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use std::fmt;
use std::str::FromStr;
use std::ops::Deref;
use rustc_hex::FromHex;
use serde::{Deserialize, Deserializer};
use serde::de::{Error, Visitor};
#[derive(Default, Debug, PartialEq, Eq, Clone, PartialOrd, Ord)]
pub struct Bytes(Vec<u8>);
impl Bytes {
pub fn new(v: Vec<u8>) -> Self {
Bytes(v)
}
}
impl Into<Vec<u8>> for Bytes {
fn into(self) -> Vec<u8> {
self.0
}
}
impl Deref for Bytes {
type Target = [u8];
fn deref(&self) -> &[u8] {
&self.0
}
}
impl FromStr for Bytes {
type Err = String;
fn from_str(value: &str) -> Result<Self, Self::Err> {
let v = match value.len() {
0 => vec![],
2 if value.starts_with("0x") => vec![],
_ if value.starts_with("0x") && value.len() % 2 == 1 => {
let v = "0".to_owned() + &value[2..];
FromHex::from_hex(v.as_str()).unwrap_or(vec![])
},
_ if value.starts_with("0x") => FromHex::from_hex(&value[2..]).unwrap_or(vec![]),
_ => FromHex::from_hex(value).unwrap_or(vec![]),
};
Ok(Bytes(v))
}
}
impl<'a> Deserialize<'a> for Bytes {
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where D: Deserializer<'a> {
deserializer.deserialize_any(BytesVisitor)
}
}
struct BytesVisitor;
impl<'a> Visitor<'a> for BytesVisitor {
type Value = Bytes;
fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
write!(formatter, "a hex encoded string of bytes")
}
fn visit_str<E>(self, value: &str) -> Result<Self::Value, E> where E: Error {
Bytes::from_str(value).map_err(Error::custom)
}
fn visit_string<E>(self, value: String) -> Result<Self::Value, E> where E: Error {
self.visit_str(value.as_ref())
}
}
#[cfg(test)]
mod test {
use serde_json;
use bytes::Bytes;
#[test]
fn bytes_deserialization() {
let s = r#"["", "0x", "0x12", "1234", "0x001"]"#;
let deserialized: Vec<Bytes> = serde_json::from_str(s).unwrap();
assert_eq!(deserialized, vec![
Bytes(vec![]),
Bytes(vec![]),
Bytes(vec![0x12]),
Bytes(vec![0x12, 0x34]),
Bytes(vec![0, 1])
]);
}
#[test]
fn bytes_into() {
let bytes = Bytes(vec![0xff, 0x11]);
let v: Vec<u8> = bytes.into();
assert_eq!(vec![0xff, 0x11], v);
}
}