Trait vectorscan::alloc::MallocLikeAllocator

pub trait MallocLikeAllocator {
    // Required methods
    fn allocate(&self, size: usize) -> Option<NonNull<u8>>;
    fn deallocate(&self, ptr: NonNull<u8>);
}

Available on crate feature alloc only.

The alloc/free interface required by vectorscan methods.

This is named “malloc-like” because it mirrors the interface provided by libc::malloc() and libc::free(). This differs from GlobalAlloc in two ways:

• no Layout argument is provided to the deallocate method, so the implementation must record the size of each allocation somewhere.
• only a size argument is provided to the allocate method, with the alignment requirements of the memory being relegated to comments and docstrings.

Required Methods

fn allocate(&self, size: usize) -> Option<NonNull<u8>>

Allocate a region of memory of at least size bytes.

The alignment of the returned memory region is specified by the implementation. Returns None if allocation fails for any reason.

fn deallocate(&self, ptr: NonNull<u8>)

Free up a previously-allocated memory region at ptr.

The value must be the exact same location returned by a previous call to Self::allocate(). The behavior if this method is called more than once for a given ptr is unspecified.

Implementors

impl MallocLikeAllocator for LayoutTracker

LayoutTracker implements three additional guarantees over the base MallocLikeAllocator:

• 0-size allocation requests always return None instead of allocating.
• all allocations are aligned to at least 8 bytes.
• attempted double frees will panic instead.