Attaches a callback to the EventLoopFuture that preconditions the original future’s success.
func preconditionSuccess(file: StaticString = #fileID, line: UInt = #line) -> EventLoopFuture<Value> s7NIOCore15EventLoopFutureC19preconditionSuccess4file4lineACyxGs12StaticStringV_SutF What are these?6SRW3If the original future fails, it triggers a precondition failure, causing a runtime error during development. The precondition failure will include the file and line of the calling site.
import NIOCoreThe core abstractions that make up SwiftNIO.
final class EventLoopFuture<Value>Holder for a result that will be provided later.
@frozen struct StaticStringA string type designed to represent text that is known at compile time.
@frozen struct UIntAn unsigned integer value type.
static func andAllComplete(_ futures: [EventLoopFuture<Value>], on eventLoop: EventLoop) -> EventLoopFuture<Void> Returns a new EventLoopFuture that succeeds when all of the provided EventLoopFutures complete.
static func andAllComplete(_ futures: [EventLoopFuture<Value>], promise: EventLoopPromise<Void>) Completes a promise when all of the provided EventLoopFutures have completed.
static func andAllSucceed(_ futures: [EventLoopFuture<Value>], on eventLoop: EventLoop) -> EventLoopFuture<Void> Returns a new EventLoopFuture that succeeds only if all of the provided futures succeed.
static func andAllSucceed(_ futures: [EventLoopFuture<Value>], promise: EventLoopPromise<Void>) Succeeds the promise if all of the provided futures succeed. If any of the provided futures fail then the promise will be failed – even if some futures are yet to complete.
@preconcurrency static func reduce<InputValue>(_ initialResult: Value, _ futures: [EventLoopFuture<InputValue>], on eventLoop: EventLoop, _ nextPartialResult: @escaping (Value, InputValue) -> Value) -> EventLoopFuture<Value> where Value : Sendable, InputValue : Sendable Returns a new EventLoopFuture that fires only when all the provided futures complete. The new EventLoopFuture contains the result of reducing the initialResult with the values of the [EventLoopFuture<NewValue>].
@preconcurrency static func reduce<InputValue>(into initialResult: Value, _ futures: [EventLoopFuture<InputValue>], on eventLoop: EventLoop, _ updateAccumulatingResult: @escaping (inout Value, InputValue) -> Void) -> EventLoopFuture<Value> where Value : Sendable, InputValue : Sendable Returns a new EventLoopFuture that fires only when all the provided futures complete. The new EventLoopFuture contains the result of combining the initialResult with the values of the [EventLoopFuture<NewValue>]. This function is analogous to the standard library’s reduce(into:), which does not make copies of the result type for each EventLoopFuture.
@preconcurrency static func whenAllComplete(_ futures: [EventLoopFuture<Value>], on eventLoop: EventLoop) -> EventLoopFuture<[Result<Value, Error>]> where Value : Sendable Returns a new EventLoopFuture that succeeds when all of the provided EventLoopFutures complete. The new EventLoopFuture will contain an array of results, maintaining ordering for each of the EventLoopFutures.
@preconcurrency static func whenAllComplete(_ futures: [EventLoopFuture<Value>], promise: EventLoopPromise<[Result<Value, Error>]>) where Value : Sendable Completes a promise with the results of all provided EventLoopFutures.
@preconcurrency static func whenAllSucceed(_ futures: [EventLoopFuture<Value>], on eventLoop: EventLoop) -> EventLoopFuture<[Value]> where Value : Sendable Returns a new EventLoopFuture that succeeds only if all of the provided futures succeed. The new EventLoopFuture will contain all of the values fulfilled by the futures.
@preconcurrency static func whenAllSucceed(_ futures: [EventLoopFuture<Value>], promise: EventLoopPromise<[Value]>) where Value : Sendable Completes the promise with the values of all futures if all provided futures succeed. If any of the provided futures fail then promise will be failed.
let eventLoop: EventLoopThe EventLoop which is tied to the EventLoopFuture and is used to notify all registered callbacks.
static func == (lhs: EventLoopFuture, rhs: EventLoopFuture) -> Bool @preconcurrency func always(_ callback: @escaping (Result<Value, Error>) -> Void) -> EventLoopFuture<Value> Adds an observer callback to this EventLoopFuture that is called when the EventLoopFuture has any result.
@preconcurrency func and<OtherValue>(_ other: EventLoopFuture<OtherValue>) -> EventLoopFuture<(Value, OtherValue)> where OtherValue : Sendable Return a new EventLoopFuture that succeeds when this “and” another provided EventLoopFuture both succeed. It then provides the pair of results. If either one fails, the combined EventLoopFuture will fail with the first error encountered.
