Enum Either

pub enum Either<A, B> {
    Left(A),
    Right(B),
}

Available on crate feature evm only.

Combines two different futures, streams, or sinks having the same associated types into a single type.

This is useful when conditionally choosing between two distinct future types:

use futures::future::Either;

let cond = true;

let fut = if cond {
    Either::Left(async move { 12 })
} else {
    Either::Right(async move { 44 })
};

assert_eq!(fut.await, 12);

Variants

Left(A)

First branch of the type

Right(B)

Second branch of the type

Implementations

impl<A, B> Either<A, B>

pub fn as_pin_ref(self: Pin<&Either<A, B>>) -> Either<Pin<&A>, Pin<&B>>

Convert Pin<&Either<A, B>> to Either<Pin<&A>, Pin<&B>>, pinned projections of the inner variants.

pub fn as_pin_mut( self: Pin<&mut Either<A, B>>, ) -> Either<Pin<&mut A>, Pin<&mut B>>

Convert Pin<&mut Either<A, B>> to Either<Pin<&mut A>, Pin<&mut B>>, pinned projections of the inner variants.

impl<A, B, T> Either<(T, A), (T, B)>

pub fn factor_first(self) -> (T, Either<A, B>)

Factor out a homogeneous type from an either of pairs.

Here, the homogeneous type is the first element of the pairs.

impl<A, B, T> Either<(A, T), (B, T)>

pub fn factor_second(self) -> (Either<A, B>, T)

Factor out a homogeneous type from an either of pairs.

Here, the homogeneous type is the second element of the pairs.

impl<T> Either<T, T>

pub fn into_inner(self) -> T

Extract the value of an either over two equivalent types.

Trait Implementations

impl<A, B> AsyncBufRead for Either<A, B>

where A: AsyncBufRead, B: AsyncBufRead,

fn poll_fill_buf( self: Pin<&mut Either<A, B>>, cx: &mut Context<'_>, ) -> Poll<Result<&[u8], Error>>

Attempt to return the contents of the internal buffer, filling it with more data from the inner reader if it is empty.

fn consume(self: Pin<&mut Either<A, B>>, amt: usize)

Tells this buffer that amt bytes have been consumed from the buffer, so they should no longer be returned in calls to poll_read.

impl<A, B> AsyncRead for Either<A, B>

where A: AsyncRead, B: AsyncRead,

fn poll_read( self: Pin<&mut Either<A, B>>, cx: &mut Context<'_>, buf: &mut [u8], ) -> Poll<Result<usize, Error>>

Attempt to read from the AsyncRead into buf.

fn poll_read_vectored( self: Pin<&mut Either<A, B>>, cx: &mut Context<'_>, bufs: &mut [IoSliceMut<'_>], ) -> Poll<Result<usize, Error>>

Attempt to read from the AsyncRead into bufs using vectored IO operations.

impl<A, B> AsyncSeek for Either<A, B>

where A: AsyncSeek, B: AsyncSeek,

fn poll_seek( self: Pin<&mut Either<A, B>>, cx: &mut Context<'_>, pos: SeekFrom, ) -> Poll<Result<u64, Error>>

Attempt to seek to an offset, in bytes, in a stream.

impl<A, B> AsyncWrite for Either<A, B>

where A: AsyncWrite, B: AsyncWrite,

fn poll_write( self: Pin<&mut Either<A, B>>, cx: &mut Context<'_>, buf: &[u8], ) -> Poll<Result<usize, Error>>

Attempt to write bytes from buf into the object.

fn poll_write_vectored( self: Pin<&mut Either<A, B>>, cx: &mut Context<'_>, bufs: &[IoSlice<'_>], ) -> Poll<Result<usize, Error>>

Attempt to write bytes from bufs into the object using vectored IO operations.

fn poll_flush( self: Pin<&mut Either<A, B>>, cx: &mut Context<'_>, ) -> Poll<Result<(), Error>>

Attempt to flush the object, ensuring that any buffered data reach their destination.

fn poll_close( self: Pin<&mut Either<A, B>>, cx: &mut Context<'_>, ) -> Poll<Result<(), Error>>

Attempt to close the object.

impl<A, B> BlockExecutorProvider for Either<A, B>

where A: BlockExecutorProvider, B: BlockExecutorProvider<Primitives = <A as BlockExecutorProvider>::Primitives>,

type Primitives = <A as BlockExecutorProvider>::Primitives

Receipt type.

type Executor<DB: Database> = Either<<A as BlockExecutorProvider>::Executor<DB>, <B as BlockExecutorProvider>::Executor<DB>>

An executor that can execute a single block given a database.

fn executor<DB>( &self, db: DB, ) -> <Either<A, B> as BlockExecutorProvider>::Executor<DB>

where DB: Database,

Creates a new executor for single block execution.

