Struct MXMetricManager

Source

pub struct MXMetricManager { /* private fields */ }

Available on crate feature MXMetricManager only.

Expand description

An instance of this class can be used to retrieve periodic, aggregated power and performance metrics.

To receive metrics, clients must acquire a reference to the shared instance of the metric manager and add an eligible MXMetricManagerSubscriber.

Metrics are not guaranteed to be delivered, but can be expected atleast once per day when conditions permit.

Subscribers to the metric manager can remove themselves using removeSubscriber:subscriber if they no longer wish to receive metrics.

Implementations§

Source §

impl MXMetricManager

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pub unsafe fn pastPayloads(&self) -> Retained<NSArray<MXMetricPayload>>

Available on crate feature MXMetricPayload only.

A list of past metric payloads received.

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pub unsafe fn pastDiagnosticPayloads( &self, ) -> Retained<NSArray<MXDiagnosticPayload>>

Available on crate feature MXDiagnosticPayload only.

A list of past diagnostic payloads received.

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pub unsafe fn sharedManager() -> Retained<MXMetricManager>

Singleton instance of MXMetricManager.

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pub unsafe fn addSubscriber( &self, subscriber: &ProtocolObject<dyn MXMetricManagerSubscriber>, )

Adds a subscriber to the metric manager.

Parameter subscriber: An object that conforms to the MXMetricManagerSubscriber protocol.

Subscribers can receive metric payloads by conforming to the MXMetricManagerSubscriber protocol.

Source

pub unsafe fn removeSubscriber( &self, subscriber: &ProtocolObject<dyn MXMetricManagerSubscriber>, )

Removes a subscriber from the metric manager.

Parameter subscriber: An object that conforms to the MXMetricManagerSubscriber protocol.

The subscriber indicated, if previously registered, will no longer receive metric payloads.

Source

pub unsafe fn extendLaunchMeasurementForTaskID_error( task_id: &MXLaunchTaskID, ) -> Result<(), Retained<NSError>>

Start measuring an extended launch task with the given task id.

This method tracks extra setup tasks required to make the application perceived as fully launched, such as loading up content from the disk or refreshing data from the network, rendering images, etc.

The first task needs to start before or during UISceneDelegate.scene(_:restoreInteractionStateWith:)or before UISceneDelegate.sceneDidBecomeActive(_:)is called on the first scene to connect. For example, at the time UIApplicationDelegate.application(_:didFinishLaunchingWithOptions:)is called. Other tasks need to start before the last current task is finished, otherwise the extended launch measurement will end.

The maximum number of tasks is 16.

This method needs to be called on the main thread.

Parameter taskID: The task identifier. Must be an unique nonnull custom string.

Parameter error: If an error occurs, this will contain a valid NSErrorobject on exit.

Returns: Returns YESif the measurement started successfully and NOotherwise.

Source

pub unsafe fn finishExtendedLaunchMeasurementForTaskID_error( task_id: &MXLaunchTaskID, ) -> Result<(), Retained<NSError>>

Signal the end of an extended launch task previously started with extendLaunchMeasurementForTaskID:error:.

This method needs to be called on the main thread.

Parameter taskID: The task identifier. Must match the task identifier passed to extendLaunchMeasurementForTaskID:error:.

Parameter error: If an error occurs, this will contain a valid NSErrorobject on exit.

Returns: Returns YESif the measurement for the task finished successfully and NOotherwise.

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impl MXMetricManager

Methods declared on superclass NSObject.

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

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

Methods from Deref<Target = NSObject>§

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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());

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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`
    }
}