diff options
Diffstat (limited to 'tvix/store/src/path_info.rs')
| -rw-r--r-- | tvix/store/src/path_info.rs | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/tvix/store/src/path_info.rs b/tvix/store/src/path_info.rs new file mode 100644 index 000000000000..487261b4bdcb --- /dev/null +++ b/tvix/store/src/path_info.rs @@ -0,0 +1,87 @@ +use nix_compat::{ + narinfo::{Flags, Signature}, + nixhash::CAHash, + store_path::StorePath, +}; + +/// Holds metadata about a store path, but not its contents. +/// +/// This is somewhat equivalent to the information Nix holds in its SQLite +/// database, or publishes as .narinfo files, except we also embed the +/// [tvix_castore::Node] describing the contents in the castore model. +#[derive(Debug, Clone, PartialEq, Eq)] +pub struct PathInfo { + /// The store path this is about. + pub store_path: StorePath<String>, + /// The contents in the tvix-castore model. + //// Can be a directory, file or symlink. + pub node: tvix_castore::Node, + /// A list of references. + pub references: Vec<StorePath<String>>, + /// The size of the NAR representation of the contents, in bytes. + pub nar_size: u64, + /// The sha256 digest of the NAR representation of the contents. + pub nar_sha256: [u8; 32], + /// The signatures, usually shown in a .narinfo file. + pub signatures: Vec<Signature<String>>, + /// The StorePath of the .drv file producing this output. + /// The .drv suffix is omitted in its `name` field. + pub deriver: Option<StorePath<String>>, + /// The CA field in the .narinfo. + /// Its textual representations seen in the wild are one of the following: + /// + /// * `fixed:r:sha256:1gcky5hlf5vqfzpyhihydmm54grhc94mcs8w7xr8613qsqb1v2j6` + /// fixed-output derivations using "recursive" `outputHashMode`. + /// * `fixed:sha256:19xqkh72crbcba7flwxyi3n293vav6d7qkzkh2v4zfyi4iia8vj8 fixed-output derivations using "flat" `outputHashMode\` + /// * `text:sha256:19xqkh72crbcba7flwxyi3n293vav6d7qkzkh2v4zfyi4iia8vj8` + /// Text hashing, used for uploaded .drv files and outputs produced by + /// builtins.toFile. + /// + /// Semantically, they can be split into the following components: + /// + /// * "content address prefix". Currently, "fixed" and "text" are supported. + /// * "hash mode". Currently, "flat" and "recursive" are supported. + /// * "hash type". The underlying hash function used. + /// Currently, sha1, md5, sha256, sha512. + /// * "digest". The digest itself. + /// + /// There are some restrictions on the possible combinations. + /// For example, `text` and `fixed:recursive` always imply sha256. + pub ca: Option<CAHash>, +} + +impl PathInfo { + /// Reconstructs a [nix_compat::narinfo::NarInfo<'_>]. + /// + /// It does very little allocation (a Vec each for `signatures` and + /// `references`), the rest points to data owned elsewhere. + /// + /// It can be used to validate Signatures, or render a .narinfo file + /// (after some more fields are populated) + /// + /// Keep in mind this is not able to reconstruct all data present in the + /// NarInfo<'_>, as some of it is not stored at all: + /// - the `system`, `file_hash` and `file_size` fields are set to `None`. + /// - the URL is set to an empty string. + /// - Compression is set to "none" + /// + /// If you want to render it out to a string and be able to parse it back + /// in, at least URL *must* be set again. + pub fn to_narinfo(&self) -> nix_compat::narinfo::NarInfo<'_> { + nix_compat::narinfo::NarInfo { + flags: Flags::empty(), + store_path: self.store_path.as_ref(), + nar_hash: self.nar_sha256, + nar_size: self.nar_size, + references: self.references.iter().map(StorePath::as_ref).collect(), + signatures: self.signatures.iter().map(Signature::as_ref).collect(), + ca: self.ca.clone(), + system: None, + deriver: self.deriver.as_ref().map(StorePath::as_ref), + url: "", + compression: Some("none"), + file_hash: None, + file_size: None, + } + } +} |