Restructure solution layout by module

src/Signals/StellaOps.Signals/Persistence/ICallgraphRepository.cs

@@ -0,0 +1,13 @@
+using System.Threading;
+using System.Threading.Tasks;
+using StellaOps.Signals.Models;
+
+namespace StellaOps.Signals.Persistence;
+
+/// <summary>
+/// Persists normalized callgraphs.
+/// </summary>
+public interface ICallgraphRepository
+{
+    Task<CallgraphDocument> UpsertAsync(CallgraphDocument document, CancellationToken cancellationToken);
+}

src/Signals/StellaOps.Signals/Persistence/MongoCallgraphRepository.cs

@@ -0,0 +1,48 @@
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.Extensions.Logging;
+using MongoDB.Bson;
+using MongoDB.Driver;
+using StellaOps.Signals.Models;
+
+namespace StellaOps.Signals.Persistence;
+
+internal sealed class MongoCallgraphRepository : ICallgraphRepository
+{
+    private readonly IMongoCollection<CallgraphDocument> collection;
+    private readonly ILogger<MongoCallgraphRepository> logger;
+
+    public MongoCallgraphRepository(IMongoCollection<CallgraphDocument> collection, ILogger<MongoCallgraphRepository> logger)
+    {
+        this.collection = collection ?? throw new ArgumentNullException(nameof(collection));
+        this.logger = logger ?? throw new ArgumentNullException(nameof(logger));
+    }
+
+    public async Task<CallgraphDocument> UpsertAsync(CallgraphDocument document, CancellationToken cancellationToken)
+    {
+        ArgumentNullException.ThrowIfNull(document);
+
+        var filter = Builders<CallgraphDocument>.Filter.Eq(d => d.Component, document.Component)
+            & Builders<CallgraphDocument>.Filter.Eq(d => d.Version, document.Version)
+            & Builders<CallgraphDocument>.Filter.Eq(d => d.Language, document.Language);
+
+        if (string.IsNullOrWhiteSpace(document.Id))
+        {
+            document.Id = ObjectId.GenerateNewId().ToString();
+        }
+
+        document.IngestedAt = DateTimeOffset.UtcNow;
+
+        var options = new ReplaceOptions { IsUpsert = true };
+        var result = await collection.ReplaceOneAsync(filter, document, options, cancellationToken).ConfigureAwait(false);
+
+        if (result.UpsertedId != null)
+        {
+            document.Id = result.UpsertedId.AsObjectId.ToString();
+        }
+
+        logger.LogInformation("Upserted callgraph {Language}:{Component}:{Version} (id={Id}).", document.Language, document.Component, document.Version, document.Id);
+        return document;
+    }
+}