feat: stabilize Config

I've been using this in projects for a couple months now, and would like to land support in Surf directly, for which this should be stabilized.

Refs: http-rs/surf#310
Refs: #86
Closes: #93

Author: Fishrock123

Diff for: Cargo.toml

@@ -21,7 +21,7 @@ rustdoc-args = ["--cfg", "feature=\"docs\""]
 
 [features]
 default = ["h1_client", "native-tls"]
-docs = ["h1_client", "curl_client", "wasm_client", "hyper_client", "unstable-config"]
+docs = ["h1_client", "curl_client", "wasm_client", "hyper_client"]
 
 h1_client = ["async-h1", "async-std", "deadpool", "futures"]
 native_client = ["curl_client", "wasm_client"]
@@ -32,7 +32,7 @@ hyper_client = ["hyper", "hyper-tls", "http-types/hyperium_http", "futures-util"
 native-tls = ["async-native-tls"]
 rustls = ["async-tls", "rustls_crate"]
 
-unstable-config = []
+unstable-config = [] # deprecated
 
 [dependencies]
 async-trait = "0.1.37"

Diff for: src/config.rs

@@ -4,7 +4,6 @@ use std::fmt::Debug;
 use std::time::Duration;
 
 /// Configuration for `HttpClient`s.
-#[cfg_attr(feature = "docs", doc(cfg(feature = "unstable-config")))]
 #[non_exhaustive]
 #[derive(Clone)]
 pub struct Config {
@@ -24,6 +23,17 @@ pub struct Config {
     ///
     /// Default: `Some(Duration::from_secs(60))`.
     pub timeout: Option<Duration>,
+    /// Maximum number of simultaneous connections that this client is allowed to keep open to individual hosts at one time.
+    ///
+    /// Default: `50`.
+    /// This number is based on a few random benchmarks and see whatever gave decent perf vs resource use in Orogene.
+    ///
+    /// Note: The behavior of this is different depending on the backend in use.
+    /// - `h1_client`: `0` is disallowed and asserts as otherwise it would cause a semaphore deadlock.
+    /// - `curl_client`: `0` allows for limitless connections per host.
+    /// - `hyper_client`: No effect. Hyper does not support such an option.
+    /// - `wasm_client`: No effect. Web browsers do not support such an option.
+    pub max_connections_per_host: usize,
     /// TLS Configuration (Rustls)
     #[cfg_attr(feature = "docs", doc(cfg(feature = "h1_client")))]
     #[cfg(all(feature = "h1_client", feature = "rustls"))]
@@ -40,7 +50,8 @@ impl Debug for Config {
         dbg_struct
             .field("http_keep_alive", &self.http_keep_alive)
             .field("tcp_no_delay", &self.tcp_no_delay)
-            .field("timeout", &self.timeout);
+            .field("timeout", &self.timeout)
+            .field("max_connections_per_host", &self.max_connections_per_host);
 
         #[cfg(all(feature = "h1_client", feature = "rustls"))]
         {
@@ -66,6 +77,7 @@ impl Config {
             http_keep_alive: true,
             tcp_no_delay: false,
             timeout: Some(Duration::from_secs(60)),
+            max_connections_per_host: 50,
             #[cfg(all(feature = "h1_client", any(feature = "rustls", feature = "native-tls")))]
             tls_config: None,
         }
@@ -97,6 +109,12 @@ impl Config {
         self
     }
 
+    /// Set the maximum number of simultaneous connections that this client is allowed to keep open to individual hosts at one time.
+    pub fn max_connections_per_host(mut self, max_connections_per_host: usize) -> Self {
+        self.max_connections_per_host = max_connections_per_host;
+        self
+    }
+
     /// Set TLS Configuration (Rustls)
     #[cfg_attr(feature = "docs", doc(cfg(feature = "h1_client")))]
     #[cfg(all(feature = "h1_client", feature = "rustls"))]

Diff for: src/h1/mod.rs

@@ -1,8 +1,6 @@
 //! http-client implementation for async-h1, with connection pooling ("Keep-Alive").
 
