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adjust cost
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@chenyan-dfinity
chenyan-dfinity committed Feb 4, 2024
1 parent 15dc9c0 commit 0498d89
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Showing 2 changed files with 31 additions and 23 deletions.
40 changes: 24 additions & 16 deletions rust/candid/src/de.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -364,12 +364,13 @@ impl<'de> Deserializer<'de> {
self.unroll_type()?;
assert!(*self.expect_type == TypeInner::Int);
let mut bytes = vec![0u8];
let pos = self.input.position();
let int = match self.wire_type.as_ref() {
TypeInner::Int => Int::decode(&mut self.input).map_err(Error::msg)?,
TypeInner::Nat => Int(Nat::decode(&mut self.input).map_err(Error::msg)?.0.into()),
t => return Err(Error::subtype(format!("{t} cannot be deserialized to int"))),
};
self.dec_value_cost(1)?;
self.dec_value_cost((self.input.position() - pos) as usize)?;
bytes.extend_from_slice(&int.0.to_signed_bytes_le());
visitor.visit_byte_buf(bytes)
}
Expand All @@ -384,9 +385,10 @@ impl<'de> Deserializer<'de> {
*self.expect_type == TypeInner::Nat && *self.wire_type == TypeInner::Nat,
"nat"
);
self.dec_value_cost(1)?;
let mut bytes = vec![1u8];
let pos = self.input.position();
let nat = Nat::decode(&mut self.input).map_err(Error::msg)?;
self.dec_value_cost((self.input.position() - pos) as usize)?;
bytes.extend_from_slice(&nat.0.to_bytes_le());
visitor.visit_byte_buf(bytes)
}
Expand Down Expand Up @@ -526,13 +528,13 @@ impl<'de> Deserializer<'de> {
}

macro_rules! primitive_impl {
($ty:ident, $type:expr, $($value:tt)*) => {
($ty:ident, $type:expr, $cost:literal, $($value:tt)*) => {
paste::item! {
fn [<deserialize_ $ty>]<V>(self, visitor: V) -> Result<V::Value>
where V: Visitor<'de> {
self.unroll_type()?;
check!(*self.expect_type == $type && *self.wire_type == $type, stringify!($type));
self.dec_value_cost(1)?;
self.dec_value_cost($cost)?;
let val = self.input.$($value)*().map_err(|_| Error::msg(format!("Cannot read {} value", stringify!($type))))?;
visitor.[<visit_ $ty>](val)
}
Expand Down Expand Up @@ -606,16 +608,16 @@ impl<'de, 'a> de::Deserializer<'de> for &'a mut Deserializer<'de> {
v
}

primitive_impl!(i8, TypeInner::Int8, read_i8);
primitive_impl!(i16, TypeInner::Int16, read_i16::<LittleEndian>);
primitive_impl!(i32, TypeInner::Int32, read_i32::<LittleEndian>);
primitive_impl!(i64, TypeInner::Int64, read_i64::<LittleEndian>);
primitive_impl!(u8, TypeInner::Nat8, read_u8);
primitive_impl!(u16, TypeInner::Nat16, read_u16::<LittleEndian>);
primitive_impl!(u32, TypeInner::Nat32, read_u32::<LittleEndian>);
primitive_impl!(u64, TypeInner::Nat64, read_u64::<LittleEndian>);
primitive_impl!(f32, TypeInner::Float32, read_f32::<LittleEndian>);
primitive_impl!(f64, TypeInner::Float64, read_f64::<LittleEndian>);
primitive_impl!(i8, TypeInner::Int8, 1, read_i8);
primitive_impl!(i16, TypeInner::Int16, 2, read_i16::<LittleEndian>);
primitive_impl!(i32, TypeInner::Int32, 4, read_i32::<LittleEndian>);
primitive_impl!(i64, TypeInner::Int64, 8, read_i64::<LittleEndian>);
primitive_impl!(u8, TypeInner::Nat8, 1, read_u8);
primitive_impl!(u16, TypeInner::Nat16, 2, read_u16::<LittleEndian>);
primitive_impl!(u32, TypeInner::Nat32, 4, read_u32::<LittleEndian>);
primitive_impl!(u64, TypeInner::Nat64, 8, read_u64::<LittleEndian>);
primitive_impl!(f32, TypeInner::Float32, 4, read_f32::<LittleEndian>);
primitive_impl!(f64, TypeInner::Float64, 8, read_f64::<LittleEndian>);

