Implement basic networking code

Cargo.lock

@@ -32,6 +32,27 @@ dependencies = [
  "rustc-demangle",
 ]
 
+[[package]]
+name = "base64"
+version = "0.21.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9d297deb1925b89f2ccc13d7635fa0714f12c87adce1c75356b39ca9b7178567"
+
+[[package]]
+name = "bitflags"
+version = "2.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cf4b9d6a944f767f8e5e0db018570623c85f3d925ac718db4e06d0187adb21c1"
+dependencies = [
+ "serde",
+]
+
+[[package]]
+name = "bytes"
+version = "1.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "514de17de45fdb8dc022b1a7975556c53c86f9f0aa5f534b98977b171857c2c9"
+
 [[package]]
 name = "cc"
 version = "1.0.99"
@@ -51,6 +72,7 @@ dependencies = [
  "proc-macro2",
  "quote",
  "rand",
+ "ron",
  "serde",
  "syn",
  "tokio",
@@ -100,6 +122,17 @@ dependencies = [
  "adler",
 ]
 
+[[package]]
+name = "mio"
+version = "0.8.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a4a650543ca06a924e8b371db273b2756685faae30f8487da1b56505a8f78b0c"
+dependencies = [
+ "libc",
+ "wasi",
+ "windows-sys 0.48.0",
+]
+
 [[package]]
 name = "num_cpus"
 version = "1.16.0"
@@ -179,6 +212,18 @@ dependencies = [
  "getrandom",
 ]
 
+[[package]]
+name = "ron"
+version = "0.8.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b91f7eff05f748767f183df4320a63d6936e9c6107d97c9e6bdd9784f4289c94"
+dependencies = [
+ "base64",
+ "bitflags",
+ "serde",
+ "serde_derive",
+]
+
 [[package]]
 name = "rustc-demangle"
 version = "0.1.24"
@@ -205,6 +250,16 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "socket2"
+version = "0.5.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ce305eb0b4296696835b71df73eb912e0f1ffd2556a501fcede6e0c50349191c"
+dependencies = [
+ "libc",
+ "windows-sys 0.52.0",
+]
+
 [[package]]
 name = "syn"
 version = "2.0.66"
@@ -223,9 +278,14 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ba4f4a02a7a80d6f274636f0aa95c7e383b912d41fe721a31f29e29698585a4a"
 dependencies = [
  "backtrace",
+ "bytes",
+ "libc",
+ "mio",
  "num_cpus",
  "pin-project-lite",
+ "socket2",
  "tokio-macros",
+ "windows-sys 0.48.0",
 ]
 