-#[cfg(feature = "unstable-config")]
 use std::convert::{Infallible, TryFrom};
-
 use std::fmt::Debug;
 use std::net::SocketAddr;
 use std::sync::Arc;
@@ -33,19 +31,15 @@ use tcp::{TcpConnWrapper, TcpConnection};
 #[cfg(any(feature = "native-tls", feature = "rustls"))]
 use tls::{TlsConnWrapper, TlsConnection};
 
-// This number is based on a few random benchmarks and see whatever gave decent perf vs resource use.
-const DEFAULT_MAX_CONCURRENT_CONNECTIONS: usize = 50;
-
 type HttpPool = DashMap<SocketAddr, Pool<TcpStream, std::io::Error>>;
 #[cfg(any(feature = "native-tls", feature = "rustls"))]
 type HttpsPool = DashMap<SocketAddr, Pool<TlsStream<TcpStream>, Error>>;
 
-/// Async-h1 based HTTP Client, with connecton pooling ("Keep-Alive").
+/// async-h1 based HTTP Client, with connection pooling ("Keep-Alive").
 pub struct H1Client {
     http_pools: HttpPool,
     #[cfg(any(feature = "native-tls", feature = "rustls"))]
     https_pools: HttpsPool,
-    max_concurrent_connections: usize,
     config: Arc<Config>,
 }
 
@@ -82,10 +76,6 @@ impl Debug for H1Client {
                     .collect::<Vec<String>>(),
             )
             .field("https_pools", &https_pools)
-            .field(
-                "max_concurrent_connections",
-                &self.max_concurrent_connections,
-            )
             .field("config", &self.config)
             .finish()
     }
@@ -104,19 +94,25 @@ impl H1Client {
             http_pools: DashMap::new(),
             #[cfg(any(feature = "native-tls", feature = "rustls"))]
             https_pools: DashMap::new(),
-            max_concurrent_connections: DEFAULT_MAX_CONCURRENT_CONNECTIONS,
             config: Arc::new(Config::default()),
         }
     }
 
     /// Create a new instance.
     pub fn with_max_connections(max: usize) -> Self {
+        #[cfg(features = "h1_client")]
+        assert!(max > 0, "max_connections_per_host with h1_client must be greater than zero or it will deadlock!");
+
+        let config = Config {
+            max_connections_per_host: max,
+            ..Default::default()
+        };
+
         Self {
             http_pools: DashMap::new(),
             #[cfg(any(feature = "native-tls", feature = "rustls"))]
             https_pools: DashMap::new(),
-            max_concurrent_connections: max,
-            config: Arc::new(Config::default()),
+            config: Arc::new(config),
         }
     }
 }
@@ -157,7 +153,6 @@ impl HttpClient for H1Client {
         for (idx, addr) in addrs.into_iter().enumerate() {
             let has_another_addr = idx != max_addrs_idx;
 
-            #[cfg(feature = "unstable-config")]
             if !self.config.http_keep_alive {
                 match scheme {
                     "http" => {
@@ -196,7 +191,7 @@ impl HttpClient for H1Client {
                         let manager = TcpConnection::new(addr, self.config.clone());
                         let pool = Pool::<TcpStream, std::io::Error>::new(
                             manager,
-                            self.max_concurrent_connections,
+                            self.config.max_connections_per_host,
                         );
                         self.http_pools.insert(addr, pool);
                         self.http_pools.get(&addr).unwrap()
@@ -216,14 +211,11 @@ impl HttpClient for H1Client {
                     req.set_local_addr(stream.local_addr().ok());
 
                     let tcp_conn = client::connect(TcpConnWrapper::new(stream), req);
-                    #[cfg(feature = "unstable-config")]
                     return if let Some(timeout) = self.config.timeout {
                         async_std::future::timeout(timeout, tcp_conn).await?
                     } else {
                         tcp_conn.await
                     };
-                    #[cfg(not(feature = "unstable-config"))]
-                    return tcp_conn.await;
                 }
                 #[cfg(any(feature = "native-tls", feature = "rustls"))]
                 "https" => {
@@ -233,7 +225,7 @@ impl HttpClient for H1Client {
                         let manager = TlsConnection::new(host.clone(), addr, self.config.clone());
                         let pool = Pool::<TlsStream<TcpStream>, Error>::new(
                             manager,
-                            self.max_concurrent_connections,
+                            self.config.max_connections_per_host,
                         );
                         self.https_pools.insert(addr, pool);
                         self.https_pools.get(&addr).unwrap()
@@ -253,14 +245,11 @@ impl HttpClient for H1Client {
                     req.set_local_addr(stream.get_ref().local_addr().ok());
 
                     let tls_conn = client::connect(TlsConnWrapper::new(stream), req);
-                    #[cfg(feature = "unstable-config")]
                     return if let Some(timeout) = self.config.timeout {
                         async_std::future::timeout(timeout, tls_conn).await?
                     } else {
                         tls_conn.await
                     };
-                    #[cfg(not(feature = "unstable-config"))]
-                    return tls_conn.await;
                 }
                 _ => unreachable!(),
             }
@@ -272,36 +261,35 @@ impl HttpClient for H1Client {
         ))
     }
 
