hash-bank

simple storage for creating and managing object hashes

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Description

A flexible in memory store for creating and housing object hashes with expirability.

Example

import HashBank from 'hash-bank'

const b = HashBank({
  serialize: (obj) => obj.password + obj.id,
  defaultMeta: { expire: 60 * 1000 },
  interval: 2000
}).start()

const obj = {
  id: 'bob',
  password: 'xxxx-xxxx'
}

const objMeta = {
  expire: 1000,
  otherMeta: 'likes cats'
}

const hash = b.add(obj, objMeta)
b.exists(obj) // true
b.getMeta(obj)
// {
//   expire: 1000,
//   otherMeta: 'likes cats'
// }

sleep(2000)

b.hashExists(hash) // false

Usage

instantiate queue

const b = HashBank(options)

options

• serialize:fn (default: identity) - The transform called on add before converting and storing the hash.
• defaultMeta:obj (default: { expire: 3600 * 1000 }) - The default meta added to every hash. The bank checks expire (ms) meta when removing expired hashes. This is merged with the meta created when b.add(obj, meta)ing a hash.
• interval:int (default: 60 * 1000) - How often (in ms) to purge expired hashes.

using instance

• b.add(any, [meta:obj]) -> hash - Takes any object to convert to a hash and an meta object with expire time for the hash. Will use the default expire time if not provided.
• b.exists(any) -> bool - Tells you if a hash for the object exists in the bank.
• b.hashExists(hash) -> bool - Tells you if a hash exists in the bank.
• b.remove(any) -> bool - Remove a hash given the object. Returns true if found and deleted, otherwise false.
• b.hashRemove(hash) -> bool - Removes a hash given the hash. Returns true if found and deleted, otherwise false.
• b.getMeta(any) -> obj - Gets the meta data about hash from object like expire.
• b.getHashMeta(hash) -> obj - Gets the meta data about hash from hash like expire.
• b.start() -> b - Starts the bank running at the specified interval or the default.
• b.stop() -> b - Stops the bank running.

special meta object properties

• expire - The expire time (in ms) for a hash.

Installation

Download node at nodejs.org and install it, if you haven't already.

npm install hash-bank --save

License

ISC