Use stable hash comparer for nuget/oss model

This makes it eaiser to merge PRs when stats are run/updated, since otherwise keys move around since the hashes aren't really stable OOB.

src/Commands/NuGetStatsCommand.cs

@@ -117,9 +117,9 @@ public override async Task<int> ExecuteAsync(CommandContext context, NuGetStatsS
         // The resulting model we'll populate.
         OpenSource model;
         if (File.Exists(fileName) && settings.Force != true)
-            model = JsonSerializer.Deserialize<OpenSource>(File.ReadAllText(fileName), JsonOptions.Default) ?? new OpenSource([], [], []);
+            model = JsonSerializer.Deserialize<OpenSource>(File.ReadAllText(fileName), JsonOptions.Default) ?? new OpenSource();
         else
-            model = new OpenSource([], [], []);
+            model = new OpenSource();
 
         using var http = httpFactory.CreateClient();
 
@@ -399,22 +399,22 @@ await Parallel.ForEachAsync(tasks, paralell, async (source, cancellation) =>
 
                                 if (contribs != null)
                                 {
-                                    model.Repositories.TryAdd(ownerRepo, new(contribs));
+                                    model.Repositories.TryAdd(ownerRepo, new(contribs, FnvHashComparer.Default));
                                 }
                                 else
                                 {
                                     // Might not be a GH repo at all, or perhaps it's just empty?
-                                    model.Repositories.TryAdd(ownerRepo, []);
+                                    model.Repositories.TryAdd(ownerRepo, new(FnvHashComparer.Default));
                                     AnsiConsole.MarkupLine($":warning: [yellow]{link}[/]: no contributors found for [white]{ownerRepo}[/]");
                                 }
                             }
 
                             foreach (var author in model.Repositories[ownerRepo])
-                                model.Authors.GetOrAdd(author, []).Add(ownerRepo);
+                                model.Authors.GetOrAdd(author, _ => new(FnvHashComparer.Default)).Add(ownerRepo);
                         }
 
                         // If we allow non-oss packages, we won't have an ownerRepo, so consider that an empty string.
-                        model.Packages.GetOrAdd(ownerRepo ?? "", []).TryAdd(id.Id, dailyDownloads);
+                        model.Packages.GetOrAdd(ownerRepo ?? "", _ => new(FnvHashComparer.Default)).TryAdd(id.Id, dailyDownloads);
                         if (ownerRepo != null)
                             task.Description = $":check_mark_button: [deepskyblue1]{link}[/]: [white]{ownerRepo}[/] [grey]has[/] [lime]{model.Repositories[ownerRepo].Count}[/] [grey]contributors.[/]";
                     }

src/Core/FnvHashComparer.cs

@@ -0,0 +1,39 @@
+using System.Runtime.CompilerServices;
+
+namespace Devlooped.Sponsors;
+
+public class FnvHashComparer : IEqualityComparer<string>
+{
+    // FNV-1a 32 bit prime and offset basis
+    const uint FnvPrime = 0x01000193;
+    const uint FnvOffsetBasis = 0x811C9DC5;
+
+    public static IEqualityComparer<string> Default { get; } = new FnvHashComparer();
+
+    public bool Equals(string? x, string? y)
+    {
+        // If both are null, or both are same instance, consider them equal
+        if (x == y) return true;
+        if (x == null || y == null) return false;
+        return x.Equals(y, StringComparison.Ordinal); // Use Ordinal for performance
+    }
+
+    public int GetHashCode(string obj)
+    {
+        // Convert the 32-bit unsigned hash to a signed int for .NET's GetHashCode
+        return unchecked((int)Fnv1aHash(obj));
+    }
+
+    // Method to compute FNV-1a hash for a string
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    static uint Fnv1aHash(string str)
+    {
+        var hash = FnvOffsetBasis;
+        foreach (var c in str)
+        {
+            hash ^= c; // XOR the character
+            hash *= FnvPrime; // Multiply by the FNV prime
+        }
+        return hash;
+    }
+}

src/Core/Records.cs

@@ -42,6 +42,10 @@ public record OpenSource(ConcurrentDictionary<string, HashSet<string>> Authors,
     OpenSourceSummary? summary;
     OpenSourceTotals? totals;
 
+    public OpenSource() : this(new(FnvHashComparer.Default), new(FnvHashComparer.Default), new(FnvHashComparer.Default))
+    {            
+    }
+
     public OpenSourceSummary Summary => summary ??= new(Totals);
 
     public OpenSourceTotals Totals => totals ??= new(this);