Files
TelegramTwitterMediaBot/crates/xmedia-bot/src/ctx.rs
T
YoursFunny 64cf43dc01 perf: degrade a link-cache entry instead of dropping it on a failed send
`link_cache` exists so a repeat link costs nothing: no source request, no
download, no upload. It was written only on a *successful* send, and a send
that failed permanently deleted the entry — so the user's immediate retry, the
one case where they are most likely to try again, re-fetched everything:
site requests, a download, and for a ugoira or a bsky video a full ffmpeg
encode. Invalidation is right about the cause (the cached Telegram file id is
what went stale) and wrong about the cure (the media and its URLs are usually
fine).

Cached media now carries the source URL it was sent from, and a permanent
failure *degrades* the entry: the file ids are cleared, the URLs and the
caption fields stay, and the next request sends from those URLs — Telegram
fetches the media (or the upload fallback does) with no source round trip.
That is the same media a fresh fetch would have produced (site CDN URLs are
stable per post), and it is bounded: an entry that is already degraded, or one
from before this field existed, is removed instead, so a dead post still ends
up re-fetched and reported rather than retried forever.

Verified: a cached send that fails permanently leaves the entry with its URL
and no file id, a second failure drops it, and a degraded entry sends the
media with no fetch at all (the mock records no reply, which is what the
fetch-error path would have produced). 124 bot tests + 91 x-media tests pass,
including a direct test of the two payload shapes.

`cargo fmt --check`, `cargo clippy --workspace --all-targets --locked -- -D
warnings` and `cargo test --workspace --locked` clean.
2026-09-21 14:35:57 +08:00

