increase speed of mysql when searching posts

modules/RichSiteSummary/Service/RssFetch.cs

@@ -19,6 +19,7 @@ using Telegram.Bot.Types.Enums;
 using Feed = Kruzya.TelegramBot.RichSiteSummary.Data.Feed;
 
 using CodeHollow.FeedReader.Feeds;
+using Kruzya.TelegramBot.Core.Service;
 
 namespace Kruzya.TelegramBot.RichSiteSummary.Service;
 
@@ -35,14 +36,16 @@ public class RssFetch : IHostedService, IDisposable
     private readonly ILogger _logger;
     private readonly IServiceScopeFactory _scopeFactory;
     private readonly ConcurrentQueue<UserMessage> _queue;
+    private readonly Hash _hash;
 
     private static TimeSpan TimerPeriod => TimeSpan.FromSeconds(45);
 
-    public RssFetch(ILogger<RssFetch> logger, ConcurrentQueue<UserMessage> queue, IServiceScopeFactory scopeFactory)
+    public RssFetch(ILogger<RssFetch> logger, ConcurrentQueue<UserMessage> queue, IServiceScopeFactory scopeFactory, Hash hash)
     {
         _scopeFactory = scopeFactory;
         _logger = logger;
         _queue = queue;
+        _hash = hash;
     }
 
     #region IHostedService
@@ -132,7 +135,7 @@ public class RssFetch : IHostedService, IDisposable
         var postsImages = new Dictionary<Post, string>();
         foreach (var post in parsedFeed.Items)
         {
-            feedPost = await dbContext.Posts.ByFeedAndUrl(post.Link, feed);
+            feedPost = await dbContext.Posts.ByFeedAndUrlHash(_hash.GenerateHash(post.Link), feed);
             if (feedPost != null)
             {
                 // skip. This post already exists.
@@ -144,6 +147,7 @@ public class RssFetch : IHostedService, IDisposable
             feedPost.Title = post.Title;
             feedPost.Url = post.Link;
             feedPost.PostedAt = post.PublishingDate.GetValueOrDefault(DateTime.Now);
+            feedPost.UrlHash = _hash.GenerateHash(feedPost.Url);
 
             postsImages.Add(feedPost, await FetchImageUrl(post));
             newPosts.Add(feedPost);