impl<A, B> BodiesClient for Either<A, B>

where A: BodiesClient, B: BodiesClient<Body = <A as BodiesClient>::Body>,

type Body = <A as BodiesClient>::Body

The body type this client fetches.

type Output = Either<<A as BodiesClient>::Output, <B as BodiesClient>::Output>

The output of the request future for querying block bodies.

fn get_block_bodies_with_priority( &self, hashes: Vec<FixedBytes<32>>, priority: Priority, ) -> <Either<A, B> as BodiesClient>::Output

Fetches the block body for the requested block with priority

fn get_block_bodies(&self, hashes: Vec<FixedBytes<32>>) -> Self::Output

Fetches the block body for the requested block.

fn get_block_body( &self, hash: FixedBytes<32>, ) -> SingleBodyRequest<Self::Output>

Fetches a single block body for the requested hash.

fn get_block_body_with_priority( &self, hash: FixedBytes<32>, priority: Priority, ) -> SingleBodyRequest<Self::Output>

Fetches a single block body for the requested hash with priority

impl<A, B> Clone for Either<A, B>

where A: Clone, B: Clone,

fn clone(&self) -> Either<A, B>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<A, B> Debug for Either<A, B>

where A: Debug, B: Debug,

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

Formats the value using the given formatter.

impl<A, B> DownloadClient for Either<A, B>

where A: DownloadClient, B: DownloadClient,

fn report_bad_message(&self, peer_id: FixedBytes<64>)

Penalize the peer for responding with a message that violates validation rules

fn num_connected_peers(&self) -> usize

Returns how many peers the network is currently connected to.

impl<A, B, DB> Executor<DB> for Either<A, B>

where A: Executor<DB>, B: Executor<DB, Primitives = <A as Executor<DB>>::Primitives, Error = <A as Executor<DB>>::Error>, DB: Database,

type Primitives = <A as Executor<DB>>::Primitives

The primitive types used by the executor.

type Error = <A as Executor<DB>>::Error

The error type returned by the executor.

fn execute_one( &mut self, block: &RecoveredBlock<<<Either<A, B> as Executor<DB>>::Primitives as NodePrimitives>::Block>, ) -> Result<BlockExecutionResult<<<Either<A, B> as Executor<DB>>::Primitives as NodePrimitives>::Receipt>, <Either<A, B> as Executor<DB>>::Error>

Executes a single block and returns BlockExecutionResult, without the state changes.

fn execute_one_with_state_hook<F>( &mut self, block: &RecoveredBlock<<<Either<A, B> as Executor<DB>>::Primitives as NodePrimitives>::Block>, state_hook: F, ) -> Result<BlockExecutionResult<<<Either<A, B> as Executor<DB>>::Primitives as NodePrimitives>::Receipt>, <Either<A, B> as Executor<DB>>::Error>

where F: OnStateHook + 'static,

Executes the EVM with the given input and accepts a state hook closure that is invoked with the EVM state after execution.

fn execute( self, block: &RecoveredBlock<<<Either<A, B> as Executor<DB>>::Primitives as NodePrimitives>::Block>, ) -> Result<BlockExecutionOutput<<<Either<A, B> as Executor<DB>>::Primitives as NodePrimitives>::Receipt>, <Either<A, B> as Executor<DB>>::Error>

Consumes the type and executes the block.

fn execute_with_state_closure<F>( self, block: &RecoveredBlock<<<Either<A, B> as Executor<DB>>::Primitives as NodePrimitives>::Block>, state: F, ) -> Result<BlockExecutionOutput<<<Either<A, B> as Executor<DB>>::Primitives as NodePrimitives>::Receipt>, <Either<A, B> as Executor<DB>>::Error>

where F: FnMut(&State<DB>),

Executes the EVM with the given input and accepts a state closure that is invoked with the EVM state after execution.

fn into_state(self) -> State<DB>

Consumes the executor and returns the [State] containing all state changes.

fn size_hint(&self) -> usize

The size hint of the batch’s tracked state size.

fn execute_batch<'a, I>( self, blocks: I, ) -> Result<ExecutionOutcome<<Self::Primitives as NodePrimitives>::Receipt>, Self::Error>

where I: IntoIterator<Item = &'a RecoveredBlock<<Self::Primitives as NodePrimitives>::Block>>,

Executes multiple inputs in the batch, and returns an aggregated ExecutionOutcome.

fn execute_with_state_hook<F>( self, block: &RecoveredBlock<<Self::Primitives as NodePrimitives>::Block>, state_hook: F, ) -> Result<BlockExecutionOutput<<Self::Primitives as NodePrimitives>::Receipt>, Self::Error>

where F: OnStateHook + 'static,

Executes the EVM with the given input and accepts a state hook closure that is invoked with the EVM state after execution.

