https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/24550 fixed the
case where the wrong path on disk was being searched, but it
inadvertently ommitted the `/uploads/-/system` prefix when rendering the
Markdown for personal snippet uploads when they were stored directly in
object storage.
A personal snippet path is stored using FileUploader#upload_path.
The format for the path:
Local storage: :random_hex/:filename.
Object storage: personal_snippet/:id/:random_hex/:filename.
upload_paths represent the possible paths for a given identifier,
which will vary depending on whether the file is stored in local or
object storage. upload_path should match an element in upload_paths.
base_dir represents the path seen by the user in Markdown, and it
should always be prefixed with uploads/-/system.
store_dirs represent the paths that are actually used on disk. For
object storage, this should omit the prefix /uploads/-/system.
For example, consider the requested path
/uploads/-/system/personal_snippet/172/ff4ad5c2/file.png.
For local storage:
base_dir: uploads/-/system/personal_snippet/172
upload_path: ff4ad5c2/file.png
upload_paths: ["ff4ad5c2/file.png", "personal_snippet/172/ff4ad5c2/file.png"].
store_dirs: {1=>"uploads/-/system/personal_snippet/172/ff4ad5c2",
2=>"personal_snippet/172/ff4ad5c2"}
For object storage:
upload_path: personal_snippet/172/ff4ad5c2/file.png
Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/61671
String#underscore isn't particularly slow, but it's possible for us to
call it many times in a users autocomplete request, with mostly-static
values ('User', 'Group', etc.). We can memoise this and save a
surprising amount of time (around 10% of the total request time in some
cases).
Previously, an HTTP request for
`/uploads/-/system/personal_snippet/:snippet_id/:hash/:filename` would
look for an uploader of `PersonalFileUploader` class and use
`PersonalFileUploader#upload_paths` to search the datbase for one of the
following paths:
1. `:hash/:filename`
2. `uploads/-/system/personal_snippet/:id/:hash/:filename`
However, when the upload were stored in object storage,
`PersonalFileUploader#store_dirs` stored the path as:
`personal_snippet/:snippet_id/:hash`
The extraneous `uploads/-/system` prefix prevented the path from being
matched, and uploads in object storage would return a 404 error. Uploads
in local storage would work fine.
To fix this, we set the `#base_dir` properly so that `#upload_paths`
generates the right value for object storage. Note that this also makes
`#store_dirs` do the right thing in `FileUploader`.
Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/52595
