Move the control protocol enum to main client lib

Side benefit: forcing documentation

src/control_protocol.rs

@@ -0,0 +1,59 @@
+//! Utilities for interacting with the control protocol of the Media Driver
+use aeron_driver_sys::*;
+
+/// Construct a C-compatible enum out of a set of constants.
+/// Commonly used for types in Aeron that have fixed values via `#define`,
+/// but aren't actually enums (e.g. AERON_COMMAND_.*, AERON_ERROR_CODE_.*).
+/// Behavior is ultimately very similar to `num::FromPrimitive`.
+macro_rules! define_enum {
+    (
+        $(#[$outer:meta])*
+        $name:ident, [$(
+            $(#[$inner:meta]),*
+            $left:ident = $right:ident
+        ),+]
+    ) => {
+        #[repr(u32)]
+        #[derive(Debug, PartialEq)]
+        $(#[$outer])*
+        pub enum $name {$(
+            $(#[$inner])*
+            $left = $right,
+        )*}
+
+        impl ::std::convert::TryFrom<u32> for $name {
+            type Error = ();
+            fn try_from(val: u32) -> Result<$name, ()> {
+                match val {
+                    $(v if v == $name::$left as u32 => Ok($name::$left)),*,
+                    _ => Err(())
+                }
+            }
+        }
+    }
+}
+
+define_enum!(
+    #[doc = "Commands sent from clients to the Media Driver"]
+    ClientCommand,
+    [
+        #[doc = "Client declaring a new publication"]
+        AddPublication = AERON_COMMAND_ADD_PUBLICATION,
+        #[doc = "Client removing a publication"]
+        RemovePublication = AERON_COMMAND_REMOVE_PUBLICATION
+    ]
+);
+
+#[cfg(test)]
+mod tests {
+    use crate::control_protocol::ClientCommand;
+    use std::convert::TryInto;
+
+    #[test]
+    fn client_command_convert() {
+        assert_eq!(
+            Ok(ClientCommand::AddPublication),
+            ::aeron_driver_sys::AERON_COMMAND_ADD_PUBLICATION.try_into()
+        )
+    }
+}

src/lib.rs

@@ -2,4 +2,5 @@
 #![deny(missing_docs)]
 
 pub mod client;
+pub mod control_protocol;
 pub mod driver;