- method ParseLatestRepliers()

- method `OnBeforeCommitSave()` and it's overridden parent in abstract class `CrawlFacade`
@ ThreadCrawlFacade.cs

- method `ShouldIgnoreEntityRevision()` and its overridden parent in abstract class ` SaverWithRevision` @ UserSaver.cs
- method `CreateLatestReplier()` & nested class `EqualityComparer` @ User.cs
@ c#

c#/crawler/src/Db/User.cs

@@ -9,34 +9,4 @@ public class User : BaseUser
     public string? FansNickname { get; set; }
     public byte[]? Icon { get; set; }
     public string? IpGeolocation { get; set; }
-
-    public static User CreateLatestReplier(long uid, string? name, string? displayName) =>
-        new() {Uid = uid, Name = name, DisplayName = displayName, Portrait = ""};
-
-    public class EqualityComparer : EqualityComparer<User>
-    {
-        public static EqualityComparer Instance { get; } = new();
-
-        public override bool Equals(User? x, User? y) => x == y || (
-            x != null && y != null &&
-            (x.Uid, x.Name, x.DisplayName, x.Portrait, x.PortraitUpdatedAt, x.Gender, x.FansNickname, x.IpGeolocation)
-            == (y.Uid, y.Name, y.DisplayName, y.Portrait, y.PortraitUpdatedAt, y.Gender, y.FansNickname, y.IpGeolocation)
-            && (x.Icon == y.Icon
-                || (x.Icon != null && y.Icon != null && ByteArrayEqualityComparer.Instance.Equals(x.Icon, y.Icon))));
-
-        public override int GetHashCode(User obj)
-        {
-            var hash = default(HashCode);
-            hash.Add(obj.Uid);
-            hash.Add(obj.Name);
-            hash.Add(obj.DisplayName);
-            hash.Add(obj.Portrait);
-            hash.Add(obj.PortraitUpdatedAt);
-            hash.Add(obj.Gender);
-            hash.Add(obj.FansNickname);
-            hash.AddBytes(obj.Icon);
-            hash.Add(obj.IpGeolocation);
-            return hash.ToHashCode();
-        }
-    }
 }

c#/crawler/src/Tieba/Crawl/Facade/CrawlFacade.cs

@@ -56,8 +56,6 @@ public virtual void Dispose()
                     postSaver.UserFieldUpdateIgnorance,
                     postSaver.UserFieldRevisionIgnorance);
 
-                OnBeforeCommitSave(db, userSaver);
-
                 db.TimestampingEntities();
                 _ = db.SaveChanges();
                 transaction.Commit();
@@ -133,7 +131,6 @@ protected virtual void OnPostParse(
         TResponse response,
         CrawlRequestFlag flag,
         IReadOnlyDictionary<PostId, TPost> parsedPostsInResponse) { }
-    protected virtual void OnBeforeCommitSave(CrawlerDbContext db, UserSaver userSaver) { }
     protected virtual void OnPostCommitSave(
         SaverChangeSet<TPost> savedPosts,
         CancellationToken stoppingToken = default) { }

c#/crawler/src/Tieba/Crawl/Facade/ThreadArchiveCrawlFacade.cs

@@ -24,7 +24,6 @@ protected override void OnPostParse(
         if (flag == CrawlRequestFlag.ThreadClientVersion602) return;
         var data = response.Data;
         UserParser.Parse(data.ThreadList.Select(th => th.Author));
-        ParseLatestRepliers(data.ThreadList);
         FillFromRequestingWith602(data.ThreadList);
 
         // parsed author uid will be 0 when request with client version 6.0.2

c#/crawler/src/Tieba/Crawl/Facade/ThreadCrawlFacade.cs

@@ -18,28 +18,6 @@ public class ThreadCrawlFacade(
 
     public delegate ThreadCrawlFacade New(Fid fid, string forumName);
 
