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gemachain_bpf_loader_program/
allocator_bump.rs

1use crate::alloc;
2
3use alloc::{Alloc, AllocErr};
4use gemachain_rbpf::aligned_memory::AlignedMemory;
5use std::alloc::Layout;
6
7#[derive(Debug)]
8pub struct BpfAllocator {
9    heap: AlignedMemory,
10    start: u64,
11    len: u64,
12    pos: u64,
13}
14
15impl BpfAllocator {
16    pub fn new(heap: AlignedMemory, virtual_address: u64) -> Self {
17        let len = heap.len() as u64;
18        Self {
19            heap,
20            start: virtual_address,
21            len,
22            pos: 0,
23        }
24    }
25}
26
27impl Alloc for BpfAllocator {
28    fn alloc(&mut self, layout: Layout) -> Result<u64, AllocErr> {
29        let bytes_to_align = (self.pos as *const u8).align_offset(layout.align()) as u64;
30        if self
31            .pos
32            .saturating_add(layout.size() as u64)
33            .saturating_add(bytes_to_align)
34            <= self.len
35        {
36            self.pos += bytes_to_align;
37            let addr = self.start + self.pos;
38            self.pos += layout.size() as u64;
39            Ok(addr)
40        } else {
41            Err(AllocErr)
42        }
43    }
44
45    fn dealloc(&mut self, _addr: u64, _layout: Layout) {
46        // It's a bump allocator, free not supported
47    }
48}