-    #[cfg_attr(feature = "docs", doc(cfg(feature = "unstable-config")))]
-    #[cfg(feature = "unstable-config")]
     /// Override the existing configuration with new configuration.
     ///
     /// Config options may not impact existing connections.
     fn set_config(&mut self, config: Config) -> http_types::Result<()> {
+        #[cfg(features = "h1_client")]
+        assert!(config.max_connections_per_host > 0, "max_connections_per_host with h1_client must be greater than zero or it will deadlock!");
+
         self.config = Arc::new(config);
 
         Ok(())
     }
 
-    #[cfg_attr(feature = "docs", doc(cfg(feature = "unstable-config")))]
-    #[cfg(feature = "unstable-config")]
     /// Get the current configuration.
     fn config(&self) -> &Config {
         &*self.config
     }
 }
 
-#[cfg_attr(feature = "docs", doc(cfg(feature = "unstable-config")))]
-#[cfg(feature = "unstable-config")]
 impl TryFrom<Config> for H1Client {
     type Error = Infallible;
 
     fn try_from(config: Config) -> Result<Self, Self::Error> {
+        #[cfg(features = "h1_client")]
+        assert!(config.max_connections_per_host > 0, "max_connections_per_host with h1_client must be greater than zero or it will deadlock!");
+
         Ok(Self {
             http_pools: DashMap::new(),
             #[cfg(any(feature = "native-tls", feature = "rustls"))]
             https_pools: DashMap::new(),
-            max_concurrent_connections: DEFAULT_MAX_CONCURRENT_CONNECTIONS,
             config: Arc::new(config),
         })
     }

Diff for: src/h1/tcp.rs

@@ -65,7 +65,6 @@ impl Manager<TcpStream, std::io::Error> for TcpConnection {
     async fn create(&self) -> Result<TcpStream, std::io::Error> {
         let tcp_stream = TcpStream::connect(self.addr).await?;
 
-        #[cfg(feature = "unstable-config")]
         tcp_stream.set_nodelay(self.config.tcp_no_delay)?;
 
         Ok(tcp_stream)
@@ -75,7 +74,6 @@ impl Manager<TcpStream, std::io::Error> for TcpConnection {
         let mut buf = [0; 4];
         let mut cx = Context::from_waker(futures::task::noop_waker_ref());
 
-        #[cfg(feature = "unstable-config")]
         conn.set_nodelay(self.config.tcp_no_delay)?;
 
         match Pin::new(conn).poll_read(&mut cx, &mut buf) {

Diff for: src/h1/tls.rs

@@ -74,7 +74,6 @@ impl Manager<TlsStream<TcpStream>, Error> for TlsConnection {
     async fn create(&self) -> Result<TlsStream<TcpStream>, Error> {
         let raw_stream = async_std::net::TcpStream::connect(self.addr).await?;
 
-        #[cfg(feature = "unstable-config")]
         raw_stream.set_nodelay(self.config.tcp_no_delay)?;
 
         let tls_stream = add_tls(&self.host, raw_stream, &self.config).await?;
@@ -85,7 +84,6 @@ impl Manager<TlsStream<TcpStream>, Error> for TlsConnection {
         let mut buf = [0; 4];
         let mut cx = Context::from_waker(futures::task::noop_waker_ref());
 
