tvl-depot/tvix/castore/src/digests.rs
Yureka 3ca0b53840 refactor(tvix/castore): use Directory struct separate from proto one
This uses our own data type to deal with Directories in the castore model.

It makes some undesired states unrepresentable, removing the need for conversions and checking in various places:

 - In the protobuf, blake3 digests could have a wrong length, as proto doesn't know fixed-size fields. We now use `B3Digest`, which makes cloning cheaper, and removes the need to do size-checking everywhere.
 - In the protobuf, we had three different lists for `files`, `symlinks` and `directories`. This was mostly a protobuf size optimization, but made interacting with them a bit awkward. This has now been replaced with a list of enums, and convenience iterators to get various nodes, and add new ones.

Change-Id: I7b92691bb06d77ff3f58a5ccea94a22c16f84f04
Reviewed-on: https://cl.tvl.fyi/c/depot/+/12057
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2024-08-13 12:17:01 +00:00

97 lines
2.3 KiB
Rust

use bytes::Bytes;
use data_encoding::BASE64;
use thiserror::Error;
#[derive(PartialEq, Eq, Hash)]
pub struct B3Digest(Bytes);
// TODO: allow converting these errors to crate::Error
#[derive(Error, Debug, PartialEq)]
pub enum Error {
#[error("invalid digest length: {0}")]
InvalidDigestLen(usize),
}
pub const B3_LEN: usize = 32;
impl B3Digest {
pub fn as_slice(&self) -> &[u8] {
&self.0[..]
}
}
impl From<B3Digest> for bytes::Bytes {
fn from(val: B3Digest) -> Self {
val.0
}
}
impl From<blake3::Hash> for B3Digest {
fn from(value: blake3::Hash) -> Self {
Self(Bytes::copy_from_slice(value.as_bytes()))
}
}
impl From<digest::Output<blake3::Hasher>> for B3Digest {
fn from(value: digest::Output<blake3::Hasher>) -> Self {
let v = Into::<[u8; B3_LEN]>::into(value);
Self(Bytes::copy_from_slice(&v))
}
}
impl TryFrom<Vec<u8>> for B3Digest {
type Error = Error;
// constructs a [B3Digest] from a [Vec<u8>].
// Returns an error if the digest has the wrong length.
fn try_from(value: Vec<u8>) -> Result<Self, Self::Error> {
if value.len() != B3_LEN {
Err(Error::InvalidDigestLen(value.len()))
} else {
Ok(Self(value.into()))
}
}
}
impl TryFrom<bytes::Bytes> for B3Digest {
type Error = Error;
// constructs a [B3Digest] from a [bytes::Bytes].
// Returns an error if the digest has the wrong length.
fn try_from(value: bytes::Bytes) -> Result<Self, Self::Error> {
if value.len() != B3_LEN {
Err(Error::InvalidDigestLen(value.len()))
} else {
Ok(Self(value))
}
}
}
impl From<&[u8; B3_LEN]> for B3Digest {
fn from(value: &[u8; B3_LEN]) -> Self {
Self(value.to_vec().into())
}
}
impl From<B3Digest> for [u8; B3_LEN] {
fn from(value: B3Digest) -> Self {
value.0.to_vec().try_into().unwrap()
}
}
impl Clone for B3Digest {
fn clone(&self) -> Self {
Self(self.0.to_owned())
}
}
impl std::fmt::Display for B3Digest {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
write!(f, "b3:{}", BASE64.encode(&self.0))
}
}
impl std::fmt::Debug for B3Digest {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
write!(f, "b3:{}", BASE64.encode(&self.0))
}
}