Service de cache de database fonctionnel

GrossesMitaines/GrossesMitainesAPI/Services/DatabaseCacheService.cs

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+using GrossesMitainesAPI.Data;
+using GrossesMitainesAPI.Models;
+using Microsoft.EntityFrameworkCore;
+
+namespace GrossesMitainesAPI.Services {
+    public class DatabaseCacheService {
+        private readonly IServiceScopeFactory _contextFactory; // https://entityframeworkcore.com/knowledge-base/51939451/how-to-use-a-database-context-in-a-singleton-service-
+        private readonly ILogger<DatabaseCacheService> _logger;
+        private Product[] _cache = new Product[1];
+        private bool _ok = false, _needUpd = true;
+        private PeriodicTimer _timer = new PeriodicTimer(TimeSpan.FromSeconds(10));
+
+        public DatabaseCacheService(ILogger<DatabaseCacheService> logger, IServiceScopeFactory scopeFactory) {
+            _contextFactory = scopeFactory;
+            _logger = logger;
+            _ok = UpdateCache();
+            _needUpd = !_ok;
+            UpdateJob();
+        }
+
+        private async void UpdateJob() {
+            while (await _timer.WaitForNextTickAsync()) 
+                if (_needUpd) { 
+                    _ok = UpdateCache();
+                    _needUpd = !_ok;
+                }
+        }
+
+        private bool UpdateCache() {
+            try {
+                Product[] prods;
+                using (var scope = _contextFactory.CreateScope()) {
+                    var db = scope.ServiceProvider.GetRequiredService<InventoryContext>();
+                    prods = db.Products.ToArray();
+                }
+                lock (_cache) {
+                    _cache = prods;
+                }
+            } catch (Exception e) {
+                _logger.LogError(e, "Erreur de mise à jour de cache.");
+                return false;
+            }
+            return true;
+        }
+
+        public bool isOk() { return _ok; }
+        public void askForRefresh() { _needUpd = true; }
+        public Product[]? GetCacheCopy() {
+            if (!_ok) return null;
+
+            Product[] copy;
+            try {
+                lock (_cache) {
+                    copy = new Product[_cache.Length];
+                    _cache.CopyTo(copy, 0);
+                }
+            } catch (Exception e) {
+                _logger.LogError(e, "Erreur de copie de cache.");
+                return null;
+            }
+            return copy;
+        }
+    }
+}