Fix some DateTime and caching bugs (#70)

* Fix two DateTime-related bugs * Restore original data files directory (It's already in use in the deployed app.) * Don't cache feed rewind info if it is null * Consolidate file save methods * Handle bad feed URLs better * Bump version: 0.5.1
dougwaldron · Jan 1, 2024 · 1ab9e3b · 1ab9e3b
1 parent 220cbed
commit 1ab9e3b
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Showing 6 changed files with 66 additions and 43 deletions.
diff --git a/.gitignore b/.gitignore
@@ -540,6 +540,7 @@ FodyWeavers.xsd
 
 # Data files
 .DataFiles/
+_DataFiles/
 
 # Environment settings files
 appsettings.*.json

diff --git a/PodcastRewind/Models/FeedRewindData.cs b/PodcastRewind/Models/FeedRewindData.cs
@@ -51,7 +51,9 @@ private void LoadRewoundFeed()
         RewoundEntries = originalFeed.Items.OrderBy(item => item.PublishDate).ToList();
         var feedItemsCount = RewoundEntries.Count;
         var keyIndex = RewoundEntries.FindIndex(item => item.Id == feedRewindInfo.KeyEntryId);
-        var dateOfFirstEntry = feedRewindInfo.DateOfKeyEntry.AddDays(-feedRewindInfo.Interval * (keyIndex));
+        var dateOfFirstEntry = DateTime.SpecifyKind(
+            feedRewindInfo.DateOfKeyEntry.AddDays(-feedRewindInfo.Interval * keyIndex),
+            DateTimeKind.Unspecified);
 
         for (var i = 0; i < feedItemsCount; i++)
         {
@@ -88,16 +90,19 @@ private void LoadRewoundFeed()
         };
 
         RewoundFeed.Description = new TextSyndicationContent(newDescription, descriptionType);
-        RewoundFeed.Items = RewoundEntries.Where(item => item.PublishDate <= DateTimeOffset.Now)
-            .OrderByDescending(item => item.PublishDate);
-        MostRecentRewoundFeedEntryDate = RewoundFeed.Items.First().PublishDate;
+        RewoundFeed.Items = RewoundEntries
+            .Where(item => item.PublishDate <= DateTimeOffset.Now)
+            .OrderByDescending(item => item.PublishDate).ToList();
+        if (RewoundFeed.Items.Any())
+            MostRecentRewoundFeedEntryDate = RewoundFeed.Items.First().PublishDate;
     }
 
     private void LoadScheduledFeed()
     {
         if (string.IsNullOrEmpty(feedRewindInfo.FeedUrl)) return;
         ScheduledFeed = originalFeed.Clone(true);
-        ScheduledFeed.Items = RewoundEntries.Where(item => item.PublishDate > DateTimeOffset.Now)
+        ScheduledFeed.Items = RewoundEntries
+            .Where(item => item.PublishDate > DateTimeOffset.Now)
             .OrderBy(item => item.PublishDate);
     }
 

diff --git a/PodcastRewind/PodcastRewind.csproj b/PodcastRewind/PodcastRewind.csproj
@@ -4,7 +4,7 @@
     <TargetFramework>net8.0</TargetFramework>
     <Nullable>enable</Nullable>
     <ImplicitUsings>enable</ImplicitUsings>
-    <Version>0.5.0</Version>
+    <Version>0.5.1</Version>
   </PropertyGroup>
 
   <ItemGroup>

diff --git a/PodcastRewind/Services/FeedRewindInfoRepository.cs b/PodcastRewind/Services/FeedRewindInfoRepository.cs
@@ -34,19 +34,14 @@ public async Task<Guid> SaveAsync(CreateFeedRewindInfoDto create)
             Interval = create.Interval,
         };
 
-        var filePath = Path.Combine(_dataFilesDirectory, string.Concat(id.ToString(), ".json"));
-        Directory.CreateDirectory(_dataFilesDirectory);
-        await using var stream = File.Create(filePath);
-        await JsonSerializer.SerializeAsync(stream, feedRewind);
-
-        cache.Set(id, feedRewind, CacheEntryOptions);
+        await SaveFeedRewindInfoToFileAsync(id, feedRewind);
         return id;
     }
 
     public async Task UpdateAsync(EditFeedRewindInfoDto edit)
     {
-        var original = await GetAsync(edit.Id);
-        if (original is null) throw new ArgumentException($"Item {edit.Id} does not exist.", nameof(edit));
+        var original = await GetAsync(edit.Id)
+                       ?? throw new ArgumentException($"Item {edit.Id} does not exist.", nameof(edit));
 
         var feedRewind = new FeedRewindInfo
         {
@@ -58,25 +53,37 @@ public async Task UpdateAsync(EditFeedRewindInfoDto edit)
             CreatedOn = original.CreatedOn,
         };
 
