[services][backup] CreateBackup 1/3 - create handler module
Summary:
- Created module structure for gRPC service handlers to keep it organized:
- mod service (existing grpc service mod) - mod handlers (groups all handler submodules) - create_backup - add_attachments - ...
- Scaffolded the CreateBackupHandler structure, containing the whole endpoint logic. This is 1:1 analogy with Blob service PutHandler
- Implemented usage of this structure in the endpoint handler function.
The CreateBackupHandler consists of two phases
- Non-data mode - processing non-chunk inputs like device_id, user_id etc.
- Data mode - processing backup data chunks
- Finish - postprocessing, saving to db etc.
Depends on D6181
Test Plan: This does nothing yet, subsequent diffs will add logic to this code.
Reviewers: varun, tomek, jon, max
Reviewed By: varun, tomek
Subscribers: ashoat, atul
Differential Revision: https://phab.comm.dev/D6196