Added an rpc cmd queue

lib/explorer.js

@@ -1,4 +1,5 @@
 var request = require('postman-request'),
+    async = require('async'),
     settings = require('./settings'),
     locale = require('./locale'),
     Address = require('../models/address');
@@ -8,6 +9,15 @@ var base_url = base_server + 'api/';
 const onode = require('./node');
 const client = new onode.Client(settings.wallet);
 
+const rpc_queue = async.queue((task_params, cb) => {
+  client.cmd([task_params], function(err, response) {
+    if (err)
+      return cb('There was an error. Check your console.');
+    else
+      return cb(response);
+  });
+}, settings.api_cmds.rpc_concurrent_tasks);
+
 // returns coinbase total sent as current coin supply
 function coinbase_supply(cb) {
   Address.findOne({a_id: 'coinbase'}).then((address) => {
@@ -22,12 +32,7 @@ function coinbase_supply(cb) {
 }
 
 function rpcCommand(params, cb) {
-  client.cmd([{method: params[0].method, params: params[0].parameters}], function(err, response) {
-    if (err)
-      return cb('There was an error. Check your console.');
-    else
-      return cb(response);
-  });
+  rpc_queue.push({method: params[0].method, params: params[0].parameters}, cb);
 }
 
 function prepareRpcCommand(cmd, addParams) {

lib/settings.js

@@ -1258,6 +1258,8 @@ exports.api_cmds = {
   // use_rpc: Determine whether to call rpc api cmds directly using the faster rpc method or using the older method via internal http api (true/false)
   //          NOTE: This should always be set to true unless there is a specific need to test or log certain apis
   "use_rpc": true,
+  // rpc_concurrent_tasks: The maximum number of rpc cmds that can be run simultaneously. Additional rpc cmds will go into a queue and be run on a first-in-first-out basis
+  "rpc_concurrent_tasks": 1,
   // getnetworkhashps: Returns the estimated network hashes per second. This should be a positive whole number
   "getnetworkhashps": "getnetworkhashps",
   // getmininginfo: Returns a json object containing mining-related information