diff options
Diffstat (limited to 'tvix/nix-compat/src/path_info.rs')
-rw-r--r-- | tvix/nix-compat/src/path_info.rs | 121 |
1 files changed, 121 insertions, 0 deletions
diff --git a/tvix/nix-compat/src/path_info.rs b/tvix/nix-compat/src/path_info.rs new file mode 100644 index 000000000000..bf60f673cead --- /dev/null +++ b/tvix/nix-compat/src/path_info.rs @@ -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() + ); + } +} |