scripting: add support for disposible mode

Scripting/UTM.sdef

@@ -141,11 +141,14 @@
         
         <command name="start" code="UTMvstar">
           <direct-parameter description="Virtual machine to start." type="virtual machine"/>
+          <parameter name="saving" code="SaVe" description="When false, do not save the VM changes to disk. Default value is true." type="boolean" optional="yes">
+            <cocoa key="saveFlag"/>
+          </parameter>
         </command>
         
         <command name="suspend" code="UTMvsusp">
           <direct-parameter description="Virtual machine to suspend." type="virtual machine"/>
-          <parameter name="saving" code="SaVe" description="Save VM state after suspend." type="boolean">
+          <parameter name="saving" code="SaVe" description="Save VM state after suspend. Default value is false." type="boolean" optional="yes">
             <cocoa key="saveFlag"/>
           </parameter>
         </command>

Scripting/UTMScripting.swift

@@ -125,7 +125,7 @@ extension SBObject: UTMScriptingWindow {}
     @objc optional var memory: String { get } // RAM size.
     @objc optional var backend: UTMScriptingBackend { get } // Emulation/virtualization engine used.
     @objc optional var status: UTMScriptingStatus { get } // Current running status.
-    @objc optional func start()
+    @objc optional func startSaving(_ saving: Bool)
     @objc optional func suspendSaving(_ saving: Bool)
     @objc optional func stopBy(_ by: UTMScriptingStopMethod)
 }

Scripting/UTMScriptingVirtualMachineImpl.swift

@@ -121,7 +121,14 @@ class UTMScriptingVirtualMachineImpl: NSObject {
     }
     
     @objc func start(_ command: NSScriptCommand) {
+        let shouldSaveState = command.evaluatedArguments?["saveFlag"] as? Bool ?? true
         withScriptCommand(command) { [self] in
+            if !shouldSaveState {
+                guard let vm = vm as? UTMQemuVirtualMachine else {
+                    throw ScriptingError.operationNotSupported
+                }
+                vm.isRunningAsSnapshot = true
+            }
             data.run(vm: vm, startImmediately: false)
             if vm.state == .vmStopped {
                 try await vm.vmStart()
@@ -134,7 +141,7 @@ class UTMScriptingVirtualMachineImpl: NSObject {
     }
     
     @objc func suspend(_ command: NSScriptCommand) {
-        let shouldSaveState = command.evaluatedArguments?["doneFlag"] as? Bool ?? false
+        let shouldSaveState = command.evaluatedArguments?["saveFlag"] as? Bool ?? false
         withScriptCommand(command) { [self] in
             try await vm.vmPause(save: shouldSaveState)
         }
@@ -158,10 +165,12 @@ class UTMScriptingVirtualMachineImpl: NSObject {
 extension UTMScriptingVirtualMachineImpl {
     enum ScriptingError: Error, LocalizedError {
         case operationNotAvailable
+        case operationNotSupported
         
         var localizedDescription: String {
             switch self {
             case .operationNotAvailable: return NSLocalizedString("Operation not available.", comment: "UTMScriptingVirtualMachineImpl")
+            case .operationNotSupported: return NSLocalizedString("Operation not supported by the backend.", comment: "UTMScriptingVirtualMachineImpl")
             }
         }
     }

utmctl/UTMCtl.swift

@@ -203,9 +203,12 @@ extension UTMCtl {
         @Flag(name: .shortAndLong, help: "Attach to the first serial port after start.")
         var attach: Bool = false
         
+        @Flag(help: "Run VM as a snapshot and do not save changes to disk.")
+        var disposible: Bool = false
+        
         func run(with application: UTMScriptingApplication) throws {
             let vm = try virtualMachine(forIdentifier: identifer, in: application)
-            vm.start!()
+            vm.startSaving!(!disposible)
             if attach {
                 var attachCommand = Attach()
                 attachCommand.environment = environment