follow and download from ready members only

1 files changed, 20 insertions, 0 deletions

diff --git a/src/remake/mod.rs b/src/remake/mod.rs
index 2dd646b..aa1d583 100644
--- a/src/remake/mod.rs
+++ b/src/remake/mod.rs
@@ -141,10 +141,30 @@ pub(crate) struct PeerSummary {
     pub(crate) id: String,
     /// Not dormant.
     pub(crate) active: bool,
+    /// Completed the handshake and belongs to our swarm. A peer that merely sent us
+    /// something (a node of another swarm on the same network, a stranger before
+    /// admission) is not one, and nothing it advertises is followed.
+    pub(crate) member: bool,
+    /// What it last said about being ready; None before it said anything.
+    pub(crate) ready: Option<bool>,
     /// The epoch the peer last advertised.
     pub(crate) epoch: Option<Epoch>,
 }
 
+impl PeerSummary {
+    /// A peer whose epoch can be followed and downloaded from: an active member that
+    /// holds the document it advertises. A rejoining peer advertises its target epoch
+    /// with an empty document and `ready: false`.
+    pub(crate) fn serves_epoch(&self, epoch: Epoch) -> bool {
+        self.serves() && self.epoch == Some(epoch)
+    }
+
+    /// An active, ready member.
+    pub(crate) fn serves(&self) -> bool {
+        self.active && self.member && self.ready == Some(true)
+    }
+}
+
 /// Largest remake request (bytes). The proposal carries the new document to every
 /// node in one sync message, which Mycelium must deliver within its deadline, so
 /// documents near this size are already a stretch.