garage/src/util/data.rs
2020-04-24 10:10:01 +00:00

125 lines
2.7 KiB
Rust

use rand::Rng;
use serde::de::{self, Visitor};
use serde::{Deserialize, Deserializer, Serialize, Serializer};
use sha2::{Digest, Sha256};
use std::fmt;
use std::time::{SystemTime, UNIX_EPOCH};
#[derive(Default, PartialOrd, Ord, Clone, Hash, PartialEq, Copy)]
pub struct FixedBytes32([u8; 32]);
impl From<[u8; 32]> for FixedBytes32 {
fn from(x: [u8; 32]) -> FixedBytes32 {
FixedBytes32(x)
}
}
impl std::convert::AsRef<[u8]> for FixedBytes32 {
fn as_ref(&self) -> &[u8] {
&self.0[..]
}
}
impl Eq for FixedBytes32 {}
impl fmt::Debug for FixedBytes32 {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "{}…", hex::encode(&self.0[..8]))
}
}
struct FixedBytes32Visitor;
impl<'de> Visitor<'de> for FixedBytes32Visitor {
type Value = FixedBytes32;
fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
formatter.write_str("a byte slice of size 32")
}
fn visit_bytes<E: de::Error>(self, value: &[u8]) -> Result<Self::Value, E> {
if value.len() == 32 {
let mut res = [0u8; 32];
res.copy_from_slice(value);
Ok(res.into())
} else {
Err(E::custom(format!(
"Invalid byte string length {}, expected 32",
value.len()
)))
}
}
}
impl<'de> Deserialize<'de> for FixedBytes32 {
fn deserialize<D: Deserializer<'de>>(deserializer: D) -> Result<FixedBytes32, D::Error> {
deserializer.deserialize_bytes(FixedBytes32Visitor)
}
}
impl Serialize for FixedBytes32 {
fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
serializer.serialize_bytes(&self.0[..])
}
}
impl FixedBytes32 {
pub fn as_slice(&self) -> &[u8] {
&self.0[..]
}
pub fn as_slice_mut(&mut self) -> &mut [u8] {
&mut self.0[..]
}
pub fn to_vec(&self) -> Vec<u8> {
self.0.to_vec()
}
}
pub type UUID = FixedBytes32;
pub type Hash = FixedBytes32;
pub fn hash(data: &[u8]) -> Hash {
let mut hasher = Sha256::new();
hasher.input(data);
let mut hash = [0u8; 32];
hash.copy_from_slice(&hasher.result()[..]);
hash.into()
}
pub fn gen_uuid() -> UUID {
rand::thread_rng().gen::<[u8; 32]>().into()
}
pub fn now_msec() -> u64 {
SystemTime::now()
.duration_since(UNIX_EPOCH)
.expect("Fix your clock :o")
.as_millis() as u64
}
// RMP serialization with names of fields and variants
pub fn rmp_to_vec_all_named<T>(val: &T) -> Result<Vec<u8>, rmp_serde::encode::Error>
where
T: Serialize + ?Sized,
{
let mut wr = Vec::with_capacity(128);
let mut se = rmp_serde::Serializer::new(&mut wr)
.with_struct_map()
.with_string_variants();
val.serialize(&mut se)?;
Ok(wr)
}
pub fn debug_serialize<T: Serialize>(x: T) -> String {
match serde_json::to_string(&x) {
Ok(ss) => {
if ss.len() > 100 {
ss[..100].to_string()
} else {
ss
}
}
Err(e) => format!("<JSON serialization error: {}>", e),
}
}