web3-proxy/redis-cell-client/src/lib.rs
2022-08-06 05:26:43 +00:00

121 lines
3.6 KiB
Rust

//#![warn(missing_docs)]
use bb8_redis::redis::cmd;
pub use bb8_redis::redis::RedisError;
pub use bb8_redis::{bb8, RedisConnectionManager};
use std::time::Duration;
pub type RedisClientPool = bb8::Pool<RedisConnectionManager>;
pub struct RedisCellClient {
pool: RedisClientPool,
key: String,
default_max_burst: u32,
default_count_per_period: u32,
default_period: u32,
}
impl RedisCellClient {
// todo: seems like this could be derived
// TODO: take something generic for conn
// TODO: use r2d2 for connection pooling?
pub fn new(
pool: bb8::Pool<RedisConnectionManager>,
app: &str,
key: &str,
default_max_burst: u32,
default_count_per_period: u32,
default_period: u32,
) -> Self {
let key = format!("{}:redis-cell:{}", app, key);
Self {
pool,
key,
default_max_burst,
default_count_per_period,
default_period,
}
}
#[inline]
async fn _throttle(
&self,
key: &str,
max_burst: Option<u32>,
count_per_period: Option<u32>,
period: Option<u32>,
quantity: u32,
) -> Result<(), Option<Duration>> {
let mut conn = self.pool.get().await.unwrap();
let count_per_period = count_per_period.unwrap_or(self.default_count_per_period);
if count_per_period == 0 {
return Err(None);
}
let max_burst = max_burst.unwrap_or(self.default_max_burst);
let period = period.unwrap_or(self.default_period);
/*
https://github.com/brandur/redis-cell#response
CL.THROTTLE <key> <max_burst> <count per period> <period> [<quantity>]
0. Whether the action was limited:
0 indicates the action is allowed.
1 indicates that the action was limited/blocked.
1. The total limit of the key (max_burst + 1). This is equivalent to the common X-RateLimit-Limit HTTP header.
2. The remaining limit of the key. Equivalent to X-RateLimit-Remaining.
3. The number of seconds until the user should retry, and always -1 if the action was allowed. Equivalent to Retry-After.
4. The number of seconds until the limit will reset to its maximum capacity. Equivalent to X-RateLimit-Reset.
*/
// TODO: don't unwrap. maybe return anyhow::Result<Result<(), Duration>>
// TODO: should we return more error info?
let x: Vec<isize> = cmd("CL.THROTTLE")
.arg(&(key, max_burst, count_per_period, period, quantity))
.query_async(&mut *conn)
.await
.unwrap();
assert_eq!(x.len(), 5);
// TODO: trace log the result
let retry_after = *x.get(3).unwrap();
if retry_after == -1 {
Ok(())
} else {
Err(Some(Duration::from_secs(retry_after as u64)))
}
}
#[inline]
pub async fn throttle(&self) -> Result<(), Option<Duration>> {
self._throttle(&self.key, None, None, None, 1).await
}
#[inline]
pub async fn throttle_key(
&self,
key: &str,
max_burst: Option<u32>,
count_per_period: Option<u32>,
period: Option<u32>,
) -> Result<(), Option<Duration>> {
let key = format!("{}:{}", self.key, key);
self._throttle(key.as_ref(), max_burst, count_per_period, period, 1)
.await
}
#[inline]
pub async fn throttle_quantity(&self, quantity: u32) -> Result<(), Option<Duration>> {
self._throttle(&self.key, None, None, None, quantity).await
}
}