Struct ScratchBuffer 

pub struct ScratchBuffer<const SIZE: usize = DEFAULT_SCRATCH_SIZE> { /* private fields */ }

Thread-local scratch buffer for temporary allocations.

Provides fast, allocation-free temporary storage that can be used in Ring 0 hot path code. The buffer is automatically reset after each event is processed.

Usage Pattern

use laminar_core::alloc::ScratchBuffer;

fn process_event(event: &Event) {
    // Allocate temporary space from scratch buffer
    let temp = ScratchBuffer::alloc(256);
    temp.copy_from_slice(&event.data[..256]);

    // Use temp...

    // Reset at end of event processing
    ScratchBuffer::reset();
}

Thread Safety

Each thread has its own scratch buffer. The buffer is NOT thread-safe and should only be accessed from a single thread.

Panics

Panics if allocation request exceeds buffer capacity.

Implementations

impl<const SIZE: usize> ScratchBuffer<SIZE>

pub const fn new() -> Self

Create a new scratch buffer.

pub const fn capacity(&self) -> usize

Get the total capacity of the scratch buffer.

pub fn remaining(&self) -> usize

Get the number of bytes remaining.

pub fn used(&self) -> usize

Get the number of bytes used.

pub fn reset(&mut self)

Reset the scratch buffer for reuse.

Does NOT zero the memory - just resets the position.

pub fn alloc_slice(&mut self, size: usize) -> &mut [u8]

Allocate a slice from the scratch buffer.

Arguments

• size - Number of bytes to allocate

Returns

Mutable slice of the requested size.

Panics

Panics if there isn’t enough space remaining.

pub fn try_alloc_slice(&mut self, size: usize) -> Option<&mut [u8]>

Try to allocate a slice, returning None if not enough space.

pub fn alloc<T: Copy + Default>(&mut self) -> &mut T

Allocate space for a value and return a mutable reference.

The space is properly aligned for the type.

Panics

Panics if there isn’t enough space.

pub fn alloc_with<T: Copy>(&mut self, value: T) -> &mut T

Allocate space for a value with initialization.

Panics

Panics if there isn’t enough space remaining in the buffer.

impl ScratchBuffer<DEFAULT_SCRATCH_SIZE>

Static methods for accessing thread-local scratch buffer.

pub fn thread_local_alloc(size: usize) -> &'static mut [u8]

Allocate from the thread-local scratch buffer.

Arguments

• size - Number of bytes to allocate

Returns

Mutable slice that is valid until reset() is called.

Panics

Panics if the requested size exceeds remaining capacity.

Safety Note

The returned reference is only valid until the next reset() call. It’s the caller’s responsibility to ensure the slice is not used after reset.

pub fn thread_local_reset()

Reset the thread-local scratch buffer.

Call this at the end of each event to reclaim space.

pub fn thread_local_remaining() -> usize

Get remaining capacity in thread-local buffer.

pub fn thread_local_used() -> usize

Get used bytes in thread-local buffer.

Trait Implementations

impl<const SIZE: usize> Default for ScratchBuffer<SIZE>

fn default() -> Self

Returns the “default value” for a type.