From ead5ddb81745b0fe7f0c605cedad070ddd3b5fc9 Mon Sep 17 00:00:00 2001
From: Justin Langston <justin@bitpay.com>
Date: Tue, 7 Nov 2017 15:58:54 -0500
Subject: [PATCH] Adding insight request queue

---
 lib/blockchainexplorers/insight.js | 22 ++++++++++++----------
 lib/common/defaults.js             | 20 +++++++++++---------
 2 files changed, 23 insertions(+), 19 deletions(-)

diff --git a/lib/blockchainexplorers/insight.js b/lib/blockchainexplorers/insight.js
index 8e9a75f..667599a 100644
--- a/lib/blockchainexplorers/insight.js
+++ b/lib/blockchainexplorers/insight.js
@@ -1,6 +1,7 @@
 'use strict';
 
 var _ = require('lodash');
+var async = require('async');
 var $ = require('preconditions').singleton();
 var log = require('npmlog');
 log.debug = log.verbose;
@@ -22,7 +23,8 @@ function Insight(opts) {
   this.network = opts.network || 'livenet';
   this.hosts = opts.url;
   this.userAgent = opts.userAgent || 'bws';
-};
+  this.requestQueue = async.queue(this._doRequest.bind(this), Defaults.INSIGHT_REQUEST_POOL_SIZE);
+}
 
 
 var _parseErr = function(err, res) {
@@ -43,7 +45,7 @@ Insight.prototype._doRequest = function(args, cb) {
   };
 
   var s  = JSON.stringify(args);
-  if ( s.length > 100 ) 
+  if ( s.length > 100 )
     s= s.substr(0,100) + '...';
   log.debug('', 'Insight Q: %s', s);
   requestList(_.defaults(args, opts), cb);
@@ -66,7 +68,7 @@ Insight.prototype.getUtxos = function(addresses, cb) {
     },
   };
 
-  this._doRequest(args, function(err, res, unspent) {
+  this.requestQueue.push(args, function(err, res, unspent) {
     if (err || res.statusCode !== 200) return cb(_parseErr(err, res));
     return cb(null, unspent);
   });
@@ -84,7 +86,7 @@ Insight.prototype.broadcast = function(rawTx, cb) {
     },
   };
 
-  this._doRequest(args, function(err, res, body) {
+  this.requestQueue.push(args, function(err, res, body) {
     if (err || res.statusCode !== 200) return cb(_parseErr(err, res));
     return cb(null, body ? body.txid : null);
   });
@@ -97,7 +99,7 @@ Insight.prototype.getTransaction = function(txid, cb) {
     json: true,
   };
 
-  this._doRequest(args, function(err, res, tx) {
+  this.requestQueue.push(args, function(err, res, tx) {
     if (res && res.statusCode == 404) return cb();
     if (err || res.statusCode !== 200)
       return cb(_parseErr(err, res));
@@ -127,7 +129,7 @@ Insight.prototype.getTransactions = function(addresses, from, to, cb) {
   };
 
 
-  this._doRequest(args, function(err, res, txs) {
+  this.requestQueue.push(args, function(err, res, txs) {
     if (err || res.statusCode !== 200) return cb(_parseErr(err, res));
 
     if (_.isObject(txs)) {
@@ -154,7 +156,7 @@ Insight.prototype.getAddressActivity = function(address, cb) {
     json: true,
   };
 
-  this._doRequest(args, function(err, res, result) {
+  this.requestQueue.push(args, function(err, res, result) {
     if (res && res.statusCode == 404) return cb();
     if (err || res.statusCode !== 200)
       return cb(_parseErr(err, res));
@@ -175,7 +177,7 @@ Insight.prototype.estimateFee = function(nbBlocks, cb) {
     path: path,
     json: true,
   };
-  this._doRequest(args, function(err, res, body) {
+  this.requestQueue.push(args, function(err, res, body) {
     if (err || res.statusCode !== 200) return cb(_parseErr(err, res));
     return cb(null, body);
   });
@@ -189,7 +191,7 @@ Insight.prototype.getBlockchainHeight = function(cb) {
     path: path,
     json: true,
   };
-  this._doRequest(args, function(err, res, body) {
+  this.requestQueue.push(args, function(err, res, body) {
     if (err || res.statusCode !== 200) return cb(_parseErr(err, res));
     return cb(null, body.blockChainHeight);
   });
@@ -204,7 +206,7 @@ Insight.prototype.getTxidsInBlock = function(blockHash, cb) {
     json: true,
   };
 
-  this._doRequest(args, function(err, res, body) {
+  this.requestQueue.push(args, function(err, res, body) {
     if (err || res.statusCode !== 200) return cb(_parseErr(err, res));
     return cb(null, body.tx);
   });
diff --git a/lib/common/defaults.js b/lib/common/defaults.js
index ff14564..d386345 100644
--- a/lib/common/defaults.js
+++ b/lib/common/defaults.js
@@ -89,7 +89,7 @@ Defaults.UTXO_SELECTION_MAX_FEE_VS_SINGLE_UTXO_FEE_FACTOR = 5;
 // Minimum allowed amount for tx outputs (including change) in SAT
 Defaults.MIN_OUTPUT_AMOUNT = 5000;
 
-// Number of confirmations from which tx in history will be cached 
+// Number of confirmations from which tx in history will be cached
 // (ie we consider them inmutables)
 Defaults.CONFIRMATIONS_TO_START_CACHING = 6 * 6; // ~ 6hrs
 
@@ -114,27 +114,29 @@ Defaults.SESSION_EXPIRATION = 1 * 60 * 60; // 1 hour to session expiration
 
 Defaults.RateLimit = {
   createWallet: {
-    windowMs: 60 * 60 * 1000, // hour window 
-    delayAfter: 8, // begin slowing down responses after the 3rd request 
-    delayMs: 3000, // slow down subsequent responses by 3 seconds per request 
+    windowMs: 60 * 60 * 1000, // hour window
+    delayAfter: 8, // begin slowing down responses after the 3rd request
+    delayMs: 3000, // slow down subsequent responses by 3 seconds per request
     max: 15, // start blocking after 20 request
     message: "Too many wallets created from this IP, please try again after an hour"
   },
   estimateFee: {
    windowMs: 60 * 10 *1000, // 10 min window
-    delayAfter: 5, // begin slowing down responses after the 3rd request 
-    delayMs: 300, // slow down subsequent responses by 3 seconds per request 
- 
+    delayAfter: 5, // begin slowing down responses after the 3rd request
+    delayMs: 300, // slow down subsequent responses by 3 seconds per request
+
     max: 10, // start blocking after 200 request
     message: "Too many request"
   },
- 
+
   // otherPosts: {
-  //   windowMs: 60 * 60 * 1000, // 1 hour window 
+  //   windowMs: 60 * 60 * 1000, // 1 hour window
   //   max: 1200 , // 1 post every 3 sec average, max.
   // },
 };
 
 Defaults.COIN = 'btc';
 
+Defaults.INSIGHT_REQUEST_POOL_SIZE = 20;
+
 module.exports = Defaults;