Performance improvements, refactoring of multi-tenant support, split Alias and Tenant entities for cleaner separation of concerns, create an additional site during installation for demonstratng multitenancy

Oqtane.Server/Repository/TenantResolver.cs

@@ -0,0 +1,48 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using Oqtane.Models;
+using Microsoft.AspNetCore.Http;
+using Microsoft.Extensions.Caching.Memory;
+
+namespace Oqtane.Repository
+{
+    public class TenantResolver : ITenantResolver
+    {
+        private HostContext db;
+        private readonly string aliasname;
+        private readonly IAliasRepository _aliasrepository;
+        private readonly ITenantRepository _tenantrepository;
+
+        public TenantResolver(HostContext context, IHttpContextAccessor accessor, IAliasRepository aliasrepository, ITenantRepository tenantrepository)
+        {
+            db = context;
+            _aliasrepository = aliasrepository;
+            _tenantrepository = tenantrepository;
+
+            // get alias based on request context
+            aliasname = accessor.HttpContext.Request.Host.Value;
+            string path = accessor.HttpContext.Request.Path.Value;
+            string[] segments = path.Split('/');
+            if (segments[1] != "~")
+            {
+                aliasname += "/" + segments[1];
+            }
+        }
+
+        public Tenant GetTenant()
+        {
+            try
+            {
+                IEnumerable<Alias> aliases = _aliasrepository.GetAliases(); // cached
+                Alias alias = aliases.Where(item => item.Name == aliasname).FirstOrDefault();
+                IEnumerable<Tenant> tenants = _tenantrepository.GetTenants(); // cached
+                return tenants.Where(item => item.TenantId == alias.TenantId).FirstOrDefault();
+            }
+            catch
+            {
+                throw;
+            }
+        }
+    }
+}