租戶功能

MultiTenancyMiddleware中間件

(1)ITenantResolver：獲取TenantResolveResult，即TenantIdOrName以及用到AppliedResolvers，它的實現TenantResolver涉及遍歷AbpTenantResolveOptions

多個ITenantResolveContributor，包括CurrentUser,基於http多個方法等等，默認是CurrentUserTenantResolveContributor

(2)ICurrentTenant:引入是為了給CurrentTenant賦值，它賦值在線程安全的ICurrentTenantAccessor，以后使用直接從容器解析出來就可以使用

它是通過CurrentTenant的Change方法,將_currentTenantAccessor.Current的值設置為通過ITenantSolve解析出來的TenantIdOrName，

同時並且存儲一份在ITenantResolveResultAccessor里面，其實現HttpContextTenantResolveResultAccessor的TenantResolveResult，來源於httpContextAccessor.HttpContext.Items["__AbpTenantResolveResult"]里面

ITenantStore：查找並得到TenantConfiguration，包括Id，Name,連接字符串，

• DefaultTenantStore：[Dependency(TryRegister = true)]，根據AbpDefaultTenantStoreOptions.TenantConfiguration
• Volo.Abp.TenantManagement.TenantStore，使用是數據庫

  

 public async Task InvokeAsync(HttpContext context, RequestDelegate next)
        {
            var resolveResult = _tenantResolver.ResolveTenantIdOrName();
            _tenantResolveResultAccessor.Result = resolveResult;

            TenantConfiguration tenant = null;
            if (resolveResult.TenantIdOrName != null)
            {
                tenant = await FindTenantAsync(resolveResult.TenantIdOrName);
                if (tenant == null)
                {
                    //TODO: A better exception?
                    throw new AbpException(
                        "There is no tenant with given tenant id or name: " + resolveResult.TenantIdOrName
                    );
                }
            }

            using (_currentTenant.Change(tenant?.Id, tenant?.Name))
            {
                await next(context);
            }
        }

  

1、AbpMultiTenancyModule模塊，AbpDefaultTenantStoreOptions存儲配置租戶信息TenantConfiguration數組，每個租戶包括Guid,Name,ConnectionStrings

1）配置文件Configure<AbpDefaultTenantStoreOptions>(configuration)，來源於IConfiguration

  [DependsOn(
        typeof(AbpDataModule),
        typeof(AbpSecurityModule)
        )]
    public class AbpMultiTenancyModule : AbpModule
    {
        public override void ConfigureServices(ServiceConfigurationContext context)
        {
            var configuration = context.Services.GetConfiguration();
            Configure<AbpDefaultTenantStoreOptions>(configuration);
        }
    }
}

比如：通過手工配置

services.Configure<AbpDefaultTenantStoreOptions>(options =>
            {
                options.Tenants = new[]
                {
                    new TenantConfiguration(_tenant1Id, "tenant1")
                    {
                        ConnectionStrings =
                        {
                            { ConnectionStrings.DefaultConnectionStringName, "tenant1-default-value"},
                            {"db1", "tenant1-db1-value"}
}
                    },
                    new TenantConfiguration(_tenant2Id, "tenant2")
                };
            });

　配置通用的連接字符串

  services.Configure<DbConnectionOptions>(options =>
            {
                options.ConnectionStrings.Default = "default-value";
                options.ConnectionStrings["db1"] = "db1-default-value";
            });

AbpMultiTenancyOptions， 提供給應用，配置是否開啟多租戶功能，默認是不開啟

模式1、共享數據庫，2、每個租戶單獨數據庫，3混合模式，默認是混合模式

public class MultiTenancyOptions
    {
        /// <summary>
        /// A central point to enable/disable multi-tenancy.
        /// Default: false. 
        /// </summary>
        public bool IsEnabled { get; set; }

        /// <summary>
        /// Database style for tenants.
        /// Default: <see cref="MultiTenancyDatabaseStyle.Hybrid"/>.
        /// </summary>
        public MultiTenancyDatabaseStyle DatabaseStyle { get; set; } = MultiTenancyDatabaseStyle.Hybrid;
    }

　　2、ICurrentTenant 當前租戶，依賴ICurrentTenantAccessor來確定，Change方法IDisposable Change(Guid? id, string name = null);

     public IDisposable Change(Guid? id, string name = null)
        {
            return SetCurrent(id, name);
        }

        private IDisposable SetCurrent(Guid? tenantId, string name = null)
        {
            var parentScope = _currentTenantAccessor.Current;
            _currentTenantAccessor.Current = new BasicTenantInfo(tenantId, name);
            return new DisposeAction(() =>
            {
                _currentTenantAccessor.Current = parentScope;
            });
        }

3、ICurrentTenantAccessor，BasicTenantInfo判斷（null值，表明沒有設置使用host,不是null值，看TenantId是否賦值，基TenantId正確賦值，表明是准確設定Tenant

public class AsyncLocalCurrentTenantAccessor : ICurrentTenantAccessor, ISingletonDependency
    {
        public BasicTenantInfo Current
        {
            get => _currentScope.Value;
            set => _currentScope.Value = value;
        }

        private readonly AsyncLocal<BasicTenantInfo> _currentScope;

        public AsyncLocalCurrentTenantAccessor()
        {
            _currentScope = new AsyncLocal<BasicTenantInfo>();
        }
    }

