From 828baa05c888fb8c1d6fc41dea12087d89fd972a Mon Sep 17 00:00:00 2001
From: Scott Arbeit <scottarbeit@github.com>
Date: Fri, 3 Nov 2023 23:55:25 -0700
Subject: [PATCH] Added MemoryCache to speed up validations.

---
 src/Grace.Actors/Grace.Actors.fsproj          |   1 +
 src/Grace.Actors/Services.Actor.fs            |   5 +
 src/Grace.Server/ApplicationContext.Server.fs |  10 +-
 src/Grace.Server/Branch.Server.fs             |   9 +-
 src/Grace.Server/Directory.Server.fs          |   6 +-
 src/Grace.Server/Grace.Server.fsproj          |   9 +-
 src/Grace.Server/Organization.Server.fs       |  29 +--
 src/Grace.Server/Owner.Server.fs              |  12 +-
 src/Grace.Server/Program.Server.fs            |   5 +
 src/Grace.Server/Repository.Server.fs         |  14 +-
 src/Grace.Server/Startup.Server.fs            |   3 +-
 src/Grace.Server/Storage.Server.fs            |   6 +-
 src/Grace.Server/Validations.Server.fs        | 171 ++++++++++++------
 src/Grace.Shared/Constants.Shared.fs          |   3 +
 14 files changed, 183 insertions(+), 100 deletions(-)

diff --git a/src/Grace.Actors/Grace.Actors.fsproj b/src/Grace.Actors/Grace.Actors.fsproj
index 3106401..8f58341 100644
--- a/src/Grace.Actors/Grace.Actors.fsproj
+++ b/src/Grace.Actors/Grace.Actors.fsproj
@@ -44,6 +44,7 @@
 		<PackageReference Include="Dapr.Client" Version="1.12.0" />
 		<PackageReference Include="FSharpPlus" Version="1.5.0" />
 		<PackageReference Include="Microsoft.Azure.Cosmos" Version="3.36.0" />
+		<PackageReference Include="Microsoft.Extensions.Caching.Memory" Version="8.0.0-rc.2.23479.6" />
 		<PackageReference Include="Nito.AsyncEx" Version="5.1.2" />
 		<PackageReference Include="NodaTime" Version="3.1.9" />
 		<PackageReference Include="NodaTime.Serialization.SystemTextJson" Version="1.1.2" />
diff --git a/src/Grace.Actors/Services.Actor.fs b/src/Grace.Actors/Services.Actor.fs
index deb6986..dc58141 100644
--- a/src/Grace.Actors/Services.Actor.fs
+++ b/src/Grace.Actors/Services.Actor.fs
@@ -18,6 +18,7 @@ open Grace.Shared.Types
 open Grace.Shared.Utilities
 open Microsoft.Azure.Cosmos
 open Microsoft.Azure.Cosmos.Linq
+open Microsoft.Extensions.Caching.Memory
 open Microsoft.Extensions.Logging
 open System
 open System.Collections.Concurrent
@@ -72,6 +73,10 @@ module Services =
     let setLoggerFactory (factory: ILoggerFactory) =
         loggerFactory <- factory
 
+    let mutable internal memoryCache: IMemoryCache = null
+    let setMemoryCache (cache: IMemoryCache) =
+        memoryCache <- cache
+
     let linqSerializerOptions = CosmosLinqSerializerOptions(PropertyNamingPolicy = CosmosPropertyNamingPolicy.CamelCase)
 
     /// Custom QueryRequestOptions that requests Index Metrics only in DEBUG build.
diff --git a/src/Grace.Server/ApplicationContext.Server.fs b/src/Grace.Server/ApplicationContext.Server.fs
index cde196b..eae047e 100644
--- a/src/Grace.Server/ApplicationContext.Server.fs
+++ b/src/Grace.Server/ApplicationContext.Server.fs
@@ -10,6 +10,7 @@ open Grace.Shared
 open Grace.Shared.Types
 open Grace.Shared.Utilities
 open Microsoft.Azure.Cosmos
+open Microsoft.Extensions.Caching.Memory
 open Microsoft.Extensions.Configuration
 open Microsoft.Extensions.DependencyInjection
 open Microsoft.Extensions.Logging
@@ -31,6 +32,7 @@ module ApplicationContext =
     let mutable private actorProxyFactory: IActorProxyFactory = null
     let mutable private actorStateStorageProvider: ActorStateStorageProvider = ActorStateStorageProvider.Unknown
     let mutable loggerFactory: ILoggerFactory = null
+    let mutable memoryCache: IMemoryCache = null
 
     let ActorProxyFactory() = actorProxyFactory
     let ActorStateStorageProvider() = actorStateStorageProvider
@@ -131,7 +133,11 @@ module ApplicationContext =
             let! containerResponse = database.CreateContainerIfNotExistsAsync(containerProperties)
             let cosmosContainer = containerResponse.Container
 
+            // Create a MemoryCache instance.
+            memoryCache <- new MemoryCache(MemoryCacheOptions(), loggerFactory)
+
             // Inject the CosmosClient and CosmosContainer into Actor Services.
-            Grace.Actors.Services.setCosmosClient (cosmosClient)
-            Grace.Actors.Services.setCosmosContainer (cosmosContainer)
+            Grace.Actors.Services.setCosmosClient cosmosClient
+            Grace.Actors.Services.setCosmosContainer cosmosContainer
+            Grace.Actors.Services.setMemoryCache memoryCache
         } :> Task
diff --git a/src/Grace.Server/Branch.Server.fs b/src/Grace.Server/Branch.Server.fs
index 3a5d61c..2d07cb4 100644
--- a/src/Grace.Server/Branch.Server.fs
+++ b/src/Grace.Server/Branch.Server.fs
@@ -35,7 +35,7 @@ module Branch =
 
     let actorProxyFactory = ApplicationContext.ActorProxyFactory()
 
