots of any UI changes: See also https://github.com/apache/helix/pull/2306 Refactor the zookeeper-api module as preparation for DataChangeListener notification implementation in ZkMetaClient. A new set of listeners need to be triggered on ZK events, and in order to support this, the watcher has to be registered from the new meta-client module. We CANNOT reuse ZkClient to implement the new listener interface because it's introducing circular dependency. The change includes: 1. Accepts `watcher` as param in ZkClient construction, in order to override the watcher registration while maintain backward compatibility. 2. Introduce `boolean connectOnInit`, zkclient was default to connect right after class initialization, this is causing trouble in ZkMetaClient implementation because the instance might not be fully constructed and causing `NullPointerException`. In MetaClient API, `connect` is a standalone method and supposed to be invoked separately. 3. Marking a few methods and class public to be reused in meta-client module 4. Fixing some typo and styling. This PR also enables Helix PR CI for this feature branch to have better coverage during development. ### Tests - [ ] The following tests are written for this issue: (List the names of added unit/integration tests) - The following is the result of the "mvn test" command on the appropriate module: (If CI test fails due to known issue, please specify the issue and test PR locally. Then copy & paste the result of "mvn test" to here.) ### Changes that Break Backward Compatibility (Optional) - My PR contains changes that break backward compatibility or previous assumptions for certain methods or API. They include: (Consider including all behavior changes for public methods or API. Also include these changes in merge description so that other developers are aware of these changes. This allows them to make relevant code changes in feature branches accounting for the new method/API behavior.) ### Documentation (Optional) - In case of new functionality, my PR adds documentation in the following wiki page: (Link the GitHub wiki you added) ### Commits - My commits all reference appropriate Apache Helix GitHub issues in their subject lines. In addition, my commits follow the guidelines from "[How to write a good git commit message](http://chris.beams.io/posts/git-commit/)": 1. Subject is separated from body by a blank line 1. Subject is limited to 50 characters (not including Jira issue reference) 1. Subject does not end with a period 1. Subject uses the imperative mood ("add", not "adding") 1. Body wraps at 72 characters 1. Body explains "what" and "why", not "how" ### Code Quality - My diff has been formatted using helix-style.xml (helix-style-intellij.xml if IntelliJ IDE is used) -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
