Skip to main content

DestinationAlloc

hurray_io::stream

Trait DestinationAlloc 

Source 
pub trait DestinationAlloc: Send {
    type Dest: Destination;

    // Required method
    fn allocate(&mut self, request: DestinationRequest) -> Result<Self::Dest>;
}
Expand description

Allocates the destinations a StreamReaderCore fills.

§Examples

use hurray_io::stream::{Destination, DestinationAlloc, SystemDestinations, DestinationRequest};

let mut alloc = SystemDestinations;
let mut dest = alloc
    .allocate(DestinationRequest { index: 0, byte_size: 128, alignment: 4096 })?;
assert_eq!(dest.as_mut_slice().len(), 128);

Required Associated Types§

Source

type Dest: Destination

The memory this allocator hands out.

An associated type rather than Box<dyn Destination>: the core is generic over the allocator, so the destination’s concrete type is known throughout. That costs one type parameter and saves a heap allocation per buffer — and it keeps the core’s auto traits (Sync, UnwindSafe, RefUnwindSafe) intact, which a trait object would erase from every type that contains a reader.

Required Methods§

Source

fn allocate(&mut self, request: DestinationRequest) -> Result<Self::Dest>

Allocates one destination, zero-initialised, at the requested alignment.

§Errors

Error::UnallocatableBuffer when the request cannot be satisfied — a byte_size beyond the address space, or an alignment this allocator cannot meet. A descriptor off the wire can ask for either, so this MUST NOT panic.

Dyn Compatibility§

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors§