Struct VZDiskBlockDeviceStorageDeviceAttachment

#[repr(C)]
pub struct VZDiskBlockDeviceStorageDeviceAttachment { /* private fields */ }

Available on crate features VZDiskBlockDeviceStorageDeviceAttachment and VZStorageDeviceAttachment only.

Storage device attachment using a disk block device to store data.

The disk block device implements a storage attachment by using an actual disk rather than a disk image on a file system.

For example, a disk block device on the disk at /dev/rdisk42 would execute the I/O operations directly on that disk rather than through a file system.

Note that if the disk has a file system formatted on it, the guest is able to destroy data in a way that is not recoverable. The disk passed to this attachment needs to be handled with caution.

An example use of this API is:

NSFileHandle *fileHandle = [NSFileHandle fileHandleForReadingAtPath:
"
/dev/rdisk42"];
if (!fileHandle) {
// Handle errors.
}

NSError *error;
VZDiskBlockDeviceStorageDeviceAttachment *attachment =
[[VZDiskBlockDeviceStorageDeviceAttachment alloc] initWithFileHandle:fileHandle
readOnly:YES
synchronizationMode:VZDiskSynchronizationModeFull
error:error];
if (!attachment) {
// Handle errors.
}

Disk file handles are typically only accessible by the root user unless permission is explicitly granted. Running virtual machines as root is not recommended. If root access is required to open the file descriptor, it is recommended to do that operation in a separate process then pass the file descriptor to a less privileged process running Virtualization framework.

See: VZDiskImageStorageDeviceAttachment

See: VZNVMExpressControllerDeviceConfiguration

See: VZUSBMassStorageDeviceConfiguration

See: VZVirtioBlockDeviceConfiguration

See also Apple’s documentation

Implementations

impl VZDiskBlockDeviceStorageDeviceAttachment

pub unsafe fn initWithFileHandle_readOnly_synchronizationMode_error( this: Allocated<Self>, file_handle: &NSFileHandle, read_only: bool, synchronization_mode: VZDiskSynchronizationMode, ) -> Result<Retained<Self>, Retained<NSError>>

Available on crate feature VZDiskSynchronizationMode only.

Initialize the disk attachment from a file handle.

Parameter fileHandle: File handle to a block device.

Parameter readOnly: If YES, the disk attachment is read only, otherwise, if the file handle allows writes, the device can write data into it.

Parameter synchronizationMode: Defines how the disk synchronizes with the underlying storage when the guest operating system flushes data.

Parameter error: If not nil, assigned with the error if the initialization failed.

Returns: An initialized VZDiskBlockDeviceStorageDeviceAttachment or nil if there was an error.

The file handle is retained by the disk attachment. The handle must be open when the virtual machine starts.

The readOnly parameter affects how the disk is exposed to the guest operating system by the storage controller. If the disk is intended to be used read-only, it is also recommended to open the file handle as read-only.

pub unsafe fn fileHandle(&self) -> Retained<NSFileHandle>

File handle to the underlying disk used for storage by the attachment.

pub unsafe fn isReadOnly(&self) -> bool

Whether the underlying disk attachment is read-only.

pub unsafe fn synchronizationMode(&self) -> VZDiskSynchronizationMode

Available on crate feature VZDiskSynchronizationMode only.

The mode in which the disk image synchronizes data with the underlying storage device.

impl VZDiskBlockDeviceStorageDeviceAttachment

Methods declared on superclass VZStorageDeviceAttachment.

pub unsafe fn new() -> Retained<Self>

pub unsafe fn init(this: Allocated<Self>) -> Retained<Self>

Methods from Deref<Target = NSObject>

pub fn doesNotRecognizeSelector(&self, sel: Sel) -> !

Handle messages the object doesn’t recognize.

See Apple’s documentation for details.

Methods from Deref<Target = AnyObject>

pub fn class(&self) -> &'static AnyClass

Dynamically find the class of this object.

Panics

May panic if the object is invalid (which may be the case for objects returned from unavailable init/new methods).

