56 lines
1.4 KiB
Rust
56 lines
1.4 KiB
Rust
#![allow(clippy::integer_arithmetic)]
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use {
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solana_program_runtime::invoke_context::{Alloc, AllocErr},
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solana_rbpf::{aligned_memory::AlignedMemory, ebpf::HOST_ALIGN},
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std::alloc::Layout,
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};
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#[derive(Debug)]
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pub struct BpfAllocator {
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#[allow(dead_code)]
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heap: AlignedMemory<HOST_ALIGN>,
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start: u64,
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len: u64,
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pos: u64,
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}
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impl BpfAllocator {
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pub fn new(heap: AlignedMemory<HOST_ALIGN>, virtual_address: u64) -> Self {
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let len = heap.len() as u64;
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Self {
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heap,
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start: virtual_address,
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len,
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pos: 0,
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}
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}
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pub fn heap_mut(&mut self) -> &mut AlignedMemory<HOST_ALIGN> {
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&mut self.heap
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}
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}
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impl Alloc for BpfAllocator {
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fn alloc(&mut self, layout: Layout) -> Result<u64, AllocErr> {
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let bytes_to_align = (self.pos as *const u8).align_offset(layout.align()) as u64;
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if self
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.pos
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.saturating_add(layout.size() as u64)
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.saturating_add(bytes_to_align)
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<= self.len
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{
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self.pos += bytes_to_align;
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let addr = self.start + self.pos;
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self.pos += layout.size() as u64;
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Ok(addr)
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} else {
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Err(AllocErr)
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}
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}
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fn dealloc(&mut self, _addr: u64, _layout: Layout) {
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// It's a bump allocator, free not supported
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}
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}
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