-    let getActorProxy (context: HttpContext) (branchId: BranchId) =
+    let getActorProxy (context: HttpContext) (branchId: string) =
         let actorId = ActorId($"{branchId}")
         actorProxyFactory.CreateActorProxy<IBranchActor>(actorId, ActorName.Branch)
 
@@ -53,7 +53,7 @@ module Branch =
                         parameters.RepositoryId <- repositoryId
                         match! resolveBranchId repositoryId parameters.BranchId parameters.BranchName with
                         | Some branchId ->
-                            let actorProxy = getActorProxy context (Guid.Parse(branchId))
+                            let actorProxy = getActorProxy context branchId
                             let! cmd = command parameters
                             match! actorProxy.Handle cmd (Services.createMetadata context) with
                                 | Ok graceReturn -> return! context |> result200Ok graceReturn
@@ -83,11 +83,12 @@ module Branch =
                 if validationsPassed then
                     match! resolveBranchId parameters.RepositoryId parameters.BranchId parameters.BranchName with
                     | Some branchId ->
-                        let actorProxy = getActorProxy context (Guid.Parse(branchId))
+                        let actorProxy = getActorProxy context branchId
                         let! queryResult = query context maxCount actorProxy
                         let! returnValue = context |> result200Ok (GraceReturnValue.Create queryResult (getCorrelationId context))
                         return returnValue
-                    | None -> return! context |> result400BadRequest (GraceError.Create (BranchError.getErrorMessage BranchDoesNotExist) (getCorrelationId context))
+                    | None ->
+                        return! context |> result400BadRequest (GraceError.Create (BranchError.getErrorMessage BranchDoesNotExist) (getCorrelationId context))
                 else
                     let! error = validationResults |> getFirstError
                     let graceError = GraceError.Create (BranchError.getErrorMessage error) (getCorrelationId context)
diff --git a/src/Grace.Server/Directory.Server.fs b/src/Grace.Server/Directory.Server.fs
index 9384fef..64f8214 100644
--- a/src/Grace.Server/Directory.Server.fs
+++ b/src/Grace.Server/Directory.Server.fs
@@ -35,8 +35,8 @@ module DirectoryVersion =
 
     let actorProxyFactory = ApplicationContext.ActorProxyFactory()
 
-    let getActorProxy (context: HttpContext) (directoryId: DirectoryId) =
-        let actorId = GetActorId directoryId
+    let getActorProxy (context: HttpContext) (directoryId: string) =
+        let actorId = ActorId(directoryId)
         actorProxyFactory.CreateActorProxy<IDirectoryVersionActor>(actorId, ActorName.DirectoryVersion)
 
