nomt-core 1.0.3

Core trie operations for NOMT
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82

//! Witnesses of NOMT sessions. These types encapsulate entire sets of reads and writes.

use crate::{
    proof::PathProof,
    trie::{KeyPath, ValueHash},
    trie_pos::TriePosition,
};

#[cfg(not(feature = "std"))]
use alloc::vec::Vec;

/// A witness that can be used to prove the correctness of state trie retrievals and updates.
///
/// Expected to be serializable.
#[cfg_attr(
    feature = "borsh",
    derive(borsh::BorshDeserialize, borsh::BorshSerialize)
)]
#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
pub struct Witness {
    /// Various paths down the trie used as part of this witness.
    /// Note that the paths are not necessarily in lexicographic order.
    pub path_proofs: Vec<WitnessedPath>,
    /// The operations witnessed by the paths.
    pub operations: WitnessedOperations,
}

/// Operations provable by a corresponding witness.
#[cfg_attr(
    feature = "borsh",
    derive(borsh::BorshDeserialize, borsh::BorshSerialize)
)]
#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
pub struct WitnessedOperations {
    /// Read operations.
    pub reads: Vec<WitnessedRead>,
    /// Write operations.
    pub writes: Vec<WitnessedWrite>,
}

/// A path observed in the witness.
#[cfg_attr(
    feature = "borsh",
    derive(borsh::BorshDeserialize, borsh::BorshSerialize)
)]
#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
pub struct WitnessedPath {
    /// Proof of a query path along the trie.
    pub inner: PathProof,
    /// The query path itself.
    pub path: TriePosition,
}

/// A witness of a read value.
#[cfg_attr(
    feature = "borsh",
    derive(borsh::BorshDeserialize, borsh::BorshSerialize)
)]
#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
pub struct WitnessedRead {
    /// The key of the read value.
    pub key: KeyPath,
    /// The hash of the value witnessed. None means no value.
    pub value: Option<ValueHash>,
    /// The index of the path in the corresponding witness.
    pub path_index: usize,
}

/// A witness of a write operation.
#[cfg_attr(
    feature = "borsh",
    derive(borsh::BorshDeserialize, borsh::BorshSerialize)
)]
#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
pub struct WitnessedWrite {
    /// The key of the written value.
    pub key: KeyPath,
    /// The hash of the written value. `None` means "delete".
    pub value: Option<ValueHash>,
    /// The index of the path in the corresponding witness.
    pub path_index: usize,
}