From 53b704cad8f64fa71ce18d1cb6a4cb5b3cd0e5cd Mon Sep 17 00:00:00 2001
From: HDegroote <75906619+HDegroote@users.noreply.github.com>
Date: Fri, 28 Jun 2024 13:07:54 +0200
Subject: [PATCH] Add connections to stats (opened, closed, attempted) (#174)

* Add connections to stats (opened, closed, attempted)

* Rename connections->connects

* Also keep track of server connections

* Fix server opened + no server attempted + split out client and server stats
---
 index.js      | 26 ++++++++++++++++++++++-
 test/all.js   |  1 +
 test/stats.js | 58 +++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 84 insertions(+), 1 deletion(-)
 create mode 100644 test/stats.js

diff --git a/index.js b/index.js
index 80628d9..c1c8e17 100644
--- a/index.js
+++ b/index.js
@@ -56,7 +56,21 @@ module.exports = class Hyperswarm extends EventEmitter {
     this.peers = new Map()
     this.explicitPeers = new Set()
     this.listening = null
-    this.stats = { updates: 0 }
+    this.stats = {
+      updates: 0,
+      connects: {
+        client: {
+          opened: 0,
+          closed: 0,
+          attempted: 0
+        },
+        server: {
+          // Note: there is no notion of 'attempts' for server connections
+          opened: 0,
+          closed: 0
+        }
+      }
+    }
 
     this._discovery = new Map()
     this._timer = new RetryTimer(this._requeue.bind(this), {
@@ -169,12 +183,16 @@ module.exports = class Hyperswarm extends EventEmitter {
     })
     this._allConnections.add(conn)
 
+    this.stats.connects.client.attempted++
+
     this.connecting++
     this._clientConnections++
     let opened = false
 
     conn.on('open', () => {
       opened = true
+      this.stats.connects.client.opened++
+
       this._connectDone()
       this.connections.add(conn)
       conn.removeListener('error', noop)
@@ -194,6 +212,8 @@ module.exports = class Hyperswarm extends EventEmitter {
     })
     conn.on('close', () => {
       if (!opened) this._connectDone()
+      this.stats.connects.client.closed++
+
       this.connections.delete(conn)
       this._allConnections.delete(conn)
       this._clientConnections--
@@ -295,6 +315,9 @@ module.exports = class Hyperswarm extends EventEmitter {
       return
     }
 
+    // When reaching here, the connection will always be 'opened' next tick
+    this.stats.connects.server.opened++
+
     const peerInfo = this._upsertPeer(conn.remotePublicKey, null)
 
     this.connections.add(conn)
@@ -305,6 +328,7 @@ module.exports = class Hyperswarm extends EventEmitter {
       this.connections.delete(conn)
       this._allConnections.delete(conn)
       this._serverConnections--
+      this.stats.connects.server.closed++
 
       this._maybeDeletePeer(peerInfo)
 
diff --git a/test/all.js b/test/all.js
index 2f02dd8..daae2b0 100644
--- a/test/all.js
+++ b/test/all.js
@@ -14,6 +14,7 @@ async function runTests () {
   await import('./peer-join.js')
   await import('./retry-timer.js')
   await import('./suspend.js')
+  await import('./stats.js')
   await import('./swarm.js')
   await import('./update.js')
 
diff --git a/test/stats.js b/test/stats.js
new file mode 100644
index 0000000..c7da246
--- /dev/null
+++ b/test/stats.js
@@ -0,0 +1,58 @@
+const test = require('brittle')
+const createTestnet = require('hyperdht/testnet')
+
+const Hyperswarm = require('..')
+
+test('connectionsOpened and connectionsClosed stats', async (t) => {
+  const { bootstrap } = await createTestnet(3, t.teardown)
+
+  const swarm1 = new Hyperswarm({ bootstrap })
+  const swarm2 = new Hyperswarm({ bootstrap })
+
+  const tOpen = t.test('Open connection')
+  tOpen.plan(3)
+  const tClose = t.test('Close connection')
+  tClose.plan(4)
+
+  t.teardown(async () => {
+    await swarm1.destroy()
+    await swarm2.destroy()
+  })
+
+  swarm2.on('connection', (conn) => {
+    conn.on('error', noop)
+
+    tOpen.is(swarm2.stats.connects.client.opened, 1, 'opened connection is in stats')
+    tOpen.is(swarm2.stats.connects.client.attempted, 1, 'attemped connection is in stats')
+    tClose.is(swarm2.stats.connects.client.closed, 0, 'sanity check')
+
+    conn.on('close', () => {
+      tClose.is(swarm2.stats.connects.client.closed, 1, 'closed connection is in stats')
+    })
+
+    conn.end()
+  })
+
+  swarm1.on('connection', (conn) => {
+    conn.on('error', () => noop)
+
+    conn.on('open', () => {
+      tOpen.is(swarm1.stats.connects.server.opened, 1, 'opened server connection is in stats')
+      tClose.is(swarm1.stats.connects.server.closed, 0, 'Sanity check')
+    })
+
+    conn.on('close', () => {
+      tClose.is(swarm1.stats.connects.server.closed, 1, 'closed connections is in stats')
+    })
+
+    conn.end()
+  })
+
+  const topic = Buffer.alloc(32).fill('hello world')
+  await swarm1.join(topic, { server: true, client: false }).flushed()
+  swarm2.join(topic, { client: true, server: false })
+
+  await tClose
+})
+
+function noop () {}