dev (backend-rs): add basic Redis cache setter/getter

Cargo.lock

@@ -222,6 +222,7 @@ dependencies = [
  "rand",
  "redis",
  "regex",
+ "rmp-serde",
  "schemars",
  "sea-orm",
  "serde",
@@ -2012,6 +2013,28 @@ dependencies = [
  "syn 1.0.109",
 ]
 
+[[package]]
+name = "rmp"
+version = "0.8.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "228ed7c16fa39782c3b3468e974aec2795e9089153cd08ee2e9aefb3613334c4"
+dependencies = [
+ "byteorder",
+ "num-traits",
+ "paste",
+]
+
+[[package]]
+name = "rmp-serde"
+version = "1.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "938a142ab806f18b88a97b0dea523d39e0fd730a064b035726adcfc58a8a5188"
+dependencies = [
+ "byteorder",
+ "rmp",
+ "serde",
+]
+
 [[package]]
 name = "rsa"
 version = "0.9.6"

Cargo.toml

@@ -28,6 +28,7 @@ quote = "1.0.36"
 rand = "0.8.5"
 redis = "0.25.3"
 regex = "1.10.4"
+rmp-serde = "1.2.0"
 schemars = "0.8.16"
 sea-orm = "0.12.15"
 serde = "1.0.197"

packages/backend-rs/Cargo.toml

@@ -32,6 +32,7 @@ parse-display = { workspace = true }
 rand = { workspace = true }
 redis = { workspace = true }
 regex = { workspace = true }
+rmp-serde = { workspace = true }
 schemars = { workspace = true, features = ["chrono"] }
 sea-orm = { workspace = true, features = ["sqlx-postgres", "runtime-tokio-rustls"] }
 serde = { workspace = true, features = ["derive"] }

packages/backend-rs/src/misc/mod.rs

@@ -11,3 +11,4 @@ pub mod meta;
 pub mod nyaify;
 pub mod password;
 pub mod reaction;
+pub mod redis_cache;

packages/backend-rs/src/misc/redis_cache.rs

@@ -0,0 +1,84 @@
+use crate::database::{redis_conn, redis_key};
+use redis::{Commands, RedisError};
+use serde::{Deserialize, Serialize};
+
+#[derive(thiserror::Error, Debug)]
+pub enum Error {
+    #[error("Redis error: {0}")]
+    RedisError(#[from] RedisError),
+    #[error("Data serialization error: {0}")]
+    SerializeError(#[from] rmp_serde::encode::Error),
+    #[error("Data deserialization error: {0}")]
+    DeserializeError(#[from] rmp_serde::decode::Error),
+}
+
+pub fn set_cache<V: for<'a> Deserialize<'a> + Serialize>(
+    key: &str,
+    value: &V,
+    expire_seconds: u64,
+) -> Result<(), Error> {
+    redis_conn()?.set_ex(
+        redis_key(key),
+        rmp_serde::encode::to_vec(&value)?,
+        expire_seconds,
+    )?;
+    Ok(())
+}
+
+pub fn get_cache<V: for<'a> Deserialize<'a> + Serialize>(key: &str) -> Result<Option<V>, Error> {
+    let serialized_value: Option<Vec<u8>> = redis_conn()?.get(redis_key(key))?;
+    Ok(match serialized_value {
+        Some(v) => Some(rmp_serde::from_slice::<V>(v.as_ref())?),
+        None => None,
+    })
+}
+
+#[cfg(test)]
+mod unit_test {
+    use super::{get_cache, set_cache};
+    use pretty_assertions::assert_eq;
+
+    #[test]
+    fn set_get_expire() {
+        #[derive(serde::Deserialize, serde::Serialize, PartialEq, Debug)]
+        struct Data {
+            id: u32,
+            kind: String,
+        }
+
+        let key_1 = "CARGO_TEST_CACHE_KEY_1";
+        let value_1: Vec<i32> = vec![1, 2, 3, 4, 5];
+
+        let key_2 = "CARGO_TEST_CACHE_KEY_2";
+        let value_2 = "Hello fedizens".to_string();
+
+        let key_3 = "CARGO_TEST_CACHE_KEY_3";
+        let value_3 = Data {
+            id: 1000000007,
+            kind: "prime number".to_string(),
+        };
+
+        set_cache(key_1, &value_1, 1).unwrap();
+        set_cache(key_2, &value_2, 1).unwrap();
+        set_cache(key_3, &value_3, 1).unwrap();
+
+        let cached_value_1: Vec<i32> = get_cache(key_1).unwrap().unwrap();
+        let cached_value_2: String = get_cache(key_2).unwrap().unwrap();
+        let cached_value_3: Data = get_cache(key_3).unwrap().unwrap();
+
+        assert_eq!(value_1, cached_value_1);
+        assert_eq!(value_2, cached_value_2);
+        assert_eq!(value_3, cached_value_3);
+
+        // wait for the cache to expire
+        std::thread::sleep(std::time::Duration::from_millis(1100));
+
+        let expired_value_1: Option<Vec<i32>> = get_cache(key_1).unwrap();
+        let expired_value_2: Option<Vec<i32>> = get_cache(key_2).unwrap();
+        let expired_value_3: Option<Vec<i32>> = get_cache(key_3).unwrap();
+
+        assert!(expired_value_1.is_none());
+        assert!(expired_value_2.is_none());
+        assert!(expired_value_3.is_none());
+    }
+}