add UnitHandle, so a unit still can be passed around even though unloaded

sysf/src/unit.rs

@@ -1,11 +1,39 @@
 use crate::unit::JobMode::Replace;
 use crate::time::{TimeSpan, FiniteTimeSpan};
 use crate::time::TimeSpan::Infinite;
-use crate::unit::UnitState::Stopped;
+use crate::unit::UnitState::{Stopped, Unloaded};
 use crate::config::Config;
 use crate::unit::JobMode::{Fail, ReplaceIrreversibly, Isolate, Flush, IgnoreDependencies, IgnoreRequirements};
 use crate::unit::CollectMode::{Inactive, InactiveOrFailed};
 
+#[derive(Ord, PartialOrd, Eq, PartialEq, Debug, Clone)]
+pub struct UnitHandle {
+    name: String,
+    config: Option<Unit>,
+}
+
+impl UnitHandle {
+    pub fn is_loaded(&self) -> bool {
+        self.config.is_some()
+    }
+
+    pub fn get_state(&self) -> UnitState {
+        if let Some(unit) = &self.config {
+            unit.state
+        } else {
+            Unloaded
+        }
+    }
+
+    pub fn get_config(&self) -> Option<&Unit> {
+        if let Some(ref unit) = self.config {
+            Some(unit)
+        } else {
+            None
+        }
+    }
+}
+
 #[derive(Ord, PartialOrd, Eq, PartialEq, Debug, Clone)]
 pub struct Unit {
     name: String,
@@ -290,6 +318,7 @@ pub enum UnitState {
     Stopped,
     Failed,
     Running,
+    Unloaded,
 }
 
 #[derive(Ord, PartialOrd, Eq, PartialEq, Debug, Copy, Clone)]
@@ -366,6 +395,19 @@ pub enum UnitActionSeverity {
     Immediate,
 }
 
+pub enum UnitType {
+    Service,
+    Socket,
+    Device,
+    Mount,
+    AutoMount,
+    Swap,
+    Target,
+    Path,
+    Slice,
+    Scope,
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;