report mempool fetched and missing counts to prometheus

Author: philippem

src/new_index/mempool.rs

@@ -526,6 +526,19 @@ impl Mempool {
                 indexed_txids.len() + fetched_txs.len(),
                 new_txids.len()
             );
+
+            mempool.read().unwrap().count
+                .with_label_values(&["all_txs"])
+                .set(all_txids.len() as f64);
+
+            mempool.read().unwrap().count
+                .with_label_values(&["fetched_txs"])
+                .set((indexed_txids.len() + fetched_txs.len()) as f64);
+
+            mempool.read().unwrap().count
+                .with_label_values(&["missing_txs"])
+                .set(new_txids.len() as f64);
+
             let new_txs = daemon.gettransactions_available(&new_txids)?;
 
             // Abort if the chain tip moved while fetching transactions