-    protected override void OnBeforeCommitSave(CrawlerDbContext db, UserSaver userSaver)
-    { // OnBeforeCommitSave() should get invoked after UserSaver.Save() by the base.SaveCrawled()
-        // so only latest repliers that not exists in parsed users are being inserted
-        // note this will bypass user revision detection since not invoking SaverWithRevision.SaveEntitiesWithRevision() but directly DbContext.AddRange()
-
-        // users has already been added into DbContext and tracking
-        var existingUsersId = db.ChangeTracker.Entries<User>().Select(ee => ee.Entity.Uid);
-        var newLatestRepliers = _latestRepliers.ExceptByKey(existingUsersId).Values().ToList();
-        if (newLatestRepliers.Count == 0) return;
-
-        var newlyLockedLatestRepliers = userSaver.AcquireUidLocksForSave
-            (newLatestRepliers.Select(u => u.Uid));
-        var newLatestRepliersExceptLocked = newLatestRepliers
-            .IntersectBy(newlyLockedLatestRepliers, u => u.Uid)
-            .Select(u =>
-            {
-                u.CreatedAt = SharedHelper.GetNowTimestamp();
-                return u;
-            });
-        db.Users.AddRange(newLatestRepliersExceptLocked);
-    }
-
     protected override void OnPostParse(
         ThreadResponse response,
         CrawlRequestFlag flag,
@@ -50,24 +28,12 @@ protected override void OnPostParse(
         if (flag != CrawlRequestFlag.None) return;
         UserParser.Parse(data.UserList);
         UserParser.ResetUsersIcon();
-        ParseLatestRepliers(data.ThreadList);
 
         // remove livepost threads since their real parent forum may not match with current crawling fid
         data.ThreadList.Where(th => th.LivePostType != "")
             .ForEach(th => Posts.TryRemove((Tid)th.Tid, out _));
     }
 
-    protected void ParseLatestRepliers(IEnumerable<Thread> threads) =>
-        threads.Select(th => th.LastReplyer ?? null) // LastReplyer will be null when LivePostType != ""
-            .OfType<TbClient.User>() // filter out nulls
-
-            // some rare deleted thread but still visible in 6.0.2 response
-            // will have the latest replier uid=0 name="" nameShow=".*"
-            .Where(u => u.Uid != 0)
-            .Select(u => User.CreateLatestReplier(u.Uid, u.Name.NullIfEmpty(),
-                u.Name == u.NameShow ? null : u.NameShow))
-            .ForEach(u => _latestRepliers[u.Uid] = u);
-
     protected void FillFromRequestingWith602(IEnumerable<Thread> threads) =>
         (from inResponse in threads
             join parsed in Posts.Values on (Tid)inResponse.Tid equals parsed.Tid

c#/crawler/src/Tieba/Crawl/Saver/SaverWithRevision.cs

@@ -58,7 +58,6 @@ protected class RevisionIdWithDuplicateIndexProjection
 }
 public partial class SaverWithRevision<TBaseRevision, TRevisionId>
 {
-    protected virtual bool ShouldIgnoreEntityRevision(string propName, PropertyEntry propEntry, EntityEntry entityEntry) => false;
     protected virtual bool FieldUpdateIgnorance(string propName, object? oldValue, object? newValue) => false;
     protected virtual bool FieldRevisionIgnorance(string propName, object? oldValue, object? newValue) => false;
     private static bool GlobalFieldUpdateIgnorance(string propName, object? oldValue, object? newValue) => propName switch
@@ -107,7 +106,6 @@ bool IsTimestampingFieldName(string name) => name is nameof(BasePost.LastSeenAt)
             {
                 var pName = p.Metadata.Name;
                 if (!p.IsModified || IsTimestampingFieldName(pName)) continue;
-                if (ShouldIgnoreEntityRevision(pName, p, entityEntry)) return null;
 
                 if (FieldUpdateIgnorance(
                         pName, p.OriginalValue, p.CurrentValue)

c#/crawler/src/Tieba/Crawl/Saver/UserSaver.cs

@@ -70,18 +70,6 @@ protected override Expression<Func<BaseUserRevision, RevisionIdWithDuplicateInde
 }
 public partial class UserSaver
 {
-    protected override bool ShouldIgnoreEntityRevision(string propName, PropertyEntry propEntry, EntityEntry entityEntry)
-    {
-        // ThreadCrawlFacade.ParseLatestRepliers() will save partial filled user of latest repliers for livepost thread
-        // they may later get updated by (sub) reply crawler after it find out the latest reply
-        // so we should ignore its revision update for all fields
-        if (propName != nameof(User.Portrait) || propEntry.OriginalValue is not "") return false;
-        var user = (User)entityEntry.OriginalValues.ToObject();
-        var latestReplier = User.CreateLatestReplier(user.Uid, user.Name, user.DisplayName);
-
-        return User.EqualityComparer.Instance.Equals(user, latestReplier);
-    }
-
     protected override bool FieldUpdateIgnorance
         (string propName, object? oldValue, object? newValue) => propName switch
     { // possible randomly respond with null