From 13040f41a1ebbd87927814b8cdb1a53ad2f141ac Mon Sep 17 00:00:00 2001
From: Zoran Joka <zoran.joka@gmail.com>
Date: Wed, 21 Nov 2018 11:08:19 +0100
Subject: [PATCH] Optimize machine pings query (#222)

* refactor recordPing method

* optimize queries

* migrate machine_pings

remove id, serial_number
add primary key on device_id
add unique constraint on device_id

* remove filelds from query, rename migration, delete duplicate migration

* truncate machine_pings in migration
---
 lib/notifier.js                                 |  4 +---
 lib/plugins.js                                  | 13 ++++---------
 migrations/1542638179228-alter-machine-pings.js | 17 +++++++++++++++++
 3 files changed, 22 insertions(+), 12 deletions(-)
 create mode 100644 migrations/1542638179228-alter-machine-pings.js

diff --git a/lib/notifier.js b/lib/notifier.js
index 20b5e00a..b44ae5bd 100644
--- a/lib/notifier.js
+++ b/lib/notifier.js
@@ -130,9 +130,7 @@ function checkStuckScreen (deviceEvents) {
 
 function checkPing (deviceId) {
   const sql = `select (EXTRACT(EPOCH FROM (now() - created))) * 1000 AS age from machine_pings
-    where device_id=$1
-    order by created desc
-    limit 1`
+    where device_id=$1`
 
   return db.oneOrNone(sql, [deviceId])
     .then(row => {
diff --git a/lib/plugins.js b/lib/plugins.js
index 89b9a6da..c5585d8e 100644
--- a/lib/plugins.js
+++ b/lib/plugins.js
@@ -203,7 +203,7 @@ function plugins (settings, deviceId) {
     const tickerPromises = cryptoCodes.map(c => ticker.getRates(settings, fiatCode, c))
     const balancePromises = cryptoCodes.map(c => fiatBalance(fiatCode, c))
     const testnetPromises = cryptoCodes.map(c => wallet.cryptoNetwork(settings, c))
-    const pingPromise = recordPing(serialNumber, deviceTime, deviceRec)
+    const pingPromise = recordPing(deviceTime)
     const currentConfigVersionPromise = fetchCurrentConfigVersion()
 
     const promises = [
@@ -236,19 +236,14 @@ function plugins (settings, deviceId) {
     return wallet.sendCoins(settings, tx.toAddress, tx.cryptoAtoms, tx.cryptoCode)
   }
 
-  function recordPing (serialNumber, deviceTime, rec) {
-    const machinePings = {
-      id: uuid.v4(),
-      device_id: deviceId,
-      serial_number: serialNumber,
-      device_time: deviceTime
-    }
+  function recordPing (deviceTime) {
     const devices = {
       last_online: deviceTime
     }
 
     return Promise.all([
-      db.none(pgp.helpers.insert(machinePings, null, 'machine_pings')),
+      db.none(`insert into machine_pings(device_id, device_time) values($1, $2) 
+              ON CONFLICT (device_id) DO UPDATE SET device_time = $2`, [deviceId, deviceTime]),
       db.none(pgp.helpers.update(devices, null, 'devices') + 'WHERE device_id = ${deviceId}', { deviceId })
     ])
   }
diff --git a/migrations/1542638179228-alter-machine-pings.js b/migrations/1542638179228-alter-machine-pings.js
new file mode 100644
index 00000000..aa7cdf8c
--- /dev/null
+++ b/migrations/1542638179228-alter-machine-pings.js
@@ -0,0 +1,17 @@
+const db = require('./db')
+
+exports.up = function(next) {
+  var sql = [
+    'TRUNCATE TABLE machine_pings',
+    'ALTER TABLE machine_pings DROP id',
+    'ALTER TABLE machine_pings DROP serial_number',
+    'ALTER TABLE machine_pings ADD CONSTRAINT PK_device_id PRIMARY KEY (device_id)',
+    'ALTER TABLE machine_pings ADD CONSTRAINT U_device_id UNIQUE(device_id)'
+  ]
+
+  db.multi(sql, next)
+};
+
+exports.down = function(next) {
+  next();
+};