28 lines
842 B
Markdown
28 lines
842 B
Markdown
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Reference:
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* https://radu-matei.com/blog/practical-guide-to-wasm-memory/ [practical-guide-to-wasm-memory.pdf](https://playsecurity.org/doc/showDocDetail.jssp?id=6143)
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* https://github.com/alec-deason/wasm_plugin/blob/main/guest/src/lib.rs
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* https://github.com/reem/rust-memalloc/blob/master/src/lib.rs
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**rust-memalloc** implements `reallocate`:
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```rust
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pub unsafe fn reallocate(ptr: *mut u8, old_size: usize, new_size: usize) -> *mut u8 {
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if old_size > new_size {
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let mut buf = Vec::from_raw_parts(ptr, new_size, old_size);
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buf.shrink_to_fit();
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ptr_from_vec(buf)
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} else if new_size > old_size {
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let additional = new_size - old_size;
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let mut buf = Vec::from_raw_parts(ptr, 0, old_size);
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buf.reserve_exact(additional);
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ptr_from_vec(buf)
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} else {
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ptr
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}
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}
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```
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