peer-selection: removed counters cached

Since `PeerSelectionCounters` are stored in a `TVar` we don't need to cache them in `PeerSelectionState`.
IntersectMBO · Apr 16, 2024 · 7d30e1a · 7d30e1a
1 parent 8e863da
commit 7d30e1a
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Showing 2 changed files with 9 additions and 17 deletions.
diff --git a/ouroboros-network/src/Ouroboros/Network/PeerSelection/Governor.hs b/ouroboros-network/src/Ouroboros/Network/PeerSelection/Governor.hs
@@ -37,7 +37,6 @@ module Ouroboros.Network.PeerSelection.Governor
   , ChurnMode (..)
   ) where
 
-import Data.Cache
 import Data.Foldable (traverse_)
 import Data.Hashable
 import Data.Void (Void)
@@ -556,23 +555,23 @@ peerSelectionGovernorLoop tracer
       now <- getMonotonicTime
       let Decision { decisionTrace, decisionJobs, decisionState } =
             timedDecision now
-          !newCounters = peerSelectionStateToCounters decisionState
 
-      atomically $ do
+      mbCounters <- atomically $ do
         -- Update counters
-        withCacheA (countersCache decisionState)
-                   newCounters
-                   (writeTVar countersVar)
+        counters <- readTVar countersVar
+        let !counters' = peerSelectionStateToCounters decisionState
+        if counters' /= counters
+          then writeTVar countersVar counters'
+            >> return (Just counters')
+          else return Nothing
 
       -- Trace counters
-      traceWithCache countersTracer
-                     (countersCache decisionState)
-                     newCounters
+      traverse_ (traceWith countersTracer) mbCounters
 
       traverse_ (traceWith tracer) decisionTrace
 
       mapM_ (JobPool.forkJob jobPool) decisionJobs
-      loop (decisionState { countersCache = Cache newCounters }) dbgUpdateAt'
+      loop decisionState dbgUpdateAt'
 
     evalGuardedDecisions :: Time
                          -> PeerSelectionState peeraddr peerconn

diff --git a/ouroboros-network/src/Ouroboros/Network/PeerSelection/Governor/Types.hs b/ouroboros-network/src/Ouroboros/Network/PeerSelection/Governor/Types.hs
@@ -50,7 +50,6 @@ module Ouroboros.Network.PeerSelection.Governor.Types
   , BootstrapPeersCriticalTimeoutError (..)
   ) where
 
-import Data.Cache (Cache (..))
 import Data.Map.Strict (Map)
 import Data.Map.Strict qualified as Map
 import Data.Maybe (fromMaybe)
@@ -441,11 +440,6 @@ data PeerSelectionState peeraddr peerconn = PeerSelectionState {
        -- | Rng for fuzzy delay
        fuzzRng                     :: !StdGen,
 
-       -- | 'PeerSelectionCounters' counters cache. Allows to only trace
-       -- values when necessary.
-       --
-       countersCache               :: !(Cache PeerSelectionCounters),
-
        -- | Current ledger state judgement
        --
        ledgerStateJudgement        :: !LedgerStateJudgement,
@@ -914,7 +908,6 @@ emptyPeerSelectionState rng =
       inProgressDemoteHot         = Set.empty,
       inProgressDemoteToCold      = Set.empty,
       fuzzRng                     = rng,
-      countersCache               = Cache emptyPeerSelectionCounters,
       ledgerStateJudgement        = TooOld,
       bootstrapPeersFlag          = DontUseBootstrapPeers,
       hasOnlyBootstrapPeers       = False,