Deprecate FastBlock Flag

src/Nethermind/Nethermind.Blockchain/Synchronization/ISyncConfig.cs

@@ -28,7 +28,8 @@ public interface ISyncConfig : IConfig
     [ConfigItem(Description = "In Fast sync mode, the min height threshold limit up to which the Full sync, if already on, stays on when the chain is behind the network head. If the limit is exceeded, it switches back to Fast sync. For regular usage scenarios, setting this value lower than 32 is not recommended as this can cause issues with chain reorgs. Note that the last 2 blocks are always processed in Full sync, so setting it lower than 2 has no effect.", DefaultValue = "8192")]
     long? FastSyncCatchUpHeightDelta { get; set; }
 
-    [ConfigItem(Description = "Whether to first download blocks from the provided pivot number downwards in the Fast sync mode. This allows for parallelization of requests with many sync peers and with no need to worry about syncing a valid branch (syncing downwards to 0). You need to provide the pivot block number, hash, and total difficulty from a trusted source (e.g., Etherscan) and confirm with other sources if you want to change it.", DefaultValue = "false")]
+    [Obsolete]
+    [ConfigItem(Description = "Deprecated.", DefaultValue = "false", HiddenFromDocs = true)]
     bool FastBlocks { get; set; }
 
     [ConfigItem(Description = "Whether to make smaller requests, in Fast Blocks mode, to avoid Geth from disconnecting. On the Geth-heavy networks (e.g., Mainnet), it's  a desired behavior while on Nethermind- or OpenEthereum-heavy networks (Goerli, Aura), it slows down the sync by a factor of ~4.", DefaultValue = "true")]

src/Nethermind/Nethermind.Blockchain/Synchronization/SyncConfig.cs

@@ -1,6 +1,5 @@
 // SPDX-FileCopyrightText: 2022 Demerzel Solutions Limited
 // SPDX-License-Identifier: LGPL-3.0-only
-using System;
 using Nethermind.Config;
 using Nethermind.Db;
 
@@ -13,10 +12,10 @@ public class SyncConfig : ISyncConfig
         private bool _fastSync;
 
         public static ISyncConfig Default { get; } = new SyncConfig();
-        public static ISyncConfig WithFullSyncOnly { get; } = new SyncConfig { FastSync = false, FastBlocks = false };
+        public static ISyncConfig WithFullSyncOnly { get; } = new SyncConfig { FastSync = false };
         public static ISyncConfig WithFastSync { get; } = new SyncConfig { FastSync = true };
-        public static ISyncConfig WithFastBlocks { get; } = new SyncConfig { FastSync = true, FastBlocks = true };
-        public static ISyncConfig WithEth2Merge { get; } = new SyncConfig { FastSync = false, FastBlocks = false, BlockGossipEnabled = false };
+        public static ISyncConfig WithFastBlocks { get; } = new SyncConfig { FastSync = true };
+        public static ISyncConfig WithEth2Merge { get; } = new SyncConfig { FastSync = false, BlockGossipEnabled = false };
 
         public bool NetworkingEnabled { get; set; } = true;
 
@@ -27,13 +26,9 @@ public bool SynchronizationEnabled
         }
 
         public long? FastSyncCatchUpHeightDelta { get; set; } = 8192;
-
-        // maybe log warnign on set? Remove all references within this file.
-        // using a class method marked obsolete in reflections might not be possible.
-        // [ObsoleteAttribute("Fast blocks mode is dependent on and auto enabled in fast sync mode, please use FastSync instead.", false)]
-        public bool FastBlocks { get; set; }
+        bool ISyncConfig.FastBlocks { get; set; }
         public bool UseGethLimitsInFastBlocks { get; set; } = true;
-        public bool FastSync { get => _fastSync || SnapSync; set => _fastSync = value; } 
+        public bool FastSync { get => _fastSync || SnapSync; set => _fastSync = value; }
         public bool DownloadHeadersInFastSync { get; set; } = true;
         public bool DownloadBodiesInFastSync { get; set; } = true;
         public bool DownloadReceiptsInFastSync { get; set; } = true;

src/Nethermind/Nethermind.Synchronization.Test/FastBlocks/ReceiptsSyncFeedTests.cs

