hamt-sharding

hamt-sharding

JavaScript implementation of hamt for use in sharding

Lead Maintainer

Alex Potsides

Table of Contents

• Install
• Usage
  • Example
  • API
    • bucket.put(key, value)
    • bucket.get(key)
    • bucket.del(key)
    • bucket.leafCount()
    • bucket.childrenCount()
    • bucket.onlyChild()
    • bucket.eachLeafSeries()
    • bucket.serialize(map, reduce)
    • bucket.asyncTransform(asyncMap, asyncReduce)
    • bucket.toJSON()
    • bucket.prettyPrint()
    • bucket.tableSize()
    • hamt.isBucket(other)
• Contribute
• License

Install

> npm install hamt-sharding

Usage

Example

const hamt = require('hamt-sharding')
const crypto = require('crypto-promise')

// decide how to hash things, can return a Promise
const hashFn = async (value) => {
  return crypto
    .createHash('sha256')
    .update(value)
    .digest()
}

const bucket = hamt({
  hashFn: hashFn
})

await bucket.put('key', 'value')

const output = await bucket.get('key')
// output === 'value'

API

const hamt = require('hamt-sharding')

bucket.put(key, value)

const hamt = require('hamt-sharding')
const bucket = hamt({...})

await bucket.put('key', 'value')

bucket.get(key)

const hamt = require('hamt-sharding')
const bucket = hamt({...})

await bucket.put('key', 'value')

console.info(await bucket.get('key')) // 'value'

bucket.del(key)

const hamt = require('hamt-sharding')
const bucket = hamt({...})

await bucket.put('key', 'value')
await bucket.del('key', 'value')

console.info(await bucket.get('key')) // undefined

bucket.leafCount()

const hamt = require('hamt-sharding')
const bucket = hamt({...})

console.info(bucket.leafCount()) // 0

await bucket.put('key', 'value')

console.info(bucket.leafCount()) // 1

bucket.childrenCount()

const hamt = require('hamt-sharding')
const bucket = hamt({...})

console.info(bucket.childrenCount()) // 0

await bucket.put('key', 'value')

console.info(bucket.childrenCount()) // 234 -- dependent on hashing algorithm

bucket.onlyChild()

bucket.eachLeafSeries()

const hamt = require('hamt-sharding')
const bucket = hamt({...})

await bucket.put('key', 'value')

for await (const child of bucket.eachLeafSeries()) {
  console.info(child.value) // 'value'
}

bucket.serialize(map, reduce)

bucket.asyncTransform(asyncMap, asyncReduce)

bucket.toJSON()

bucket.prettyPrint()

bucket.tableSize()

hamt.isBucket(other)

const hamt = require('hamt-sharding')
const bucket = hamt({...})

console.info(hamt.isBucket(bucket)) // true
console.info(hamt.isBucket(true)) // false

Contribute

Feel free to join in. All welcome. Open an issue!

This repository falls under the IPFS Code of Conduct.

License

MIT