@diotoborg/quas-quo NPM

code style | standard

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|_)|(_(_)|(/_(/_(_| v5
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Space Efficient Chain of Blocks

Flat memory layout / zero copy access
Single dependency EdDSA
Fast & compact Curve25519 + Ed25519 signatures
Pure ES6 (+JSDoc Type annotations)
~450LOC / +41.3kB bundle size
Test Coverage 💯
Uint8Arrays (no node:buffer or bn.js)

Intro

Imagine git as a jar, then using pliers pull out a branch. That single detached branch is synonymous with one @diotoborg/quas-quo - a memorybuffer containing cryptographically signed blocks:

|------|-----|------------------|----------------------|
| PiC0 | Key | Block 0: "hello" | Block 1: "picoverse" |
| 4B   | 33B |    71 Bytes      |     138 Bytes        |
|------|-----|------------------|----------------------|

This library provides a high level API to append, slice and merge such feeds - block contents is upto application.

Picofeeds have so far been observed within:

QR-Codes (out-of-band-signaling)
URLs (cross-messenger / platform-as-a-public-database)
DNS-Records (webhosting)

We target user devices, this module is the basic building block for the frontend-blockchain-toolkit picostack

discord

Install

yarn add @diotoborg/quas-quo
# or
npm install @diotoborg/quas-quo

Usage

import { Feed, toHex } from '@diotoborg/quas-quo'

const { pk: publicKey, sk: secret } = Feed.signPair()

const feed = new Feed()

feed.append('Hello', secret) // => height 1
feed.blocks[0].body // => 'Hello'
feed.blocks[0].blockSize // => 72 bytes

const verifiableData = feed.buffer

// -- Share buffer anyhow --

const remoteFeed = Feed.from(verifiableData) // Verifies signatures

remoteFeed.blocks[0].body // => 'Hello'

toHex(remoteFeed.blocks[0].key) === alice.pk // true

Changelog

`5.0.1`

phat-bit replaced with varint
changed secp256k1 in favour of Ed25519
fixed merge() bug
removed u8n util

`4.x`

signPair() returns hexstring keys
sk.slice(32) no longer works, use getPublicKey(sk)
block.parentSig renamed to block.psig
block.isGenesis renamed to block.genesis
feed.get(n) renamed to feed.block(n)
feed.blocks() removed in favour of feed.blocks
feed.pickle() removed until further notice.
feed.fromBlocksArray() incorporated into feedFrom() / Feed.from()
Not backwards compatible with 3.x feeds

`3.4.0`

updated README.md
added Feed.fromBlocksArray(Block[]) to perform bulk-merge, 24x perf increase compared to Feed.merge(block)
removed Feed subclassing/metaprogramming support, it was fun but footgun (don't solve problems by subclassing Feed).

`3.3.0`

added Feed.first
added Feed.get(-3) as equivalent of f.get(f.length - 3)
added Block.isGenesis getter
added static Feed.KEY_SIZE constant
replaced hardcoded key-size lenghts with KEY_SIZE constant

`3.2.2`

optimization feed._steal() also steals cache

`3.2.1`

fixed bug feed._steal(other) causing cache corruption
changed return value of feed.inspect() is now conditional
fixed bug where A < B; A.merge(B, withCallback) did not merge
fixed bug where keychain cache contained boatloads of duplicate keys

`3.1.0`

added feed.merge(block) support

`3.0.0`

removed automatic encodings
changed feed.get(n) returns instance of BlockMapper.
changed feed.slice(start, end)
added block cache to avoid redundant signature-verifications
added BlockMapper now also contains public-key
sodium-universal upgraded to 3.0.0

`2.2.0`

Added feed.merge(other, opts, indexingCallback) that allows validation + abort merge interactively
Added feed.last which returns the block-contents using provided encoding.