mirror of
https://github.com/fluencelabs/wasmer
synced 2024-12-15 07:05:41 +00:00
102 lines
2.1 KiB
Rust
102 lines
2.1 KiB
Rust
use crate::error::PageError;
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use std::{
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fmt,
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ops::{Add, Sub},
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};
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pub const WASM_PAGE_SIZE: usize = 65_536;
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pub const WASM_MAX_PAGES: usize = 65_536;
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// From emscripten resize_heap implementation
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pub const WASM_MIN_PAGES: usize = 256;
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/// Units of WebAssembly pages (as specified to be 65,536 bytes).
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#[derive(Serialize, Deserialize, Copy, Clone, PartialEq, Eq, PartialOrd, Ord)]
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pub struct Pages(pub u32);
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impl Pages {
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pub fn checked_add(self, rhs: Pages) -> Result<Pages, PageError> {
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let added = (self.0 as usize) + (rhs.0 as usize);
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if added <= WASM_MAX_PAGES {
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Ok(Pages(added as u32))
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} else {
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Err(PageError::ExceededMaxPages(
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self.0 as usize,
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rhs.0 as usize,
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added,
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))
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}
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}
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pub fn bytes(self) -> Bytes {
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self.into()
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}
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}
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impl fmt::Debug for Pages {
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fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
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write!(f, "{} pages", self.0)
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}
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}
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/// Units of WebAssembly memory in terms of 8-bit bytes.
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#[derive(Serialize, Deserialize, Copy, Clone, PartialEq, Eq, PartialOrd, Ord)]
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pub struct Bytes(pub usize);
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impl fmt::Debug for Bytes {
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fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
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write!(f, "{} bytes", self.0)
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}
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}
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impl From<Pages> for Bytes {
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fn from(pages: Pages) -> Bytes {
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Bytes((pages.0 as usize) * WASM_PAGE_SIZE)
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}
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}
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impl<T> Sub<T> for Pages
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where
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T: Into<Pages>,
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{
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type Output = Pages;
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fn sub(self, rhs: T) -> Pages {
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Pages(self.0 - rhs.into().0)
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}
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}
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impl<T> Add<T> for Pages
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where
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T: Into<Pages>,
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{
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type Output = Pages;
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fn add(self, rhs: T) -> Pages {
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Pages(self.0 + rhs.into().0)
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}
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}
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impl From<Bytes> for Pages {
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fn from(bytes: Bytes) -> Pages {
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Pages((bytes.0 / WASM_PAGE_SIZE) as u32)
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}
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}
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impl<T> Sub<T> for Bytes
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where
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T: Into<Bytes>,
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{
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type Output = Bytes;
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fn sub(self, rhs: T) -> Bytes {
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Bytes(self.0 - rhs.into().0)
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}
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}
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impl<T> Add<T> for Bytes
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where
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T: Into<Bytes>,
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{
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type Output = Bytes;
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fn add(self, rhs: T) -> Bytes {
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Bytes(self.0 + rhs.into().0)
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}
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}
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