From 014f0a1491b1de8e7cb9414a25c520458efc1723 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Simon=20Mart=C3=ADn?= <oleurud@gmail.com>
Date: Fri, 8 Jun 2018 16:58:32 +0200
Subject: [PATCH] refactor of copy to PoC

---
 app/controllers/copy_controller.js | 12 +++---------
 app/services/stream_copy.js        | 20 ++++++++++++++++++--
 2 files changed, 21 insertions(+), 11 deletions(-)

diff --git a/app/controllers/copy_controller.js b/app/controllers/copy_controller.js
index 33a5b032..97659819 100644
--- a/app/controllers/copy_controller.js
+++ b/app/controllers/copy_controller.js
@@ -75,8 +75,7 @@ function handleCopyTo () {
         res.header("Content-Disposition", `attachment; filename=${encodeURIComponent(filename)}`);
         res.header("Content-Type", "application/octet-stream");
 
-        const pg = new PSQL(userDbParams);
-        pg.connect(function (err, client, done) {
+        streamCopy.to(sql, userDbParams, function (err, pgstream, client, done) {
             if (err) {
                 return next(err);
             }
@@ -84,8 +83,6 @@ function handleCopyTo () {
             let responseEnded = false;
             let connectionClosedByClient = false;
             
-            const copyToStream = copyTo(sql);
-            const pgstream = client.query(copyToStream);
 
             res
                 .on('error', err => {
@@ -123,12 +120,9 @@ function handleCopyTo () {
                     }
                 })
                 .on('data', data => metrics.addSize(data.length))
-                .on('end', () => {
-                    metrics.end(copyToStream.rowCount);
-                    done();
-                    return next(null, metrics);
-                })
                 .pipe(res);
+        }, function (err, rows) {
+            metrics.end(rows);
         });
     };
 }
diff --git a/app/services/stream_copy.js b/app/services/stream_copy.js
index 9e96332b..df42bb07 100644
--- a/app/services/stream_copy.js
+++ b/app/services/stream_copy.js
@@ -7,8 +7,24 @@ const { Client } = require('pg');
 const Logger = require('./logger');
 
 module.exports = {
-    to() {
-        
+    to(sql, userDbParams, cb, next) {
+        const pg = new PSQL(userDbParams);
+        pg.connect(function (err, client, done) {
+            if (err) {
+                cb(err);
+            }
+
+            const copyToStream = copyTo(sql);
+            const pgstream = client.query(copyToStream);
+
+            pgstream
+                .on('end', () => {
+                    done();
+                    next(null, copyToStream.rowCount);
+                })
+
+            cb(null, pgstream, client, done)
+        });
     },
 
     from(sql, userDbParams, cb, next) {