//TenantModelCacheKeyFactory的作用主要是创建TenantModelCacheKey实例。TenantModelCacheKey的作用是作为一个键值，标识dbContext中的OnModelCreating否需要调用。
//为什么这样做呢？因为ef core为了优化效率，避免在dbContext每次实例化的时候，都需要重新构建数据实体模型。
//在默认情况下，OnModelCreating只会调用一次就会存在缓存。但由于我们创建了TenantModelCacheKey，使得我们有机会判断在什么情况下需要重新调用OnModelCreating
internal static IServiceCollection AddDatabase <TDbContext>(this IServiceCollection services,
ConnectionResolverOption option)
where TDbContext : DbContext, ITenantDbContext
{
//容器的三部曲：实例化一个容器、注册、获取服务
// 单例生命周期 在容器中永远只有当前这一个 AddSingleton
services.AddSingleton(option);
//当前请求作用域内 只有当前这个实例 AddScoped
services.AddScoped <TenantInfo>();
services.AddScoped <ISqlConnectionResolver, TenantSqlConnectionResolver>();
services.AddDbContext <TDbContext>((serviceProvider, options) =>
{
var resolver = serviceProvider.GetRequiredService <ISqlConnectionResolver>();
var dbOptionBuilder = options.UseSqlServer(resolver.GetConnection());
// TenantModelCacheKeyFactory 配置到dbOptionBuilder
if (option.Type == ConnectionResolverType.ByTabel)
{
dbOptionBuilder.ReplaceService <IModelCacheKeyFactory, TenantModelCacheKeyFactory <TDbContext> >();
}
});
return(services);
}
public static IServiceCollection AddDatabasePerConnection <TDbContext>(this IServiceCollection services,
string key = "default")
where TDbContext : DbContext, ITenantDbContext
{
var option = new ConnectionResolverOption()
{
Key = key,
Type = ConnectionResolverType.ByDatabase
};
return(services.AddDatabasePerConnection <TDbContext>(option));
}
public static IServiceCollection AddTenantDatabasePerTable <TDbContext>(this IServiceCollection services,
string connectionStringName, string key = "default")
where TDbContext : DbContext, ITenantDbContext
{
var option = new ConnectionResolverOption()
{
Key = key,
Type = ConnectionResolverType.ByTabel,
ConnectinStringName = connectionStringName
};
return(services.AddTenantDatabasePerTable <TDbContext>(option));
}
public static IServiceCollection AddDatabasePerConnection <TDbContext>(this IServiceCollection services,
ConnectionResolverOption option)
where TDbContext : DbContext, ITenantDbContext
{
if (option == null)
{
option = new ConnectionResolverOption()
{
Key = "default",
Type = ConnectionResolverType.ByDatabase,
};
}
return(services.AddDatabase <TDbContext>(option));
}
public TenantSqlConnectionResolver(TenantInfo tenantInfo, IConfiguration configuration, ConnectionResolverOption option)
{
this._option = option;
this._tenantInfo = tenantInfo;
this._configuration = configuration;
}