ResourceBase: Performance optimizations (#47)

Author: dan-hughes

CHANGELOG.md

@@ -13,6 +13,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - `ResourceBase`
   - Cache properties not in desired state.
   - Make `Set()` call `Test()` and `Test()` call `Get()`.
+  - Remove use of array addition and `ForEach-Object`.
 
 ### Removed
 

RequiredModules.psd1

@@ -8,7 +8,12 @@
     }
 
     # Build dependencies needed for using the module
-    'DscResource.Common'           = 'latest'
+    'DscResource.Common'           = @{
+        Version    = 'latest'
+        Parameters = @{
+            AllowPrerelease = $true
+        }
+    }
 
     # Build dependencies for the pipeline
     InvokeBuild                    = 'latest'
@@ -20,7 +25,12 @@
     Sampler                        = 'latest'
     'Sampler.GitHubTasks'          = 'latest'
     MarkdownLinkCheck              = 'latest'
-    'DscResource.Test'             = 'latest'
+    'DscResource.Test'             = @{
+        Version    = 'latest'
+        Parameters = @{
+            AllowPrerelease = $true
+        }
+    }
 
     'DscResource.DocGenerator'     = 'latest'
     PlatyPS                        = 'latest'

source/Classes/010.ResourceBase.ps1

@@ -78,10 +78,12 @@ class ResourceBase
 
         $dscResourceObject = [System.Activator]::CreateInstance($this.GetType())
 
+        $currentStateResultKeys = @($getCurrentStateResult.Keys)
+
         # Set values returned from the derived class' GetCurrentState().
         foreach ($propertyName in $this.PSObject.Properties.Name)
         {
-            if ($propertyName -in @($getCurrentStateResult.Keys) -and $null -ne $getCurrentStateResult.$propertyName)
+            if ($propertyName -in $currentStateResultKeys -and $null -ne $getCurrentStateResult.$propertyName)
             {
                 $dscResourceObject.$propertyName = $getCurrentStateResult.$propertyName
             }
@@ -92,7 +94,7 @@ class ResourceBase
         # Set key property values unless it was returned from the derived class' GetCurrentState().
         foreach ($propertyName in $this.CachedKeyProperties.Keys)
         {
-            if ($propertyName -notin @($getCurrentStateResult.Keys))
+            if ($propertyName -notin $currentStateResultKeys)
             {
                 # Add the key value to the instance to be returned.
                 $dscResourceObject.$propertyName = $this.$propertyName
@@ -157,10 +159,10 @@ class ResourceBase
         # The Get() method is called by Test().
         $propertiesToModify = $this.PropertiesNotInDesiredState | ConvertFrom-CompareResult
 
-        $propertiesToModify.Keys |
-            ForEach-Object -Process {
-                Write-Verbose -Message ($this.localizedData.SetProperty -f $_, $propertiesToModify.$_)
-            }
+        foreach ($property in $propertiesToModify.Keys)
+        {
+            Write-Verbose -Message ($this.localizedData.SetProperty -f $property, $propertiesToModify.$property)
+        }
 
         <#
             Call the Modify() method with the properties that should be enforced
@@ -202,7 +204,7 @@ class ResourceBase
             CurrentValues     = $currentState
             DesiredValues     = $this.CachedDesiredState
             Properties        = $this.CachedDesiredState.Keys
-            ExcludeProperties = ($excludeProperties + $this.ExcludeDscProperties) | Select-Object -Unique
+            ExcludeProperties = @(($excludeProperties + $this.ExcludeDscProperties) | Sort-Object -Unique)
             IncludeValue      = $true
             # This is needed to sort complex types.
             SortArrayValues   = $true

source/Private/ConvertFrom-CompareResult.ps1

@@ -35,8 +35,9 @@ function ConvertFrom-CompareResult
 
     process
     {
-        $CompareResult | ForEach-Object -Process {
-            $returnHashtable[$_.Property] = $_.ExpectedValue
+        foreach ($r in $CompareResult)
+        {
+            $returnHashtable[$r.Property] = $r.ExpectedValue
         }
     }
 

source/Private/ConvertFrom-Reason.ps1

@@ -37,22 +37,24 @@ function ConvertFrom-Reason
     begin
     {
         # Always return an empty array if there are nothing to convert.
-        $reasonsAsHashtable = [System.Collections.Hashtable[]] @()
+        $reasonsAsHashtable = [System.Collections.Generic.List[System.Collections.Hashtable]]::new()
     }
 