     let processCommand<'T when 'T :> DirectoryParameters> (context: HttpContext) (validations: Validations<'T>) (command: 'T -> HttpContext -> Task<GraceResult<string>>) =
@@ -70,7 +70,7 @@ module DirectoryVersion =
                 let validationResults = validations parameters context
                 let! validationsPassed = validationResults |> allPass
                 if validationsPassed then
-                    let actorProxy = getActorProxy context (Guid.Parse(parameters.DirectoryId))
+                    let actorProxy = getActorProxy context parameters.DirectoryId
                     let! queryResult = query context maxCount actorProxy
                     let! returnValue = context |> result200Ok (GraceReturnValue.Create queryResult (getCorrelationId context))
                     return returnValue
diff --git a/src/Grace.Server/Grace.Server.fsproj b/src/Grace.Server/Grace.Server.fsproj
index f8f1899..7017c04 100644
--- a/src/Grace.Server/Grace.Server.fsproj
+++ b/src/Grace.Server/Grace.Server.fsproj
@@ -21,10 +21,10 @@
 		<PackageProjectUrl>https://github.com/ScottArbeit/Grace</PackageProjectUrl>
 	</PropertyGroup>
 	<ItemGroup>
-		<ContainerPort Include="5000" Type="tcp"/>
-		<ContainerPort Include="5001" Type="tcp"/>
-		<ContainerPort Include="50001" Type="tcp"/>
-		<ContainerPort Include="57256" Type="tcp"/>
+		<ContainerPort Include="5000" Type="tcp" />
+		<ContainerPort Include="5001" Type="tcp" />
+		<ContainerPort Include="50001" Type="tcp" />
+		<ContainerPort Include="57256" Type="tcp" />
 	</ItemGroup>
 	<ItemGroup>
 		<Compile Include="CosmosSystemTextJsonSerializer.Server.fs" />
@@ -63,6 +63,7 @@
 		<PackageReference Include="Dapr.Actors.AspNetCore" Version="1.12.0" />
 		<PackageReference Include="Dapr.Extensions.Configuration" Version="1.12.0" />
 		<PackageReference Include="Microsoft.Azure.Cosmos" Version="3.36.0" />
+		<PackageReference Include="Microsoft.Extensions.Caching.Memory" Version="8.0.0-rc.2.23479.6" />
 		<!--<PackageReference Include="Microsoft.Extensions.ApiDescription.Server" Version="7.0.1">
 		  <PrivateAssets>all</PrivateAssets>
 		  <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
diff --git a/src/Grace.Server/Organization.Server.fs b/src/Grace.Server/Organization.Server.fs
index 582855c..d33cd6e 100644
--- a/src/Grace.Server/Organization.Server.fs
+++ b/src/Grace.Server/Organization.Server.fs
@@ -70,13 +70,14 @@ module Organization =
                 let validationResults = validations parameters context
                 let! validationsPassed = validationResults |> allPass
                 if validationsPassed then
-                    let actorProxy = getActorProxy context parameters.OrganizationId
-                    let! exists = actorProxy.Exists()
-                    if exists then
+                    match! resolveOrganizationId parameters.OwnerId parameters.OwnerName parameters.OrganizationId parameters.OrganizationName with
+                    | Some organizationId ->
+                        context.Items.Add(nameof(OrganizationId), OrganizationId organizationId)
+                        let actorProxy = getActorProxy context organizationId
                         let! queryResult = query context maxCount actorProxy
                         return! context |> result200Ok (GraceReturnValue.Create queryResult (getCorrelationId context))
-                    else
-                        return! context |> result400BadRequest (GraceError.Create (OrganizationError.getErrorMessage OrganizationIdDoesNotExist) (getCorrelationId context))
+                    | None ->
+                        return! context |> result400BadRequest (GraceError.Create (OrganizationError.getErrorMessage OrganizationDoesNotExist) (getCorrelationId context))
                 else
                     let! error = validationResults |> getFirstError
                     let graceError = GraceError.Create (OrganizationError.getErrorMessage error) (getCorrelationId context)
@@ -99,7 +100,7 @@ module Organization =
                       String.isNotEmpty parameters.OrganizationName OrganizationNameIsRequired
                       String.isValidGraceName parameters.OrganizationName InvalidOrganizationName
                       Owner.ownerExists parameters.OwnerId parameters.OwnerName OwnerDoesNotExist
-                      Organization.organizationIdDoesNotExist parameters.OrganizationId OrganizationIdAlreadyExists
+                      Organization.organizationExists parameters.OwnerId parameters.OwnerName parameters.OrganizationId parameters.OrganizationName OrganizationDoesNotExist
                       Organization.organizationNameIsUnique parameters.OwnerId parameters.OwnerName parameters.OrganizationName OrganizationNameAlreadyExists ]
 
                 let command (parameters: CreateOrganizationParameters) = 
@@ -123,7 +124,7 @@ module Organization =
                       String.isValidGraceName parameters.OrganizationName InvalidOrganizationName
                       String.isNotEmpty parameters.NewName OrganizationNameIsRequired
                       String.isValidGraceName parameters.NewName InvalidOrganizationName
-                      Organization.organizationIdExists parameters.OrganizationId OrganizationIdDoesNotExist
+                      Organization.organizationExists parameters.OwnerId parameters.OwnerName parameters.OrganizationId parameters.OrganizationName OrganizationDoesNotExist
                       Organization.organizationIsNotDeleted parameters.OwnerId parameters.OwnerName parameters.OrganizationId parameters.OrganizationName OrganizationIsDeleted ]
 
                 let command (parameters: SetOrganizationNameParameters) = 
@@ -142,7 +143,7 @@ module Organization =
                       String.isValidGraceName parameters.OrganizationName InvalidOrganizationName
                       String.isNotEmpty parameters.OrganizationType OrganizationTypeIsRequired
                       DiscriminatedUnion.isMemberOf<OrganizationType, OrganizationError> parameters.OrganizationType InvalidOrganizationType
-                      Organization.organizationIdExists parameters.OrganizationId OrganizationIdDoesNotExist
+                      Organization.organizationExists parameters.OwnerId parameters.OwnerName parameters.OrganizationId parameters.OrganizationName OrganizationDoesNotExist
                       Organization.organizationIsNotDeleted parameters.OwnerId parameters.OwnerName parameters.OrganizationId parameters.OrganizationName OrganizationIsDeleted ]
 
                 let command (parameters: SetOrganizationTypeParameters) = OrganizationCommand.SetType (Utilities.discriminatedUnionFromString<OrganizationType>(parameters.OrganizationType).Value) |> returnTask
@@ -160,7 +161,7 @@ module Organization =
                       String.isValidGraceName parameters.OrganizationName InvalidOrganizationName
                       String.isNotEmpty parameters.SearchVisibility SearchVisibilityIsRequired
                       DiscriminatedUnion.isMemberOf<SearchVisibility, OrganizationError> parameters.SearchVisibility InvalidSearchVisibility
-                      Organization.organizationIdExists parameters.OrganizationId OrganizationIdDoesNotExist
+                      Organization.organizationExists parameters.OwnerId parameters.OwnerName parameters.OrganizationId parameters.OrganizationName OrganizationDoesNotExist
                       Organization.organizationIsNotDeleted parameters.OwnerId parameters.OwnerName parameters.OrganizationId parameters.OrganizationName OrganizationIsDeleted ]
 