189 lines
6.9 KiB
Rust

//! Runtime context: the collaborators a handler needs, injected as one struct
//! so tests can substitute a scripted sender and tempdir-backed stores.
//!
//! The production context is assembled from the process-wide statics
//! ([`AppContext::from_statics`]); the spawned worker closures hold
//! [`CONTEXT`], which is `'static` for that reason.
use crate::config::Config;
use crate::handlers::{CHAT_STORE, CONFIG, LINK_CACHE, TASK_QUEUE};
use crate::link_cache::LinkCache;
use crate::media_sender::MediaSender;
use crate::queue::PersistentTaskQueue;
use crate::send::BOT;
use crate::state::ChatStore;
use std::sync::LazyLock;
pub struct AppContext<'a> {
pub sender: &'a dyn MediaSender,
pub chat_store: &'a ChatStore,
pub task_queue: &'a PersistentTaskQueue,
pub link_cache: &'a LinkCache,
pub config: &'a Config,
}
impl<'a> AppContext<'a> {
/// The stores are the process-wide statics; `sender` is whatever the caller
/// was handed (the dispatcher's `Bot` clone for update handlers, the shared
/// queue `Bot` for the worker loops). Update handlers build their own
/// context from the `Bot` they received so the same code path works with an
/// injected mock in tests.
pub fn from_statics(sender: &'a dyn MediaSender) -> AppContext<'a> {
AppContext {
sender,
chat_store: &CHAT_STORE,
task_queue: &TASK_QUEUE,
link_cache: &LINK_CACHE,
config: &CONFIG,
}
}
}
/// The URL/queue workers' context: `'static` because `tokio::spawn`ed closures
/// and the queue's handler type require it.
pub static CONTEXT: LazyLock<AppContext<'static>> =
LazyLock::new(|| AppContext::from_statics(&*BOT));
/// Test support: a tempdir-backed set of stores plus the context borrowing
/// them, so a handler test needs one line of setup.
#[cfg(test)]
pub(crate) mod test_support {
use super::*;
use crate::link_cache::{CachedMedia, CachedMediaKind, CachedPost};
use crate::state::EditMessage;
use std::sync::Arc;
use teloxide::{ApiError, RequestError};
/// The edit-before-forward prompt's message id, and the message the prompt
/// refers to (the one whose caption a reply swaps).
pub(crate) const PROMPT_ID: i64 = 7;
pub(crate) const FORWARDED_ID: i64 = 9;
/// A Telegram API error, for the tests that script a failure.
pub(crate) fn api_error(message: &str) -> RequestError {
RequestError::Api(ApiError::Unknown(message.to_string()))
}
/// The cached post every test that touches the link cache starts from: one
/// photo with a Telegram file id at the canonical URL (key `twitter:1`).
/// Tests that need another field mutate the returned value.
pub(crate) fn cached_photo() -> CachedPost {
CachedPost {
url: "https://x.com/u/status/1".into(),
caption: "cap".into(),
title: "t".into(),
content: "c".into(),
author: "a".into(),
author_url: "au".into(),
tags: String::new(),
sensitive: false,
media: vec![CachedMedia {
kind: CachedMediaKind::Photo,
file_id: "AgAC-file-id".into(),
url: "https://pbs.twimg.com/media/photo.jpg".into(),
}],
}
}
/// Seeds the live prompt a post-send leaves behind in chat 1: the chat's
/// template, a bound forward channel (the prompt's "forward" button
/// branches on it) and the record for [`PROMPT_ID`] pointing at
/// [`FORWARDED_ID`]. `template` is the record's template — what a reply
/// swaps the caption through, `""` for none — and `created_at` backdates
/// the record for the expiry cases.
pub(crate) async fn seed_prompt(ctx: &AppContext<'_>, template: &str, created_at: i64) {
ctx.chat_store
.update(1, |data| {
data.forward_channel_id = Some(2);
data.template
.insert("tpl".to_string(), "<b>[]</b>".to_string());
data.edit_message.insert(
PROMPT_ID,
EditMessage {
url: "https://x.com/u/status/1".into(),
chat_id: 1,
forward_message_ids: vec![FORWARDED_ID],
template: template.to_string(),
created_at,
},
);
})
.await;
}
pub(crate) struct TestStores {
_dir: tempfile::TempDir,
pool: Arc<crate::db::DbPool>,
chat_store: ChatStore,
task_queue: PersistentTaskQueue,
link_cache: LinkCache,
config: Config,
}
impl TestStores {
pub(crate) fn new() -> Self {
let dir = tempfile::tempdir().unwrap();
let pool = crate::db::open_store(dir.path().join("ctx.db").to_str().unwrap()).unwrap();
TestStores {
_dir: dir,
chat_store: ChatStore::new(Arc::clone(&pool)),
task_queue: PersistentTaskQueue::new(Arc::clone(&pool)),
link_cache: LinkCache::new(Arc::clone(&pool)),
config: Config::load(),
pool,
}
}
pub(crate) fn ctx<'a>(&'a self, sender: &'a dyn MediaSender) -> AppContext<'a> {
AppContext {
sender,
chat_store: &self.chat_store,
task_queue: &self.task_queue,
link_cache: &self.link_cache,
config: &self.config,
}
}
pub(crate) fn chat_store(&self) -> &ChatStore {
&self.chat_store
}
/// The parsed config, mutable so a test can pin a knob (e.g. the
/// caption-quote threshold) instead of depending on the environment.
pub(crate) fn config_mut(&mut self) -> &mut Config {
&mut self.config
}
pub(crate) fn link_cache(&self) -> &LinkCache {
&self.link_cache
}
pub(crate) fn task_queue(&self) -> &PersistentTaskQueue {
&self.task_queue
}
/// Rows persisted in the task queue: what "queued for retry" looks like
/// from the outside.
pub(crate) async fn queued_tasks(&self) -> i64 {
let pool = Arc::clone(&self.pool);
pool.with_conn(|conn| {
conn.query_row("SELECT COUNT(*) FROM tasks", [], |row| row.get(0))
})
.await
.unwrap()
}
/// The single queued task payload, for asserting what was rescheduled.
pub(crate) async fn queued_payload(&self) -> serde_json::Value {
let pool = Arc::clone(&self.pool);
let payload: String = pool
.with_conn(|conn| {
conn.query_row("SELECT payload FROM tasks LIMIT 1", [], |row| row.get(0))
})
.await
.unwrap();
serde_json::from_str(&payload).unwrap()
}
}
}