Summary:
See T344. Currently, there's a hard-coded 12MB filesize limit and some awkward
interactions with MySQL's max_allowed_packet. Make this system generally more
robust:
- Move the upload limit to configuration.
- Add setup steps which reconcile max_allowed_packet vs MySQL file storage
limits.
- Add a layer of indirection between uploading files and storage engines.
- Allow the definition of new storage engines.
- Define a local disk storage engine.
- Add a "storage engine selector" class which manages choosing which storage
engines to put files in.
- Document storage engines.
- Document file storage classes.
Test Plan:
Setup mode:
- Disabled MySQL storage engine, misconfigured it, configured it correctly.
- Disabled file storage engine, set it to something invalid, set it to
something valid.
- Verified max_allowed_packet is read correctly.
Application mode:
- Configured local file storage.
- Uploaded large and small files.
- Verified larger files were written to local storage.
- Verified smaller files were written to MySQL blob storage.
Documentation:
- Read documentation.
Reviewed By: jungejason
Reviewers: jungejason, tuomaspelkonen, aran
CC: aran, epriestley, jungejason
Differential Revision: 695