                 let command (parameters: SetOrganizationSearchVisibilityParameters) =
@@ -177,7 +178,7 @@ module Organization =
                     [ String.isNotEmpty parameters.OrganizationId OrganizationIdIsRequired
                       Guid.isValidAndNotEmpty parameters.OrganizationId InvalidOrganizationId
                       String.isNotEmpty parameters.Description OrganizationDescriptionIsRequired
-                      Organization.organizationIdExists parameters.OrganizationId OrganizationIdDoesNotExist
+                      Organization.organizationExists parameters.OwnerId parameters.OwnerName parameters.OrganizationId parameters.OrganizationName OrganizationDoesNotExist
                       Organization.organizationIsNotDeleted parameters.OwnerId parameters.OwnerName parameters.OrganizationId parameters.OrganizationName OrganizationIsDeleted ]
 
                 let command (parameters: SetOrganizationDescriptionParameters) = OrganizationCommand.SetDescription(parameters.Description) |> returnTask
@@ -194,7 +195,7 @@ module Organization =
                         [ String.isNotEmpty parameters.OrganizationId OrganizationIdIsRequired
                           Guid.isValidAndNotEmpty parameters.OrganizationId InvalidOrganizationId
                           String.isValidGraceName parameters.OrganizationName InvalidOrganizationName
-                          Organization.organizationIdExists parameters.OrganizationId OrganizationIdDoesNotExist
+                          Organization.organizationExists parameters.OwnerId parameters.OwnerName parameters.OrganizationId parameters.OrganizationName OrganizationDoesNotExist
                           Organization.organizationIsNotDeleted parameters.OwnerId parameters.OwnerName parameters.OrganizationId parameters.OrganizationName OrganizationIsDeleted ]
 
                     let query (context: HttpContext) (maxCount: int) (actorProxy: IOrganizationActor) =
@@ -218,7 +219,7 @@ module Organization =
                       Guid.isValidAndNotEmpty parameters.OrganizationId InvalidOrganizationId
                       String.isValidGraceName parameters.OrganizationName InvalidOrganizationName
                       String.isNotEmpty parameters.DeleteReason DeleteReasonIsRequired
-                      Organization.organizationIdExists parameters.OrganizationId OrganizationIdDoesNotExist
+                      Organization.organizationExists parameters.OwnerId parameters.OwnerName parameters.OrganizationId parameters.OrganizationName OrganizationDoesNotExist
                       Organization.organizationIsNotDeleted parameters.OwnerId parameters.OwnerName parameters.OrganizationId parameters.OrganizationName OrganizationIsDeleted ]
 
                 let command (parameters: DeleteOrganizationParameters) = OrganizationCommand.DeleteLogical (parameters.Force, parameters.DeleteReason) |> returnTask
@@ -235,7 +236,7 @@ module Organization =
                       Guid.isValidAndNotEmpty parameters.OrganizationId InvalidOrganizationId
                       String.isValidGraceName parameters.OrganizationName InvalidOrganizationName
                       Input.eitherIdOrNameMustBeProvided parameters.OrganizationId parameters.OrganizationName EitherOrganizationIdOrOrganizationNameRequired
-                      Organization.organizationIdExists parameters.OrganizationId OrganizationIdDoesNotExist
+                      Organization.organizationExists parameters.OwnerId parameters.OwnerName parameters.OrganizationId parameters.OrganizationName OrganizationDoesNotExist
                       Organization.organizationIsDeleted parameters.OwnerId parameters.OwnerName parameters.OrganizationId parameters.OrganizationName OrganizationIsNotDeleted ]
 
                 let command (parameters: OrganizationParameters) = OrganizationCommand.Undelete |> returnTask
@@ -256,7 +257,7 @@ module Organization =
                           String.isNotEmpty parameters.OrganizationId OrganizationIdIsRequired
                           Guid.isValidAndNotEmpty parameters.OrganizationId InvalidOrganizationId
                           String.isValidGraceName parameters.OrganizationName InvalidOrganizationName
-                          Organization.organizationIdExists parameters.OrganizationId OrganizationIdDoesNotExist
+                          Organization.organizationExists parameters.OwnerId parameters.OwnerName parameters.OrganizationId parameters.OrganizationName OrganizationDoesNotExist
                           Organization.organizationIsNotDeleted parameters.OwnerId parameters.OwnerName parameters.OrganizationId parameters.OrganizationName OrganizationIsDeleted ]
 
                     let query (context: HttpContext) (maxCount: int) (actorProxy: IOrganizationActor) =
diff --git a/src/Grace.Server/Owner.Server.fs b/src/Grace.Server/Owner.Server.fs
index 94b3146..4d5b1a0 100644
--- a/src/Grace.Server/Owner.Server.fs
+++ b/src/Grace.Server/Owner.Server.fs
@@ -74,16 +74,12 @@ module Owner =
                 let validationResults = validations parameters context
                 let! validationsPassed = validationResults |> allPass
                 if validationsPassed then
-                    let! ownerId = resolveOwnerId parameters.OwnerId parameters.OwnerName
-                    match ownerId with
+                    match! resolveOwnerId parameters.OwnerId parameters.OwnerName with
                     | Some ownerId ->
+                        context.Items.Add(nameof(OwnerId), OwnerId ownerId)
                         let actorProxy = getActorProxy context ownerId
-                        let! exists = actorProxy.Exists()
-                        if exists then
-                            let! queryResult = query context maxCount actorProxy
-                            return! context |> result200Ok (GraceReturnValue.Create queryResult (getCorrelationId context))
-                        else
-                            return! context |> result400BadRequest (GraceError.Create (OwnerError.getErrorMessage OwnerIdDoesNotExist) (getCorrelationId context))
+                        let! queryResult = query context maxCount actorProxy
+                        return! context |> result200Ok (GraceReturnValue.Create queryResult (getCorrelationId context))
                     | None -> 
                         return! context |> result400BadRequest (GraceError.Create (OwnerError.getErrorMessage OwnerDoesNotExist) (getCorrelationId context))
                 else
diff --git a/src/Grace.Server/Program.Server.fs b/src/Grace.Server/Program.Server.fs
index 84c2c37..4c4e901 100644
--- a/src/Grace.Server/Program.Server.fs
+++ b/src/Grace.Server/Program.Server.fs
@@ -15,6 +15,8 @@ open System.Threading.Tasks
 open System.Net
 open Grace.Shared.Utilities
 open Microsoft.Extensions.Logging
+open ApplicationContext
+open Microsoft.Extensions.Caching.Memory
 
