@ethereumjs/rlp
Recursive Length Prefix encoding for Node.js and the browser.
Installation
To obtain the latest version, simply require the project using npm:
npm install @ethereumjs/rlpInstall with -g if you want to use the CLI.
Usage
import assert from 'assert'
import { RLP } from '@ethereumjs/rlp'
const nestedList = [[], [[]], [[], [[]]]]
const encoded = RLP.encode(nestedList)
const decoded = RLP.decode(encoded)
assert.deepEqual(nestedList, decoded)API
RLP.encode(plain) - RLP encodes an Array, Uint8Array or String and returns a Uint8Array.
RLP.decode(encoded, [stream=false]) - Decodes an RLP encoded Uint8Array, Array or String and returns a Uint8Array or NestedUint8Array. If stream is enabled, it will just decode the first rlp sequence in the Uint8Array. By default, it would throw an error if there are more bytes in Uint8Array than used by the rlp sequence.
Buffer compatibility
If you would like to continue using Buffers like in rlp v2, you can use:
import assert from 'assert'
import { arrToBufArr, bufArrToArr } from '@ethereumjs/util'
import { RLP } from '@ethereumjs/rlp'
const bufferList = [Buffer.from('123', 'hex'), Buffer.from('456', 'hex')]
const encoded = RLP.encode(bufArrToArr(bufferList))
const encodedAsBuffer = Buffer.from(encoded)
const decoded = RLP.decode(Uint8Array.from(encodedAsBuffer)) // or RLP.decode(encoded)
const decodedAsBuffers = arrToBufArr(decoded)
assert.deepEqual(bufferList, decodedAsBuffers)BigInt Support
Starting with v4 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.
CLI
rlp encode <JSON string>
rlp decode <0x-prefixed hex string>
Examples
-
rlp encode '5'->0x05 -
rlp encode '[5]'->0xc105 -
rlp encode '["cat", "dog"]'->0xc88363617483646f67 -
rlp decode 0xc88363617483646f67->["cat","dog"]
Tests
Tests use mocha.
To run tests and linting: npm test
To auto-fix linting problems run: npm run lint:fix
Code Coverage
Install dev dependencies: npm install
Run coverage: npm run coverage
The results will be at: coverage/lcov-report/index.html
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.