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use serde::de::{Deserializer, SeqAccess, Visitor};
use serde::ser::{SerializeSeq, Serializer};
use serde::{Deserialize, Serialize};
#[derive(Clone)]
pub struct Order {
pub price: f64,
pub quantity_base: f64,
pub quantity_quote: f64,
pub quantity_contract: Option<f64>,
}
impl Serialize for Order {
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where
S: Serializer,
{
let len: usize = if self.quantity_contract.is_some() {
4
} else {
3
};
let mut seq = serializer.serialize_seq(Some(len))?;
seq.serialize_element(&self.price)?;
seq.serialize_element(&self.quantity_base)?;
seq.serialize_element(&self.quantity_quote)?;
if let Some(qc) = self.quantity_contract {
seq.serialize_element(&qc)?;
}
seq.end()
}
}
struct OrderVisitor;
impl<'de> Visitor<'de> for OrderVisitor {
type Value = Order;
fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
formatter.write_str("a nonempty sequence of numbers")
}
fn visit_seq<V>(self, mut visitor: V) -> Result<Order, V::Error>
where
V: SeqAccess<'de>,
{
let mut vec = Vec::<f64>::new();
while let Some(elem) = visitor.next_element()? {
vec.push(elem);
}
let order = Order {
price: vec[0],
quantity_base: vec[1],
quantity_quote: vec[2],
quantity_contract: if vec.len() == 4 { Some(vec[3]) } else { None },
};
Ok(order)
}
}
impl<'de> Deserialize<'de> for Order {
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where
D: Deserializer<'de>,
{
deserializer.deserialize_seq(OrderVisitor)
}
}
#[cfg(test)]
mod tests {
use crate::order::Order;
#[test]
fn order_serialize() {
let order = Order {
price: 59999.8,
quantity_base: 1.7,
quantity_quote: 59999.8 * 1.7,
quantity_contract: Some(1.7),
};
let text = serde_json::to_string(&order).unwrap();
assert_eq!(text.as_str(), "[59999.8,1.7,101999.66,1.7]");
}
#[test]
fn order_deserialize() {
let expected = Order {
price: 59999.8,
quantity_base: 1.7,
quantity_quote: 59999.8 * 1.7,
quantity_contract: Some(1.7),
};
let actual = serde_json::from_str::<Order>("[59999.8,1.7,101999.66,1.7]").unwrap();
assert_eq!(expected.price, actual.price);
assert_eq!(expected.quantity_base, actual.quantity_base);
assert_eq!(expected.quantity_quote, actual.quantity_quote);
assert_eq!(expected.quantity_contract, actual.quantity_contract);
}
}