 module Program =
     let createHostBuilder (args: string[]) : IHostBuilder =
@@ -50,8 +52,11 @@ module Program =
         files |> Seq.iter (fun file -> logToConsole $"{file.Name}: {file.Length} bytes")
         logToConsole "-----------------------------------------------------------"
         let host = createHostBuilder(args).Build()
+        
+        // Just placing some much-used services into the ApplicationContext where they're easy to find.
         let loggerFactory = host.Services.GetService(typeof<ILoggerFactory>) :?> ILoggerFactory
         ApplicationContext.setLoggerFactory(loggerFactory)
+
         host.Run()
 
         0 // Exit code
diff --git a/src/Grace.Server/Repository.Server.fs b/src/Grace.Server/Repository.Server.fs
index b0dac2c..cc1375a 100644
--- a/src/Grace.Server/Repository.Server.fs
+++ b/src/Grace.Server/Repository.Server.fs
@@ -44,7 +44,7 @@ module Repository =
 
     let actorProxyFactory = ApplicationContext.ActorProxyFactory()
 
-    let getActorProxy (repositoryId: string) (context: HttpContext) =
+    let getActorProxy (context: HttpContext) (repositoryId: string) =
         let actorId = ActorId(repositoryId)
         actorProxyFactory.CreateActorProxy<IRepositoryActor>(actorId, ActorName.Repository)
 
@@ -70,7 +70,7 @@ module Repository =
                     match repositoryId with
                     | Some repositoryId ->
                         if String.IsNullOrEmpty(parameters.RepositoryId) then parameters.RepositoryId <- repositoryId
-                        let actorProxy = getActorProxy repositoryId context
+                        let actorProxy = getActorProxy context repositoryId
                         let! cmd = command parameters
                         let! result = actorProxy.Handle cmd (Services.createMetadata context)
                         match result with
@@ -98,13 +98,13 @@ module Repository =
                 //let validationResults = validations parameters context
                 let! validationsPassed = validationResults |> allPass
                 if validationsPassed then
-                    context.Items.Add(nameof(RepositoryId), RepositoryId parameters.RepositoryId)
-                    let actorProxy = getActorProxy parameters.RepositoryId context
-                    let! exists = actorProxy.Exists()
-                    if exists then
+                    match! resolveRepositoryId parameters.OwnerId parameters.OwnerName parameters.OrganizationId parameters.OrganizationName parameters.RepositoryId parameters.RepositoryName with
+                    | Some repositoryId ->
+                        context.Items.Add(nameof(RepositoryId), RepositoryId repositoryId)
+                        let actorProxy = getActorProxy context repositoryId
                         let! queryResult = query context maxCount actorProxy
                         return! context |> result200Ok (GraceReturnValue.Create queryResult (getCorrelationId context))
-                    else
+                    | None ->
                         return! context |> result400BadRequest (GraceError.Create (RepositoryError.getErrorMessage RepositoryIdDoesNotExist) (getCorrelationId context))
                 else
                     let! error = validationResults |> getFirstError
diff --git a/src/Grace.Server/Startup.Server.fs b/src/Grace.Server/Startup.Server.fs
index 3f0ee57..6e63e6c 100644
--- a/src/Grace.Server/Startup.Server.fs
+++ b/src/Grace.Server/Startup.Server.fs
@@ -40,7 +40,6 @@ open System.IO
 open Microsoft.Extensions.Configuration
 open Grace.Shared.Converters
 open Grace.Shared.Types
-open Giraffe.ViewEngine.HtmlElements
 
 module Application =
     type FunctionThat_AddsOrUpdatesFile = DirectoryVersion -> FileVersion -> DirectoryVersion
@@ -249,7 +248,7 @@ module Application =
             let actorProxyOptions = ActorProxyOptions(JsonSerializerOptions = Constants.JsonSerializerOptions)  // DaprApiToken = Environment.GetEnvironmentVariable("DAPR_API_TOKEN")) (when we actually implement auth)
             actorProxyOptions.HttpEndpoint <- $"{Environment.GetEnvironmentVariable(Constants.EnvironmentVariables.DaprServerUri)}:{Environment.GetEnvironmentVariable(Constants.EnvironmentVariables.DaprHttpPort)}"
             logToConsole $"actorProxyOptions.HttpEndpoint: {actorProxyOptions.HttpEndpoint}"
-            let actorProxyFactory = ActorProxyFactory(actorProxyOptions)
+            let actorProxyFactory = new ActorProxyFactory(actorProxyOptions)
             ApplicationContext.setActorProxyFactory actorProxyFactory
             ApplicationContext.setActorStateStorageProvider ActorStateStorageProvider.AzureCosmosDb
 
