diff options
author | Vincent Ambo <mail@tazj.in> | 2022-05-14T22·19+0200 |
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committer | clbot <clbot@tvl.fyi> | 2022-05-14T22·31+0000 |
commit | 89f25b431d9447f7c2cf9781aba10418578ec68a (patch) | |
tree | ef1bd369047a83f3030ab88f85c5c55c3f93a006 /users | |
parent | af31da8cfc9caee8c2cd44df5ee5c1ed3a9b3ed7 (diff) |
feat(tazjin/tgsa): Expire cached telegram entries after one hour r/4074
Telegram expires certain links in messages after some (unknown) amount of time; this commit is the first step to working around that by providing an image URL proxy. In order to do that, we tick two important boxes here: 1. Store an extensible data structure in the cache. 2. Expire them periodically. Change-Id: Iba192d8b71db4493c942d1baf5680bd086f8f60b Reviewed-on: https://cl.tvl.fyi/c/depot/+/5607 Reviewed-by: tazjin <tazjin@tvl.su> Autosubmit: tazjin <tazjin@tvl.su> Tested-by: BuildkiteCI
Diffstat (limited to 'users')
-rw-r--r-- | users/tazjin/tgsa/src/main.rs | 27 |
1 files changed, 22 insertions, 5 deletions
diff --git a/users/tazjin/tgsa/src/main.rs b/users/tazjin/tgsa/src/main.rs index 92ecc5572896..28b5d4253aa4 100644 --- a/users/tazjin/tgsa/src/main.rs +++ b/users/tazjin/tgsa/src/main.rs @@ -1,6 +1,7 @@ use anyhow::{anyhow, Context, Result}; use std::collections::HashMap; use std::sync::RwLock; +use std::time::{Duration, Instant}; #[derive(Clone, Debug, Eq, Hash, PartialEq)] struct TgLink { @@ -184,19 +185,35 @@ fn to_bbcode(link: &TgLink, msg: &TgMessage) -> String { out } -type Cache = RwLock<HashMap<TgLink, String>>; +// cache everything for one hour +const CACHE_EXPIRY: Duration = Duration::from_secs(60 * 60); + +struct CacheEntry { + bbcode: String, + at: Instant, +} + +type Cache = RwLock<HashMap<TgLink, CacheEntry>>; fn handle_tg_link(cache: &Cache, link: &TgLink) -> Result<String> { - if let Some(bbcode) = cache.read().unwrap().get(&link) { - println!("serving {}#{} from cache", link.username, link.message_id); - return Ok(bbcode.to_string()); + if let Some(entry) = cache.read().unwrap().get(&link) { + if Instant::now() - entry.at < CACHE_EXPIRY { + println!("serving {}#{} from cache", link.username, link.message_id); + return Ok(entry.bbcode.to_string()); + } } let embed = fetch_embed(&link)?; let msg = parse_tgmessage(&embed)?; let bbcode = to_bbcode(&link, &msg); - cache.write().unwrap().insert(link.clone(), bbcode.clone()); + cache.write().unwrap().insert( + link.clone(), + CacheEntry { + bbcode: bbcode.clone(), + at: Instant::now(), + }, + ); Ok(bbcode) } |