 

4、AbpTenantResolveOptions:   ITenantResolveContributor實現方法的列表

TenantResolver的實現，遍歷AbpTenantResolveOptions的ITenantResolveContributor，

ITenantResolveContributor.Name有哪些，結果存儲方法在Resolve參數ITenantResolveContext，而且通過參數傳遞IServiceProvider

ITenantResolveContributor》TenantResolveContributorBase，

1、CurrentUser，根據currentUser.TenantId

2、Action，利用委托方法，

3、(重要)：基於HttpTenantResolveContributorBase的方法， Volo.Abp.AspNetCore.MultiTenancy模塊，獲取租戶的Id和名稱有五種方法，Cookie,Domain,Header,QueryString，Route,實現在模塊Volo.Abp.AspNetCore.MultiTenancy里面

ITenantResolveContributor.Resolve方法,參數ITenantResolveContext （IServiceProvider、TenantIdOrName），結果存儲在TenantResolveContext的TenantIdOrName

TenantResolveResult,返回結果包裝，AppliedResolvers存儲ITenantResolveContributor.Name的列表， Handled || TenantIdOrName != null; 決定TenantIdOrName

ITenantResolveContributor，其http的基類，從GetTenantIdOrNameFromHttpContextOrNull　

比如：Domain實現方法，沒有配置在Option里面，因為它的實現需要域名參數格式，它需要手工注冊

因此它的順序是CurrentUser>Domain( 需要手工注冊)>QueryString>RouteTenant>Header>Cookie,它使用是短路法

 public override void ConfigureServices(ServiceConfigurationContext context)
        {
            Configure<AbpTenantResolveOptions>(options =>
            {
                options.TenantResolvers.Add(new QueryStringTenantResolveContributor());
                options.TenantResolvers.Add(new RouteTenantResolveContributor());
                options.TenantResolvers.Add(new HeaderTenantResolveContributor());
                options.TenantResolvers.Add(new CookieTenantResolveContributor());
            });
        }

Domain獲取字符串的方法

 protected override string GetTenantIdOrNameFromHttpContextOrNull(
            ITenantResolveContext context, 
            HttpContext httpContext)
        {
            if (httpContext.Request?.Host == null)
            {
                return null;
            }
            var hostName = httpContext.Request.Host.Host.RemovePreFix(ProtocolPrefixes);
            var extractResult = FormattedStringValueExtracter.Extract(hostName, _domainFormat, ignoreCase: true);
            context.Handled = true;
            if (!extractResult.IsMatch)
            {
                return null;
            }
            return extractResult.Matches[0].Value;
        }

public const string DefaultTenantKey = "__tenant";

 

6、ITenantStore，查找租戶TenantConfiguration,

 

IConnectionStringResolver，解決獲取連接字符串

DefaultConnectionStringResolver，在AbpDataModule配置Configure<AbpDbConnectionOptions>(IConfiguration),先用模塊特定的字符串

若空，則使用Default

   public virtual string Resolve(string connectionStringName = null)
        {
            //Get module specific value if provided
            if (!connectionStringName.IsNullOrEmpty())
            {
                var moduleConnString = Options.ConnectionStrings.GetOrDefault(connectionStringName);
                if (!moduleConnString.IsNullOrEmpty())
                {
                    return moduleConnString;
                }
            }            
            //Get default value
            return Options.ConnectionStrings.Default;
        }

MultiTenantConnectionStringResolver,解決是租戶的字符串，來源TenantConfiguration的ConnectionStrings 不能為空

還沒connectionStringName ，決定用的是tenant.ConnectionStrings.Default，還是Options.ConnectionStrings.Default

若有connectionStringName，根據特定租戶的字符串

還沒有，再回到Option特定字符串，Defaut字符串。

 public override string Resolve(string connectionStringName = null)
        {
            //No current tenant, fallback to default logic
            if (_currentTenant.Id == null)
            {
                return base.Resolve(connectionStringName);
            }

            using (var serviceScope = _serviceProvider.CreateScope())
            {
                var tenantStore = serviceScope
                    .ServiceProvider
                    .GetRequiredService<ITenantStore>();

                var tenant = tenantStore.Find(_currentTenant.Id.Value);

                if (tenant?.ConnectionStrings == null)
                {
                    return base.Resolve(connectionStringName);
                }

                //Requesting default connection string
                if (connectionStringName == null)
                {
                    return tenant.ConnectionStrings.Default ??
                           Options.ConnectionStrings.Default;
                }

                //Requesting specific connection string
                var connString = tenant.ConnectionStrings.GetOrDefault(connectionStringName);
                if (connString != null)
                {
                    return connString;
                }

                /* Requested a specific connection string, but it's not specified for the tenant.
                 * - If it's specified in options, use it.
                 * - If not, use tenant's default conn string.
                 */

                var connStringInOptions = Options.ConnectionStrings.GetOrDefault(connectionStringName);
                if (connStringInOptions != null)
                {
                    return connStringInOptions;
                }

                return tenant.ConnectionStrings.Default ??
                       Options.ConnectionStrings.Default;
            }
        }