On Fri, 7 Nov 2025 15:40:48 GMT, David Beaumont <[email protected]> wrote:

>> Adds support for writing preview related flags into jimage files.
>> 
>> Preview mode is complex. It's not nearly as simple as "does something in 
>> /modules/xxx/... have an entry in /modules/xxx/META-INF/preview/...".
>> 
>> Specific issues include:
>> 
>> Supporting preview-only resources without forcing a double lookup on 
>> everything.
>> Changing the set of entries in /packages/xxx directories to account for 
>> preview only packages in some modules.
>> Minimising the work done during image reader initialization to only need to 
>> process the small number of preview resources (rather than scanning the 
>> whole file to look for them).
>> The new flags added by this code address these issues, but calculating them 
>> correctly with only minor adjustments to the existing code was not feasible, 
>> it just became a lot larger and very complex.
>> 
>> To address this, a new type (ModuleReference) is introduced to track and 
>> then merge information about packages seen in each module. This allows a 
>> much simpler inner loop for processing resource paths when building the node 
>> tree, combined with a subsequent merging stage to produce the final package 
>> information for each module.
>> 
>> Not that since ModuleReference is needed during jimage reading, that class 
>> is already present in the previous PR on which this is based, but it starts 
>> to be used to calculate the module flags in this PR.
>> 
>> This PR can also adds the ImageReader unit tests for preview mode, which 
>> rely on being able to generate jimage files with preview mode flags in.
>
> David Beaumont has updated the pull request with a new target base due to a 
> merge or a rebase. The pull request now contains six commits:
> 
>  - Merge branch 'lworld' into jdk_8368467_reader/squashed
>  - Rename ModuleReference methods back.
>  - fixing jlink issue
>  - Feedback and test fix
>  - Minor feedback changes
>  - Roll up of writer changes.
>    
>    * fixing tests after refactoring
>    * Fixing up after dependent PR changes
>    * feedback and remove unused code
>    * new tests for ImageLocation
>    * Restoring lost changes and updating some comments.
>    * add system property guard to preview mode
>    * Remove TODOs now jimage version is bumped
>    * jimage writer changes to support preview mode.

Looks good.

-------------

Marked as reviewed by rriggs (Committer).

PR Review: 
https://git.openjdk.org/valhalla/pull/1718#pullrequestreview-3435034773

Reply via email to