pub struct RequestFilterDataProvider<D, F>
where F: Fn(DataRequest<'_>) -> bool,
{ pub inner: D, pub predicate: F, pub filter_name: &'static str, }
Expand description

A data provider that selectively filters out data requests.

Data requests that are rejected by the filter will return a DataError with kind FilteredResource, and they will not be returned by [datagen::IterableDynamicDataProvider::supported_locales_for_key].

Although this struct can be created directly, the traits in this module provide helper functions for common filtering patterns.

Fields§

§inner: D

The data provider to which we delegate requests.

§predicate: F

The predicate function. A return value of true indicates that the request should proceed as normal; a return value of false will reject the request.

§filter_name: &'static str

A name for this filter, used in error messages.

Implementations§

source§

impl<D, F> RequestFilterDataProvider<D, F>
where F: Fn(DataRequest<'_>) -> bool + Sync,

source

pub fn filter_by_langid<'a>( self, predicate: impl Fn(&LanguageIdentifier) -> bool + Sync + 'a ) -> RequestFilterDataProvider<D, Box<dyn Fn(DataRequest<'_>) -> bool + Sync + 'a>>
where F: 'a,

Filter out data requests with certain langids according to the predicate function. The predicate should return true to allow a langid and false to reject a langid.

Data requests with no langid will be allowed. To reject data requests without a langid, chain this with Self::require_langid.

§Examples
use icu_locid::LanguageIdentifier;
use icu_locid::{langid, subtags::language};
use icu_provider::datagen::*;
use icu_provider::hello_world::*;
use icu_provider::prelude::*;
use icu_provider_adapters::filter::Filterable;

let provider = HelloWorldProvider
    .filterable("Demo no-English filter")
    .filter_by_langid(|langid| langid.language != language!("en"));

// German requests should succeed:
let req_de = DataRequest {
    locale: &langid!("de").into(),
    metadata: Default::default(),
};
let response: Result<DataResponse<HelloWorldV1Marker>, _> =
    provider.load(req_de);
assert!(matches!(response, Ok(_)));

// English requests should fail:
let req_en = DataRequest {
    locale: &langid!("en-US").into(),
    metadata: Default::default(),
};
let response: Result<DataResponse<HelloWorldV1Marker>, _> =
    provider.load(req_en);
assert!(matches!(
    response,
    Err(DataError {
        kind: DataErrorKind::FilteredResource,
        ..
    })
));

// English should not appear in the iterator result:
let supported_langids = provider
    .supported_locales()
    .expect("Should successfully make an iterator of supported locales")
    .into_iter()
    .map(|options| options.get_langid())
    .collect::<Vec<LanguageIdentifier>>();
assert!(supported_langids.contains(&langid!("de")));
assert!(!supported_langids.contains(&langid!("en")));
source

pub fn filter_by_langid_allowlist_strict<'a>( self, allowlist: &'a [LanguageIdentifier] ) -> RequestFilterDataProvider<D, Box<dyn Fn(DataRequest<'_>) -> bool + Sync + 'a>>
where F: 'a,

Filter out data request except those having a language identifier that exactly matches one in the allowlist.

This will be replaced with a smarter algorithm for locale filtering; see https://github.com/unicode-org/icu4x/issues/834

Data requests with no langid will be allowed. To reject data requests without a langid, chain this with Self::require_langid.

§Examples
use icu_locid::langid;
use icu_provider::hello_world::*;
use icu_provider::prelude::*;
use icu_provider_adapters::filter::Filterable;

let allowlist = [langid!("de"), langid!("zh")];
let provider = HelloWorldProvider
    .filterable("Demo German+Chinese filter")
    .filter_by_langid_allowlist_strict(&allowlist);

// German requests should succeed:
let req_de = DataRequest {
    locale: &langid!("de").into(),
    metadata: Default::default(),
};
let response: Result<DataResponse<HelloWorldV1Marker>, _> =
    provider.load(req_de);
assert!(matches!(response, Ok(_)));

// English requests should fail:
let req_en = DataRequest {
    locale: &langid!("en-US").into(),
    metadata: Default::default(),
};
let response: Result<DataResponse<HelloWorldV1Marker>, _> =
    provider.load(req_en);
assert!(matches!(
    response,
    Err(DataError {
        kind: DataErrorKind::FilteredResource,
        ..
    })
));
assert_eq!(
    response.unwrap_err().str_context,
    Some("Demo German+Chinese filter")
);
source

pub fn require_langid<'a>( self ) -> RequestFilterDataProvider<D, Box<dyn Fn(DataRequest<'_>) -> bool + Sync + 'a>>
where F: 'a,

Require that data requests contain a langid.

