snix_store/
path_info.rs

1use nix_compat::{
2    narinfo::{Flags, Signature},
3    nixhash::CAHash,
4    store_path::StorePath,
5};
6
7/// Holds metadata about a store path, but not its contents.
8///
9/// This is somewhat equivalent to the information Nix holds in its SQLite
10/// database, or publishes as .narinfo files, except we also embed the
11/// [snix_castore::Node] describing the contents in the castore model.
12#[derive(Debug, Clone, PartialEq, Eq)]
13pub struct PathInfo {
14    /// The store path this is about.
15    pub store_path: StorePath<String>,
16    /// The contents in the snix-castore model.
17    //// Can be a directory, file or symlink.
18    pub node: snix_castore::Node,
19    /// A list of references.
20    pub references: Vec<StorePath<String>>,
21    /// The size of the NAR representation of the contents, in bytes.
22    pub nar_size: u64,
23    /// The sha256 digest of the NAR representation of the contents.
24    pub nar_sha256: [u8; 32],
25    /// The signatures, usually shown in a .narinfo file.
26    pub signatures: Vec<Signature<String>>,
27    /// The StorePath of the .drv file producing this output.
28    /// The .drv suffix is omitted in its `name` field.
29    pub deriver: Option<StorePath<String>>,
30    /// The CA field in the .narinfo.
31    /// Its textual representations seen in the wild are one of the following:
32    ///
33    /// * `fixed:r:sha256:1gcky5hlf5vqfzpyhihydmm54grhc94mcs8w7xr8613qsqb1v2j6`
34    ///   fixed-output derivations using "recursive" `outputHashMode`.
35    /// * `fixed:sha256:19xqkh72crbcba7flwxyi3n293vav6d7qkzkh2v4zfyi4iia8vj8 fixed-output derivations using "flat" `outputHashMode\`
36    /// * `text:sha256:19xqkh72crbcba7flwxyi3n293vav6d7qkzkh2v4zfyi4iia8vj8`
37    ///   Text hashing, used for uploaded .drv files and outputs produced by
38    ///   builtins.toFile.
39    ///
40    /// Semantically, they can be split into the following components:
41    ///
42    /// * "content address prefix". Currently, "fixed" and "text" are supported.
43    /// * "hash mode". Currently, "flat" and "recursive" are supported.
44    /// * "hash type". The underlying hash function used.
45    ///   Currently, sha1, md5, sha256, sha512.
46    /// * "digest". The digest itself.
47    ///
48    /// There are some restrictions on the possible combinations.
49    /// For example, `text` and `fixed:recursive` always imply sha256.
50    pub ca: Option<CAHash>,
51}
52
53impl PathInfo {
54    /// Reconstructs a [nix_compat::narinfo::NarInfo<'_>].
55    ///
56    /// It does very little allocation (a Vec each for `signatures` and
57    /// `references`), the rest points to data owned elsewhere.
58    ///
59    /// It can be used to validate Signatures, or render a .narinfo file
60    /// (after some more fields are populated)
61    ///
62    /// Keep in mind this is not able to reconstruct all data present in the
63    /// NarInfo<'_>, as some of it is not stored at all:
64    /// - the `system`, `file_hash` and `file_size` fields are set to `None`.
65    /// - the URL is set to an empty string.
66    /// - Compression is set to "none"
67    ///
68    /// If you want to render it out to a string and be able to parse it back
69    /// in, at least URL *must* be set again.
70    pub fn to_narinfo(&self) -> nix_compat::narinfo::NarInfo<'_> {
71        nix_compat::narinfo::NarInfo {
72            flags: Flags::empty(),
73            store_path: self.store_path.as_ref(),
74            nar_hash: self.nar_sha256,
75            nar_size: self.nar_size,
76            references: self.references.iter().map(StorePath::as_ref).collect(),
77            signatures: self.signatures.iter().map(Signature::as_ref).collect(),
78            ca: self.ca.clone(),
79            system: None,
80            deriver: self.deriver.as_ref().map(StorePath::as_ref),
81            url: "",
82            compression: Some("none"),
83            file_hash: None,
84            file_size: None,
85        }
86    }
87}
snix_store/path_info.rs

snix_store/
path_info.rs
