From 9e216a818a4f3a44fa1ed1cfa92f2af555a9af3a Mon Sep 17 00:00:00 2001
From: Chris Kleeschulte <chrisk@bitpay.com>
Date: Fri, 20 Oct 2017 10:40:57 -0400
Subject: [PATCH] Streamed multiutxos.

---
 lib/addresses.js | 30 ++++++++++++++++++++++--------
 1 file changed, 22 insertions(+), 8 deletions(-)

diff --git a/lib/addresses.js b/lib/addresses.js
index 70566a4..64b302e 100644
--- a/lib/addresses.js
+++ b/lib/addresses.js
@@ -152,10 +152,13 @@ AddressController.prototype.utxo = function(req, res) {
   });
 };
 
+// this call could take a while to run depending on what addresses are used
+// considering memory constraints,  we will streaming out the results for addresses
+// not necessarily in the order we received them
 AddressController.prototype.multiutxo = function(req, res) {
   var self = this;
 
-  var finalUtxos = [];
+  var sep = ',';
 
   var addresses;
   if (_.isArray(req.addrs)) {
@@ -164,6 +167,9 @@ AddressController.prototype.multiutxo = function(req, res) {
     addresses = req.addrs.split(',');
   }
 
+  var addressesLeft = addresses.length;
+  res.write('[');
+
   async.eachLimit(addresses, 4, function(addr, next) {
 
     self._address.getAddressUnspentOutputs(addr, {}, function(err, utxos) {
@@ -172,20 +178,28 @@ AddressController.prototype.multiutxo = function(req, res) {
         return next(err);
       }
 
-      finalUtxos = finalUtxos.concat(utxos);
+      for(var i = 0; i < utxos.length; i++) {
+
+        if (--addressesLeft <= 0 && utxos[i] === utxos[utxos.length - 1] ) {
+          sep = '';
+        }
+
+        res.write(JSON.stringify(self.transformUtxo(utxos[i])) + sep);
+      }
+
       next();
     });
 
   }, function(err) {
 
-    if (err) {
-      return self.common.handleErrors(err, res);
-    }
-
-    var finalRes = finalUtxos.map(self.transformUtxo.bind(self));
-    res.jsonp(finalRes);
+      if (err) {
+        return self.common.handleErrors(err, res);
+      }
 
+      res.write(']');
+      res.end();
   });
+
 };
 
 AddressController.prototype.transformUtxo = function(utxoArg) {