60 lines
1.2 KiB
Rust
60 lines
1.2 KiB
Rust
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use std::rc::Rc;
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use std::cell::Cell;
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use parity_wasm::elements::ValueType;
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use value::RuntimeValue;
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use Error;
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#[derive(Clone, Debug)]
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pub struct GlobalRef(Rc<GlobalInstance>);
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impl ::std::ops::Deref for GlobalRef {
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type Target = GlobalInstance;
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fn deref(&self) -> &GlobalInstance {
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&self.0
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}
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}
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#[derive(Debug)]
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pub struct GlobalInstance {
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val: Cell<RuntimeValue>,
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mutable: bool,
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}
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impl GlobalInstance {
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pub fn alloc(val: RuntimeValue, mutable: bool) -> GlobalRef {
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let global = GlobalInstance::new(val, mutable);
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GlobalRef(Rc::new(global))
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}
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fn new(val: RuntimeValue, mutable: bool) -> GlobalInstance {
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GlobalInstance {
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val: Cell::new(val),
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mutable,
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}
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}
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pub fn set(&self, val: RuntimeValue) -> Result<(), Error> {
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if !self.mutable {
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return Err(Error::Global("Attempt to change an immutable variable".into()));
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}
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if self.value_type() != val.value_type() {
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return Err(Error::Global("Attempt to change variable type".into()));
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}
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self.val.set(val);
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Ok(())
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}
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pub fn get(&self) -> RuntimeValue {
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self.val.get()
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}
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pub fn is_mutable(&self) -> bool {
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self.mutable
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}
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pub fn value_type(&self) -> ValueType {
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self.val.get().value_type()
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}
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}
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