ei: add support for libei

src/ei.rs

@@ -0,0 +1,33 @@
+use {crate::ei::ei_object::EiVersion, std::cell::Cell};
+
+pub mod ei_acceptor;
+pub mod ei_client;
+pub mod ei_ifs;
+pub mod ei_object;
+
+#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+pub enum EiContext {
+    Sender,
+    Receiver,
+}
+
+pub struct EiInterfaceVersion {
+    pub server_max_version: EiVersion,
+    pub client_max_version: Cell<EiVersion>,
+    pub version: Cell<EiVersion>,
+}
+
+impl EiInterfaceVersion {
+    pub fn new(server_max_version: u32) -> Self {
+        Self {
+            server_max_version: EiVersion(server_max_version),
+            client_max_version: Cell::new(EiVersion(0)),
+            version: Cell::new(EiVersion(0)),
+        }
+    }
+
+    pub fn set_client_version(&self, version: EiVersion) {
+        self.client_max_version.set(version);
+        self.version.set(self.server_max_version.min(version));
+    }
+}