javascript - Read json file content with require vs fs.readFile

Question

Suppose that for every response from an API, i need to map the value from the response to an existing json file in my web application and display the value from the json. What are the better approach in this case to read the json file? require or fs.readfile. Note that there might be thousands of request comes in at a same time.

Note that I do not expect there is any changes to the file during runtime.

request(options, function(error, response, body) {
   // compare response identifier value with json file in node
   // if identifier value exist in the json file
   // return the corresponding value in json file instead
});

Answer 1

I suppose you'll JSON.parse the json file for the comparison, in that case, require is better because it'll parse the file right away and it's sync:

var obj = require('./myjson'); // no need to add the .json extension

If you have thousands of request using that file, require it once outside your request handler and that's it:

var myObj = require('./myjson');
request(options, function(error, response, body) {
   // myObj is accessible here and is a nice JavaScript object

   var value = myObj.someValue;

   // compare response identifier value with json file in node
   // if identifier value exist in the json file
   // return the corresponding value in json file instead
});