max / makenotwork

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1	//! Live chat shared by Multithreaded forums and MNW stream pages.
2	//!
3	//! Design + decisions: maintainer wiki.
4	//! <!-- wiki: livechat-design -->
5	//!
6	//! A thin crate. It owns the message and event vocabulary, bounded retention,
7	//! and (as they land) the hub and SSE transport. It owns no schema, no authz, and
8	//! no moderation policy: those arrive through four traits the host implements, so
9	//! Multithreaded can gate on `CommunityScope` and the MNW server on
10	//! `SubscriptionGate` without either concept appearing here.
11	//!
12	//! # Shape
13	//!
14	//! SSE downstream, plain `POST` upstream. Not a WebSocket. The upstream volume is
15	//! one request per message typed, so bidirectionality buys nothing, and a `POST`
16	//! passes through the CSRF, rate-limit, and session middleware both apps already
17	//! run. It also avoids adding a `connect-src` CSP directive on the Multithreaded
18	//! side, which currently has none.
19	//!
20	//! # Ephemeral, but written down
21	//!
22	//! Chat in both consumers expires. Messages are stored anyway, for two reasons:
23	//! a deploy is a symlink swap plus a restart with no connection draining, so
24	//! every client reconnects and needs its backlog replayed from a cursor; and
25	//! moderation has to be able to reach a message that already scrolled past.
26	//!
27	//! [`Retention`] makes the bound un-opt-out-able. There is no `Option`, no
28	//! "forever" sentinel, and no public field: the only constructor rejects anything
29	//! over the crate ceilings.
30	//!
31	//! # Not here, on purpose
32	//!
33	//! No presence, no typing indicators, no edit path, and no link previews. The
34	//! first two are the largest drivers of event volume against a hard 512M cgroup
35	//! cap where an OOM restarts the whole site. Edit is surface with no benefit in a
36	//! stream nobody re-reads. Link previews would point a server-side fetcher at
37	//! unreviewed user input at chat volume, which is a much hotter SSRF surface than
38	//! the forum-post path it would borrow.
39
40	mod chat;
41	mod error;
42	mod event;
43	mod hub;
44	mod ids;
45	mod message;
46	mod rate_limit;
47	mod retention;
48	mod room;
49	mod send;
50	#[cfg(feature = "axum")]
51	mod sse;
52	mod stream;
53	mod traits;
54
55	pub use chat::{Chat, SendRequest};
56	pub use error::{ChatError, LimitScope};
57	pub use event::ChatEvent;
58	pub use hub::{Hub, HubLimits, Subscription};
59	pub use ids::{MessageId, Nonce, RoomId, UserId};
60	pub use message::{MAX_MESSAGE_LEN, Message, MessageBody};
61	pub use rate_limit::{RateDecision, RateLimiter, RateLimits};
62	pub use retention::{MAX_AGE_CEILING, MAX_MESSAGES_CEILING, Retention};
63	pub use room::{Room, RoomState};
64	pub use send::SendRejection;
65	#[cfg(feature = "axum")]
66	pub use sse::{KEEPALIVE_INTERVAL, sse_response};
67	pub use stream::ChatStream;
68	pub use traits::{
69	ChatAuthz, ChatIdentity, ChatModeration, ChatRooms, DenyReason, Identity, WriteAccess,
70	};
71