node-ethash

Native node bindings for Ethash cpp implementation. This library is experimental. Use at your own risk. Currently working on Linux only. Tested on node v5.10.1.

For details on this project, please see the Ethereum wiki (https://github.com/ethereum/wiki/wiki/Ethash) and ethereumjs/ethashjs (https://github.com/ethereumjs/ethashjs).

Installation

$ git clone https://github.com/ethereumjs/node-ethash.git
$ cd node-ethash/
$ git submodule init
$ git submodule update
$ npm install

API

• new Ethash([cacheDB])
• ethash.verifyPOW(block, cb)
• ethash.mkcache(cacheSize, seed)
• ethash.run(val, nonce, fullSize)
• ethash.loadEpoc(number, cb)

new Ethash([cacheDB])

Creates a new instance of Ethash.

Parameters

• cacheDB - an instance of a levelup DB which is used to store the cache(s). Need by ethash.verifyPOW() and ethash.loadEpoc()

ethash.verifyPOW(block, cb)

Verifies the POW on a block and its uncles.

Note: uses ethash.loadEpoc() to load cache.

Parameters

• block - the block to verify
• cb - callback which is given a Boolean determining the validity of the block

ethash.mkcache(cacheSize, seed)

Creates a cache.

NOTE: this is automatically done for in ethash.verifyPOW() so you do not need to use this function if you are just validating blocks.

Parameters

• cacheSize - the size of the cache
• seed - the seed as a Buffer

ethash.run(val, nonce, fullSize)

Runs ethash on a given val/nonce pair.

NOTE: you need to run ethash.mkcache() first before using this function.

Parameters

• val - header hash as Buffer
• seed - the seed as a Buffer
• fullSize - the fullsize of the cache

Return an Object containing

• hash - the hash of the value
• mix - the mix result

ethash.loadEpoc(number, cb)

Loads block number epoc's cache from DB.

Parameters

• number - the block's number
• cb - callback called after the epoc was loaded

Test

$ npm test

Performance (node-ethash vs ethashjs):

$ node benchmark/benchmark.js
Create 1 fixtures
++++++++++++++++++++++++++++++++++++++++++++++++++
Benchmarking: mkcache
--------------------------------------------------
bindings x 1.47 ops/sec ±2.31% (8 runs sampled)
ethashjs x 0.17 ops/sec ±13.59% (5 runs sampled)
==================================================
Benchmarking: run
--------------------------------------------------
bindings x 571 ops/sec ±3.52% (79 runs sampled)
ethashjs x 17.82 ops/sec ±1.58% (48 runs sampled)
==================================================

TODO:

• Implement tests for:
  • ethash.verifyPOW()
  • ethash.loadEpoc()
• Create more fixtures for ethash.run()'s tests

LICENSE

This library is free and open-source software released under the MIT license.