feat: initial work on tenor gif searching

crates/core/coalesced/Cargo.toml

@@ -0,0 +1,22 @@
+[package]
+name = "revolt-coalesced"
+version = "0.8.8"
+edition = "2021"
+license = "MIT"
+authors = ["Paul Makles <me@insrt.uk>", "Zomatree <me@zomatree.live>"]
+description = "Revolt Backend: Coalescion service"
+
+[features]
+tokio = ["dep:tokio"]
+queue = ["dep:indexmap"]
+cache = ["dep:lru"]
+
+default = ["tokio", "queue", "cache"]
+
+[dependencies]
+tokio = { version = "1.47.0", features = ["sync"], optional = true }
+indexmap = { version = "*", optional = true }
+lru = { version = "*", optional = true }
+
+[dev-dependencies]
+tokio = { version = "1.47.0", features = ["rt", "rt-multi-thread", "macros", "time"] }

crates/core/coalesced/LICENSE

@@ -0,0 +1,9 @@
+MIT License
+
+Copyright (c) 2024 Pawel Makles
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

crates/core/coalesced/src/config.rs

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+#[derive(Clone, PartialEq, Eq, Debug)]
+pub struct CoalescionServiceConfig {
+    /// How many tasks are running at once
+    pub max_concurrent: Option<usize>,
+    /// Whether to queue tasks once `max_concurrent` is reached
+    #[cfg(feature = "queue")]
+    pub queue_requests: bool,
+    /// Max amount of tasks in the buffer queue
+    #[cfg(feature = "queue")]
+    pub max_queue: Option<usize>,
+}
+
+impl Default for CoalescionServiceConfig {
+    fn default() -> Self {
+        Self {
+            max_concurrent: Some(100),
+            #[cfg(feature = "queue")]
+            queue_requests: true,
+            #[cfg(feature = "queue")]
+            max_queue: Some(100)
+        }
+    }
+}

crates/core/coalesced/src/error.rs

@@ -0,0 +1,20 @@
+use std::fmt::Display;
+
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub enum Error {
+    RecvError,
+    MaxConcurrent,
+    MaxQueue,
+}
+
+impl Display for Error {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Error::RecvError => write!(f, "Unable to receive data from the channel"),
+            Error::MaxConcurrent => write!(f, "Max number of tasks running at once"),
+            Error::MaxQueue => write!(f, "Max number of tasks in queue"),
+        }
+    }
+}
+
+impl std::error::Error for Error {}

crates/core/coalesced/src/lib.rs

@@ -0,0 +1,7 @@
+mod config;
+mod error;
+mod service;
+
+pub use config::CoalescionServiceConfig;
+pub use error::Error;
+pub use service::CoalescionService;