Example

Check that an instance of NSObject has the precise class NSObject.

use objc2::ClassType;
use objc2::runtime::NSObject;

let obj = NSObject::new();
assert_eq!(obj.class(), NSObject::class());

pub unsafe fn get_ivar<T>(&self, name: &str) -> &T

where T: Encode,

👎Deprecated: this is difficult to use correctly, use Ivar::load instead.

Use Ivar::load instead.

Safety

The object must have an instance variable with the given name, and it must be of type T.

See Ivar::load_ptr for details surrounding this.

pub fn downcast_ref<T>(&self) -> Option<&T>

where T: DowncastTarget,

Attempt to downcast the object to a class of type T.

This is the reference-variant. Use Retained::downcast if you want to convert a retained object to another type.

Mutable classes

Some classes have immutable and mutable variants, such as NSString and NSMutableString.

When some Objective-C API signature says it gives you an immutable class, it generally expects you to not mutate that, even though it may technically be mutable “under the hood”.

So using this method to convert a NSString to a NSMutableString, while not unsound, is generally frowned upon unless you created the string yourself, or the API explicitly documents the string to be mutable.

See Apple’s documentation on mutability and on isKindOfClass: for more details.

Generic classes

Objective-C generics are called “lightweight generics”, and that’s because they aren’t exposed in the runtime. This makes it impossible to safely downcast to generic collections, so this is disallowed by this method.

You can, however, safely downcast to generic collections where all the type-parameters are AnyObject.

Panics

This works internally by calling isKindOfClass:. That means that the object must have the instance method of that name, and an exception will be thrown (if CoreFoundation is linked) or the process will abort if that is not the case. In the vast majority of cases, you don’t need to worry about this, since both root objects NSObject and NSProxy implement this method.

Examples

Cast an NSString back and forth from NSObject.

use objc2::rc::Retained;
use objc2_foundation::{NSObject, NSString};

let obj: Retained<NSObject> = NSString::new().into_super();
let string = obj.downcast_ref::<NSString>().unwrap();
// Or with `downcast`, if we do not need the object afterwards
let string = obj.downcast::<NSString>().unwrap();

Try (and fail) to cast an NSObject to an NSString.

use objc2_foundation::{NSObject, NSString};

let obj = NSObject::new();
assert!(obj.downcast_ref::<NSString>().is_none());

Try to cast to an array of strings.

use objc2_foundation::{NSArray, NSObject, NSString};

let arr = NSArray::from_retained_slice(&[NSObject::new()]);
// This is invalid and doesn't type check.
let arr = arr.downcast_ref::<NSArray<NSString>>();

This fails to compile, since it would require enumerating over the array to ensure that each element is of the desired type, which is a performance pitfall.

Downcast when processing each element instead.

use objc2_foundation::{NSArray, NSObject, NSString};

let arr = NSArray::from_retained_slice(&[NSObject::new()]);

for elem in arr {
    if let Some(data) = elem.downcast_ref::<NSString>() {
        // handle `data`
    }
}

Trait Implementations

impl AsRef<AnyObject> for VZDiskBlockDeviceStorageDeviceAttachment

fn as_ref(&self) -> &AnyObject

Converts this type into a shared reference of the (usually inferred) input type.

impl AsRef<NSObject> for VZDiskBlockDeviceStorageDeviceAttachment

fn as_ref(&self) -> &NSObject

Converts this type into a shared reference of the (usually inferred) input type.

impl AsRef<VZDiskBlockDeviceStorageDeviceAttachment> for VZDiskBlockDeviceStorageDeviceAttachment

fn as_ref(&self) -> &Self

Converts this type into a shared reference of the (usually inferred) input type.

impl AsRef<VZStorageDeviceAttachment> for VZDiskBlockDeviceStorageDeviceAttachment

fn as_ref(&self) -> &VZStorageDeviceAttachment

Converts this type into a shared reference of the (usually inferred) input type.

