feat(client): expose HTTP/2 current max stream count (#4026)

Propogate hyperium/h2#784 up to hyper interface

Ref #3623

Author: howardjohn

Cargo.toml

@@ -31,7 +31,7 @@ atomic-waker = { version = "1.1.2", optional = true }
 futures-channel = { version = "0.3", optional = true }
 futures-core = { version = "0.3.31", optional = true }
 futures-util = { version = "0.3", default-features = false, features = ["alloc"], optional = true }
-h2 = { version = "0.4.2", optional = true }
+h2 = { version = "0.4.6", optional = true }
 http-body-util = { version = "0.1", optional = true }
 httparse = { version = "1.9", optional = true }
 httpdate = { version = "1.0", optional = true }

src/client/conn/http2.rs

@@ -216,6 +216,26 @@ where
     pub fn is_extended_connect_protocol_enabled(&self) -> bool {
         self.inner.1.is_extended_connect_protocol_enabled()
     }
+
+    /// Returns the current maximum send stream count.
+    ///
+    /// This setting is configured in a [`SETTINGS_MAX_CONCURRENT_STREAMS` parameter][1] in a `SETTINGS` frame,
+    /// and may change throughout the connection lifetime.
+    ///
+    /// [1]: https://datatracker.ietf.org/doc/html/rfc7540#section-5.1.2
+    pub fn current_max_send_streams(&self) -> usize {
+        self.inner.1.current_max_send_streams()
+    }
+
+    /// Returns the current maximum receive stream count.
+    ///
+    /// This setting is configured in a [`SETTINGS_MAX_CONCURRENT_STREAMS` parameter][1] in a `SETTINGS` frame,
+    /// and may change throughout the connection lifetime.
+    ///
+    /// [1]: https://datatracker.ietf.org/doc/html/rfc7540#section-5.1.2
+    pub fn current_max_recv_streams(&self) -> usize {
+        self.inner.1.current_max_recv_streams()
+    }
 }
 
 impl<T, B, E> fmt::Debug for Connection<T, B, E>

src/proto/h2/client.rs

@@ -442,6 +442,12 @@ where
     pub(crate) fn is_extended_connect_protocol_enabled(&self) -> bool {
         self.h2_tx.is_extended_connect_protocol_enabled()
     }
+    pub(crate) fn current_max_send_streams(&self) -> usize {
+        self.h2_tx.current_max_send_streams()
+    }
+    pub(crate) fn current_max_recv_streams(&self) -> usize {
+        self.h2_tx.current_max_recv_streams()
+    }
 }
 
 pin_project! {