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 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202
// This file is part of Substrate.
// Copyright (C) Parity Technologies (UK) Ltd.
// SPDX-License-Identifier: Apache-2.0
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
use codec::{Decode, Encode};
use hash_db::{HashDB, Hasher};
use scale_info::TypeInfo;
use sp_std::{
collections::btree_set::BTreeSet,
iter::{DoubleEndedIterator, IntoIterator},
vec::Vec,
};
// Note that `LayoutV1` usage here (proof compaction) is compatible
// with `LayoutV0`.
use crate::LayoutV1 as Layout;
/// A proof that some set of key-value pairs are included in the storage trie. The proof contains
/// the storage values so that the partial storage backend can be reconstructed by a verifier that
/// does not already have access to the key-value pairs.
///
/// The proof consists of the set of serialized nodes in the storage trie accessed when looking up
/// the keys covered by the proof. Verifying the proof requires constructing the partial trie from
/// the serialized nodes and performing the key lookups.
#[derive(Debug, PartialEq, Eq, Clone, Encode, Decode, TypeInfo)]
pub struct StorageProof {
trie_nodes: BTreeSet<Vec<u8>>,
}
impl StorageProof {
/// Constructs a storage proof from a subset of encoded trie nodes in a storage backend.
pub fn new(trie_nodes: impl IntoIterator<Item = Vec<u8>>) -> Self {
StorageProof { trie_nodes: BTreeSet::from_iter(trie_nodes) }
}
/// Returns a new empty proof.
///
/// An empty proof is capable of only proving trivial statements (ie. that an empty set of
/// key-value pairs exist in storage).
pub fn empty() -> Self {
StorageProof { trie_nodes: BTreeSet::new() }
}
/// Returns whether this is an empty proof.
pub fn is_empty(&self) -> bool {
self.trie_nodes.is_empty()
}
/// Convert into an iterator over encoded trie nodes in lexicographical order constructed
/// from the proof.
pub fn into_iter_nodes(self) -> impl Sized + DoubleEndedIterator<Item = Vec<u8>> {
self.trie_nodes.into_iter()
}
/// Create an iterator over encoded trie nodes in lexicographical order constructed
/// from the proof.
pub fn iter_nodes(&self) -> impl Sized + DoubleEndedIterator<Item = &Vec<u8>> {
self.trie_nodes.iter()
}
/// Convert into plain node vector.
pub fn into_nodes(self) -> BTreeSet<Vec<u8>> {
self.trie_nodes
}
/// Creates a [`MemoryDB`](crate::MemoryDB) from `Self`.
pub fn into_memory_db<H: Hasher>(self) -> crate::MemoryDB<H> {
self.into()
}
/// Creates a [`MemoryDB`](crate::MemoryDB) from `Self` reference.
pub fn to_memory_db<H: Hasher>(&self) -> crate::MemoryDB<H> {
self.into()
}
/// Merges multiple storage proofs covering potentially different sets of keys into one proof
/// covering all keys. The merged proof output may be smaller than the aggregate size of the
/// input proofs due to deduplication of trie nodes.
pub fn merge(proofs: impl IntoIterator<Item = Self>) -> Self {
let trie_nodes = proofs
.into_iter()
.flat_map(|proof| proof.into_iter_nodes())
.collect::<BTreeSet<_>>()
.into_iter()
.collect();
Self { trie_nodes }
}
/// Encode as a compact proof with default trie layout.
pub fn into_compact_proof<H: Hasher>(
self,
root: H::Out,
) -> Result<CompactProof, crate::CompactProofError<H::Out, crate::Error<H::Out>>> {
let db = self.into_memory_db();
crate::encode_compact::<Layout<H>, crate::MemoryDB<H>>(&db, &root)
}
/// Encode as a compact proof with default trie layout.
pub fn to_compact_proof<H: Hasher>(
&self,
root: H::Out,
) -> Result<CompactProof, crate::CompactProofError<H::Out, crate::Error<H::Out>>> {
let db = self.to_memory_db();
crate::encode_compact::<Layout<H>, crate::MemoryDB<H>>(&db, &root)
}
/// Returns the estimated encoded size of the compact proof.
///
/// Running this operation is a slow operation (build the whole compact proof) and should only
/// be in non sensitive path.
///
/// Return `None` on error.
pub fn encoded_compact_size<H: Hasher>(self, root: H::Out) -> Option<usize> {
let compact_proof = self.into_compact_proof::<H>(root);
compact_proof.ok().map(|p| p.encoded_size())
}
}
impl<H: Hasher> From<StorageProof> for crate::MemoryDB<H> {
fn from(proof: StorageProof) -> Self {
From::from(&proof)
}
}
impl<H: Hasher> From<&StorageProof> for crate::MemoryDB<H> {
fn from(proof: &StorageProof) -> Self {
let mut db = crate::MemoryDB::default();
proof.iter_nodes().for_each(|n| {
db.insert(crate::EMPTY_PREFIX, &n);
});
db
}
}
/// Storage proof in compact form.
#[derive(Debug, PartialEq, Eq, Clone, Encode, Decode, TypeInfo)]
pub struct CompactProof {
pub encoded_nodes: Vec<Vec<u8>>,
}
impl CompactProof {
/// Return an iterator on the compact encoded nodes.
pub fn iter_compact_encoded_nodes(&self) -> impl Iterator<Item = &[u8]> {
self.encoded_nodes.iter().map(Vec::as_slice)
}
/// Decode to a full storage_proof.
pub fn to_storage_proof<H: Hasher>(
&self,
expected_root: Option<&H::Out>,
) -> Result<(StorageProof, H::Out), crate::CompactProofError<H::Out, crate::Error<H::Out>>> {
let mut db = crate::MemoryDB::<H>::new(&[]);
let root = crate::decode_compact::<Layout<H>, _, _>(
&mut db,
self.iter_compact_encoded_nodes(),
expected_root,
)?;
Ok((
StorageProof::new(db.drain().into_iter().filter_map(|kv| {
if (kv.1).1 > 0 {
Some((kv.1).0)
} else {
None
}
})),
root,
))
}
/// Convert self into a [`MemoryDB`](crate::MemoryDB).
///
/// `expected_root` is the expected root of this compact proof.
///
/// Returns the memory db and the root of the trie.
pub fn to_memory_db<H: Hasher>(
&self,
expected_root: Option<&H::Out>,
) -> Result<(crate::MemoryDB<H>, H::Out), crate::CompactProofError<H::Out, crate::Error<H::Out>>>
{
let mut db = crate::MemoryDB::<H>::new(&[]);
let root = crate::decode_compact::<Layout<H>, _, _>(
&mut db,
self.iter_compact_encoded_nodes(),
expected_root,
)?;
Ok((db, root))
}
}