SYNOPSIS

or #ethereumjs on freenode

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'),
levelup = require('levelup'),
db = levelup('./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 levelup = require('levelup')
var Trie = require('./secure')

var stateRoot = "0xd7f8974fb5ac78d9ac099b9ad5018bedc2ce0a72dad1827a1709da30580f0544" // Block #222

var db = levelup('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

./docs/

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

LICENSE

MPL-2.0