support avoiding snapshots

taskchampion/src/replica.rs

@@ -126,8 +126,21 @@ impl Replica {
     /// Synchronize this replica against the given server.  The working set is rebuilt after
     /// this occurs, but without renumbering, so any newly-pending tasks should appear in
     /// the working set.
-    pub fn sync(&mut self, server: &mut Box<dyn Server>) -> anyhow::Result<()> {
-        self.taskdb.sync(server).context("Failed to synchronize")?;
+    ///
+    /// If `avoid_snapshots` is true, the sync operations produces a snapshot only when the server
+    /// indicate it is urgent (snapshot urgency "high").  This allows time for other replicas to
+    /// create a snapshot before this one does.
+    ///
+    /// Set this to true on systems more constrained in CPU, memory, or bandwidth than a typical desktop
+    /// system
+    pub fn sync(
+        &mut self,
+        server: &mut Box<dyn Server>,
+        avoid_snapshots: bool,
+    ) -> anyhow::Result<()> {
+        self.taskdb
+            .sync(server, avoid_snapshots)
+            .context("Failed to synchronize")?;
         self.rebuild_working_set(false)
             .context("Failed to rebuild working set after sync")?;
         Ok(())