CalCachedFolderCount - faster processing by killing at least 1 request.

Author: KelvinTegelaar

Modules/CIPPCore/Public/Entrypoints/Activity Triggers/Mailbox Permissions/Push-GetCalendarPermissionsBatch.ps1

@@ -4,7 +4,10 @@ function Push-GetCalendarPermissionsBatch {
         Process a batch of calendar permission queries
 
     .DESCRIPTION
-        Queries calendar permissions for a batch of mailboxes
+        Queries calendar permissions for a batch of mailboxes.
+        Uses a folder name cache to avoid the expensive Get-MailboxFolderStatistics call
+        on subsequent runs. First run discovers and caches the locale-specific calendar
+        folder name; all future runs skip that call entirely (50% fewer Exchange requests).
 
     .FUNCTIONALITY
         Entrypoint
@@ -19,39 +22,83 @@ function Push-GetCalendarPermissionsBatch {
     try {
         Write-Information "Processing calendar permissions batch $BatchNumber of $TotalBatches for tenant $TenantFilter with $($Mailboxes.Count) mailboxes"
 
+        # Load cached calendar folder names for this tenant
+        $FolderCacheTable = Get-CippTable -tablename 'CalendarFolderCache'
+        $CachedFolders = @{}
+        try {
+
+            $CacheEntries = Get-CIPPAzDataTableEntity @FolderCacheTable -Filter "PartitionKey eq '$TenantFilter'"
+            foreach ($Entry in $CacheEntries) {
+                $CachedFolders[$Entry.RowKey] = $Entry.FolderName
+            }
+            Write-Host "CAL Cached Folders count is $($CachedFolders.count)"
+        } catch {
+            Write-Information "Could not load folder name cache for $TenantFilter, will discover all folder names"
+        }
+
+        $CacheHits = 0
+        $CacheMisses = 0
+        $NewCacheEntries = [System.Collections.Generic.List[hashtable]]::new()
         $AllCalendarPermissions = [System.Collections.Generic.List[object]]::new()
 
         foreach ($MailboxUPN in $Mailboxes) {
             try {
-                # Step 1: Get the calendar folder name (locale-specific)
-                $GetCalParam = @{Identity = $MailboxUPN; FolderScope = 'Calendar' }
-                $CalendarFolder = New-ExoRequest -tenantid $TenantFilter -cmdlet 'Get-MailboxFolderStatistics' -anchor $MailboxUPN -cmdParams $GetCalParam | Select-Object -First 1
-
-                if ($CalendarFolder -and $CalendarFolder.name) {
-                    # Step 2: Get calendar permissions using the folder name
-                    $CalParam = @{Identity = "$($MailboxUPN):\$($CalendarFolder.name)" }
-                    $CalendarPermissions = New-ExoRequest -tenantid $TenantFilter -cmdlet 'Get-MailboxFolderPermission' -anchor $MailboxUPN -cmdParams $CalParam -UseSystemMailbox $true
-
-                    # Normalize the results
-                    foreach ($Perm in $CalendarPermissions) {
-                        $AllCalendarPermissions.Add([PSCustomObject]@{
-                                id           = [guid]::NewGuid().ToString()
-                                Identity     = $Perm.Identity
-                                User         = $Perm.User
-                                AccessRights = $Perm.AccessRights
-                                FolderName   = $Perm.FolderName
+                # Check cache for folder name
+                $FolderName = $CachedFolders[$MailboxUPN]
+
+                if (-not $FolderName) {
+                    # Cache miss — discover the locale-specific calendar folder name
+                    $CacheMisses++
+                    $GetCalParam = @{Identity = $MailboxUPN; FolderScope = 'Calendar' }
+                    $CalendarFolder = New-ExoRequest -tenantid $TenantFilter -cmdlet 'Get-MailboxFolderStatistics' -anchor $MailboxUPN -cmdParams $GetCalParam | Select-Object -First 1
+
+                    if ($CalendarFolder -and $CalendarFolder.name) {
+                        $FolderName = $CalendarFolder.name
+                        # Queue for cache write
+                        $NewCacheEntries.Add(@{
+                                PartitionKey = $TenantFilter
+                                RowKey       = $MailboxUPN
+                                FolderName   = $FolderName
                             })
+                    } else {
+                        Write-Information "No calendar folder found for mailbox $MailboxUPN"
+                        continue
                     }
                 } else {
-                    Write-Information "No calendar folder found for mailbox $MailboxUPN"
+                    $CacheHits++
+                }
+
+                # Get calendar permissions using the folder name
+                $CalParam = @{Identity = "$($MailboxUPN):\$($FolderName)" }
+                $CalendarPermissions = New-ExoRequest -tenantid $TenantFilter -cmdlet 'Get-MailboxFolderPermission' -anchor $MailboxUPN -cmdParams $CalParam -UseSystemMailbox $true
+
+                # Normalize the results
+                foreach ($Perm in $CalendarPermissions) {
+                    $AllCalendarPermissions.Add([PSCustomObject]@{
+                            id           = [guid]::NewGuid().ToString()
+                            Identity     = $Perm.Identity
+                            User         = $Perm.User
+                            AccessRights = $Perm.AccessRights
+                            FolderName   = $Perm.FolderName
+                        })
                 }
             } catch {
                 Write-Information "Failed to get calendar permissions for $MailboxUPN : $($_.Exception.Message)"
                 # Continue processing other mailboxes
             }
         }
 
-        Write-Information "Completed calendar permissions batch $BatchNumber of $TotalBatches - processed $($Mailboxes.Count) mailboxes: $($AllCalendarPermissions.Count) calendar permissions"
+        # Persist newly discovered folder names to cache
+        if ($NewCacheEntries.Count -gt 0) {
+            try {
+                Add-CIPPAzDataTableEntity @FolderCacheTable -Entity $NewCacheEntries -Force
+                Write-Information "Cached $($NewCacheEntries.Count) new calendar folder names for $TenantFilter"
+            } catch {
+                Write-Information "Failed to write folder name cache for $TenantFilter : $($_.Exception.Message)"
+            }
+        }
+
+        Write-Information "Completed calendar permissions batch $BatchNumber of $TotalBatches - processed $($Mailboxes.Count) mailboxes: $($AllCalendarPermissions.Count) permissions (cache hits: $CacheHits, misses: $CacheMisses)"
 
         # Return results grouped by command type for consistency with mailbox permissions
         return @{