feat(tvix/nix-compat): introduce ExportedPathInfo struct

This is another representation about information Nix has on a Store
Path. It's encountered in the exportReferencesGraph feature.

Change-Id: Ia0c08c369f4af9e50ebe3a5053bd98fadaa0003d
Reviewed-on: https://cl.tvl.fyi/c/depot/+/11396
Tested-by: BuildkiteCI
Autosubmit: flokli <flokli@flokli.de>
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
This commit is contained in:
Florian Klink 2024-04-12 15:38:40 +03:00 committed by flokli
parent 329c4a1ace
commit 82cf89ee6e
2 changed files with 122 additions and 0 deletions

View file

@ -4,5 +4,6 @@ pub mod nar;
pub mod narinfo; pub mod narinfo;
pub mod nixbase32; pub mod nixbase32;
pub mod nixhash; pub mod nixhash;
pub mod path_info;
pub mod store_path; pub mod store_path;
pub mod wire; pub mod wire;

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@ -0,0 +1,121 @@
use crate::{nixbase32, nixhash::NixHash, store_path::StorePathRef};
use serde::{Deserialize, Serialize};
use std::collections::BTreeSet;
/// Represents information about a Store Path that Nix provides inside the build
/// if the exportReferencesGraph feature is used.
/// This is not to be confused with the format Nix uses in its `nix path-info` command.
/// It includes some more fields, like `registrationTime`, `signatures` and `ultimate`,
/// does not include the `closureSize` and encodes `narHash` as SRI.
#[derive(Clone, Debug, Eq, PartialEq, Serialize, Deserialize)]
pub struct ExportedPathInfo<'a> {
#[serde(rename = "closureSize")]
pub closure_size: u64,
#[serde(
rename = "narHash",
serialize_with = "to_nix_nixbase32_string",
deserialize_with = "from_nix_nixbase32_string"
)]
pub nar_sha256: [u8; 32],
#[serde(rename = "narSize")]
pub nar_size: u64,
#[serde(borrow)]
pub path: StorePathRef<'a>,
/// The list of other Store Paths this Store Path refers to.
/// StorePathRef does Ord by the nixbase32-encoded string repr, so this is correct.
pub references: BTreeSet<StorePathRef<'a>>,
// more recent versions of Nix also have a `valid: true` field here, Nix 2.3 doesn't,
// and nothing seems to use it.
}
/// ExportedPathInfo are ordered by their `path` field.
impl Ord for ExportedPathInfo<'_> {
fn cmp(&self, other: &Self) -> std::cmp::Ordering {
self.path.cmp(&other.path)
}
}
impl PartialOrd for ExportedPathInfo<'_> {
fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
Some(self.cmp(other))
}
}
fn to_nix_nixbase32_string<S>(v: &[u8; 32], serializer: S) -> Result<S::Ok, S::Error>
where
S: serde::Serializer,
{
let string = NixHash::Sha256(*v).to_nix_nixbase32_string();
string.serialize(serializer)
}
/// The length of a sha256 digest, nixbase32-encoded.
const NIXBASE32_SHA256_ENCODE_LEN: usize = nixbase32::encode_len(32);
fn from_nix_nixbase32_string<'de, D>(deserializer: D) -> Result<[u8; 32], D::Error>
where
D: serde::Deserializer<'de>,
{
let str: &'de str = Deserialize::deserialize(deserializer)?;
let digest_str = str.strip_prefix("sha256:").ok_or_else(|| {
serde::de::Error::invalid_value(serde::de::Unexpected::Str(str), &"sha256:…")
})?;