@preconcurrency func and<OtherValue>(value: OtherValue) -> EventLoopFuture<(Value, OtherValue)> where OtherValue : Sendable Return a new EventLoopFuture that contains this “and” another value. This is just syntactic sugar for future.and(loop.makeSucceedFuture(value)).
func assertFailure(file: StaticString = #fileID, line: UInt = #line) -> EventLoopFuture<Value> Attaches a callback to the EventLoopFuture that asserts the original future’s failure.
func assertSuccess(file: StaticString = #fileID, line: UInt = #line) -> EventLoopFuture<Value> Attaches a callback to the EventLoopFuture that asserts the original future’s success.
func assumeIsolated() -> Isolated Returns a variant of this EventLoopFuture with less strict Sendable requirements. Can only be called from on the EventLoop to which this EventLoopFuture is bound, will crash if that invariant fails to be met.
func assumeIsolatedUnsafeUnchecked() -> Isolated Returns a variant of this EventLoopFuture with less strict Sendable requirements. Can only be called from on the EventLoop to which this EventLoopFuture is bound, will crash if that invariant fails to be met in debug builds.
@preconcurrency func cascade(to promise: EventLoopPromise<Value>?) where Value : Sendable Fulfills the given EventLoopPromise with the results from this EventLoopFuture.
func cascadeFailure<NewValue>(to promise: EventLoopPromise<NewValue>?) Fails the given EventLoopPromise with the error from this EventLoopFuture if encountered.
@preconcurrency func cascadeSuccess(to promise: EventLoopPromise<Value>?) where Value : Sendable Fulfills the given EventLoopPromise only when this EventLoopFuture succeeds.
@preconcurrency func flatMap<NewValue>(_ callback: @escaping (Value) -> EventLoopFuture<NewValue>) -> EventLoopFuture<NewValue> where NewValue : Sendable When the current EventLoopFuture<Value> is fulfilled, run the provided callback, which will provide a new EventLoopFuture.
@preconcurrency func flatMapBlocking<NewValue>(onto queue: DispatchQueue, _ callbackMayBlock: @escaping (Value) throws -> NewValue) -> EventLoopFuture<NewValue> where Value : Sendable, NewValue : Sendable Chain an EventLoopFuture<NewValue> providing the result of a IO / task that may block. For example:
@preconcurrency func flatMapError(_ callback: @escaping (Error) -> EventLoopFuture<Value>) -> EventLoopFuture<Value> where Value : Sendable When the current EventLoopFuture<Value> is in an error state, run the provided callback, which may recover from the error by returning an EventLoopFuture<NewValue>. The callback is intended to potentially recover from the error by returning a new EventLoopFuture that will eventually contain the recovered result.
@preconcurrency func flatMapErrorThrowing(_ callback: @escaping (Error) throws -> Value) -> EventLoopFuture<Value> When the current EventLoopFuture<Value> is in an error state, run the provided callback, which may recover from the error and returns a new value of type Value. The provided callback may optionally throw, in which case the EventLoopFuture will be in a failed state with the new thrown error.
@preconcurrency func flatMapErrorWithEventLoop(_ callback: @escaping (Error, EventLoop) -> EventLoopFuture<Value>) -> EventLoopFuture<Value> where Value : Sendable When the current EventLoopFuture<Value> is in an error state, run the provided callback, which may recover from the error by returning an EventLoopFuture<NewValue>. The callback is intended to potentially recover from the error by returning a new EventLoopFuture that will eventually contain the recovered result.
@preconcurrency func flatMapResult<NewValue, SomeError>(_ body: @escaping (Value) -> Result<NewValue, SomeError>) -> EventLoopFuture<NewValue> where SomeError : Error When the current EventLoopFuture<Value> is fulfilled, run the provided callback, which performs a synchronous computation and returns either a new value (of type NewValue) or an error depending on the Result returned by the closure.
@preconcurrency func flatMapThrowing<NewValue>(_ callback: @escaping (Value) throws -> NewValue) -> EventLoopFuture<NewValue> When the current EventLoopFuture<Value> is fulfilled, run the provided callback, which performs a synchronous computation and returns a new value of type NewValue. The provided callback may optionally throw.
@preconcurrency func flatMapWithEventLoop<NewValue>(_ callback: @escaping (Value, EventLoop) -> EventLoopFuture<NewValue>) -> EventLoopFuture<NewValue> where NewValue : Sendable When the current EventLoopFuture<Value> is fulfilled, run the provided callback, which will provide a new EventLoopFuture alongside the EventLoop associated with this future.
@preconcurrency func fold<OtherValue>(_ futures: [EventLoopFuture<OtherValue>], with combiningFunction: @escaping (Value, OtherValue) -> EventLoopFuture<Value>) -> EventLoopFuture<Value> where Value : Sendable, OtherValue : Sendable Returns a new EventLoopFuture that fires only when this EventLoopFuture and all the provided futures complete. It then provides the result of folding the value of this EventLoopFuture with the values of all the provided futures.
@preconcurrency func foldWithEventLoop<OtherValue>(_ futures: [EventLoopFuture<OtherValue>], with combiningFunction: @escaping (Value, OtherValue, EventLoop) -> EventLoopFuture<Value>) -> EventLoopFuture<Value> where Value : Sendable, OtherValue : Sendable Returns a new EventLoopFuture that fires only when this EventLoopFuture and all the provided futures complete. It then provides the result of folding the value of this EventLoopFuture with the values of all the provided futures.
@preconcurrency func get() async throws -> Value where Value : Sendable Get the value/error from an EventLoopFuture in an async context.
