keyboard: replace xkbcommon by kbvm

src/keyboard.rs

@@ -1,13 +1,22 @@
 use {
-    crate::utils::vecset::VecSet,
+    crate::utils::{oserror::OsError, vecset::VecSet},
     kbvm::Components,
     std::{
         cell::{Ref, RefCell},
         rc::Rc,
     },
-    uapi::OwnedFd,
+    thiserror::Error,
+    uapi::{c, Errno, OwnedFd},
 };
 
+#[derive(Debug, Error)]
+pub enum KeyboardError {
+    #[error("Could not create a keymap memfd")]
+    KeymapMemfd(#[source] OsError),
+    #[error("Could not copy the keymap")]
+    KeymapCopy(#[source] OsError),
+}
+
 linear_ids!(KeyboardStateIds, KeyboardStateId, u64);
 
 pub struct KeyboardState {
@@ -27,3 +36,23 @@ impl DynKeyboardState for RefCell<KeyboardState> {
         self.borrow()
     }
 }
+
+impl KeyboardState {
+    pub fn create_new_keymap_fd(&self) -> Result<Rc<OwnedFd>, KeyboardError> {
+        let fd = match uapi::memfd_create("shared-keymap", c::MFD_CLOEXEC) {
+            Ok(fd) => fd,
+            Err(e) => return Err(KeyboardError::KeymapMemfd(e.into())),
+        };
+        let target = self.map_len as c::off_t;
+        let mut pos = 0;
+        while pos < target {
+            let rem = target - pos;
+            let res = uapi::sendfile(fd.raw(), self.map.raw(), Some(&mut pos), rem as usize);
+            match res {
+                Ok(_) | Err(Errno(c::EINTR)) => {}
+                Err(e) => return Err(KeyboardError::KeymapCopy(e.into())),
+            }
+        }
+        Ok(Rc::new(fd))
+    }
+}