crates/core/coalesced/src/service.rs

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+use std::{collections::{HashMap}, fmt::Debug, hash::Hash, sync::Arc, future::Future};
+
+use tokio::{sync::{watch::{channel as watch_channel, Receiver}, RwLock, Mutex}};
+
+#[cfg(feature = "cache")]
+use lru::LruCache;
+
+#[cfg(feature = "queue")]
+use indexmap::IndexMap;
+
+use crate::{CoalescionServiceConfig, Error};
+
+#[derive(Clone, Debug)]
+#[allow(clippy::type_complexity)]
+pub struct CoalescionService<Id: Hash + Eq, Value> {
+    config: Arc<CoalescionServiceConfig>,
+    watchers: Arc<RwLock<HashMap<Id, Receiver<Option<Result<Arc<Value>, Error>>>>>>,
+    #[cfg(feature = "queue")]
+    queue: Arc<RwLock<IndexMap<Id, Receiver<Option<Result<Arc<Value>, Error>>>>>>,
+    #[cfg(feature = "cache")]
+    cache: Option<Arc<Mutex<LruCache<Id, Arc<Value>>>>>,
+}
+
+impl<Id: Hash + PartialEq + Eq + Clone + Ord, Value> CoalescionService<Id, Value> {
+    pub fn new() -> Self {
+        Self::default()
+    }
+
+    pub fn from_config(config: CoalescionServiceConfig) -> Self {
+        Self {
+            config: Arc::new(config),
+            watchers: Arc::new(RwLock::new(HashMap::new())),
+            #[cfg(feature = "queue")]
+            queue: Arc::new(RwLock::new(IndexMap::new())),
+            #[cfg(feature = "cache")]
+            cache: None,
+        }
+    }
+
+    #[cfg(feature = "cache")]
+    pub fn from_cache(config: CoalescionServiceConfig, cache: LruCache<Id, Arc<Value>>) -> Self {
+        Self {
+            cache: Some(Arc::new(Mutex::new(cache))),
+            ..Self::from_config(config)
+        }
+    }
+
+    async fn wait_for(&self, mut receiver: Receiver<Option<Result<Arc<Value>, Error>>>) -> Result<Arc<Value>, Error> {
+        receiver
+            .wait_for(|v| v.is_some())
+            .await
+            .map_err(|_| Error::RecvError)
+            .and_then(|r| r.clone().unwrap())
+    }
+
+    async fn insert_and_execute<F: FnOnce() -> Fut, Fut: Future<Output = Value>>(&self, id: Id, func: F) -> Result<Arc<Value>, Error> {
+        let (send, recv) = watch_channel(None);
+
+        self.watchers.write().await.insert(id.clone(), recv);
+
+        let value = Ok(Arc::new(func().await));
+
+        send.send_modify(|opt| {
+            opt.replace(value.clone());
+        });
+
+        #[cfg(feature = "cache")]
+        if let Some(cache) = self.cache.as_ref() {
+            if let Ok(value) = &value {
+                cache.lock().await.push(id.clone(), value.clone());
+            }
+        };
+
+        self.watchers.write().await.remove(&id);
+
+        value
+    }
+
+    pub async fn execute<F: FnOnce() -> Fut, Fut: Future<Output = Value>>(&self, id: Id, func: F) -> Result<Arc<Value>, Error> {
+        #[cfg(feature = "cache")]
+        if let Some(cache) = self.cache.as_ref() {
+            if let Some(value) = cache.lock().await.get(&id) {
+                return Ok(value.clone())
+            }
+        };
+
+        let (receiver, length) = {
+            let watchers = self.watchers.read().await;
+            let length = watchers.len();
+
+            (watchers.get(&id).cloned(), length)
+        };
+
+        if let Some(receiver) = receiver {
+            self.wait_for(receiver).await
+        } else {
+            match self.config.max_concurrent {
+                Some(max_concurrent) if length >= max_concurrent => {
+                    #[cfg(feature = "queue")]
+                    if self.config.queue_requests {
+                        let (receiver, length) = {
+                            let queue = self.queue.read().await;
+
+                            (queue.get(&id).cloned(), queue.len())
+                        };
+
+                        if let Some(receiver) = receiver {
+                            return self.wait_for(receiver).await
+                        } else {
+                            if self.config.max_queue.is_some_and(|max_queue| max_queue >= length) {
+                                return Err(Error::MaxQueue)
+                            };
+
+                            let (send, recv) = watch_channel(None);
+
+                            self.queue.write().await.insert(id.clone(), recv);
+
+                            loop {
+                                let length = self.watchers.read().await.len();
+
+                                if length < max_concurrent {
+                                    let first_key = {
+                                        let queue = self.queue.read().await;
+                                        queue.first().map(|v| v.0).cloned()
+                                    };
+
+                                    if first_key == Some(id.clone()) {
+                                        self.queue.write().await.shift_remove(&id);
+
+                                        let response = self.insert_and_execute(id, func).await;
+
+                                        send.send_modify(|opt| {
+                                            opt.replace(response.clone());
+                                        });
+
+                                        return response
+                                    }
+                                }
+                            }
+                        }
+                    } else {
+                        Err(Error::MaxConcurrent)
+                    }
+
+                    #[cfg(not(feature = "queue"))]
+                    Err(Error::MaxConcurrent)
+                }
+                _ => {
+                    self.insert_and_execute(id, func).await
+                }
+            }
+        }
+    }
+
+    pub async fn current_task_count(&self) -> usize {
+        self.watchers.read().await.len()
+    }
+
+    pub async fn current_queue_len(&self) -> usize {
+        self.queue.read().await.len()
+    }
+}
+
+impl<Id: Hash + PartialEq + Eq + Clone + Ord, Value> Default for CoalescionService<Id, Value> {
+    fn default() -> Self {
+        Self::from_config(CoalescionServiceConfig::default())
+    }
+}