impl<A, B> FusedFuture for Either<A, B>

where A: FusedFuture, B: FusedFuture<Output = <A as Future>::Output>,

fn is_terminated(&self) -> bool

Returns true if the underlying future should no longer be polled.

impl<A, B> FusedStream for Either<A, B>

where A: FusedStream, B: FusedStream<Item = <A as Stream>::Item>,

fn is_terminated(&self) -> bool

Returns true if the stream should no longer be polled.

impl<A, B> Future for Either<A, B>

where A: Future, B: Future<Output = <A as Future>::Output>,

type Output = <A as Future>::Output

The type of value produced on completion.

fn poll( self: Pin<&mut Either<A, B>>, cx: &mut Context<'_>, ) -> Poll<<Either<A, B> as Future>::Output>

Attempts to resolve the future to a final value, registering the current task for wakeup if the value is not yet available.

impl<A, B> HeadersClient for Either<A, B>

where A: HeadersClient, B: HeadersClient<Header = <A as HeadersClient>::Header>,

type Header = <A as HeadersClient>::Header

The header type this client fetches.

type Output = Either<<A as HeadersClient>::Output, <B as HeadersClient>::Output>

The headers future type

fn get_headers_with_priority( &self, request: HeadersRequest, priority: Priority, ) -> <Either<A, B> as HeadersClient>::Output

Sends the header request to the p2p network with priority set and returns the header response received from a peer.

fn get_headers(&self, request: HeadersRequest) -> Self::Output

Sends the header request to the p2p network and returns the header response received from a peer.

fn get_header(&self, start: HashOrNumber) -> SingleHeaderRequest<Self::Output>

Fetches a single header for the requested number or hash.

fn get_header_with_priority( &self, start: HashOrNumber, priority: Priority, ) -> SingleHeaderRequest<Self::Output>

Fetches a single header for the requested number or hash with priority

impl<A, B, Item> Sink<Item> for Either<A, B>

where A: Sink<Item>, B: Sink<Item, Error = <A as Sink<Item>>::Error>,

Available on crate feature sink only.

type Error = <A as Sink<Item>>::Error

The type of value produced by the sink when an error occurs.

fn poll_ready( self: Pin<&mut Either<A, B>>, cx: &mut Context<'_>, ) -> Poll<Result<(), <Either<A, B> as Sink<Item>>::Error>>

Attempts to prepare the Sink to receive a value.

fn start_send( self: Pin<&mut Either<A, B>>, item: Item, ) -> Result<(), <Either<A, B> as Sink<Item>>::Error>

Begin the process of sending a value to the sink. Each call to this function must be preceded by a successful call to poll_ready which returned Poll::Ready(Ok(())).

fn poll_flush( self: Pin<&mut Either<A, B>>, cx: &mut Context<'_>, ) -> Poll<Result<(), <Either<A, B> as Sink<Item>>::Error>>

Flush any remaining output from this sink.

fn poll_close( self: Pin<&mut Either<A, B>>, cx: &mut Context<'_>, ) -> Poll<Result<(), <Either<A, B> as Sink<Item>>::Error>>

Flush any remaining output and close this sink, if necessary.

impl<A, B> Stream for Either<A, B>

where A: Stream, B: Stream<Item = <A as Stream>::Item>,

type Item = <A as Stream>::Item

Values yielded by the stream.

fn poll_next( self: Pin<&mut Either<A, B>>, cx: &mut Context<'_>, ) -> Poll<Option<<Either<A, B> as Stream>::Item>>

Attempt to pull out the next value of this stream, registering the current task for wakeup if the value is not yet available, and returning None if the stream is exhausted.

fn size_hint(&self) -> (usize, Option<usize>)

Returns the bounds on the remaining length of the stream.

impl<A, B> TransactionValidator for Either<A, B>

where A: TransactionValidator, B: TransactionValidator<Transaction = <A as TransactionValidator>::Transaction>,

type Transaction = <A as TransactionValidator>::Transaction

The transaction type to validate.

async fn validate_transaction( &self, origin: TransactionOrigin, transaction: <Either<A, B> as TransactionValidator>::Transaction, ) -> TransactionValidationOutcome<<Either<A, B> as TransactionValidator>::Transaction>

Validates the transaction and returns a [TransactionValidationOutcome] describing the validity of the given transaction.

async fn validate_transactions( &self, transactions: Vec<(TransactionOrigin, <Either<A, B> as TransactionValidator>::Transaction)>, ) -> Vec<TransactionValidationOutcome<<Either<A, B> as TransactionValidator>::Transaction>>

Validates a batch of transactions.

fn on_new_head_block<Bl>(&self, new_tip_block: &SealedBlock<Bl>)

where Bl: Block,

Invoked when the head block changes.

Layout

Note: Unable to compute type layout, possibly due to this type having generic parameters. Layout can only be computed for concrete, fully-instantiated types.