@ethereumjs/ethash

Note: this README reflects the state of the library from v1.0.0 onwards. See README from the standalone repository for an introduction on the last preceding release.

Installation

To obtain the latest version, simply require the project using npm:

npm install @ethereumjs/ethash

Usage

PoW Validation

// ./examples/powBlock.ts

import { Ethash } from '@ethereumjs/ethash'
import { Block } from '@ethereumjs/block'
import { DBObject, hexToBytes, MapDB } from '@ethereumjs/util'

const cacheDB = new MapDB()

const ethash = new Ethash(cacheDB)
const validblockRlp =
  '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'

const validBlock = Block.fromRLPSerializedBlock(hexToBytes(validblockRlp), {
  setHardfork: true,
  skipConsensusFormatValidation: true,
})

const result = await ethash.verifyPOW(validBlock)
console.log(result) // => true

PoW Ethash CPU Miner

There is a simple CPU miner included within Ethash package which can be used for testing purposes.

See the following example on how to use the new Miner class:

// ./examples/miner.ts

import { Block } from '@ethereumjs/block'
import { Ethash } from '@ethereumjs/ethash'
import { DBObject, MapDB, bytesToHex } from '@ethereumjs/util'

const block = Block.fromBlockData(
  {
    header: {
      difficulty: BigInt(100),
      number: BigInt(1),
    },
  },
  { setHardfork: true, skipConsensusFormatValidation: true }
)

const cacheDB = new MapDB()

const e = new Ethash(cacheDB)
const miner = e.getMiner(block.header)
const solution = await miner.iterate(-1) // iterate until solution is found
console.log(bytesToHex(solution!.mixHash)) // 0x892177e7bbb1f31ade0610707c96c6bf86e1415b26073d17b2da2dbd2daefd1e

API

Docs

Generated TypeDoc API Documentation

Hybrid CJS/ESM Builds

With the breaking releases from Summer 2023 we have started to ship our libraries with both CommonJS (cjs folder) and ESM builds (esm folder), see package.json for the detailed setup.

If you use an ES6-style import in your code files from the ESM build will be used:

import { EthereumJSClass } from '@ethereumjs/[PACKAGE_NAME]'

If you use Node.js specific require, the CJS build will be used:

const { EthereumJSClass } = require('@ethereumjs/[PACKAGE_NAME]')

Using ESM will give you additional advantages over CJS beyond browser usage like static code analysis / Tree Shaking which CJS can not provide.

Buffer -> Uint8Array

With the breaking releases from Summer 2023 we have removed all Node.js specific Buffer usages from our libraries and replace these with Uint8Array representations, which are available both in Node.js and the browser (Buffer is a subclass of Uint8Array).

We have converted existing Buffer conversion methods to Uint8Array conversion methods in the @ethereumjs/util bytes module, see the respective README section for guidance.

BigInt Support

Starting with v2 the usage of BN.js for big numbers has been removed from the library and replaced with the usage of the native JS BigInt data type (introduced in ES2020).

Please note that number-related API signatures have changed along with this version update and the minimal build target has been updated to ES2020.

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 carry out improvements on the libraries, please review our contribution guidelines first.

LICENSE

MPL-2.0