diff --git a/src/Grace.Server/Storage.Server.fs b/src/Grace.Server/Storage.Server.fs
index e0f3c55..1e266ba 100644
--- a/src/Grace.Server/Storage.Server.fs
+++ b/src/Grace.Server/Storage.Server.fs
@@ -57,7 +57,7 @@ module Storage =
             task {
                 try
                     let! fileVersion = context.BindJsonAsync<FileVersion>()
-                    let repositoryActor = Repository.getActorProxy $"{fileVersion.RepositoryId}" context
+                    let repositoryActor = Repository.getActorProxy context $"{fileVersion.RepositoryId}"
                     let! repositoryDto = repositoryActor.Get()
                     match! getReadSharedAccessSignature repositoryDto fileVersion with
                     | Ok downloadUri ->
@@ -80,7 +80,7 @@ module Storage =
                 try
                     logToConsole $"In GetUploadUri..."
                     let! fileVersion = context.BindJsonAsync<FileVersion>()
-                    let repositoryActor = Repository.getActorProxy $"{fileVersion.RepositoryId}" context
+                    let repositoryActor = Repository.getActorProxy context $"{fileVersion.RepositoryId}"
                     let! repositoryDto = repositoryActor.Get()
                     let! uploadUri = getWriteSharedAccessSignature repositoryDto fileVersion
                     context.SetStatusCode StatusCodes.Status200OK
@@ -100,7 +100,7 @@ module Storage =
                     let! fileVersions = context.BindJsonAsync<List<FileVersion>>()
                     Activity.Current.SetTag("fileVersions.Count", $"{fileVersions.Count}") |> ignore
                     if fileVersions.Count > 0 then
-                        let repositoryActor = Repository.getActorProxy $"{fileVersions[0].RepositoryId}" context
+                        let repositoryActor = Repository.getActorProxy context $"{fileVersions[0].RepositoryId}"
                         let! repositoryDto = repositoryActor.Get()
 
                         let uploadMetadata = ConcurrentQueue<UploadMetadata>()
diff --git a/src/Grace.Server/Validations.Server.fs b/src/Grace.Server/Validations.Server.fs
index cd51218..1e3267c 100644
--- a/src/Grace.Server/Validations.Server.fs
+++ b/src/Grace.Server/Validations.Server.fs
@@ -13,12 +13,14 @@ open Grace.Shared.Types
 open Grace.Shared.Utilities
 open Microsoft.AspNetCore.Http
 open System
+open System.Collections.Concurrent
 open System.Collections.Generic
 open System.Threading.Tasks
 
 module Validations =
 
     let actorProxyFactory = ApplicationContext.ActorProxyFactory()
+    let memoryCache = ApplicationContext.memoryCache
 
