Write down some design notes

README.md

@@ -1,3 +1,33 @@
 # tablejohn
 
 A tool to run benchmarks for a git repo and display their results.
+
+## Design notes
+
+- A tablejohn instance tracks exactly one git repository.
+- A tablejohn instance has exactly one sqlite db.
+- Tablejohn does not clone or update repos, only inspect them.
+- Tablejohn can inspect bare and non-bare repos.
+- Server settings should go in a config file.
+- Repo settings should go in the db and be managed via the web UI.
+- Locally, tablejohn should just work™ without custom config.
+- Run via `tablejohn <db> [<repo>]`
+
+- The db contains...
+    - Known commits
+    - Runs and their measurements
+    - Queue of tasks (not-yet-run runs)
+    - Tracked branches (new commits are added to the queue automatically)
+    - Github commands
+
+- Runners...
+    - Ping tablejohn instance regularly with their info?
+        - WS connection complex, but quicker to update
+    - Reserve tasks (for a limited amount of time 10 min?)
+    - Steal tasks based on time already spent on task
+    - Update server on tasks
+        - Maybe this is the same as reserving a task?
+        - Include last few lines of output
+    - Turn tasks into runs
+        - Handle errors sensibly
+        - Include full output (stdout and stderr), especially if task fails