fn is_human_readable(&self) -> bool {
false
Expand All @@ -627,13 +629,14 @@ impl<'de, 'a> de::Deserializer<'de> for &'a mut Deserializer<'de> {
use crate::types::leb128::{decode_int, decode_nat};
self.unroll_type()?;
assert!(*self.expect_type == TypeInner::Int);
let pos = self.input.position();
let value: i128 = match self.wire_type.as_ref() {
TypeInner::Int => decode_int(&mut self.input)?,
TypeInner::Nat => i128::try_from(decode_nat(&mut self.input)?)
.map_err(|_| Error::msg("Cannot convert nat to i128"))?,
t => return Err(Error::subtype(format!("{t} cannot be deserialized to int"))),
};
self.dec_value_cost(1)?;
self.dec_value_cost((self.input.position() - pos) as usize)?;
visitor.visit_i128(value)
}
fn deserialize_u128<V>(self, visitor: V) -> Result<V::Value>
Expand All @@ -645,8 +648,9 @@ impl<'de, 'a> de::Deserializer<'de> for &'a mut Deserializer<'de> {
*self.expect_type == TypeInner::Nat && *self.wire_type == TypeInner::Nat,
"nat"
);
self.dec_value_cost(1)?;
let pos = self.input.position();
let value = crate::types::leb128::decode_nat(&mut self.input)?;
self.dec_value_cost((self.input.position() - pos) as usize)?;
visitor.visit_u128(value)
}
fn deserialize_unit<V>(self, visitor: V) -> Result<V::Value>
Expand Down Expand Up @@ -1015,6 +1019,7 @@ impl<'de, 'a> de::SeqAccess<'de> for Compound<'a, 'de> {
if expect.is_empty() && wire.is_empty() {
return Ok(None);
}
self.de.dec_value_cost(1)?;
self.de.expect_type = expect
.pop_front()
.map(|f| f.ty)
Expand Down Expand Up @@ -1044,6 +1049,7 @@ impl<'de, 'a> de::MapAccess<'de> for Compound<'a, 'de> {
match (expect.front(), wire.front()) {
(Some(e), Some(w)) => {
use std::cmp::Ordering;
self.de.dec_value_cost(1)?;
match e.id.get_id().cmp(&w.id.get_id()) {
Ordering::Equal => {
self.de.set_field_name(e.id.clone());
Expand Down Expand Up @@ -1073,6 +1079,7 @@ impl<'de, 'a> de::MapAccess<'de> for Compound<'a, 'de> {
}
}
(None, Some(_)) => {
self.de.dec_value_cost(1)?;
self.de.set_field_name(Label::Named("_".to_owned()).into());
self.de.wire_type = wire.pop_front().unwrap().ty;
self.de.expect_type = TypeInner::Reserved.into();
Expand Down Expand Up @@ -1110,6 +1117,7 @@ impl<'de, 'a> de::MapAccess<'de> for Compound<'a, 'de> {
{
match &self.style {
Style::Map { expect, wire, .. } => {
self.de.dec_value_cost(1)?;
self.de.expect_type = expect.1.clone();
self.de.wire_type = wire.1.clone();
seed.deserialize(&mut *self.de)
Expand Down
14 changes: 7 additions & 7 deletions spec/Candid.md
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1259,11 +1259,11 @@ Some values on the wire take fewer space than the values on the host language, e

```
C : <val> -> <primtype> -> nat
C(n : nat) = 1
C(i : int) = 1
C(n : nat<N>) = 1
C(i : int<N>) = 1
C(z : float<N>) = 1
C(n : nat) = |leb128(n)|
C(i : int) = |sleb128(i)|
C(n : nat<N>) = N / 8
C(i : int<N>) = N / 8
C(z : float<N>) = N / 8
C(b : bool) = 1
C(t : text) = 1 + |t|
C(_ : null) = 1
Expand All @@ -1275,10 +1275,10 @@ C(null : opt <datatype>) = 1
C(?v : opt <datatype>) = 1 + C(v : <datatype>)
C(v^N : vec <datatype>) = 1 + sum_i C(v[i] : <datatype>)
C(kv* : record {<fieldtype>*}) = 1 + sum_i C(kv : <fieldtype>*[i])
C(kv : variant {<fieldtype>*}) = 1 + C(kv : <fieldtype>*[i])
C(kv : variant {<fieldtype>*}) = C(kv : <fieldtype>*[i])
C : (<nat>, <val>) -> <fieldtype> -> nat
C((k,v) : k:<datatype>) = C(v : <datatype>)
C((k,v) : k:<datatype>) = 1 + C(v : <datatype>)
C : <val> -> <reftype> -> nat
C(ref(r) : service <actortype>) = 1
Expand Down

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