     module Owner =
 
@@ -27,13 +29,20 @@ module Validations =
             task {
                 let mutable ownerGuid = Guid.Empty
                 if (not <| String.IsNullOrEmpty(ownerId)) && Guid.TryParse(ownerId, &ownerGuid) then
-                    let actorId = Owner.GetActorId(ownerGuid)
-                    let ownerActorProxy = actorProxyFactory.CreateActorProxy<IOwnerActor>(actorId, ActorName.Owner)
-                    let! exists = ownerActorProxy.Exists()
-                    if exists then
+                    let mutable x = null
+                    let cached = memoryCache.TryGetValue(ownerGuid, &x)
+                    if cached then
                         return Ok ()
                     else
-                        return Error error
+                        let actorId = Owner.GetActorId(ownerGuid)
+                        let ownerActorProxy = actorProxyFactory.CreateActorProxy<IOwnerActor>(actorId, ActorName.Owner)
+                        let! exists = ownerActorProxy.Exists()
+                        if exists then
+                            use newCacheEntry = memoryCache.CreateEntry(ownerGuid, Value = null, SlidingExpiration = DefaultSlidingExpiration)
+                            newCacheEntry.Dispose()
+                            return Ok ()
+                        else
+                            return Error error
                 else
                     return Error error
             }
@@ -61,13 +70,20 @@ module Validations =
                 match! resolveOwnerId ownerId ownerName with
                 | Some ownerId ->
                     if Guid.TryParse(ownerId, &ownerGuid) then
-                        let actorId = Owner.GetActorId(ownerGuid)
-                        let ownerActorProxy = actorProxyFactory.CreateActorProxy<IOwnerActor>(actorId, ActorName.Owner)
-                        let! exists = ownerActorProxy.Exists()
-                        if exists then
+                        let mutable x = null
+                        let cached = memoryCache.TryGetValue(ownerGuid, &x)
+                        if cached then
                             return Ok ()
                         else
-                            return Error error
+                            let actorId = Owner.GetActorId(ownerGuid)
+                            let ownerActorProxy = actorProxyFactory.CreateActorProxy<IOwnerActor>(actorId, ActorName.Owner)
+                            let! exists = ownerActorProxy.Exists()
+                            if exists then
+                                use newCacheEntry = memoryCache.CreateEntry(ownerGuid, Value = null, SlidingExpiration = DefaultSlidingExpiration)
+                                newCacheEntry.Dispose()
+                                return Ok ()
+                            else
+                                return Error error
                     else
                         return Ok ()
                 | None -> return Error error
@@ -137,13 +153,20 @@ module Validations =
             task {
                 let mutable organizationGuid = Guid.Empty
                 if (not <| String.IsNullOrEmpty(organizationId)) && Guid.TryParse(organizationId, &organizationGuid) then
-                    let actorId = Organization.GetActorId(organizationGuid)
-                    let organizationActorProxy = actorProxyFactory.CreateActorProxy<IOrganizationActor>(actorId, ActorName.Organization)
-                    let! exists = organizationActorProxy.Exists()
-                    if exists then
+                    let mutable x = null
+                    let cached = memoryCache.TryGetValue(organizationGuid, &x)
+                    if cached then
                         return Ok ()
                     else
-                        return Error error
+                        let actorId = Organization.GetActorId(organizationGuid)
+                        let organizationActorProxy = actorProxyFactory.CreateActorProxy<IOrganizationActor>(actorId, ActorName.Organization)
+                        let! exists = organizationActorProxy.Exists()
+                        if exists then
+                            use newCacheEntry = memoryCache.CreateEntry(organizationGuid, Value = null, SlidingExpiration = DefaultSlidingExpiration)
+                            newCacheEntry.Dispose()
+                            return Ok ()
+                        else
+                            return Error error
                 else
                     return Ok ()
             }
@@ -183,13 +206,20 @@ module Validations =
                 match! resolveOrganizationId ownerId ownerName organizationId organizationName with
                 | Some organizationId ->
                     if Guid.TryParse(organizationId, &organizationGuid) then
-                        let actorId = Organization.GetActorId(organizationGuid)
-                        let organizationActorProxy = actorProxyFactory.CreateActorProxy<IOrganizationActor>(actorId, ActorName.Organization)
-                        let! exists = organizationActorProxy.Exists()
-                        if exists then
+                        let mutable x = null
+                        let cached = memoryCache.TryGetValue(organizationGuid, &x)
+                        if cached then
                             return Ok ()
                         else
-                            return Error error
+                            let actorId = Organization.GetActorId(organizationGuid)
+                            let organizationActorProxy = actorProxyFactory.CreateActorProxy<IOrganizationActor>(actorId, ActorName.Organization)
+                            let! exists = organizationActorProxy.Exists()
+                            if exists then
+                                use newCacheEntry = memoryCache.CreateEntry(organizationGuid, Value = null, SlidingExpiration = DefaultSlidingExpiration)
+                                newCacheEntry.Dispose()
+                                return Ok ()
+                            else
+                                return Error error
                     else
                         return Ok ()
                 | None -> return Error error
@@ -240,15 +270,22 @@ module Validations =
         /// Validates that the given RepositoryId exists in the database.
         let repositoryIdExists<'T> (repositoryId: string) (error: 'T) =
             task {
-                let mutable guid = Guid.Empty
-                if (not <| String.IsNullOrEmpty(repositoryId)) && Guid.TryParse(repositoryId, &guid) then
-                    let actorId = ActorId($"{guid}")
-                    let repositoryActorProxy = actorProxyFactory.CreateActorProxy<IRepositoryActor>(actorId, ActorName.Repository)
-                    let! exists = repositoryActorProxy.Exists()
-                    if exists then
+                let mutable repositoryGuid = Guid.Empty
+                if (not <| String.IsNullOrEmpty(repositoryId)) && Guid.TryParse(repositoryId, &repositoryGuid) then
+                    let mutable x = null
+                    let cached = memoryCache.TryGetValue(repositoryGuid, &x)
+                    if cached then
                         return Ok ()
                     else
-                        return Error error
+                        let actorId = ActorId(repositoryId)
+                        let repositoryActorProxy = actorProxyFactory.CreateActorProxy<IRepositoryActor>(actorId, ActorName.Repository)
+                        let! exists = repositoryActorProxy.Exists()
+                        if exists then
+                            use newCacheEntry = memoryCache.CreateEntry(repositoryGuid, Value = null, SlidingExpiration = DefaultSlidingExpiration)
+                            newCacheEntry.Dispose()
+                            return Ok ()
+                        else
+                            return Error error
                 else
                     return Ok ()
             }
@@ -267,17 +304,24 @@ module Validations =
