Added mailboxes as local data sources (#1022)

app/MindWork AI Studio/Tools/RAG/RetrievalRun.cs

@@ -0,0 +1,26 @@
+namespace AIStudio.Tools.RAG;
+
+/// <summary>
+/// What kept one retrieval from covering the whole data source.
+/// </summary>
+/// <param name="queryWrittenByUser">Whether the query is the user's own message, which decides who hears about its problems.</param>
+public sealed class RetrievalRun(bool queryWrittenByUser)
+{
+    // Both channels search at the same time:
+    private readonly Lock gapLock = new();
+    private readonly HashSet<RetrievalGap> gaps = [];
+
+    public bool QueryWrittenByUser => queryWrittenByUser;
+
+    public void Add(RetrievalGap gap)
+    {
+        lock (this.gapLock)
+            this.gaps.Add(gap);
+    }
+
+    public IReadOnlyList<RetrievalGap> GetGaps()
+    {
+        lock (this.gapLock)
+            return this.gaps.Order().ToList();
+    }
+}