 [[package]]
@@ -250,3 +310,142 @@ name = "wasi"
 version = "0.11.0+wasi-snapshot-preview1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9c8d87e72b64a3b4db28d11ce29237c246188f4f51057d65a7eab63b7987e423"
+
+[[package]]
+name = "windows-sys"
+version = "0.48.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "677d2418bec65e3338edb076e806bc1ec15693c5d0104683f2efe857f61056a9"
+dependencies = [
+ "windows-targets 0.48.5",
+]
+
+[[package]]
+name = "windows-sys"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "282be5f36a8ce781fad8c8ae18fa3f9beff57ec1b52cb3de0789201425d9a33d"
+dependencies = [
+ "windows-targets 0.52.5",
+]
+
+[[package]]
+name = "windows-targets"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9a2fa6e2155d7247be68c096456083145c183cbbbc2764150dda45a87197940c"
+dependencies = [
+ "windows_aarch64_gnullvm 0.48.5",
+ "windows_aarch64_msvc 0.48.5",
+ "windows_i686_gnu 0.48.5",
+ "windows_i686_msvc 0.48.5",
+ "windows_x86_64_gnu 0.48.5",
+ "windows_x86_64_gnullvm 0.48.5",
+ "windows_x86_64_msvc 0.48.5",
+]
+
+[[package]]
+name = "windows-targets"
+version = "0.52.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6f0713a46559409d202e70e28227288446bf7841d3211583a4b53e3f6d96e7eb"
+dependencies = [
+ "windows_aarch64_gnullvm 0.52.5",
+ "windows_aarch64_msvc 0.52.5",
+ "windows_i686_gnu 0.52.5",
+ "windows_i686_gnullvm",
+ "windows_i686_msvc 0.52.5",
+ "windows_x86_64_gnu 0.52.5",
+ "windows_x86_64_gnullvm 0.52.5",
+ "windows_x86_64_msvc 0.52.5",
+]
+
+[[package]]
+name = "windows_aarch64_gnullvm"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2b38e32f0abccf9987a4e3079dfb67dcd799fb61361e53e2882c3cbaf0d905d8"
+
+[[package]]
+name = "windows_aarch64_gnullvm"
+version = "0.52.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7088eed71e8b8dda258ecc8bac5fb1153c5cffaf2578fc8ff5d61e23578d3263"
+
+[[package]]
+name = "windows_aarch64_msvc"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dc35310971f3b2dbbf3f0690a219f40e2d9afcf64f9ab7cc1be722937c26b4bc"
+
+[[package]]
+name = "windows_aarch64_msvc"
+version = "0.52.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9985fd1504e250c615ca5f281c3f7a6da76213ebd5ccc9561496568a2752afb6"
+
+[[package]]
+name = "windows_i686_gnu"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a75915e7def60c94dcef72200b9a8e58e5091744960da64ec734a6c6e9b3743e"
+
+[[package]]
+name = "windows_i686_gnu"
+version = "0.52.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "88ba073cf16d5372720ec942a8ccbf61626074c6d4dd2e745299726ce8b89670"
+
+[[package]]
+name = "windows_i686_gnullvm"
+version = "0.52.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "87f4261229030a858f36b459e748ae97545d6f1ec60e5e0d6a3d32e0dc232ee9"
+
+[[package]]
+name = "windows_i686_msvc"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8f55c233f70c4b27f66c523580f78f1004e8b5a8b659e05a4eb49d4166cca406"
+
+[[package]]
+name = "windows_i686_msvc"
+version = "0.52.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "db3c2bf3d13d5b658be73463284eaf12830ac9a26a90c717b7f771dfe97487bf"
+
+[[package]]
+name = "windows_x86_64_gnu"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "53d40abd2583d23e4718fddf1ebec84dbff8381c07cae67ff7768bbf19c6718e"
+
+[[package]]
+name = "windows_x86_64_gnu"
+version = "0.52.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4e4246f76bdeff09eb48875a0fd3e2af6aada79d409d33011886d3e1581517d9"
+
+[[package]]
+name = "windows_x86_64_gnullvm"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b7b52767868a23d5bab768e390dc5f5c55825b6d30b86c844ff2dc7414044cc"
+
+[[package]]
+name = "windows_x86_64_gnullvm"
+version = "0.52.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "852298e482cd67c356ddd9570386e2862b5673c85bd5f88df9ab6802b334c596"
+
+[[package]]
+name = "windows_x86_64_msvc"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ed94fce61571a4006852b7389a063ab983c02eb1bb37b47f8272ce92d06d9538"
+
+[[package]]
+name = "windows_x86_64_msvc"
+version = "0.52.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bec47e5bfd1bff0eeaf6d8b485cc1074891a197ab4225d504cb7a1ab88b02bf0"

Cargo.toml

@@ -9,10 +9,11 @@ publish = ["gitea"]
 proc-macro2 = "1.0.85"
 quote = "1.0.36"
 rand = "0.8.5"
+ron = "0.8.1"
 serde = { version = "1.0.203", features = ["serde_derive"] }
 syn = "2.0.66"
 # TODO: rt and macros should be removed unless we do tests
-tokio = { version = "1.38.0", features = ["sync", "rt-multi-thread", "macros", "time"] }
+tokio = { version = "1.38.0", features = ["sync", "rt-multi-thread", "macros", "time", "io-util", "net"] }
 
