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path: root/src/channel/snapshot.rs
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* Rename "channel" to "conversation" within the server.Owen Jacobson2025-07-03
| | | | | | I've split this from the schema and API changes because, frankly, it's huge. Annoyingly so. There are no semantic changes in this, it's all symbol changes, but there are a _lot_ of them because the term "channel" leaks all over everything in a service whose primary role is managing messages sent to channels (now, conversations). I found a buggy test while working on this! It's not fixed in this commit, because it felt mean to hide a real change in the middle of this much chaff.
* Make creation time an intrinsic fact about channels, the way it is for events.Owen Jacobson2025-05-13
| | | | To make unread handling of empty channels coherent (and to make it possible to mark an empty channel as having been read), they need to be associated with a specific point in time. This change exposes their creation time in the snapshot - it was already part of the event view, though the client doesn't know that yet.
* Upgrade to Rust 1.85 and Rust 2024 edition.Owen Jacobson2025-02-20
| | | | | | | | There are a couple of migration suggestions from `cargo fix --edition` that I have deliberately skipped, which are intended to make sure that the changes to `if let` scoping don't bite us. They don't, I'm pretty sure, and if I turn out to be wrong, I'd rather fix the scoping issues (as they arise) than use `match` (`cargo fix --edition`'s suggestion). This change also includes a bulk reformat and a clippy cleanup. NOTA BENE: As this requires a new Rust toolchain, you'll need to update Rust (`rustup update`, normally) or the server won't build. This also applies to the Debian builder Docker image; it'll need to be rebuilt (from scratch, pulling its base image again) as well.
* Canonicalize login and channel names.Owen Jacobson2024-10-22
| | | | | | | | | | | | | | | Canonicalization does two things: * It prevents duplicate names that differ only by case or only by normalization/encoding sequence; and * It makes certain name-based comparisons "case-insensitive" (generalizing via Unicode's case-folding rules). This change is complicated, as it means that every name now needs to be stored in two forms. Unfortunately, this is _very likely_ a breaking schema change. The migrations in this commit perform a best-effort attempt to canonicalize existing channel or login names, but it's likely any existing channels or logins with non-ASCII characters will not be canonicalize correctly. Since clients look at all channel names and all login names on boot, and since the code in this commit verifies canonicalization when reading from the database, this will effectively make the server un-usuable until any incorrectly-canonicalized values are either manually canonicalized, or removed It might be possible to do better with [the `icu` sqlite3 extension][icu], but (a) I'm not convinced of that and (b) this commit is already huge; adding database extension support would make it far larger. [icu]: https://sqlite.org/src/dir/ext/icu For some references on why it's worth storing usernames this way, see <https://www.b-list.org/weblog/2018/nov/26/case/> and the refernced talk, as well as <https://www.b-list.org/weblog/2018/feb/11/usernames/>. Bennett's treatment of this issue is, to my eye, much more readable than the referenced Unicode technical reports, and I'm inclined to trust his opinion given that he maintains a widely-used, internet-facing user registration library for Django.
* Unicode normalization on input.Owen Jacobson2024-10-21
| | | | | | | | | | | | | | | | | | This normalizes the following values: * login names * passwords * channel names * message bodies, because why not The goal here is to have a canonical representation of these values, so that, for example, the service does not inadvertently host two channels whose names are semantically identical but differ in the specifics of how diacritics are encoded, or two users whose names are identical. Normalization is done on input from the wire, using Serde hooks, and when reading from the database. The `crate::nfc::String` type implements these normalizations (as well as normalizing whenever converted from a `std::string::String` generally). This change does not cover: * Trying to cope with passwords that were created as non-normalized strings, which are now non-verifiable as all the paths to verify passwords normalize the input. * Trying to ensure that non-normalized data in the database compares reasonably to normalized data. Fortunately, we don't _do_ very many string comparisons (I think only login names), so this isn't a huge deal at this stage. Login names will probably have to Get Fixed later on, when we figure out how to handle case folding for login name verification.
* Retain deleted messages and channels temporarily, to preserve events for replay.Owen Jacobson2024-10-17
| | | | | | | | | | | | Previously, when a channel (message) was deleted, `hi` would send events to all _connected_ clients to inform them of the deletion, then delete all memory of the channel (message). Any disconnected client, on reconnecting, would not receive the deletion event, and would de-synch with the service. The creation events were also immediately retconned out of the event stream, as well. With this change, `hi` keeps a record of deleted channels (messages). When replaying events, these records are used to replay the deletion event. After 7 days, the retained data is deleted, both to keep storage under control and to conform to users' expectations that deleted means gone. To match users' likely intuitions about what deletion does, deleting a channel (message) _does_ immediately delete some of its associated data. Channels' names are blanked, and messages' bodies are also blanked. When the event stream is replayed, the original channel.created (message.sent) event is "tombstoned", with an additional `deleted_at` field to inform clients. The included client does not use this field, at least yet. The migration is, once again, screamingingly complicated due to sqlite's limited ALTER TABLE … ALTER COLUMN support. This change also contains capabilities that would allow the API to return 410 Gone for deleted channels or messages, instead of 404. I did experiment with this, but it's tricky to do pervasively, especially since most app-level interfaces return an `Option<Channel>` or `Option<Message>`. Redesigning these to return either `Ok(Channel)` (`Ok(Message)`) or `Err(Error::NotFound)` or `Err(Error::Deleted)` is more work than I wanted to take on for this change, and the utility of 410 Gone responses is not obvious to me. We have other, more pressing API design warts to address.
* Use a two-tier hierarchy for events.Owen Jacobson2024-10-09
| | | | This will make it much easier to slot in new event types (login events!).
* Flatten nested `channel` and `message` structs in events and API responses.Owen Jacobson2024-10-09
| | | | This structure didn't accomplish anything and made certain refactorings harder.
* Represent channels and messages using a split "History" and "Snapshot" model.Owen Jacobson2024-10-03
This separates the code that figures out what happened to an entity from the code that represents it to a user, and makes it easier to compute a snapshot at a point in time (for things like bootstrap). It also makes the internal logic a bit easier to follow, since it's easier to tell whether you're working with a point in time or with the whole recorded history. This hefty.