Struct VZNetworkBlockDeviceStorageDeviceAttachment

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

Available on crate features VZNetworkBlockDeviceStorageDeviceAttachment and VZStorageDeviceAttachment only.

Storage device attachment backed by a Network Block Device (NBD) client.

This storage device attachment provides an NBD client implementation. The NBD client is connected to an NBD server referred to by an NBD Uniform Resource Indicator (URI), represented as an URL in this API. The NBD server runs outside of Virtualization framework and is not controlled by Virtualization framework. The NBD client forwards the guest’s I/O operations to the NBD server, where the I/O operations are handled.

The NBD client will attempt to connect to the NBD server referred to by the URL when you start the virtual machine (e.g. when [VZVirtualMachine startWithCompletionHandler:] is called). A connection attempt is NOT made when the attachment object is initialized. Reconnection attempts will take place throughout the life cycle of the virtual machine when the NBD client encounters a recoverable error such as connection timeout and unexpected connection errors. The NBD client will disconnect from the server when the virtual machine shuts down.

Using this attachment requires the app to have the “com.apple.security.network.client” entitlement as this attachment opens an outgoing network connection.

For more information about NBD, see https://github.com/NetworkBlockDevice/nbd/blob/master/doc/proto.md. For more information about the NBD URL format, see https://github.com/NetworkBlockDevice/nbd/blob/master/doc/uri.md.

An example use of this API is:

NSURL *url = [[NSURL alloc] initWithString:
"
nbd://localhost:10809/myDisk"]
NSError *error = nil;
VZNetworkBlockDeviceStorageDeviceAttachment *attachment =
[[VZNetworkBlockDeviceStorageDeviceAttachment alloc] initWithURL:url
timeout:5.0
forcedReadOnly:NO
synchronizationMode:VZDiskSynchronizationModeFull
error:
&error
];

if (!attachment) {
// Handle the `error`.
}

VZVirtioBlockDeviceConfiguration *blockDevice = [[VZVirtioBlockDeviceConfiguration alloc] initWithAttachment:attachment];

See also Apple’s documentation

Implementations

impl VZNetworkBlockDeviceStorageDeviceAttachment

pub unsafe fn initWithURL_timeout_forcedReadOnly_synchronizationMode_error( this: Allocated<Self>, url: &NSURL, timeout: NSTimeInterval, forced_read_only: bool, synchronization_mode: VZDiskSynchronizationMode, ) -> Result<Retained<Self>, Retained<NSError>>

Available on crate feature VZDiskSynchronizationMode only.

Initialize the attachment from an NBD Uniform Resource Indicator (URI) represented as an URL.

Parameter URL: The URL referring to the NBD server to which the NBD client is to be connected.

Parameter timeout: The timeout value in seconds for the connection between the client and server. When the timeout expires, an attempt to reconnect with the server will take place.

Parameter forcedReadOnly: If YES, the disk attachment is forced to be read-only, regardless of whether or not the NBD server supports write requests.

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

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

The forcedReadOnly parameter affects how the NBD client is exposed to the guest operating system by the storage controller. As part of the NBD protocol, whether or not the disk exposed by the NBD client is read-only is advertised by the NBD server during the handshake phase of the protocol. Setting forcedReadOnly to YES will force the NBD client to show up as read-only to the guest regardless of whether or not the NBD server advertises itself as read-only.

pub unsafe fn initWithURL_error( this: Allocated<Self>, url: &NSURL, ) -> Result<Retained<Self>, Retained<NSError>>

Convenience initializer to create the attachment from an NBD URL.

Parameter URL: The URL referring to the NBD server to which the NBD client is to be connected.

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

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

This initializer automatically assigns optimized default values for the timeout, forcedReadOnly, and synchronizationMode properties.

pub unsafe fn validateURL_error(url: &NSURL) -> Result<(), Retained<NSError>>

Check if URL is a valid NBD URL.

Parameter URL: The NBD URL to validate.

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

See https://github.com/NetworkBlockDevice/nbd/blob/master/doc/uri.md for more detailed descriptions of valid URIs.

