1 files changed, 54 insertions, 0 deletions
diff --git a/vendor/gix-sec/src/permission.rs b/vendor/gix-sec/src/permission.rs
new file mode 100644
index 000000000..5bd5f2c32
--- /dev/null
+++ b/vendor/gix-sec/src/permission.rs
@@ -0,0 +1,54 @@
+use std::fmt::{Debug, Display, Formatter};
+
+use crate::Permission;
+
+/// An error to use if an operation cannot proceed due to insufficient permissions.
+///
+/// It's up to the implementation to decide which permission is required for an operation, and which one
+/// causes errors.
+#[derive(Debug)]
+pub struct Error<R: std::fmt::Debug> {
+    /// The resource which cannot be used.
+    pub resource: R,
+}
+
+impl<R> Display for Error<R>
+where
+    R: std::fmt::Debug,
+{
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        write!(
+            f,
+            "Not allowed to handle resource {:?}: permission denied",
+            self.resource
+        )
+    }
+}
+
+impl<R> std::error::Error for Error<R> where R: std::fmt::Debug {}
+
+impl Permission {
+    /// Return true if this instance is `Permission::Allow`.
+    pub fn is_allowed(&self) -> bool {
+        matches!(self, Permission::Allow)
+    }
+    /// Check this permissions and produce a reply to indicate if the `resource` can be used and in which way.
+    ///
+    /// Only if this permission is set to `Allow` will the resource be usable.
+    pub fn check<R: std::fmt::Debug>(&self, resource: R) -> Result<Option<R>, Error<R>> {
+        match self {
+            Permission::Allow => Ok(Some(resource)),
+            Permission::Deny => Ok(None),
+            Permission::Forbid => Err(Error { resource }),
+        }
+    }
+
+    /// Like [`check()`][Self::check()], but degenerates the type to an option to make it more useful in cases where
+    /// `Forbid` shouldn't abort the entire operation.
+    pub fn check_opt<R: std::fmt::Debug>(&self, resource: R) -> Option<R> {
+        match self {
+            Permission::Allow => Some(resource),
+            Permission::Deny | Permission::Forbid => None,
+        }
+    }
+}