Method grow

crates/tinywasm/src/store/memory/instance.rs:243–289

(&mut self, pages_delta: i64, trap_on_oom: bool)

    }

    pub(crate) fn grow(&mut self, pages_delta: i64, trap_on_oom: bool) -> Result<Option<i64>, Trap> {
        if pages_delta < 0 {
            cold_path();
            crate::log::debug!("memory.grow failed: negative delta {}", pages_delta);
            return Ok(None);
        }

        let current_pages = self.page_count;
        let Some(pages_delta) = usize::try_from(pages_delta).ok() else {
            return Ok(None);
        };
        let Some(new_pages) = current_pages.checked_add(pages_delta) else {
            return Ok(None);
        };
        let max_pages = self.kind.page_count_max().try_into().unwrap_or(usize::MAX);

        if new_pages > max_pages {
            cold_path();
            crate::log::debug!("memory.grow failed: new_pages={}, max_pages={}", new_pages, max_pages);
            return Ok(None);
        }

        let Some(new_size) = (new_pages as u64).checked_mul(self.kind.page_size()) else {
            return Ok(None);
        };
        if new_size > self.kind.max_size() {
            cold_path();
            crate::log::debug!("memory.grow failed: new_size={}, max_size={}", new_size, self.kind.max_size());
            return Ok(None);
        }

        let Some(new_size) = usize::try_from(new_size).ok() else {
            return Ok(None);
        };
        if new_size == self.inner.len() {
            return Ok(i64::try_from(current_pages).ok());
        }

        if let Err(err) = self.inner.grow_to(new_size) {
            if trap_on_oom {
                return Err(err);
            }
            return Ok(None);
        }
        self.page_count = new_pages;
        Ok(i64::try_from(current_pages).ok())
    }
}