This method checks that the URL is well-formed, it does not attempt to access the URL.

pub unsafe fn URL(&self) -> Retained<NSURL>

URL referring to the NBD server to which the NBD client is to be connected.

pub unsafe fn timeout(&self) -> NSTimeInterval

The timeout value in seconds for the connection between the client and server. When the timeout expires, an attempt to reconnect with the server will take place.

pub unsafe fn isForcedReadOnly(&self) -> bool

Whether the underlying disk attachment is forced to be read-only.

The forcedReadOnly parameter affects how the NBD client is exposed to the guest operating system by the storage controller. As part of the NBD protocol, whether or not the disk exposed by the NBD client is read-only is advertised by the NBD server during the handshake phase of the protocol. Setting forcedReadOnly to YES will force the NBD client to show up as read-only to the guest regardless of whether or not the NBD server advertises itself as read-only.

pub unsafe fn synchronizationMode(&self) -> VZDiskSynchronizationMode

Available on crate feature VZDiskSynchronizationMode only.

The mode in which the NBD client synchronizes data with the NBD server.

pub unsafe fn delegate( &self, ) -> Option<Retained<ProtocolObject<dyn VZNetworkBlockDeviceStorageDeviceAttachmentDelegate>>>

The attachment’s delegate.

pub unsafe fn setDelegate( &self, delegate: Option<&ProtocolObject<dyn VZNetworkBlockDeviceStorageDeviceAttachmentDelegate>>, )

This is a weak property. Setter for delegate.

impl VZNetworkBlockDeviceStorageDeviceAttachment

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 VZNetworkBlockDeviceStorageDeviceAttachment

fn as_ref(&self) -> &AnyObject

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

impl AsRef<NSObject> for VZNetworkBlockDeviceStorageDeviceAttachment

fn as_ref(&self) -> &NSObject

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

impl AsRef<VZNetworkBlockDeviceStorageDeviceAttachment> for VZNetworkBlockDeviceStorageDeviceAttachment

fn as_ref(&self) -> &Self

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

impl AsRef<VZStorageDeviceAttachment> for VZNetworkBlockDeviceStorageDeviceAttachment

fn as_ref(&self) -> &VZStorageDeviceAttachment

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

impl Borrow<AnyObject> for VZNetworkBlockDeviceStorageDeviceAttachment

fn borrow(&self) -> &AnyObject

Immutably borrows from an owned value.

impl Borrow<NSObject> for VZNetworkBlockDeviceStorageDeviceAttachment

fn borrow(&self) -> &NSObject

Immutably borrows from an owned value.

impl Borrow<VZStorageDeviceAttachment> for VZNetworkBlockDeviceStorageDeviceAttachment

fn borrow(&self) -> &VZStorageDeviceAttachment

Immutably borrows from an owned value.

impl ClassType for VZNetworkBlockDeviceStorageDeviceAttachment

const NAME: &'static str = "VZNetworkBlockDeviceStorageDeviceAttachment"

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

type Super = VZStorageDeviceAttachment

The superclass of this class.

type ThreadKind = <<VZNetworkBlockDeviceStorageDeviceAttachment 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 VZNetworkBlockDeviceStorageDeviceAttachment

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

Formats the value using the given formatter.

impl Deref for VZNetworkBlockDeviceStorageDeviceAttachment

type Target = VZStorageDeviceAttachment

The resulting type after dereferencing.

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

Dereferences the value.

impl Hash for VZNetworkBlockDeviceStorageDeviceAttachment

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 VZNetworkBlockDeviceStorageDeviceAttachment

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

where Self: Sized,

Increment the reference count of the receiver.

impl NSObjectProtocol for VZNetworkBlockDeviceStorageDeviceAttachment

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 VZNetworkBlockDeviceStorageDeviceAttachment

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 VZNetworkBlockDeviceStorageDeviceAttachment

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

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

impl DowncastTarget for VZNetworkBlockDeviceStorageDeviceAttachment

impl Eq for VZNetworkBlockDeviceStorageDeviceAttachment