impl Borrow<AnyObject> for VZDiskBlockDeviceStorageDeviceAttachment

fn borrow(&self) -> &AnyObject

Immutably borrows from an owned value.

impl Borrow<NSObject> for VZDiskBlockDeviceStorageDeviceAttachment

fn borrow(&self) -> &NSObject

Immutably borrows from an owned value.

impl Borrow<VZStorageDeviceAttachment> for VZDiskBlockDeviceStorageDeviceAttachment

fn borrow(&self) -> &VZStorageDeviceAttachment

Immutably borrows from an owned value.

impl ClassType for VZDiskBlockDeviceStorageDeviceAttachment

const NAME: &'static str = "VZDiskBlockDeviceStorageDeviceAttachment"

The name of the Objective-C class that this type represents.

type Super = VZStorageDeviceAttachment

The superclass of this class.

type ThreadKind = <<VZDiskBlockDeviceStorageDeviceAttachment as ClassType>::Super as ClassType>::ThreadKind

Whether the type can be used from any thread, or from only the main thread.

fn class() -> &'static AnyClass

Get a reference to the Objective-C class that this type represents.

fn as_super(&self) -> &Self::Super

Get an immutable reference to the superclass.

impl Debug for VZDiskBlockDeviceStorageDeviceAttachment

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Deref for VZDiskBlockDeviceStorageDeviceAttachment

type Target = VZStorageDeviceAttachment

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl Hash for VZDiskBlockDeviceStorageDeviceAttachment

fn hash<H: Hasher>(&self, state: &mut H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Message for VZDiskBlockDeviceStorageDeviceAttachment

fn retain(&self) -> Retained<Self>

where Self: Sized,

Increment the reference count of the receiver.

impl NSObjectProtocol for VZDiskBlockDeviceStorageDeviceAttachment

fn isEqual(&self, other: Option<&AnyObject>) -> bool

where Self: Sized + Message,

Check whether the object is equal to an arbitrary other object.

fn hash(&self) -> usize

where Self: Sized + Message,

An integer that can be used as a table address in a hash table structure.

fn isKindOfClass(&self, cls: &AnyClass) -> bool

where Self: Sized + Message,

Check if the object is an instance of the class, or one of its subclasses.

fn is_kind_of<T>(&self) -> bool

where T: ClassType, Self: Sized + Message,

👎Deprecated: use isKindOfClass directly, or cast your objects with AnyObject::downcast_ref

Check if the object is an instance of the class type, or one of its subclasses.

fn isMemberOfClass(&self, cls: &AnyClass) -> bool

where Self: Sized + Message,

Check if the object is an instance of a specific class, without checking subclasses.

fn respondsToSelector(&self, aSelector: Sel) -> bool

where Self: Sized + Message,

Check whether the object implements or inherits a method with the given selector.

fn conformsToProtocol(&self, aProtocol: &AnyProtocol) -> bool

where Self: Sized + Message,

Check whether the object conforms to a given protocol.

fn description(&self) -> Retained<NSObject>

where Self: Sized + Message,

A textual representation of the object.

fn debugDescription(&self) -> Retained<NSObject>

where Self: Sized + Message,

A textual representation of the object to use when debugging.

fn isProxy(&self) -> bool

where Self: Sized + Message,

Check whether the receiver is a subclass of the NSProxy root class instead of the usual NSObject.

fn retainCount(&self) -> usize

where Self: Sized + Message,

The reference count of the object.

impl PartialEq for VZDiskBlockDeviceStorageDeviceAttachment

fn eq(&self, other: &Self) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl RefEncode for VZDiskBlockDeviceStorageDeviceAttachment

const ENCODING_REF: Encoding = <VZStorageDeviceAttachment as ::objc2::RefEncode>::ENCODING_REF

The Objective-C type-encoding for a reference of this type.

impl DowncastTarget for VZDiskBlockDeviceStorageDeviceAttachment

impl Eq for VZDiskBlockDeviceStorageDeviceAttachment