1 files changed, 77 insertions, 0 deletions
diff --git a/third_party/rust/dbus/src/matchrule.rs b/third_party/rust/dbus/src/matchrule.rs
new file mode 100644
index 0000000000..fb42abe51b
--- /dev/null
+++ b/third_party/rust/dbus/src/matchrule.rs
@@ -0,0 +1,77 @@
+use crate::{Message, MessageType, BusName, Path, Interface, Member};
+
+
+#[derive(Clone, Debug, Default)]
+/// A "match rule", that can match Messages on its headers.
+///
+/// A field set to "None" means no filter for that header, 
+/// a field set to "Some(_)" must match exactly.
+pub struct MatchRule<'a> {
+    /// Match on message type (you typically want to do this)
+    pub msg_type: Option<MessageType>,
+    /// Match on message sender
+    pub sender: Option<BusName<'a>>,
+    /// Match on message object path
+    pub path: Option<Path<'a>>,
+    /// Match on message interface
+    pub interface: Option<Interface<'a>>,
+    /// Match on message member (signal or method name)
+    pub member: Option<Member<'a>>,
+    _more_fields_may_come: (),
+}
+
+fn msg_type_str(m: MessageType) -> &'static str {
+    use MessageType::*;
+    match m {
+        Signal => "signal",
+        MethodCall => "method_call",
+        MethodReturn => "method_return",
+        Error => "error",
+        Invalid => unreachable!(),
+    }
+}
+
+
+impl<'a> MatchRule<'a> {
+    /// Make a string which you can use in the call to "add_match".
+    ///
+    /// Panics: if msg_type is set to Some(MessageType::Invalid)
+    pub fn match_str(&self) -> String {
+        let mut v = vec!();
+        if let Some(x) = self.msg_type { v.push(("type", msg_type_str(x))) };
+        if let Some(ref x) = self.sender { v.push(("sender", &x)) };
+        if let Some(ref x) = self.path { v.push(("path", &x)) };
+        if let Some(ref x) = self.interface { v.push(("interface", &x)) };
+        if let Some(ref x) = self.member { v.push(("member", &x)) };
+
+        // For now we don't need to worry about internal quotes in strings as those are not valid names. 
+        // If we start matching against arguments, we need to worry.
+        let v: Vec<_> = v.into_iter().map(|(k, v)| format!("{}='{}'", k, v)).collect();
+        v.join(",")
+    }
+
+    /// Returns whether or not the message matches the rule.
+    pub fn matches(&self, msg: &Message) -> bool {
+        if let Some(x) = self.msg_type { if x != msg.msg_type() { return false; }};
+        if self.sender.is_some() && msg.sender() != self.sender { return false };
+        if self.path.is_some() && msg.path() != self.path { return false };
+        if self.interface.is_some() && msg.interface() != self.interface { return false };
+        if self.member.is_some() && msg.member() != self.member { return false };
+        true
+    }
+
+    /// Create a new struct which matches every message.
+    pub fn new() -> Self { Default::default() }
+
+    /// Returns a clone with no static references
+    pub fn into_static(&self) -> MatchRule<'static> {
+        MatchRule {
+            msg_type: self.msg_type,
+            sender: self.sender.as_ref().map(|x| x.clone().into_static()),
+            path: self.path.as_ref().map(|x| x.clone().into_static()),
+            interface: self.interface.as_ref().map(|x| x.clone().into_static()),
+            member: self.member.as_ref().map(|x| x.clone().into_static()),
+            _more_fields_may_come: (),
+        }
+    }
+}