Add a setter for header_table_size (hyperium#638)

Signed-off-by: Sven Pfennig <s.pfennig@reply.de>

src/client.rs

@@ -1072,6 +1072,39 @@ impl Builder {
         self
     }
 
+    /// Sets the header table size.
+    ///
+    /// This setting informs the peer of the maximum size of the header compression
+    /// table used to encode header blocks, in octets. The encoder may select any value
+    /// equal to or less than the header table size specified by the sender.
+    ///
+    /// The default value is 4,096.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # use tokio::io::{AsyncRead, AsyncWrite};
+    /// # use h2::client::*;
+    /// # use bytes::Bytes;
+    /// #
+    /// # async fn doc<T: AsyncRead + AsyncWrite + Unpin>(my_io: T)
+    /// # -> Result<((SendRequest<Bytes>, Connection<T, Bytes>)), h2::Error>
+    /// # {
+    /// // `client_fut` is a future representing the completion of the HTTP/2
+    /// // handshake.
+    /// let client_fut = Builder::new()
+    ///     .header_table_size(1_000_000)
+    ///     .handshake(my_io);
+    /// # client_fut.await
+    /// # }
+    /// #
+    /// # pub fn main() {}
+    /// ```
+    pub fn header_table_size(&mut self, size: u32) -> &mut Self {
+        self.settings.set_header_table_size(Some(size));
+        self
+    }
+
     /// Sets the first stream ID to something other than 1.
     #[cfg(feature = "unstable")]
     pub fn initial_stream_id(&mut self, stream_id: u32) -> &mut Self {

src/codec/framed_read.rs

@@ -88,6 +88,12 @@ impl<T> FramedRead<T> {
     pub fn set_max_header_list_size(&mut self, val: usize) {
         self.max_header_list_size = val;
     }
+
+    /// Update the header table size setting.
+    #[inline]
+    pub fn set_header_table_size(&mut self, val: usize) {
+        self.hpack.queue_size_update(val);
+    }
 }
 
 /// Decodes a frame.

src/codec/mod.rs

@@ -95,6 +95,11 @@ impl<T, B> Codec<T, B> {
         self.framed_write().set_header_table_size(val)
     }
 
+    /// Set the decoder header table size size.
+    pub fn set_recv_header_table_size(&mut self, val: usize) {
+        self.inner.set_header_table_size(val)
+    }
+
     /// Set the max header list size that can be received.
     pub fn set_max_recv_header_list_size(&mut self, val: usize) {
         self.inner.set_max_header_list_size(val);

src/frame/settings.rs

@@ -121,11 +121,9 @@ impl Settings {
         self.header_table_size
     }
 
-    /*
     pub fn set_header_table_size(&mut self, size: Option<u32>) {
         self.header_table_size = size;
     }
-    */
 
     pub fn load(head: Head, payload: &[u8]) -> Result<Settings, Error> {
         use self::Setting::*;

src/proto/settings.rs

@@ -60,6 +60,10 @@ impl Settings {
                         codec.set_max_recv_header_list_size(max as usize);
                     }
 
+                    if let Some(val) = local.header_table_size() {
+                        codec.set_recv_header_table_size(val as usize);
+                    }
+
                     streams.apply_local_settings(local)?;
                     self.local = Local::Synced;
                     Ok(())

tests/h2-support/src/frames.rs

@@ -391,6 +391,11 @@ impl Mock<frame::Settings> {
         self.0.set_enable_connect_protocol(Some(val));
         self
     }
+
+    pub fn header_table_size(mut self, val: u32) -> Self {
+        self.0.set_header_table_size(Some(val));
+        self
+    }
 }
 
 impl From<Mock<frame::Settings>> for frame::Settings {

tests/h2-tests/tests/client_request.rs

@@ -1627,6 +1627,40 @@ async fn rogue_server_reused_headers() {
     join(srv, h2).await;
 }
 
+#[tokio::test]
+async fn client_builder_header_table_size() {
+    h2_support::trace_init!();
+    let (io, mut srv) = mock::new();
+    let mut settings = frame::Settings::default();
+
+    settings.set_header_table_size(Some(10000));
+
+    let srv = async move {
+        let recv_settings = srv.assert_client_handshake().await;
+        assert_frame_eq(recv_settings, settings);
+
+        srv.recv_frame(
+            frames::headers(1)
+                .request("GET", "https://example.com/")
+                .eos(),
+        )
+        .await;
+        srv.send_frame(frames::headers(1).response(200).eos()).await;
+    };
+
+    let mut builder = client::Builder::new();
+    builder.header_table_size(10000);
+
+    let h2 = async move {
+        let (mut client, mut h2) = builder.handshake::<_, Bytes>(io).await.unwrap();
+        let request = Request::get("https://example.com/").body(()).unwrap();
+        let (response, _) = client.send_request(request, true).unwrap();
+        h2.drive(response).await.unwrap();
+    };
+
+    join(srv, h2).await;
+}
+
 const SETTINGS: &[u8] = &[0, 0, 0, 4, 0, 0, 0, 0, 0];
 const SETTINGS_ACK: &[u8] = &[0, 0, 0, 4, 1, 0, 0, 0, 0];