My server is using NodeJS and the amqplib api to retrieve data from another application. Although the NodeJS server can successfully receive information, there seems to be a noticeable delay. I am currently exploring whether there is a more efficient way to handle this process, particularly in terms of opening and closing connections.
Project Layout
There are two controller files, request.img.server.controller.js and receive.img.server.controller.js, that manage data retrieval and reception respectively. The methods in these controllers are called by the routes file, oct.server.routes.js, when a button on the frontend is clicked.
request.img.server.controller.js
'use strict';
var amqp = require('amqplib/callback_api');
var connReady = false;
var conn, ch;
amqp.connect('amqp://localhost:5672', function(err, connection) {
conn = connection;
connReady = true;
conn.createChannel(function(err, channel) {
ch = channel;
});
});
exports.sendRequest = function(message) {
console.log('sending request');
if(connReady) {
var ex = '';
var key = 'utils';
ch.publish(ex, key, new Buffer(message));
console.log(" [x] Sent %s: '%s'", key, message);
}
};
receive.img.server.controller.js
var amqp = require('amqplib/callback_api');
var fs = require('fs');
var wstream = fs.createWriteStream('C:\\Users\\yako\\desktop\\binarytest.txt');
var image, rows, cols;
exports.getResponse = function(resCallback) {
amqp.connect('amqp://localhost:5672', function(err, conn) {
conn.createChannel(function(err, ch) {
var ex = '';
ch.assertQueue('server', {}, function(err, q) {
console.log('waiting for images');
var d = new Date();
var n = d.getTime();
ch.consume(q.queue, function(msg) {
console.log(" [x] %s: '%s'", msg.fields.routingKey, msg.content.toJSON());
rows = msg.content.readInt16LE(0);
cols = msg.content.readInt16LE(2);
console.log("rows = %s", msg.content.readInt16LE(0));
console.log("cols = %s", msg.content.readInt16LE(2));
image = msg.content;
var currMax = 0;
for (var i = 4; i < image.length; i+=2) {
if (image.readInt16LE(i) > currMax) {
currMax = image.readInt16LE(i);
}
wstream.write(image.readInt16LE(i) + ',');
}
console.log('done writing max is', currMax);
//console.log(image);
resCallback(rows, cols, image);
}, {
noAck: true
});
});
});
});
};
oct.server.routes.js
'use strict';
module.exports = function(app) {
var request_img = require('../../app/controllers/image-tools/request.img.server.controller.js');
var receive_img = require('../../app/controllers/image-tools/receive.img.server.controller.js');
// oct routes
app.get('/load_slice', function(req, res) {
console.log('load slice hit');
receive_img.getResponse(function (rows, cols, image) {
res.end(image);
});
request_img.sendRequest('123:C:\\Users\\yako\\Documents\\Developer\\medicaldiag\\test_files\\RUS-01-035-09M-21.oct');
});
};