-        var filePath = Path.Combine(_dataFilesDirectory, string.Concat(feedRewind.Id.ToString(), ".json"));
+        await SaveFeedRewindInfoToFileAsync(edit.Id, feedRewind);
+    }
+
+    public async Task<FeedRewindInfo?> GetAsync(Guid id)
+    {
+        if (cache.TryGetValue(id, out FeedRewindInfo? info)) return info;
+        info = await LoadFeedRewindInfoFromFileAsync(id);
+        if (info != null) cache.Set(id, info, CacheEntryOptions);
+        return info;
+    }
+
+    private async Task SaveFeedRewindInfoToFileAsync(Guid id, FeedRewindInfo feedRewind)
+    {
+        var filePath = Path.Combine(_dataFilesDirectory, string.Concat(id.ToString(), ".json"));
+        Directory.CreateDirectory(_dataFilesDirectory);
         await using var stream = File.Create(filePath);
         await JsonSerializer.SerializeAsync(stream, feedRewind);
-        cache.Set(edit.Id, feedRewind, CacheEntryOptions);
+        cache.Set(id, feedRewind, CacheEntryOptions);
     }
 
-    public Task<FeedRewindInfo?> GetAsync(Guid id) =>
-        cache.GetOrCreateAsync(id, async entry =>
+    private async Task<FeedRewindInfo?> LoadFeedRewindInfoFromFileAsync(Guid id)
+    {
+        var filePath = Path.Combine(_dataFilesDirectory, string.Concat(id.ToString(), ".json"));
+        try
         {
-            entry.SetOptions(CacheEntryOptions);
-            var filePath = Path.Combine(_dataFilesDirectory, string.Concat(id.ToString(), ".json"));
-            try
-            {
-                await using var stream = File.OpenRead(filePath);
-                return await JsonSerializer.DeserializeAsync<FeedRewindInfo>(stream);
-            }
-            catch (Exception e) when (e is FileNotFoundException or DirectoryNotFoundException)
-            {
-                return null;
-            }
-        });
+            await using var stream = File.OpenRead(filePath);
+            return await JsonSerializer.DeserializeAsync<FeedRewindInfo>(stream);
+        }
+        catch (Exception e) when (e is FileNotFoundException or DirectoryNotFoundException)
+        {
+            return null;
+        }
+    }
 }
diff --git a/PodcastRewind/Services/SyndicationFeedService.cs b/PodcastRewind/Services/SyndicationFeedService.cs
@@ -1,6 +1,7 @@
 using System.ServiceModel.Syndication;
 using System.Xml;
 using Microsoft.Extensions.Caching.Memory;
+using Sentry;
 
 namespace PodcastRewind.Services;
 
@@ -12,21 +13,30 @@ public interface ISyndicationFeedService
 public class SyndicationFeedService(IHttpClientFactory httpClientFactory, IMemoryCache cache)
     : ISyndicationFeedService
 {
-    public Task<SyndicationFeed?> GetSyndicationFeedAsync(string url) =>
-        !Uri.IsWellFormedUriString(url, UriKind.Absolute)
-            ? Task.FromResult<SyndicationFeed?>(null)
-            : cache.GetOrCreateAsync(url, entry =>
-            {
-                entry.AbsoluteExpirationRelativeToNow = TimeSpan.FromHours(20);
-                return GetRemoteSyndicationFeedAsync(url);
-            });
+    public async Task<SyndicationFeed?> GetSyndicationFeedAsync(string url)
+    {
+        if (!Uri.IsWellFormedUriString(url, UriKind.Absolute)) return null;
+        if (cache.TryGetValue(url, out SyndicationFeed? feed)) return feed;
+        feed = await GetRemoteSyndicationFeedAsync(url);
+        if (feed != null)
+            cache.Set(url, feed, new MemoryCacheEntryOptions().SetAbsoluteExpiration(TimeSpan.FromHours(20)));
+        return feed;
+    }
 
-    private async Task<SyndicationFeed> GetRemoteSyndicationFeedAsync(string url)
+    private async Task<SyndicationFeed?> GetRemoteSyndicationFeedAsync(string url)
     {
         var client = httpClientFactory.CreateClient("Polly");
         client.DefaultRequestHeaders.Add("user-agent", "PodcastRewind/1.0");
-        await using var stream = await client.GetStreamAsync(url);
-        using var xmlReader = XmlReader.Create(stream);
-        return SyndicationFeed.Load(xmlReader);
+        try
+        {
+            await using var stream = await client.GetStreamAsync(url);
+            using var xmlReader = XmlReader.Create(stream);
+            return SyndicationFeed.Load(xmlReader);
+        }
+        catch (HttpRequestException e)
+        {
+            SentrySdk.CaptureException(e);
+            return null;
+        }
     }
 }
diff --git a/PodcastRewind/appsettings.json b/PodcastRewind/appsettings.json
@@ -1,5 +1,5 @@
 {
-  "DataFilesDirectory": "../.DataFiles",
+  "DataFilesDirectory": "_DataFiles",
   "UseTestData": false,
   "Sentry": {
     "Environment": "production",