         /// Validates that the repository exists.
         let repositoryExists<'T> ownerId ownerName organizationId organizationName repositoryId repositoryName (error: 'T) =
             task {
-                let mutable guid = Guid.Empty
+                let mutable repositoryGuid = Guid.Empty
                 match! resolveRepositoryId ownerId ownerName organizationId organizationName repositoryId repositoryName with
                 | Some repositoryId ->
-                    if Guid.TryParse(repositoryId, &guid) then
-                        let actorId = ActorId($"{guid}")
-                        let repositoryActorProxy = actorProxyFactory.CreateActorProxy<IRepositoryActor>(actorId, ActorName.Repository)
-                        let! exists = repositoryActorProxy.Exists()
-                        if exists then
+                    if Guid.TryParse(repositoryId, &repositoryGuid) then
+                        let mutable x = null
+                        let cached = memoryCache.TryGetValue(repositoryGuid, &x)
+                        if cached then
                             return Ok ()
                         else
-                            return Error error
+                            let actorId = ActorId($"{repositoryGuid}")
+                            let repositoryActorProxy = actorProxyFactory.CreateActorProxy<IRepositoryActor>(actorId, ActorName.Repository)
+                            let! exists = repositoryActorProxy.Exists()
+                            if exists then
+                                use newCacheEntry = memoryCache.CreateEntry(repositoryGuid, Value = null, SlidingExpiration = DefaultSlidingExpiration)
+                                newCacheEntry.Dispose()
+                                return Ok ()
+                            else
+                                return Error error
                     else
                         return Ok ()
                 | None -> return Error error
@@ -326,15 +370,22 @@ module Validations =
         /// Validates that the given branchId exists in the database.
         let branchIdExists<'T> (branchId: string) (error: 'T) =
             task {
-                let mutable guid = Guid.Empty
-                if (not <| String.IsNullOrEmpty(branchId)) && Guid.TryParse(branchId, &guid) then
-                    let actorId = ActorId($"{guid}")
-                    let branchActorProxy = actorProxyFactory.CreateActorProxy<IBranchActor>(actorId, ActorName.Branch)
-                    let! exists = branchActorProxy.Exists()
-                    if exists then
+                let mutable branchGuid = Guid.Empty
+                if (not <| String.IsNullOrEmpty(branchId)) && Guid.TryParse(branchId, &branchGuid) then
+                    let mutable x = null
+                    let cached = memoryCache.TryGetValue(branchGuid, &x)
+                    if cached then
                         return Ok ()
                     else
-                        return Error error
+                        let actorId = ActorId(branchId)
+                        let branchActorProxy = actorProxyFactory.CreateActorProxy<IBranchActor>(actorId, ActorName.Branch)
+                        let! exists = branchActorProxy.Exists()
+                        if exists then
+                            use newCacheEntry = memoryCache.CreateEntry(branchGuid, Value = null, SlidingExpiration = DefaultSlidingExpiration)
+                            newCacheEntry.Dispose()
+                            return Ok ()
+                        else
+                            return Error error
                 else
                     return Ok ()
             }
@@ -359,19 +410,26 @@ module Validations =
         /// Validates that the branch exists in the database.
         let branchExists<'T> ownerId ownerName organizationId organizationName repositoryId repositoryName branchId branchName (error: 'T) =
             task {
-                let mutable guid = Guid.Empty
+                let mutable branchGuid = Guid.Empty
                 match! resolveRepositoryId ownerId ownerName organizationId organizationName repositoryId repositoryName with
                 | Some repositoryId ->
                     match! resolveBranchId repositoryId branchId branchName with
                     | Some branchId ->
-                        if Guid.TryParse(branchId, &guid) then
-                            let actorId = ActorId($"{guid}")
-                            let branchActorProxy = actorProxyFactory.CreateActorProxy<IBranchActor>(actorId, ActorName.Branch)
-                            let! exists = branchActorProxy.Exists()
-                            if exists then
+                        if Guid.TryParse(branchId, &branchGuid) then
+                            let mutable x = null
+                            let cached = memoryCache.TryGetValue(branchGuid, &x)
+                            if cached then
                                 return Ok ()
                             else
-                                return Error error
+                                let actorId = ActorId($"{branchGuid}")
+                                let branchActorProxy = actorProxyFactory.CreateActorProxy<IBranchActor>(actorId, ActorName.Branch)
+                                let! exists = branchActorProxy.Exists()
+                                if exists then
+                                    use newCacheEntry = memoryCache.CreateEntry(branchGuid, Value = null, SlidingExpiration = DefaultSlidingExpiration)
+                                    newCacheEntry.Dispose()
+                                    return Ok ()
+                                else
+                                    return Error error
                         else
                             return Error error
                     | None -> return Error error
@@ -434,13 +492,20 @@ module Validations =
         /// Validates that the given DirectoryId exists in the database.
         let directoryIdExists<'T> (directoryId: Guid) (error: 'T) =
             task {
-                let actorId = DirectoryVersion.GetActorId(directoryId)
-                let directoryVersionActorProxy = ApplicationContext.ActorProxyFactory().CreateActorProxy<IDirectoryVersionActor>(actorId, ActorName.DirectoryVersion)
-                let! exists = directoryVersionActorProxy.Exists()
-                if exists then
+                let mutable x = null
+                let cached = memoryCache.TryGetValue(directoryId, &x)
+                if cached then
                     return Ok ()
                 else
-                    return Error error
+                    let actorId = DirectoryVersion.GetActorId(directoryId)
+                    let directoryVersionActorProxy = ApplicationContext.ActorProxyFactory().CreateActorProxy<IDirectoryVersionActor>(actorId, ActorName.DirectoryVersion)
+                    let! exists = directoryVersionActorProxy.Exists()
+                    if exists then
+                        use newCacheEntry = memoryCache.CreateEntry(directoryId, Value = null, SlidingExpiration = DefaultSlidingExpiration)
+                        newCacheEntry.Dispose()
+                        return Ok ()
+                    else
+                        return Error error
             }
 
         /// Validates that all of the given DirectoryIds exist in the database.
diff --git a/src/Grace.Shared/Constants.Shared.fs b/src/Grace.Shared/Constants.Shared.fs
index 67f992b..23180db 100644
--- a/src/Grace.Shared/Constants.Shared.fs
+++ b/src/Grace.Shared/Constants.Shared.fs
@@ -221,6 +221,9 @@ module Constants =
     /// The name of the inter-process communication file used by grace watch to share status with other invocations of Grace.
     let IpcFileName = "graceWatchStatus.json"
 
+    /// The default sliding expiration time for a cache entry.
+    let DefaultSlidingExpiration = TimeSpan.FromMinutes(5.0)
+
 module Results =
     let Ok = 0
     let Exception = -1