From bfe12d3946eda2858e52075f76a44bb4c99df7b7 Mon Sep 17 00:00:00 2001
From: Natsu Kagami <natsukagami@gmail.com>
Date: Mon, 7 Sep 2020 14:31:45 -0400
Subject: [PATCH] osu: Asyncify oppai cache

---
 youmubot-osu/src/discord/hook.rs        | 44 ++++++++++++-------------
 youmubot-osu/src/discord/oppai_cache.rs | 41 +++++++++++++----------
 2 files changed, 45 insertions(+), 40 deletions(-)

diff --git a/youmubot-osu/src/discord/hook.rs b/youmubot-osu/src/discord/hook.rs
index 240a8f1..5efb21b 100644
--- a/youmubot-osu/src/discord/hook.rs
+++ b/youmubot-osu/src/discord/hook.rs
@@ -128,12 +128,14 @@ fn handle_old_links<'a>(
                         .map(|v| Mods::from_str(v.as_str()).ok())
                         .flatten()
                         .unwrap_or(Mods::NOMOD);
-                    let info = mode.unwrap_or(b.mode).to_oppai_mode().and_then(|mode| {
-                        cache
+                    let info = match mode.unwrap_or(b.mode).to_oppai_mode() {
+                        Some(mode) => cache
                             .get_beatmap(b.beatmap_id)
+                            .await
                             .and_then(|b| b.get_info_with(Some(mode), mods))
-                            .ok()
-                    });
+                            .ok(),
+                        None => None,
+                    };
                     Some(ToPrint {
                         embed: EmbedType::Beatmap(b, info, mods),
                         link: capture.get(0).unwrap().as_str(),
@@ -198,15 +200,14 @@ fn handle_new_links<'a>(
                         .name("mods")
                         .and_then(|v| Mods::from_str(v.as_str()).ok())
                         .unwrap_or(Mods::NOMOD);
-                    let info = mode
-                        .unwrap_or(beatmap.mode)
-                        .to_oppai_mode()
-                        .and_then(|mode| {
-                            cache
-                                .get_beatmap(beatmap.beatmap_id)
-                                .and_then(|b| b.get_info_with(Some(mode), mods))
-                                .ok()
-                        });
+                    let info = match mode.unwrap_or(beatmap.mode).to_oppai_mode() {
+                        Some(mode) => cache
+                            .get_beatmap(beatmap.beatmap_id)
+                            .await
+                            .and_then(|b| b.get_info_with(Some(mode), mods))
+                            .ok(),
+                        None => None,
+                    };
                     Some(ToPrint {
                         embed: EmbedType::Beatmap(beatmap, info, mods),
                         link,
@@ -265,15 +266,14 @@ fn handle_short_links<'a>(
                 .name("mods")
                 .and_then(|v| Mods::from_str(v.as_str()).ok())
                 .unwrap_or(Mods::NOMOD);
-            let info = mode
-                .unwrap_or(beatmap.mode)
-                .to_oppai_mode()
-                .and_then(|mode| {
-                    cache
-                        .get_beatmap(beatmap.beatmap_id)
-                        .and_then(|b| b.get_info_with(Some(mode), mods))
-                        .ok()
-                });
+            let info = match mode.unwrap_or(beatmap.mode).to_oppai_mode() {
+                Some(mode) => cache
+                    .get_beatmap(beatmap.beatmap_id)
+                    .await
+                    .and_then(|b| b.get_info_with(Some(mode), mods))
+                    .ok(),
+                None => None,
+            };
             let r: Result<_> = Ok(ToPrint {
                 embed: EmbedType::Beatmap(beatmap, info, mods),
                 link: capture.get(0).unwrap().as_str(),
diff --git a/youmubot-osu/src/discord/oppai_cache.rs b/youmubot-osu/src/discord/oppai_cache.rs
index 60cf6b3..c45ed3a 100644
--- a/youmubot-osu/src/discord/oppai_cache.rs
+++ b/youmubot-osu/src/discord/oppai_cache.rs
@@ -1,12 +1,12 @@
 use serenity::framework::standard::CommandError;
-use std::{ffi::CString, sync::Arc};
-use youmubot_prelude::TypeMapKey;
+use std::ffi::CString;
+use youmubot_prelude::*;
 
 /// the information collected from a download/Oppai request.
-#[derive(Clone, Debug)]
+#[derive(Debug)]
 pub struct BeatmapContent {
     id: u64,
-    content: Arc<CString>,
+    content: CString,
 }
 
 /// the output of "one" oppai run.
@@ -56,39 +56,44 @@ impl BeatmapContent {
 }
 
 /// A central cache for the beatmaps.
-#[derive(Clone, Debug)]
+#[derive(Debug)]
 pub struct BeatmapCache {
-    client: reqwest::blocking::Client,
-    cache: Arc<dashmap::DashMap<u64, BeatmapContent>>,
+    client: reqwest::Client,
+    cache: dashmap::DashMap<u64, BeatmapContent>,
 }
 
 impl BeatmapCache {
     /// Create a new cache.
-    pub fn new(client: reqwest::blocking::Client) -> Self {
+    pub fn new(client: reqwest::Client) -> Self {
         BeatmapCache {
             client,
-            cache: Arc::new(dashmap::DashMap::new()),
+            cache: dashmap::DashMap::new(),
         }
     }
 
-    fn download_beatmap(&self, id: u64) -> Result<BeatmapContent, CommandError> {
+    async fn download_beatmap(&self, id: u64) -> Result<BeatmapContent> {
         let content = self
             .client
             .get(&format!("https://osu.ppy.sh/osu/{}", id))
-            .send()?
-            .bytes()?;
+            .send()
+            .await?
+            .bytes()
+            .await?;
         Ok(BeatmapContent {
             id,
-            content: Arc::new(CString::new(content.into_iter().collect::<Vec<_>>())?),
+            content: CString::new(content.into_iter().collect::<Vec<_>>())?,
         })
     }
 
     /// Get a beatmap from the cache.
-    pub fn get_beatmap(&self, id: u64) -> Result<BeatmapContent, CommandError> {
-        self.cache
-            .entry(id)
-            .or_try_insert_with(|| self.download_beatmap(id))
-            .map(|v| v.clone())
+    pub async fn get_beatmap<'a>(
+        &'a self,
+        id: u64,
+    ) -> Result<impl std::ops::Deref<Target = BeatmapContent> + 'a, CommandError> {
+        if !self.cache.contains_key(&id) {
+            self.cache.insert(id, self.download_beatmap(id).await?);
+        }
+        Ok(self.cache.get(&id).unwrap())
     }
 }