{"html_url": "https://github.com/simonw/datasette/issues/1384#issuecomment-1066169718", "issue_url": "https://api.github.com/repos/simonw/datasette/issues/1384", "id": 1066169718, "node_id": "IC_kwDOBm6k_c4_jHV2", "user": {"value": 2670795, "label": "brandonrobertz"}, "created_at": "2022-03-13T19:48:49Z", "updated_at": "2022-03-13T19:48:49Z", "author_association": "CONTRIBUTOR", "body": "> For my reference, did you include a `render_cell` plugin calling `get_metadata` in those tests?\r\n\r\nYou shouldn't need to do this, as I mentioned previously. The code inside `render_cell` hook already has access to the most recently sync'd metadata via `datasette._metadata_local`. Refreshing the metadata for every cell seems ... excessive.", "reactions": "{\"total_count\": 0, \"+1\": 0, \"-1\": 0, \"laugh\": 0, \"hooray\": 0, \"confused\": 0, \"heart\": 0, \"rocket\": 0, \"eyes\": 0}", "issue": {"value": 930807135, "label": "Plugin hook for dynamic metadata"}, "performed_via_github_app": null}
{"html_url": "https://github.com/simonw/datasette/issues/1384#issuecomment-1066006292", "issue_url": "https://api.github.com/repos/simonw/datasette/issues/1384", "id": 1066006292, "node_id": "IC_kwDOBm6k_c4_ifcU", "user": {"value": 2670795, "label": "brandonrobertz"}, "created_at": "2022-03-13T02:09:44Z", "updated_at": "2022-03-13T02:09:44Z", "author_association": "CONTRIBUTOR", "body": "> If I'm understanding your plugin code correctly, you query the db using the sync handle every time `get_metdata` is called, right? Won't this become a pretty big bottleneck if a hook into `render_cell` is trying to read metadata / plugin config?\r\n\r\nReading from sqlite DBs is pretty quick and I didn't notice significant performance issues when I was benchmarking. I tested on very large Datasette deployments (hundreds of DBs, millions of rows). See [\"Many small queries are efficient in sqlite\"](https://sqlite.org/np1queryprob.html) for more information on the rationale here. Also note that in the [datasette-live-config](https://github.com/next-LI/datasette-live-config) reference plugin, the DB connection is cached, so that eliminated most of the performance worries we had.\r\n\r\nIf you need to ensure fresh metadata is being read inside of a `render_cell` hook specifically, you don't need to do anything further! `get_metadata` gets called before `render_cell` every request, so it already has access to the synced meta. There shouldn't be a need to call `get_metadata(...)` or `metadata(...)` inside `render_cell`, you can just use `datasette._metadata_local` if you're really worried about performance.\r\n\r\n> The plugin is close, but looks like it only grabs remote metadata, is that right? Instead what I'm wanting is to grab metadata embedded in the attached databases.\r\n\r\nYes correct, the datadette-remote-metadata plugin doesn't do that. But the datasette-live-config plugin does. [It supports a `__metadata` table](https://github.com/next-LI/datasette-live-config/blob/main/datasette_live_config/__init__.py#L107-L138) that, when it exists on an attached DB, gets pulled into the Datasette internal `_metadata` and is also accessible via `get_metadata`. Updating is instantaneous so there's no gotchas for users or security issues for users relying on the metadata-based permissions. Simon talked about eventually making something like this a standard feature of Datasette, but I'm not sure what the status is on that!\r\n\r\nGood luck!", "reactions": "{\"total_count\": 0, \"+1\": 0, \"-1\": 0, \"laugh\": 0, \"hooray\": 0, \"confused\": 0, \"heart\": 0, \"rocket\": 0, \"eyes\": 0}", "issue": {"value": 930807135, "label": "Plugin hook for dynamic metadata"}, "performed_via_github_app": null}