     process
     {
         foreach ($currentReason in $Reason)
         {
-            $reasonsAsHashtable += [System.Collections.Hashtable] @{
-                Code   = $currentReason.Code
-                Phrase = $currentReason.Phrase
-            }
+            $reasonsAsHashtable.Add(
+                [System.Collections.Hashtable] @{
+                    Code   = $currentReason.Code
+                    Phrase = $currentReason.Phrase
+                }
+            )
         }
     }
 
     end
     {
-        return , [System.Collections.Hashtable[]] $reasonsAsHashtable
+        return , [System.Collections.Hashtable[]] $reasonsAsHashtable.ToArray()
     }
 }

source/Private/Get-ClassName.ps1

@@ -43,20 +43,22 @@ function Get-ClassName
     begin
     {
         # Create a list of the inherited class names
-        $class = @()
+        $class = [System.Collections.Generic.List[System.String]]::new()
     }
 
     process
     {
-        $class += $InputObject.GetType().FullName
+        $inputObjectType = $InputObject.GetType()
+
+        $class.Add($inputObjectType.FullName)
 
         if ($Recurse.IsPresent)
         {
-            $parentClass = $InputObject.GetType().BaseType
+            $parentClass = $inputObjectType.BaseType
 
             while ($parentClass -ne [System.Object])
             {
-                $class += $parentClass.FullName
+                $class.Add($parentClass.FullName)
 
                 $parentClass = $parentClass.BaseType
             }
@@ -65,6 +67,6 @@ function Get-ClassName
 
     end
     {
-        return , [System.String[]] $class
+        return , [System.String[]] $class.ToArray()
     }
 }

source/Private/Resolve-Reason.ps1

@@ -1,6 +1,6 @@
 <#
     .SYNOPSIS
-        Returns a array of the type `[Reason]`.
+        Returns an array of the type `[Reason]`.
 
     .DESCRIPTION
         This command builds an array from the properties that is returned by the command
@@ -43,7 +43,7 @@ function Resolve-Reason
     begin
     {
         # Always return an empty array if there are no properties to add.
-        $reasons = [Reason[]] @()
+        $reasons = [System.Collections.Generic.List[Reason]]::new()
     }
 
     process
@@ -60,7 +60,7 @@ function Resolve-Reason
                 $propertyExpectedValue = $currentProperty.ExpectedValue
             }
 
-            if ($property.ActualValue -is [System.Enum])
+            if ($currentProperty.ActualValue -is [System.Enum])
             {
                 # Return the string representation of the value so that conversion to json is correct.
                 $propertyActualValue = $currentProperty.ActualValue.ToString()
@@ -99,20 +99,22 @@ function Resolve-Reason
                 $propertyExpectedValueJson = $propertyExpectedValueJson -replace '\\\\', '\'
             }
 
-            $reasons += [Reason] @{
-                Code   = '{0}:{0}:{1}' -f $ResourceName, $currentProperty.Property
-                # Convert the object to JSON to handle complex types.
-                Phrase = 'The property {0} should be {1}, but was {2}' -f @(
-                    $currentProperty.Property,
-                    $propertyExpectedValueJson,
-                    $propertyActualValueJson
-                )
-            }
+            $reasons.Add(
+                [Reason] @{
+                    Code   = ('{0}:{0}:{1}' -f $ResourceName, $currentProperty.Property)
+                    # Convert the object to JSON to handle complex types.
+                    Phrase = ('The property {0} should be {1}, but was {2}' -f
+                        $currentProperty.Property,
+                        $propertyExpectedValueJson,
+                        $propertyActualValueJson
+                    )
+                }
+            )
         }
     }
 
     end
     {
-        return $reasons
+        return [Reason[]] $reasons.ToArray()
     }
 }

tests/Unit/Classes/ResourceBase.Tests.ps1

@@ -1244,6 +1244,14 @@ $script:mockResourceBaseInstance = [MyMockResource]::new()
                     Add-Member -MemberType ScriptMethod -Name 'Modify' -Value {
                         $script:modifyMethodCallCount++
                     } -Force
+
+                $mockResourceBaseInstance.PropertiesNotInDesiredState = @(
+                    @{
+                        Property      = 'MyResourceProperty2'
+                        ExpectedValue = 'MyNewValue1'
+                        ActualValue   = 'MyValue1'
+                    }
+                )
             }
 
             Mock -CommandName ConvertFrom-CompareResult -MockWith {