memdb-ps v0.0.3

MemDB-PS

A simple in memory cache/db with pubsub.

Goals

Provide a simple in memory cache where a complete new state of a dataset (array of objects) can be set, and the differences+updates are calculated and published to subscribers.

Example

const MemDBTable = require ('../dist/index').MemDBTable;
const util = require('util')
function fullDump(obj){
  return util.inspect(obj,false,null,true)
}

let tst = new MemDBTable('test','id');

tst.createIndex({
  name: 'grp',
  paths: ['grp']
})

let token = tst.subscribe((msg,data)=>{
  console.log("%s-%s:",data.name,msg.type, fullDump(msg.old),fullDump(msg.data));
})
console.log("Subscription token:",token)
console.log("STARTING")
tst.set([
  {id:'0001',name:'test-01',nest:{data:1}, grp: '101'},
  {id:'0002',name:'test-02',nest:{data:2}, grp: '101'},
  {id:'0003',name:'test-03',nest:{data:3}, grp: '102'},
  {id:'0004',name:'test-04',nest:{data:4}, grp: '102'},
]);

console.log("UPDATING")

tst.set([
  {id:'0002',name:'test-02a',nest:{data:2}, grp: '101'},
  {id:'0003',name:'test-03a',nest:{data:3}, grp: '102'},
  {id:'0004',name:'test-04',nest:{data:4}, grp: '102'},
  {id:'0005',name:'test-05',nest:{data:1}, grp: '102'},
]);

console.log("TESTS: Get By Key")
let arr1 = ["0002","0005","x"]
arr1.forEach(element => {
  console.log(tst.selectByPk(element))
});

console.log("TESTS: Get By Index")
let arr2 = ["101","102","x"]
arr2.forEach(element => {
  console.log(tst.selectByIndex('grp',[element]))
});

console.log("DEBUG DUMP")
console.log(fullDump(tst.debug()))