-        #[cfg(feature = "unstable-config")]
         conn.get_ref()
             .set_nodelay(self.config.tcp_no_delay)
             .map_err(Error::from)?;
@@ -108,14 +106,11 @@ cfg_if::cfg_if! {
     if #[cfg(feature = "rustls")] {
         #[allow(unused_variables)]
         pub(crate) async fn add_tls(host: &str, stream: TcpStream, config: &Config) -> Result<TlsStream<TcpStream>, std::io::Error> {
-            #[cfg(all(feature = "h1_client", feature = "unstable-config"))]
             let connector = if let Some(tls_config) = config.tls_config.as_ref().cloned() {
                 tls_config.into()
             } else {
                 async_tls::TlsConnector::default()
             };
-            #[cfg(not(feature = "unstable-config"))]
-            let connector = async_tls::TlsConnector::default();
 
             connector.connect(host, stream).await
         }
@@ -126,10 +121,7 @@ cfg_if::cfg_if! {
             stream: TcpStream,
             config: &Config,
         ) -> Result<TlsStream<TcpStream>, async_native_tls::Error> {
-            #[cfg(feature = "unstable-config")]
             let connector = config.tls_config.as_ref().cloned().unwrap_or_default();
-            #[cfg(not(feature = "unstable-config"))]
-            let connector = async_native_tls::TlsConnector::new();
 
             connector.connect(host, stream).await
         }

Diff for: src/hyper.rs

@@ -1,8 +1,6 @@
 //! http-client implementation for reqwest
 
-#[cfg(feature = "unstable-config")]
-use std::convert::Infallible;
-use std::convert::TryFrom;
+use std::convert::{Infallible, TryFrom};
 use std::fmt::Debug;
 use std::io;
 use std::str::FromStr;
@@ -74,7 +72,6 @@ impl HttpClient for HyperClient {
         let req = HyperHttpRequest::try_from(req).await?.into_inner();
 
         let conn_fut = self.client.dyn_request(req);
-        #[cfg(feature = "unstable-config")]
         let response = if let Some(timeout) = self.config.timeout {
             match tokio::time::timeout(timeout, conn_fut).await {
                 Err(_elapsed) => Err(Error::from_str(400, "Client timed out")),
@@ -85,15 +82,10 @@ impl HttpClient for HyperClient {
             conn_fut.await?
         };
 
-        #[cfg(not(feature = "unstable-config"))]
-        let response = conn_fut.await?;
-
         let res = HttpTypesResponse::try_from(response).await?.into_inner();
         Ok(res)
     }
 
-    #[cfg_attr(feature = "docs", doc(cfg(feature = "unstable-config")))]
-    #[cfg(feature = "unstable-config")]
     /// Override the existing configuration with new configuration.
     ///
     /// Config options may not impact existing connections.
@@ -111,16 +103,12 @@ impl HttpClient for HyperClient {
         Ok(())
     }
 
-    #[cfg_attr(feature = "docs", doc(cfg(feature = "unstable-config")))]
-    #[cfg(feature = "unstable-config")]
     /// Get the current configuration.
     fn config(&self) -> &Config {
         &self.config
     }
 }
 
-#[cfg_attr(feature = "docs", doc(cfg(feature = "unstable-config")))]
-#[cfg(feature = "unstable-config")]
 impl TryFrom<Config> for HyperClient {
     type Error = Infallible;
 

Diff for: src/isahc.rs

@@ -1,10 +1,8 @@
 //! http-client implementation for isahc
 
-#[cfg(feature = "unstable-config")]
 use std::convert::TryFrom;
 
 use async_std::io::BufReader;
-#[cfg(feature = "unstable-config")]
 use isahc::config::Configurable;
 use isahc::{http, ResponseExt};
 
@@ -75,13 +73,12 @@ impl HttpClient for IsahcClient {
         Ok(response)
     }
 
-    #[cfg_attr(feature = "docs", doc(cfg(feature = "unstable-config")))]
-    #[cfg(feature = "unstable-config")]
     /// Override the existing configuration with new configuration.
     ///
     /// Config options may not impact existing connections.
     fn set_config(&mut self, config: Config) -> http_types::Result<()> {
-        let mut builder = isahc::HttpClient::builder();
+        let mut builder =
+            isahc::HttpClient::builder().max_connections_per_host(config.max_connections_per_host);
 
         if !config.http_keep_alive {
             builder = builder.connection_cache_size(0);
@@ -99,16 +96,12 @@ impl HttpClient for IsahcClient {
         Ok(())
     }
 
-    #[cfg_attr(feature = "docs", doc(cfg(feature = "unstable-config")))]
-    #[cfg(feature = "unstable-config")]
     /// Get the current configuration.
     fn config(&self) -> &Config {
         &self.config
     }
 }
 
-#[cfg_attr(feature = "docs", doc(cfg(feature = "unstable-config")))]
-#[cfg(feature = "unstable-config")]
 impl TryFrom<Config> for IsahcClient {
     type Error = isahc::Error;