Struct tvix_store::proto::NarInfo

pub struct NarInfo {
    pub nar_size: u64,
    pub nar_sha256: Bytes,
    pub signatures: Vec<Signature>,
    pub reference_names: Vec<String>,
    pub deriver: Option<StorePath>,
    pub ca: Option<Ca>,
}

Nix C++ uses NAR (Nix Archive) as a format to transfer store paths, and stores metadata and signatures in NARInfo files. Store all these attributes in a separate message.

This is useful to render .narinfo files to clients, or to preserve/validate these signatures. As verifying these signatures requires the whole NAR file to be synthesized, moving to another signature scheme is desired. Even then, it still makes sense to hold this data, for old clients.

Fields

nar_size: u64

This size of the NAR file, in bytes.

nar_sha256: Bytes

The sha256 of the NAR file representation.

signatures: Vec<Signature>

The signatures in a .narinfo file.

reference_names: Vec<String>

A list of references. To validate .narinfo signatures, a fingerprint needs to be constructed. This fingerprint doesn’t just contain the hashes of the output paths of all references (like PathInfo.references), but their whole (base)names, so we need to keep them somewhere.

deriver: Option<StorePath>

The StorePath of the .drv file producing this output. The .drv suffix is omitted in its name field.

ca: Option<Ca>

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.

We use an enum to encode the possible combinations, and optimize for the common case, fixed:recursive, identified as NAR_SHA256.

Trait Implementations

impl Clone for NarInfo

fn clone(&self) -> NarInfo

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for NarInfo

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for NarInfo

fn default() -> Self

Returns the “default value” for a type.

impl Message for NarInfo

fn encoded_len(&self) -> usize

Returns the encoded length of the message without a length delimiter.

fn clear(&mut self)

Clears the message, resetting all fields to their default.

fn encode(&self, buf: &mut impl BufMut) -> Result<(), EncodeError>

where Self: Sized,

Encodes the message to a buffer.

fn encode_to_vec(&self) -> Vec<u8>

where Self: Sized,

Encodes the message to a newly allocated buffer.

fn encode_length_delimited( &self, buf: &mut impl BufMut, ) -> Result<(), EncodeError>

where Self: Sized,

Encodes the message with a length-delimiter to a buffer.

fn encode_length_delimited_to_vec(&self) -> Vec<u8>

where Self: Sized,

Encodes the message with a length-delimiter to a newly allocated buffer.

fn decode(buf: impl Buf) -> Result<Self, DecodeError>

where Self: Default,

Decodes an instance of the message from a buffer.

fn decode_length_delimited(buf: impl Buf) -> Result<Self, DecodeError>

where Self: Default,

Decodes a length-delimited instance of the message from the buffer.

fn merge(&mut self, buf: impl Buf) -> Result<(), DecodeError>

where Self: Sized,

Decodes an instance of the message from a buffer, and merges it into self.

fn merge_length_delimited(&mut self, buf: impl Buf) -> Result<(), DecodeError>

where Self: Sized,

Decodes a length-delimited instance of the message from buffer, and merges it into self.

impl PartialEq for NarInfo

fn eq(&self, other: &NarInfo) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for NarInfo