@@ -138,9 +138,7 @@ private ReceiptsSyncFeed CreateFeed()
                 LimboLogs.Instance);
         }
 
-        // maybe remove test completely(obsolete) (previous throws when fast block not enabled?
         [Test]
-        [Obsolete("Fast Blocks mode is active when fast sync mode is active")]
         public void Should_throw_when_fast_block_not_enabled()
         {
             _syncConfig = new SyncConfig { FastSync = false };

src/Nethermind/Nethermind.Synchronization.Test/SyncProgressResolverTests.cs

@@ -114,9 +114,8 @@ public void Best_state_is_head_if_there_is_suggested_block_without_state()
             Assert.That(syncProgressResolver.FindBestFullState(), Is.EqualTo(head.Number));
         }
 
-        // maybe delete(mark obsolete) this test, since fastblock is always used?
         [Test]
-        public void Is_fast_block_finished_returns_true_when_no_fast_block_sync_is_used()
+        public void Is_fast_block_finished_returns_true_when_no_fast_sync_is_used()
         {
             IBlockTree blockTree = Substitute.For<IBlockTree>();
             IStateReader stateReader = Substitute.For<IStateReader>();

src/Nethermind/Nethermind.Synchronization/FastBlocks/BodiesSyncFeed.cs

@@ -66,11 +66,9 @@ public BodiesSyncFeed(
             _blocksDb = blocksDb ?? throw new ArgumentNullException(nameof(blocksDb));
             _flushDbInterval = flushDbInterval;
 
-            // maybe remove fastblock(now replaced with fastsync) condition completely?
             if (!_syncConfig.FastSync)
             {
-                throw new InvalidOperationException(
-                    "Entered fast sync with fast blocks mode without fast sync enabled in configuration.");
+                throw new InvalidOperationException("Entered fast bodies mode without fast sync enabled in configuration.");
             }
 
             _pivotNumber = -1; // First reset in `InitializeFeed`.

src/Nethermind/Nethermind.Synchronization/FastBlocks/FastHeadersSyncFeed.cs

@@ -179,10 +179,9 @@ public HeadersSyncFeed(
                 _headersRequestSize = NethermindSyncLimits.MaxHeaderFetch;
             }
 
-            // maybe remove fastblock(now replaced with fastsync) condition completely?
             if (!_syncConfig.FastSync && !alwaysStartHeaderSync)
             {
-                throw new InvalidOperationException("Entered fast sync with fast blocks mode without fast sync enabled in configuration.");
+                throw new InvalidOperationException("Entered fast headers mode without fast sync enabled in configuration.");
             }
 
             _historicalOverrides.TryGetValue(_blockTree.NetworkId, out _expectedDifficultyOverride);

src/Nethermind/Nethermind.Synchronization/FastBlocks/ReceiptsSyncFeed.cs

@@ -67,7 +67,6 @@ public ReceiptsSyncFeed(
             _syncReport = syncReport ?? throw new ArgumentNullException(nameof(syncReport));
             _blockTree = blockTree ?? throw new ArgumentNullException(nameof(blockTree));
 
-            // maybe remove fastblock(now replaced with fastsync) condition completely?
             if (!_syncConfig.FastSync)
             {
                 throw new InvalidOperationException("Entered fast blocks mode without fast blocks enabled in configuration.");

