More comments about watchNodeTip in byron and jormungandr

cardano-foundation · Jun 29, 2020 · 7532fab · 7532fab
1 parent baaf5d5
commit 7532fab
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Showing 2 changed files with 5 additions and 3 deletions.
diff --git a/lib/byron/src/Cardano/Wallet/Byron/Network.hs b/lib/byron/src/Cardano/Wallet/Byron/Network.hs
@@ -300,10 +300,8 @@ withNetworkLayer tr np addrInfo versionData action = do
     _stakeDistribution =
         notImplemented "stakeDistribution"
 
-    -- At the moment it's not necessasy to implement this method unless
-    -- monitoring a reward account.
     _watchNodeTip =
-        notImplemented "stakeDistribution"
+        notImplemented "watchNodeTip"
 
 -- | Type representing a network client running two mini-protocols to sync
 -- from the chain and, submit transactions.

diff --git a/lib/jormungandr/src/Cardano/Wallet/Jormungandr/Network.hs b/lib/jormungandr/src/Cardano/Wallet/Jormungandr/Network.hs
@@ -473,6 +473,10 @@ mkRawNetworkLayer np batchSize st tipNotify j = NetworkLayer
             _ ->
                 RollBackward $ Cursor emptyBlockHeaders
 
+    -- NOTE: Because the jormungandr REST API is a polling API, this relies on
+    -- another thread (e.g. the chain 'follow' operation) to be periodically
+    -- calling 'getNodeTip' to drive updates. This only works because the sole
+    -- user of 'watchNodeTip' is 'manageRewardBalance'.
     _watchNodeTip cb = do
         watcher <- liftIO . atomically $ dupTChan tipNotify
         prevVar <- liftIO $ newIORef Nothing