Storing compressed json data in local storage

Question

I want to store JSON data in local storage. Sometimes data stored could be more than 5MB(max threshold allowed by browsers for each domain). Is there anyway i can compress or zip the data and store it in local storage ? How much latency it will add if compression and decompression for every JS function on large data ?

I am using this json data to display on webpage..... It is like a static data which is mostly same for entire session. we provide actions like search, filter etc on this json data...Whenever user enters a keyword, i search in this json data which is stored in local storage instead of making call to server

Answer 1

As localStorage functionality seems to be limited to handle only string key/value pairs what you can do is to use lz-string library to stringify the json object and compress it before storing it in localStorage

Usage

// sample json object
var jsonobj = {'sample': 'This is supposed to be ling string', 'score': 'another long string which is going to be compressed'}

// compress string before storing in localStorage    
localStorage.setItem('mystring', LZString.compress(JSON.stringify(jsonobj)));

// decompress localStorage item stored
var string = LZString.decompress(localStorage.getItem('mystring'))

// parse it to JSON object
JSON.parse(string);

Check jsfiddle http://jsfiddle.net/raunakkathuria/7PQtC/1/ as i have copied the complete script so look for running code at end of fiddle