composable_allocators/
as_global.rs

1use crate::base::*;
2use const_default::ConstDefault;
3use core::alloc::{self, GlobalAlloc};
4use core::ptr::{NonNull, null_mut};
5
6#[derive(Debug, Copy, Clone)]
7pub struct AsGlobal<A: NonUnwinding + ?Sized>(pub A);
8
9impl<A: NonUnwinding + ConstDefault> ConstDefault for AsGlobal<A> {
10    const DEFAULT: Self = AsGlobal(A::DEFAULT);
11}
12
13unsafe impl<A: NonUnwinding + ?Sized> GlobalAlloc for AsGlobal<A> {
14    unsafe fn alloc(&self, layout: alloc::Layout) -> *mut u8 {
15        self.0.allocate(layout).map_or_else(|_| null_mut(), |x| x.as_mut_ptr())
16    }
17
18    unsafe fn alloc_zeroed(&self, layout: alloc::Layout) -> *mut u8 {
19        self.0.allocate_zeroed(layout).map_or_else(|_| null_mut(), |x| x.as_mut_ptr())
20    }
21
22    unsafe fn dealloc(&self, ptr: *mut u8, layout: alloc::Layout) {
23        self.0.deallocate(NonNull::new_unchecked(ptr), layout)
24    }
25
26    unsafe fn realloc(
27        &self, 
28        ptr: *mut u8, 
29        layout: alloc::Layout, 
30        new_size: usize
31    ) -> *mut u8 {
32        let ptr = NonNull::new_unchecked(ptr);
33        let new_layout = alloc::Layout::from_size_align_unchecked(new_size, layout.align());
34        if new_size > layout.size() {
35            self.0.grow(ptr, layout, new_layout)
36        } else {
37            self.0.shrink(ptr, layout, new_layout)
38        }.map_or_else(|_| null_mut(), |x| x.as_mut_ptr())
39    }
40}
composable_allocators/as_global.rs

composable_allocators/
as_global.rs
