Struct VZVirtioBlockDeviceConfiguration

Source

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

Available on crate features VZStorageDeviceConfiguration and VZVirtioBlockDeviceConfiguration only.

Expand description

Configuration of a paravirtualized storage device of type Virtio Block Device.

This device configuration creates a storage device using paravirtualization. The emulated device follows the Virtio Block Device specification.

The host implementation of the device is done through an attachment subclassing VZStorageDeviceAttachment like VZDiskImageStorageDeviceAttachment.

Implementations§

Source §

impl VZVirtioBlockDeviceConfiguration

Source

pub unsafe fn initWithAttachment( this: Allocated<Self>, attachment: &VZStorageDeviceAttachment, ) -> Retained<Self>

Available on crate feature VZStorageDeviceAttachment only.

Initialize a VZVirtioBlockDeviceConfiguration with a device attachment.

Parameter attachment: The storage device attachment. This defines how the virtualized device operates on the host side.

See: VZDiskImageStorageDeviceAttachment

Source

pub unsafe fn validateBlockDeviceIdentifier_error( block_device_identifier: &NSString, ) -> Result<(), Retained<NSError>>

Check if blockDeviceIdentifier is a valid Virtio block device identifier.

Parameter blockDeviceIdentifier: The device identifier to validate.

Parameter error: If not nil, assigned with an error describing why the device identifier is not valid.

The device identifier must be at most 20 bytes in length and ASCII-encodable.

Source

pub unsafe fn blockDeviceIdentifier(&self) -> Retained<NSString>

The device identifier is a string identifying the Virtio block device. Empty string by default.

The identifier can be retrieved in the guest via a VIRTIO_BLK_T_GET_ID request.

The identifier must be encodable as an ASCII string of length at most 20 bytes. This property can be checked with +[VZVirtioBlockDeviceConfiguration validateBlockDeviceIdentifier:error:].

See: +[VZVirtioBlockDeviceConfiguration validateBlockDeviceIdentifier:error:]

Source

pub unsafe fn setBlockDeviceIdentifier( &self, block_device_identifier: &NSString, )

Setter for blockDeviceIdentifier.

Source §

impl VZVirtioBlockDeviceConfiguration

Methods declared on superclass VZStorageDeviceConfiguration.

Source

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

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

Methods from Deref<Target = VZStorageDeviceConfiguration>§

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pub unsafe fn attachment(&self) -> Retained<VZStorageDeviceAttachment>

Available on crate feature VZStorageDeviceAttachment only.

Storage device attachment. Defines what local resource is exposed to the virtual machine as a disk.

See: VZDiskImageStorageDeviceAttachment

Methods from Deref<Target = NSObject>§

Source

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

Handle messages the object doesn’t recognize.

See Apple’s documentation for details.

Methods from Deref<Target = AnyObject>§

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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());

Source

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.

Source

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`
    }
}