 [lib]
 proc-macro = true

flake.nix

@@ -19,7 +19,7 @@
           doCheck = true;
         };
         devShell = with pkgs; mkShell {
-          nativeBuildInputs = with pkgs; [rustc cargo rustfmt pre-commit clippy];
+          nativeBuildInputs = with pkgs; [rustc cargo rustfmt pre-commit clippy cargo-expand];
         };
       });
 }

src/lib.rs

@@ -42,7 +42,8 @@ fn derive_protocol(input: proc_macro2::TokenStream) -> proc_macro2::TokenStream
     let question_enum_name = format_ident!("__{}Question", name);
     let query_enum_name = format_ident!("__{}Query", name);
     let queries_struct_name = format_ident!("__{}Queries", name);
-    let server_trait_name = format_ident!("{}Server", name);
+    let client_connection_struct_name = format_ident!("__{}Connection", name);
+    let server_trait_name = format_ident!("{}ServerTrait", name);
     let client_struct_name = format_ident!("{}Client", name);
 
     let vis = &input.vis;
@@ -210,6 +211,59 @@ fn derive_protocol(input: proc_macro2::TokenStream) -> proc_macro2::TokenStream
             }
         }
     };
+    // Create a struct to handle the connection from the client to the server
+    let stream_type = quote! { tokio::net::TcpStream }; // TODO: In the future we could support other stream types
+    let cc_struct = quote! {
+        struct #client_connection_struct_name {
+            to_send: tokio::sync::mpsc::Receiver<(u64, #question_enum_name)>,
+            received: tokio::sync::mpsc::Sender<(u64, #answer_enum_name)>,
+            stream: #stream_type,
+        }
+        impl #client_connection_struct_name {
+            pub fn new(
+                to_send: tokio::sync::mpsc::Receiver<(u64, #question_enum_name)>,
+                received: tokio::sync::mpsc::Sender<(u64, #answer_enum_name)>,
+                stream: #stream_type,
+            ) -> Self {
+                Self {
+                    to_send,
+                    received,
+                    stream,
+                }
+            }
+
+            pub async fn run(mut self) {
+                use tokio::io::AsyncWriteExt;
+                use tokio::io::AsyncReadExt;
+                let mut buf = Vec::with_capacity(1024);
+                loop {
+                    tokio::select! {
+                        Some((nonce, query)) = self.to_send.recv() => {
+                            let serialized = ron::ser::to_string(&query).expect("Failed to serialize query!");
+                            let len = serialized.len() as u32;
+                            self.stream.write_all(&len.to_le_bytes()).await.expect("Failed to write length!");
+                            self.stream.write_all(serialized.as_bytes()).await.expect("Failed to write query!");
+                        },
+                        Ok(_) = self.stream.readable() => {
+                            match self.stream.try_read(&mut buf) {
+                                Ok(0) => break, // Stream closed
+                                Ok(n) => {
+                                    // TODO: This doesn't cope with partial reads, we will handle that later
+                                    let len = u32::from_le_bytes(buf[..4].try_into().expect("Failed to convert bytes to u32"));
+                                    let serialized = std::str::from_utf8(&buf[4..(4 + len as usize)]).expect("Failed to convert bytes to string");
+                                    let query: #answer_enum_name = ron::de::from_str(serialized).expect("Failed to deserialize query!");
+                                    self.received.send((0, query)).await.expect("Failed to send query!");
+                                    buf.clear();
+                                },
+                                Err(ref e) if e.kind() == ::std::io::ErrorKind::WouldBlock => { continue; },
+                                Err(e) => eprintln!("Error reading from stream: {:?}", e),
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    };
     // Create a struct which the client will use to communicate
     let client_recv_queue_wrapper = format_ident!("__{}RecvQueueWrapper", name);
     let client_struct = quote! {
@@ -232,7 +286,7 @@ fn derive_protocol(input: proc_macro2::TokenStream) -> proc_macro2::TokenStream
             queries: #queries_struct_name,
             send_queue: tokio::sync::mpsc::Sender<(u64, #question_enum_name)>,
             recv_queue: #client_recv_queue_wrapper,
-        } // TODO: This struct will have some fields to handle the actual connection
+        }
         impl #client_struct_name {
             pub fn new(send_queue: tokio::sync::mpsc::Sender<(u64, #question_enum_name)>, recv_queue: tokio::sync::mpsc::Receiver<(u64, #answer_enum_name)>) -> Self {
                 Self {
@@ -279,6 +333,7 @@ fn derive_protocol(input: proc_macro2::TokenStream) -> proc_macro2::TokenStream
         #query_enum
         #queries_struct
         #server_trait
+        #cc_struct
         #client_struct
     };
     expanded