Struct Proof 

pub struct Proof {
    root: Cid,
    key: String,
    value: Option<Cid>,
    blocks: BTreeMap<Cid, Vec<u8>>,
    nodes: Vec<Cid>,
}

The blocks that prove what a repository says about one key.

A commit block, the Merkle search tree nodes from the root down to where the key sits, and the record itself when there is one. That is all, and the “that is all” is the point: a verifier that is handed every block in the repository has been given an export, and an export is not a proof of anything in particular.

What a verifier does with it

1. Resolves the DID and takes the public key out of its document.
2. Checks the commit block’s signature with it, which fixes data — the root of the tree the account signed over — as a fact rather than as this server’s word.
3. Walks: hashes the first node block, requires it to be data, decodes it, finds which entry range <collection>/<rkey> falls in, and follows that link to the next block. A block that hashes to something the parent did not name is not on the path.
4. At the end, either the key is an entry — and its v is the CID of a record block that is also in the file — or it is not, and the key is provably not in the repository.

Every one of those steps fails closed. A missing node breaks step 3, a node lifted from another tree fails the hash comparison in step 3, and a substituted record fails the CID comparison in step 4.

Fields

root: Cid

key: String

value: Option<Cid>

blocks: BTreeMap<Cid, Vec<u8>>

nodes: Vec<Cid>

Implementations

impl Proof

pub fn root(&self) -> &Cid

The commit this proof is against, which is the CAR export’s root.

pub fn key(&self) -> &str

The tree key the proof is about, <collection>/<rkey>.

pub fn record(&self) -> Option<&Cid>

The record the key names, or None when the proof is of absence.

pub fn nodes(&self) -> &[Cid]

The tree nodes walked, root first.

pub fn blocks(&self) -> &BTreeMap<Cid, Vec<u8>>

Every block in the proof, keyed by CID.

pub fn to_car(&self) -> Vec<u8>

The proof as a CARv1 file, rooted at the commit.

The same container com.atproto.sync.getRepo returns, holding a different set of blocks — which is exactly what upstream’s getRecord does, and why a client can point one CAR reader at both.

Trait Implementations

impl Clone for Proof

fn clone(&self) -> Proof

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Proof

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

Formats the value using the given formatter.