src/Nethermind/Nethermind.Synchronization/ParallelSync/MultiSyncModeSelector.cs

@@ -57,10 +57,9 @@ public class MultiSyncModeSelector : ISyncModeSelector
         private long _pivotNumber;
         private bool FastSyncEnabled => _syncConfig.FastSync;
         private bool SnapSyncEnabled => _syncConfig.SnapSync && !_isSnapSyncDisabledAfterAnyStateSync;
-        private bool FastBlocksEnabled => _syncConfig.FastSync; // maybe replace all reference with FastSyycEnabled?
-        private bool FastBodiesEnabled => FastBlocksEnabled && _syncConfig.DownloadBodiesInFastSync;
-        private bool FastReceiptsEnabled => FastBlocksEnabled && _syncConfig.DownloadReceiptsInFastSync;
-        private bool FastBlocksHeadersFinished => !FastBlocksEnabled || _syncProgressResolver.IsFastBlocksHeadersFinished();
+        private bool FastBodiesEnabled => FastSyncEnabled && _syncConfig.DownloadBodiesInFastSync;
+        private bool FastReceiptsEnabled => FastSyncEnabled && _syncConfig.DownloadReceiptsInFastSync;
+        private bool FastBlocksHeadersFinished => !FastSyncEnabled || _syncProgressResolver.IsFastBlocksHeadersFinished();
         private bool FastBlocksBodiesFinished => !FastBodiesEnabled || _syncProgressResolver.IsFastBlocksBodiesFinished();
         private bool FastBlocksReceiptsFinished => !FastReceiptsEnabled || _syncProgressResolver.IsFastBlocksReceiptsFinished();
         private long FastSyncCatchUpHeightDelta => _syncConfig.FastSyncCatchUpHeightDelta ?? FastSyncLag;

src/Nethermind/Nethermind.Synchronization/ParallelSync/SyncProgressResolver.cs

@@ -83,32 +83,18 @@ public long FindBestFullState()
             return _blockTree.FindHeader(blockHash)?.TotalDifficulty == 0 ? null : _blockTree.FindHeader(blockHash)?.TotalDifficulty;
         }
 
-        public bool IsFastBlocksHeadersFinished() => !IsFastBlocks() || (!_syncConfig.DownloadHeadersInFastSync ||
-                                                                         (_headersSyncFeed?.IsFinished == true));
+        public bool IsFastBlocksHeadersFinished() => !IsFastBlocks() || !_syncConfig.DownloadHeadersInFastSync || _headersSyncFeed?.IsFinished == true;
 
-        public bool IsFastBlocksBodiesFinished() => !IsFastBlocks() || (!_syncConfig.DownloadBodiesInFastSync ||
-                                                                        (_bodiesSyncFeed?.IsFinished == true));
+        public bool IsFastBlocksBodiesFinished() => !IsFastBlocks() || !_syncConfig.DownloadBodiesInFastSync || _bodiesSyncFeed?.IsFinished == true;
 
-        public bool IsFastBlocksReceiptsFinished() => !IsFastBlocks() || (!_syncConfig.DownloadReceiptsInFastSync ||
-                                                                          (_receiptsSyncFeed?.IsFinished == true));
+        public bool IsFastBlocksReceiptsFinished() => !IsFastBlocks() || !_syncConfig.DownloadReceiptsInFastSync || _receiptsSyncFeed?.IsFinished == true;
 
         public bool IsSnapGetRangesFinished() => _snapSyncFeed?.IsFinished ?? true;
 
         public void RecalculateProgressPointers() => _blockTree.RecalculateTreeLevels();
 
-        private bool IsFastBlocks()
-        {
-            // maybe eliminate the entire code refeferencing this function why? fast block depends on fastsync so this code might just be check that is now unnecessay!
-            // name isFastBlocks left in place for correlation with protocol specification.
-            bool isFastBlocks = _syncConfig.FastSync; 
+        private bool IsFastBlocks() => _syncConfig.FastSync && _syncConfig.PivotNumberParsed != 0L; // if pivot number is 0 then it is equivalent to fast blocks disabled
 
-            // if pivot number is 0 then it is equivalent to fast blocks disabled
-            if (!isFastBlocks || _syncConfig.PivotNumberParsed == 0L)
-            {
-                return false;
-            }
 
-            return true;
-        }
     }
 }