§Examples
use icu_locid::langid;
use icu_provider::hello_world::*;
use icu_provider::prelude::*;
use icu_provider_adapters::filter::Filterable;

let provider = HelloWorldProvider
    .filterable("Demo require-langid filter")
    .require_langid();

// Requests with a langid should succeed:
let req_with_langid = DataRequest {
    locale: &langid!("de").into(),
    metadata: Default::default(),
};
let response: Result<DataResponse<HelloWorldV1Marker>, _> =
    provider.load(req_with_langid);
assert!(matches!(response, Ok(_)));

// Requests without a langid should fail:
let req_no_langid = DataRequest {
    locale: Default::default(),
    metadata: Default::default(),
};
let response: Result<DataResponse<HelloWorldV1Marker>, _> =
    provider.load(req_no_langid);
assert!(matches!(
    response,
    Err(DataError {
        kind: DataErrorKind::FilteredResource,
        ..
    })
));

Trait Implementations§

source§

impl<D, F> AnyProvider for RequestFilterDataProvider<D, F>
where F: Fn(DataRequest<'_>) -> bool, D: AnyProvider,

source§

fn load_any( &self, key: DataKey, req: DataRequest<'_> ) -> Result<AnyResponse, DataError>

Loads an AnyPayload according to the key and request.
source§

impl<D, F> BufferProvider for RequestFilterDataProvider<D, F>
where F: Fn(DataRequest<'_>) -> bool, D: BufferProvider,

source§

fn load_buffer( &self, key: DataKey, req: DataRequest<'_> ) -> Result<DataResponse<BufferMarker>, DataError>

Loads a DataPayload<BufferMarker> according to the key and request.
source§

impl<D, F, M> DataProvider<M> for RequestFilterDataProvider<D, F>
where F: Fn(DataRequest<'_>) -> bool, M: KeyedDataMarker, D: DataProvider<M>,

source§

fn load(&self, req: DataRequest<'_>) -> Result<DataResponse<M>, DataError>

Query the provider for data, returning the result. Read more
source§

impl<D: Debug, F> Debug for RequestFilterDataProvider<D, F>
where F: Fn(DataRequest<'_>) -> bool + Debug,

source§

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

Formats the value using the given formatter. Read more
source§

impl<D, F, M> DynamicDataProvider<M> for RequestFilterDataProvider<D, F>
where F: Fn(DataRequest<'_>) -> bool, M: DataMarker, D: DynamicDataProvider<M>,

source§

fn load_data( &self, key: DataKey, req: DataRequest<'_> ) -> Result<DataResponse<M>, DataError>

Query the provider for data, returning the result. Read more

Auto Trait Implementations§

§

impl<D, F> Freeze for RequestFilterDataProvider<D, F>
where D: Freeze, F: Freeze,

§

impl<D, F> RefUnwindSafe for RequestFilterDataProvider<D, F>

§

impl<D, F> Send for RequestFilterDataProvider<D, F>
where D: Send, F: Send,

§

impl<D, F> Sync for RequestFilterDataProvider<D, F>
where D: Sync, F: Sync,

§

impl<D, F> Unpin for RequestFilterDataProvider<D, F>
where D: Unpin, F: Unpin,

§

impl<D, F> UnwindSafe for RequestFilterDataProvider<D, F>
where D: UnwindSafe, F: UnwindSafe,

Blanket Implementations§

source§

impl<T> Any for T
where T: 'static + ?Sized,

source§

fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
source§

impl<P> AsDowncastingAnyProvider for P
where P: AnyProvider + ?Sized,

source§

fn as_downcasting(&self) -> DowncastingAnyProvider<'_, P>

Returns an object implementing DynamicDataProvider<M> when called on AnyProvider
source§

impl<P> AsDynamicDataProviderAnyMarkerWrap for P

source§

fn as_any_provider(&self) -> DynamicDataProviderAnyMarkerWrap<'_, P>

Returns an object implementing AnyProvider when called on DynamicDataProvider<AnyMarker>
source§

impl<T> Borrow<T> for T
where T: ?Sized,

source§

fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
source§

impl<T> BorrowMut<T> for T
where T: ?Sized,

source§

fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
source§

impl<T> Filterable for T

source§

fn filterable( self, filter_name: &'static str ) -> RequestFilterDataProvider<T, fn(_: DataRequest<'_>) -> bool>

Creates a filterable data provider with the given name for debugging. Read more
source§

impl<T> From<T> for T

source§

fn from(t: T) -> T

Returns the argument unchanged.

source§

impl<T, U> Into<U> for T
where U: From<T>,

source§

fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

source§

impl<T, U> TryFrom<U> for T
where U: Into<T>,

§

type Error = Infallible

The type returned in the event of a conversion error.
source§

fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
source§

impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

§

type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
source§

fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.
source§

impl<T> ErasedDestructor for T
where T: 'static,

source§

impl<T> MaybeSendSync for T