mirror of https://github.com/vacp2p/pmtree.git
95 lines
2.0 KiB
Markdown
95 lines
2.0 KiB
Markdown
<p align="center">
|
|
<img src="./pmtree.png" width="150">
|
|
</p>
|
|
|
|
<p align="center">
|
|
<img src="https://github.com/Rate-Limiting-Nullifier/pmtree/workflows/Build-Test-Fmt/badge.svg" width="140">
|
|
</p>
|
|
|
|
<h1 align="center">pmtree</h1>
|
|
|
|
<h3 align="center">Persistent Merkle Tree (optimized & sparse & fixed-size) in Rust</h3>
|
|
|
|
## How to use
|
|
```toml
|
|
[dependencies]
|
|
pmtree = { git = "https://github.com/Rate-Limiting-Nullifier/pmtree" }
|
|
```
|
|
|
|
## Example
|
|
|
|
In-Memory DB (HashMap) + Keccak
|
|
```rust
|
|
struct MemoryDB(HashMap<DBKey, Value>);
|
|
struct MyKeccak(Keccak);
|
|
|
|
#[derive(Default)]
|
|
struct MemoryDBConfig;
|
|
|
|
impl Database for MemoryDB {
|
|
type Config = MemoryDBConfig;
|
|
|
|
fn new(_db_config: MemoryDBConfig) -> Result<Self> {
|
|
Ok(MemoryDB(HashMap::new()))
|
|
}
|
|
|
|
fn load(_db_config: MemoryDBConfig) -> Result<Self> {
|
|
Err(Box::new(Error("Cannot load in-memory DB".to_string())))
|
|
}
|
|
|
|
fn get(&self, key: DBKey) -> Result<Option<Value>> {
|
|
Ok(self.0.get(&key).cloned())
|
|
}
|
|
|
|
fn put(&mut self, key: DBKey, value: Value) -> Result<()> {
|
|
self.0.insert(key, value);
|
|
|
|
Ok(())
|
|
}
|
|
|
|
fn put_batch(&mut self, subtree: HashMap<DBKey, Value>) -> Result<()> {
|
|
self.0.extend(subtree.into_iter());
|
|
|
|
Ok(())
|
|
}
|
|
}
|
|
|
|
impl Hasher for MyKeccak {
|
|
type Fr = [u8; 32];
|
|
|
|
fn default_leaf() -> Self::Fr {
|
|
[0; 32]
|
|
}
|
|
|
|
fn serialize(value: Self::Fr) -> Value {
|
|
value.to_vec()
|
|
}
|
|
|
|
fn deserialize(value: Value) -> Self::Fr {
|
|
value.try_into().unwrap()
|
|
}
|
|
|
|
fn hash(input: &[Self::Fr]) -> Self::Fr {
|
|
let mut output = [0; 32];
|
|
let mut hasher = Keccak::v256();
|
|
for element in input {
|
|
hasher.update(element);
|
|
}
|
|
hasher.finalize(&mut output);
|
|
output
|
|
}
|
|
}
|
|
|
|
fn main() {
|
|
let mut mt = MerkleTree::<MemoryDB, MyKeccak>::new(2, MemoryDBConfig).unwrap();
|
|
|
|
assert_eq!(mt.capacity(), 4);
|
|
assert_eq!(mt.depth(), 2);
|
|
|
|
mt.update_next(hex!(
|
|
"c1ba1812ff680ce84c1d5b4f1087eeb08147a4d510f3496b2849df3a73f5af95"
|
|
))
|
|
.unwrap();
|
|
}
|
|
```
|