collection_ref: add accessors for collection_id and ref_name

rust-bindings/rust/src/collection_ref.rs

@@ -0,0 +1,80 @@
+use glib::translate::ToGlibPtr;
+use std::ffi::CStr;
+use CollectionRef;
+
+trait AsNonnullPtr
+where
+    Self: Sized,
+{
+    fn as_nonnull_ptr(&self) -> Option<Self>;
+}
+
+impl<T> AsNonnullPtr for *mut T {
+    fn as_nonnull_ptr(&self) -> Option<Self> {
+        if self.is_null() {
+            None
+        } else {
+            Some(*self)
+        }
+    }
+}
+
+// TODO: these methods are unsound if you change the underlying OstreeCollectionRef from C. Is that
+//  a problem?
+impl CollectionRef {
+    /// Get the collection ID from this `CollectionRef`.
+    ///
+    /// # Returns
+    /// Since the value may not be valid UTF-8, `&CStr` is returned. You can safely turn it into a
+    /// `&str` using the `as_str` method.
+    ///
+    /// If no collection ID was set in the `CollectionRef`, `None` is returned.
+    pub fn collection_id(&self) -> Option<&CStr> {
+        let inner = self.to_glib_none();
+        unsafe {
+            (*inner.0)
+                .collection_id
+                .as_nonnull_ptr()
+                .map(|ptr| CStr::from_ptr(ptr))
+        }
+    }
+
+    /// Get the ref name from this `CollectionRef`.
+    ///
+    /// # Returns
+    /// Since the value may not be valid UTF-8, `&CStr` is returned. You can safely turn it into a
+    /// `&str` using the `as_str` method.
+    pub fn ref_name(&self) -> &CStr {
+        let inner = self.to_glib_none();
+        unsafe { CStr::from_ptr((*inner.0).ref_name) }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn should_get_collection_id() {
+        let collection_ref = CollectionRef::new(Some("collection.id"), "ref").unwrap();
+        let id = collection_ref.collection_id().unwrap().to_str().unwrap();
+
+        assert_eq!(id, "collection.id");
+    }
+
+    #[test]
+    fn should_get_none_collection_id() {
+        let collection_ref = CollectionRef::new(None, "ref").unwrap();
+        let id = collection_ref.collection_id();
+
+        assert_eq!(id, None);
+    }
+
+    #[test]
+    fn should_get_ref_name() {
+        let collection_ref = CollectionRef::new(Some("collection.id"), "ref-name").unwrap();
+        let ref_name = collection_ref.ref_name().to_str().unwrap();
+
+        assert_eq!(ref_name, "ref-name");
+    }
+}

rust-bindings/rust/src/lib.rs

@@ -29,8 +29,12 @@ pub use crate::auto::functions::*;
 pub use crate::auto::*;
 
 // handwritten code
+#[cfg(any(feature = "v2018_6", feature = "dox"))]
+mod collection_ref;
 mod object_name;
 mod repo;
+#[cfg(any(feature = "v2018_6", feature = "dox"))]
+pub use crate::collection_ref::*;
 pub use crate::object_name::*;
 pub use crate::repo::*;