Description

With permissions by page activated, the CMS needs to traverse the page tree to find permissions which apply to a specific page. For each permission, django CMS calculates the list of page IDs it applies to. This calculation is cached.

For projects with large numbers of pages (>> 1,000) these calculations generate long lists of IDs and even using the cached calculations impacts responsiveness.

This PR noticeably improves the responsiveness when working with large page trees.

This PR optimizes the calculation of permission based on a page's path (actually a tuple grant_on and path, where the grant_on code defines if the permission applies to the page itself, its direct children, and/or all of its descendants). This makes both calculating the permissions and evaluating the cached permissions from O(n) to O(1) (n being the number of pages) (but stays O(m) for m being the number of permissions granted).

Thanks to @jrief for testing.
@Aiden-RC Please be invited to test and comment!

Thanks to @vinitkumar for testing a backport to django CMS 3.11.

Deprecations

This PR deprecates some (not officially documented) utility functions in cms.utils.page.permissions which are replaced by their counterparts getting the permission tuples, e.g., get_add_perm_tuples:

• get_add_ids
• get_change_ids
• get_change_advanced_settings_ids
• get_change_permissions_ids
• get_delete_ids
• get_move_page_ids
• get_publish_ids
• get_view_ids

It also deprecates the get_page_ids method of the cms.models.PagePermissions model.

Their database access is not efficient and redundant.

Related resources

• Proposal: Sub-divide the page tree so it renders faster for sites with many thousands of pages #7933 - this PR helps to solve some of the issues which are addressed by this proposal
• A time to consider how to improve the efficiency of building the menu nodes #7805
• get_visible_pages in menu.py doesn't scale #1206

Checklist

• I have opened this pull request against develop-4
• I have added or modified the tests when changing logic
• I have followed the conventional commits guidelines to add meaningful information into the changelog
• I have read the contribution guidelines and I have joined the channel #pr-reviews on our Discord Server to find a “pr review buddy” who is going to review my pull request.