ServiceStack cache in VB.net - vb.net

Question

How do I go about implementing ServiceStack cache in VB.net? I've seen many C# examples, but I am not able to transfer this onto vb.net.
The point I get stack in the 1st and 2nd argument of the ServiceStack.ServiceHost.RequestContextExtensions.ToOptimizedResultUsingCache
1st should be: ServiceStack.ServiceHost.IRequestContext - not sure
what IRequestContext is
2nd should be:
ServiceStack.CacheAccess.Providers.MemoryCacheClient - how do I set
this do cache default in config i.e. MemoryCacheClient
Code below, any suggestion much appreciated.
Global.asax.vb
Public Class Global_asax
Inherits System.Web.HttpApplication
Public Class HelloAppHost
Inherits AppHostBase
Public Sub New()
MyBase.New("Web Services", GetType(Wrapper).Assembly)
End Sub
Public Overrides Sub Configure(ByVal container As Container)
Routes.Add(Of GetProduct)("/GetProduct").Add(Of GetProduct)("/GetProduct/{*}")
Plugins.Add(New Cors.CorsFeature(allowedHeaders:="Content-Type, Authorization"))
container.Register(Of ICacheClient)(New MemoryCacheClient())
End Sub
End Class
Sub Application_Start(ByVal sender As Object, ByVal e As EventArgs)
Dim apphost = New HelloAppHost()
apphost.Init()
End Sub
End Class
WS.vb
Public Class Wrapper
Public Class WrapperGetProduct
Implements IService(Of GetProduct)
Public Function Execute(ByVal request As GetProduct) As Object Implements ServiceStack.ServiceHost.IService(Of GetProduct).Execute
Dim cachekey As String = "some_key"
Dim expireInTimespan = New TimeSpan(1, 0, 0)
Return ServiceStack.ServiceHost.RequestContextExtensions.ToOptimizedResultUsingCache(
ServiceStack.ServiceHost.IRequestContext, // not sure what this should be
ServiceStack.CacheAccess.Providers.MemoryCacheClient, // not sure what this should be - how do I set this to cache setted in configuration (in memory cache)?
cachekey, expireInTimespan,
Function() request.HandleRequest()
)
End Function
End Class
End Class

Answer 1

Use the new API
ToOptimizedResultUsingCache is an extension method for RequestContext which services inherit/expose, same with Cache (resolved automatically via IOC).
Example below converted from C#, caching/wrapping an existing service (AppConfig and Repository are resolved via IOC, registered in AppHost configure method).
Imports System.Collections.Generic
Imports ServiceStack.Common
Imports ServiceStack.ServiceHost
Imports ServiceStack.ServiceInterface.ServiceModel
Imports ServiceStack.Common.Web
Public Class SearchTerm
Public Property Latitude() As Double
Get
Return m_Latitude
End Get
Set
m_Latitude = Value
End Set
End Property
Private m_Latitude As Double
Public Property Longitude() As Double
Get
Return m_Longitude
End Get
Set
m_Longitude = Value
End Set
End Property
Private m_Longitude As Double
Public Property Term() As String
Get
Return m_Term
End Get
Set
m_Term = Value
End Set
End Property
Private m_Term As String
End Class
<Route("/lookup/searchterm", "GET")> _
Public Class SearchTermRequest
Implements IReturn(Of SearchTermResponse)
Public Property Term() As String
Get
Return m_Term
End Get
Set
m_Term = Value
End Set
End Property
Private m_Term As String
End Class
Public Class SearchTermResponse
Implements IHasResponseStatus
Public Property ResponseStatus() As ResponseStatus
Get
Return m_ResponseStatus
End Get
Set
m_ResponseStatus = Value
End Set
End Property
Private m_ResponseStatus As ResponseStatus
Public Property Results() As List(Of SearchTerm)
Get
Return m_Results
End Get
Set
m_Results = Value
End Set
End Property
Private m_Results As List(Of SearchTerm)
End Class
<Route("/cached/lookup/searchterm")> _
Public Class CachedSearchTermRequest
Implements IReturn(Of CachedSearchTermResponse)
Public ReadOnly Property CacheKey() As String
Get
Return UrnId.Create(Of CachedSearchTermRequest)(String.Format("{0}", Me.Term))
End Get
End Property
Public Property Term() As String
Get
Return m_Term
End Get
Set
m_Term = Value
End Set
End Property
Private m_Term As String
End Class
Public Class CachedSearchTermResponse
Implements IHasResponseStatus
Public Property ResponseStatus() As ResponseStatus
Get
Return m_ResponseStatus
End Get
Set
m_ResponseStatus = Value
End Set
End Property
Private m_ResponseStatus As ResponseStatus
Public Property Results() As List(Of SearchTerm)
Get
Return m_Results
End Get
Set
m_Results = Value
End Set
End Property
Private m_Results As List(Of SearchTerm)
End Class
Public Class SearchTermService
Inherits Service
Public Property Repository() As IRepository
Get
Return m_Repository
End Get
Set
m_Repository = Value
End Set
End Property
Private m_Repository As IRepository
Public Function [Get](request As SearchTermRequest) As SearchTermResponse
Return New SearchTermResponse() With { _
Key .Results = Me.Repository.SearchTermGet(request) _
}
End Function
End Class
Public Class CachedSearchTermService
Inherits Service
Public Property AppConfig() As AppConfig
Get
Return m_AppConfig
End Get
Set
m_AppConfig = Value
End Set
End Property
Private m_AppConfig As AppConfig
Public Function [Get](request As CachedSearchTermRequest) As Object
Dim cacheKey As String = request.CacheKey
Return Me.RequestContext.ToOptimizedResultUsingCache(
MyBase.Cache, cacheKey, New TimeSpan(0, Me.AppConfig.CacheTimeMinutes, 0),
Function()
Using service = Me.ResolveService(Of SearchTermService)()
Return service.[Get](request.TranslateTo(Of SearchTermRequest)()).TranslateTo(Of CachedSearchTermResponse)()
End Using
End Function
)
End Function
End Class