SYNOPSIS
This is an implementation of the modified merkle patricia tree as specified in the Ethereum's yellow paper.
The modified Merkle Patricia tree (trie) provides a persistent data structure to map between arbitrary-length binary data (byte arrays). It is defined in terms of a mutable data structure to map between 256-bit binary fragments and arbitrary-length binary data. The core of the trie, and its sole requirement in terms of the protocol specification is to provide a single 32-byte value that identifies a given set of key-value pairs.
- Ethereum's yellow paper
The only backing store supported is LevelDB through the levelup
module.
INSTALL
npm install merkle-patricia-tree
USAGE
Initialization and Basic Usage
var Trie = require('merkle-patricia-tree'),
level = require('level'),
db = level('./testdb'),
trie = new Trie(db);
trie.put('test', 'one', function () {
trie.get('test', function (err, value) {
if(value) console.log(value.toString())
});
});
Merkle Proofs
Trie.prove(trie, 'test', function (err, prove) {
if (err) return cb(err)
Trie.verifyProof(trie.root, 'test', prove, function (err, value) {
if (err) return cb(err)
console.log(value.toString())
cb()
})
})
Read stream on Geth DB
var level = require('level')
var Trie = require('./secure')
var stateRoot = "0xd7f8974fb5ac78d9ac099b9ad5018bedc2ce0a72dad1827a1709da30580f0544" // Block #222
var db = level('YOUR_PATH_TO_THE_GETH_CHAIN_DB')
var trie = new Trie(db, stateRoot)
trie.createReadStream()
.on('data', function (data) {
console.log(data)
})
.on('end', function() {
console.log('End.')
})
API
TESTING
npm test
REFERENCES
- "Exploring Ethereum's state trie with Node.js" blog post
- "Merkling in Ethereum" blog post
- Ethereum Trie Specification Wiki
- "Understanding the ethereum trie" blog post
- "Trie and Patricia Trie Overview" Video Talk on Youtube
EthereumJS
See our organizational documentation for an introduction to EthereumJS
as well as information on current standards and best practices.
If you want to join for work or do improvements on the libraries have a look at our contribution guidelines.
LICENSE
MPL-2.0