@preconcurrency func hop(to target: EventLoop) -> EventLoopFuture<Value> where Value : Sendable Returns an EventLoopFuture that fires when this future completes, but executes its callbacks on the target event loop instead of the original one.
@preconcurrency func map<NewValue>(_ callback: @escaping (Value) -> (NewValue)) -> EventLoopFuture<NewValue> When the current EventLoopFuture<Value> is fulfilled, run the provided callback, which performs a synchronous computation and returns a new value of type NewValue.
func preconditionFailure(file: StaticString = #fileID, line: UInt = #line) -> EventLoopFuture<Value> Attaches a callback to the EventLoopFuture that preconditions the original future’s failure.
@preconcurrency func recover(_ callback: @escaping (Error) -> Value) -> EventLoopFuture<Value> When the current EventLoopFuture<Value> is in an error state, run the provided callback, which can recover from the error and return a new value of type Value. The provided callback may not throw, so this function should be used when the error is always recoverable.
@preconcurrency func unwrap<NewValue>(orElse callback: @escaping () -> NewValue) -> EventLoopFuture<NewValue> where Value == NewValue? Unwrap an EventLoopFuture where its type parameter is an Optional.
func unwrap<NewValue>(orError: Error) -> EventLoopFuture<NewValue> where Value == NewValue? Unwrap an EventLoopFuture where its type parameter is an Optional.
@preconcurrency func unwrap<NewValue>(orReplace replacement: NewValue) -> EventLoopFuture<NewValue> where Value == NewValue?, NewValue : Sendable Unwrap an EventLoopFuture where its type parameter is an Optional.
@preconcurrency func wait(file: StaticString = #file, line: UInt = #line) throws -> Value where Value : Sendable Wait for the resolution of this EventLoopFuture by blocking the current thread until it resolves.
@preconcurrency func whenComplete(_ callback: @escaping (Result<Value, Error>) -> Void) Adds an observer callback to this EventLoopFuture that is called when the EventLoopFuture has any result.
@preconcurrency func whenCompleteBlocking(onto queue: DispatchQueue, _ callbackMayBlock: @escaping (Result<Value, Error>) -> Void) where Value : Sendable Adds an observer callback to this EventLoopFuture that is called when the EventLoopFuture has any result. The observer callback is permitted to block.
@preconcurrency func whenFailure(_ callback: @escaping (Error) -> Void) Adds an observer callback to this EventLoopFuture that is called when the EventLoopFuture has a failure result.
@preconcurrency func whenFailureBlocking(onto queue: DispatchQueue, _ callbackMayBlock: @escaping (Error) -> Void) Adds an observer callback to this EventLoopFuture that is called when the EventLoopFuture has a failure result. The observer callback is permitted to block.
@preconcurrency func whenSuccess(_ callback: @escaping (Value) -> Void) Adds an observer callback to this EventLoopFuture that is called when the EventLoopFuture has a success result.
@preconcurrency func whenSuccessBlocking(onto queue: DispatchQueue, _ callbackMayBlock: @escaping (Value) -> Void) where Value : Sendable Adds an observer callback to this EventLoopFuture that is called when the EventLoopFuture has a success result. The observer callback is permitted to block.
struct IsolatedA struct wrapping an EventLoopFuture that ensures all calls to any method on this struct are coming from the event loop of the future.
@preconcurrency func and<OtherValue>(_ other: EventLoopFuture<OtherValue>, file: StaticString = #fileID, line: UInt = #line) -> EventLoopFuture<(Value, OtherValue)> where OtherValue : Sendable @preconcurrency func and<OtherValue>(value: OtherValue, file: StaticString = #fileID, line: UInt = #line) -> EventLoopFuture<(Value, OtherValue)> where OtherValue : Sendable @preconcurrency func flatMap<NewValue>(file: StaticString = #fileID, line: UInt = #line, _ callback: @escaping (Value) -> EventLoopFuture<NewValue>) -> EventLoopFuture<NewValue> where NewValue : Sendable func flatMapError(file: StaticString = #fileID, line: UInt = #line, _ callback: @escaping (Error) -> EventLoopFuture<Value>) -> EventLoopFuture<Value> where Value : Sendable func flatMapErrorThrowing(file: StaticString = #fileID, line: UInt = #line, _ callback: @escaping (Error) throws -> Value) -> EventLoopFuture<Value> @preconcurrency func flatMapResult<NewValue, SomeError>(file: StaticString = #fileID, line: UInt = #line, _ body: @escaping (Value) -> Result<NewValue, SomeError>) -> EventLoopFuture<NewValue> where SomeError : Error @preconcurrency func flatMapThrowing<NewValue>(file: StaticString = #fileID, line: UInt = #line, _ callback: @escaping (Value) throws -> NewValue) -> EventLoopFuture<NewValue> where NewValue : Sendable func map<NewValue>(file: StaticString = #fileID, line: UInt = #line, _ callback: @escaping (Value) -> (NewValue)) -> EventLoopFuture<NewValue> @preconcurrency func recover(file: StaticString = #fileID, line: UInt = #line, _ callback: @escaping (Error) -> Value) -> EventLoopFuture<Value>