let digest_str: [u8; NIXBASE32_SHA256_ENCODE_LEN] =
digest_str.as_bytes().try_into().map_err(|_| {
serde::de::Error::invalid_value(serde::de::Unexpected::Str(str), &"valid digest len")
})?;
let digest: [u8; 32] = nixbase32::decode_fixed(digest_str).map_err(|_| {
serde::de::Error::invalid_value(serde::de::Unexpected::Str(str), &"valid nixbase32")
})?;
Ok(digest)
}
#[cfg(test)]
mod tests {
use hex_literal::hex;
use super::*;
/// Ensure we can create the same JSON as the exportReferencesGraph feature
#[test]
fn serialize_deserialize() {
// JSON extracted from a build of
// stdenv.mkDerivation { name = "hello"; __structuredAttrs = true; exportReferencesGraph.blub = [ pkgs.hello ]; nativeBuildInputs = [pkgs.jq]; buildCommand = "jq -rc .blub $NIX_ATTRS_JSON_FILE > $out"; }
let pathinfos_str_json = r#"[{"closureSize":1828984,"narHash":"sha256:11vm2x1ajhzsrzw7lsyss51mmr3b6yll9wdjn51bh7liwkpc8ila","narSize":1828984,"path":"/nix/store/7n0mbqydcipkpbxm24fab066lxk68aqk-libunistring-1.1","references":["/nix/store/7n0mbqydcipkpbxm24fab066lxk68aqk-libunistring-1.1"]},{"closureSize":32696176,"narHash":"sha256:0alzbhjxdcsmr1pk7z0bdh46r2xpq3xs3k9y82bi4bx5pklcvw5x","narSize":226560,"path":"/nix/store/dbghhbq1x39yxgkv3vkgfwbxrmw9nfzi-hello-2.12.1","references":["/nix/store/dbghhbq1x39yxgkv3vkgfwbxrmw9nfzi-hello-2.12.1","/nix/store/ddwyrxif62r8n6xclvskjyy6szdhvj60-glibc-2.39-5"]},{"closureSize":32469616,"narHash":"sha256:1zw5p05fh0k836ybfxkskv8apcv2m3pm2wa6y90wqn5w5kjyj13c","narSize":30119936,"path":"/nix/store/ddwyrxif62r8n6xclvskjyy6szdhvj60-glibc-2.39-5","references":["/nix/store/ddwyrxif62r8n6xclvskjyy6szdhvj60-glibc-2.39-5","/nix/store/rxganm4ibf31qngal3j3psp20mak37yy-xgcc-13.2.0-libgcc","/nix/store/s32cldbh9pfzd9z82izi12mdlrw0yf8q-libidn2-2.3.7"]},{"closureSize":159560,"narHash":"sha256:10q8iyvfmpfck3yiisnj1j8vp6lq3km17r26sr95zpdf9mgmk69s","narSize":159560,"path":"/nix/store/rxganm4ibf31qngal3j3psp20mak37yy-xgcc-13.2.0-libgcc","references":[]},{"closureSize":2190120,"narHash":"sha256:1cv997nzxbd91jhmzwnhxa1ahlzp5ffli8m4a5npcq8zg0vb1kwg","narSize":361136,"path":"/nix/store/s32cldbh9pfzd9z82izi12mdlrw0yf8q-libidn2-2.3.7","references":["/nix/store/7n0mbqydcipkpbxm24fab066lxk68aqk-libunistring-1.1","/nix/store/s32cldbh9pfzd9z82izi12mdlrw0yf8q-libidn2-2.3.7"]}]"#;
// We ensure it roundtrips (to check the sorting is correct)
let deserialized: BTreeSet<ExportedPathInfo> =
serde_json::from_str(pathinfos_str_json).expect("must serialize");
let serialized_again = serde_json::to_string(&deserialized).expect("must deserialize");
assert_eq!(pathinfos_str_json, serialized_again);
// Also compare one specific item to be populated as expected.
assert_eq!(
&ExportedPathInfo {
closure_size: 1828984,
nar_sha256: hex!(
"8a46c4eee4911eb842b1b2f144a9376be45a43d1da6b7af8cffa43a942177587"
),
nar_size: 1828984,
path: StorePathRef::from_bytes(
b"7n0mbqydcipkpbxm24fab066lxk68aqk-libunistring-1.1"
)
.expect("must parse"),
references: BTreeSet::from_iter([StorePathRef::from_bytes(
b"7n0mbqydcipkpbxm24fab066lxk68aqk-libunistring-1.1"
)
.unwrap()]),
},
deserialized.first().unwrap()
);
}
}