From e2ca7d3a2f2840e69eafef6ebecfc420ba2d745e Mon Sep 17 00:00:00 2001
From: Dmitry Zuikov <dzuikov@gmail.com>
Date: Sat, 25 Feb 2023 13:17:51 +0300
Subject: [PATCH] fixed (?) fetch speed degradation

---
 hbs2-core/lib/HBS2/Defaults.hs |  3 ++
 hbs2-peer/app/BlockDownload.hs | 52 +++++++++++++++++++++++-----------
 2 files changed, 38 insertions(+), 17 deletions(-)

diff --git a/hbs2-core/lib/HBS2/Defaults.hs b/hbs2-core/lib/HBS2/Defaults.hs
index 5f8e1fa3..bb9cbbea 100644
--- a/hbs2-core/lib/HBS2/Defaults.hs
+++ b/hbs2-core/lib/HBS2/Defaults.hs
@@ -50,6 +50,9 @@ defCookieTimeout = toTimeSpec defCookieTimeoutSec
 defRequestLimit :: TimeSpec
 defRequestLimit = toTimeSpec defRequestLimitSec
 
+defBlockSizeCacheTime :: TimeSpec
+defBlockSizeCacheTime = toTimeSpec ( 20 :: Timeout 'Seconds )
+
 defRequestLimitSec :: Timeout 'Seconds
 defRequestLimitSec = 60
 
diff --git a/hbs2-peer/app/BlockDownload.hs b/hbs2-peer/app/BlockDownload.hs
index c0330850..7ec7062b 100644
--- a/hbs2-peer/app/BlockDownload.hs
+++ b/hbs2-peer/app/BlockDownload.hs
@@ -312,7 +312,7 @@ updatePeerInfo onError pinfo = do
 
           let eps = floor (dE / dT)
 
-          let win =  min 10 $ defBurstMax - defBurst - 2
+          let win =  min 10 $ 4 * (defBurstMax - defBurst)
 
           when (down - downLast > 0 || onError) do
 
@@ -323,7 +323,7 @@ updatePeerInfo onError pinfo = do
                           else do
                             let buM = headMay $ drop 2 $ IntSet.toDescList buSet
                             writeTVar (view peerBurstMax pinfo) buM
-                            let buN = headDef defBurst $ drop 8 $ IntSet.toDescList buSet
+                            let buN = headDef defBurst $ drop 4 $ IntSet.toDescList buSet
                             pure (buN, trimDown win $ IntSet.insert buN buSet)
 
 
@@ -441,7 +441,7 @@ blockDownloadLoop env0 = do
 
 
   void $ liftIO $ async $ forever $ withPeerM e do
-    pause @'Seconds 2
+    pause @'Seconds 1.5
 
     pee <- knownPeers @e pl
     npi <- newPeerInfo
@@ -511,11 +511,13 @@ peerDownloadLoop :: forall e m . ( MyPeer e
                                  , Request e (BlockInfo e) m
                                  , EventListener e (BlockInfo e) m
                                  , DownloadFromPeerStuff e m
+                                 , HasPeerLocator e m
                                  , m ~ PeerM e IO
                                  ) => Peer e -> BlockDownloadM e m ()
 peerDownloadLoop peer = do
 
   bannedBlocks <- liftIO $ Cache.newCache (Just defBlockBanTime)
+  sizeCache <- liftIO $ Cache.newCache (Just defBlockSizeCacheTime)
   seenBlocks   <- liftIO $ newTVarIO mempty
 
   pe <- lift ask
@@ -555,21 +557,27 @@ peerDownloadLoop peer = do
                 Just x  -> Just (succ x)
                 Nothing -> Just 1
 
-
           banned <- liftIO $ Cache.lookup bannedBlocks h <&> isJust
 
           if banned then do
+              pl <- getPeerLocator @e
+              ps <- knownPeers @e pl <&> length
               let seenTotal = view bsTimes st
-              let wa = min defBlockBanTimeSec (realToFrac (ceiling $ Prelude.logBase 10 (realToFrac (50 * seenTotal))))
-              void $ liftIO $ async $ withAllStuff (pause wa >> addDownload h)
-              trace $ "block" <+> pretty h <+> "seen" <+> pretty seenTotal <+> "times" <+> parens (pretty wa)
+
+              if seenTotal < ps*100 then do
+                addDownload h
+              else do
+                let wa = min defBlockBanTimeSec (realToFrac (ceiling $ Prelude.logBase 10 (realToFrac (2 * seenTotal))))
+                void $ liftIO $ async $ withAllStuff (pause wa >> addDownload h)
+                -- trace $ "block" <+> pretty h <+> "seen" <+> pretty seenTotal <+> "times" <+> parens (pretty wa)
+
           else do
 
             liftIO $ atomically $ modifyTVar seenBlocks (HashMap.alter alterSeen h)
 
             seenTimes <- liftIO $ readTVarIO seenBlocks <&> fromMaybe 0 . HashMap.lookup h
 
-            when ( seenTimes > 1 ) do
+            when ( seenTimes > 5 ) do
               trace $ "ban block" <+> pretty h <+> "for a while" <+> parens (pretty seenTimes)
               liftIO $ atomically $ modifyTVar seenBlocks (HashMap.delete h)
               liftIO $ Cache.insert bannedBlocks h ()
@@ -577,17 +585,27 @@ peerDownloadLoop peer = do
             setBlockState h (set bsState Downloading st)
 
             r1 <- liftIO $ race ( pause defBlockInfoTimeout ) $ withPeerM e do
-                      blksq <- liftIO newTQueueIO
-                      subscribe @e (BlockSizeEventKey h) $ \case
-                        (BlockSizeEvent (_,_,s)) -> do
-                          liftIO $ atomically $ writeTQueue blksq (Just s)
-                        (NoBlockEvent p) -> do
-                          trace $ "NoBlockEvent" <+> pretty p <+> pretty h
-                          liftIO $ atomically $ writeTQueue blksq Nothing
+                      -- blksq <- liftIO newTQueueIO
 
-                      request peer (GetBlockSize @e h)
+                      cachedSize' <- liftIO $ Cache.lookup sizeCache h
 
-                      liftIO $ atomically $ readTQueue blksq
+                      case cachedSize' of
+                        Just sz -> pure (Just sz)
+                        Nothing -> do
+                          subscribe @e (BlockSizeEventKey h) $ \case
+                            (BlockSizeEvent (_,_,s)) -> do
+                              -- liftIO $ atomically $ writeTQueue blksq (Just s)
+                              liftIO $ Cache.insert sizeCache h s
+
+                            (NoBlockEvent p) -> do
+                              pure ()
+                              -- trace $ "NoBlockEvent" <+> pretty p <+> pretty h
+                              -- liftIO $ atomically $ writeTQueue blksq Nothing
+
+                          request peer (GetBlockSize @e h)
+                          pure Nothing
+
+                          -- liftIO $ atomically $ readTQueue blksq
 
             case r1 of
               Left{} -> do