garage/src/util/data.rs
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rename types to CamelCase
2021-05-03 22:15:09 +02:00

163 lines
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Rust

//! Contains common types and functions related to serialization and integrity
use rand::Rng;
use serde::de::{self, Visitor};
use serde::{Deserialize, Deserializer, Serialize, Serializer};
use std::fmt;
/// An array of 32 bytes
#[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 {
/// Access the content as a slice
pub fn as_slice(&self) -> &[u8] {
&self.0[..]
}
/// Access the content as a mutable slice
pub fn as_slice_mut(&mut self) -> &mut [u8] {
&mut self.0[..]
}
/// Copy to a slice
pub fn to_vec(self) -> Vec<u8> {
self.0.to_vec()
}
/// Try building a FixedBytes32 from a slice
/// Return None if the slice is not 32 bytes long
pub fn try_from(by: &[u8]) -> Option<Self> {
if by.len() != 32 {
return None;
}
let mut ret = [0u8; 32];
ret.copy_from_slice(by);
Some(Self(ret))
}
}
/// A 32 bytes UUID
pub type Uuid = FixedBytes32;
/// A 256 bit cryptographic hash, can be sha256 or blake2 depending on provenance
pub type Hash = FixedBytes32;
/// Compute the sha256 of a slice
pub fn sha256sum(data: &[u8]) -> Hash {
use sha2::{Digest, Sha256};
let mut hasher = Sha256::new();
hasher.update(data);
let mut hash = [0u8; 32];
hash.copy_from_slice(&hasher.finalize()[..]);
hash.into()
}
/// Compute the blake2 of a slice
pub fn blake2sum(data: &[u8]) -> Hash {
use blake2::{Blake2b, Digest};
let mut hasher = Blake2b::new();
hasher.update(data);
let mut hash = [0u8; 32];
hash.copy_from_slice(&hasher.finalize()[..32]);
hash.into()
}
/// A 64 bit non cryptographic hash
pub type FastHash = u64;
/// Compute a (non cryptographic) of a slice
pub fn fasthash(data: &[u8]) -> FastHash {
use xxhash_rust::xxh3::Xxh3;
let mut h = Xxh3::new();
h.update(data);
h.digest()
}
/// Generate a random 32 bytes UUID
pub fn gen_uuid() -> Uuid {
rand::thread_rng().gen::<[u8; 32]>().into()
}
// RMP serialization with names of fields and variants
/// Serialize to MessagePack
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)
}
/// Serialize to JSON, truncating long result
pub fn debug_serialize<T: Serialize>(x: T) -> String {
match serde_json::to_string(&x) {
Ok(ss) => {
if ss.len() > 100 {
// TODO this can panic if 100 is not a codepoint boundary, but inside a 2 Bytes
// (or more) codepoint
ss[..100].to_string()
} else {
ss
}
}
Err(e) => format!("<JSON serialization error: {}>", e),
}
}