From e3584add7c723530783156f99700edbb581cdf43 Mon Sep 17 00:00:00 2001
From: Thomas Nordquist <xxnerowingerxx@gmail.com>
Date: Mon, 8 Jul 2019 00:19:34 +0200
Subject: [PATCH] Fix broker stats

---
 .../ChartPanel/ChartWithTreeNode.tsx          |  36 +-----
 .../SettingsDrawer/BrokerStatistics.tsx       | 105 +++++++++---------
 .../helper/usePollingToFetchTreeNode.tsx      |  38 +++++++
 3 files changed, 94 insertions(+), 85 deletions(-)
 create mode 100644 app/src/components/helper/usePollingToFetchTreeNode.tsx

diff --git a/app/src/components/ChartPanel/ChartWithTreeNode.tsx b/app/src/components/ChartPanel/ChartWithTreeNode.tsx
index 2fd812c..4f910c4 100644
--- a/app/src/components/ChartPanel/ChartWithTreeNode.tsx
+++ b/app/src/components/ChartPanel/ChartWithTreeNode.tsx
@@ -1,7 +1,8 @@
 import * as q from '../../../../backend/src/Model'
-import * as React from 'react'
+import React from 'react'
 import Chart from './Chart'
 import { ChartParameters } from '../../reducers/Charts'
+import { usePollingToFetchTreeNode } from '../helper/usePollingToFetchTreeNode'
 
 interface Props {
   tree?: q.Tree<any>
@@ -14,37 +15,6 @@ export function ChartWithTreeNode(props: Props) {
     return null
   }
 
-  const initialTreeNode = tree.findNode(parameters.topic)
-  const [treeNode, setTreeNode] = React.useState<q.TreeNode<any> | undefined>(initialTreeNode)
-
-  usePollingToFetchTreeNode(treeNode, tree, parameters.topic, setTreeNode)
+  const treeNode = usePollingToFetchTreeNode(tree, parameters.topic)
   return <Chart treeNode={treeNode} parameters={parameters} />
 }
-
-/**
- * If a node is not available when the plot is shown, keep polling until it has been created
- */
-function usePollingToFetchTreeNode(
-  treeNode: q.TreeNode<any> | undefined,
-  tree: q.Tree<any>,
-  path: string,
-  setTreeNode: React.Dispatch<React.SetStateAction<q.TreeNode<any> | undefined>>
-) {
-  function pollUntilTreeNodeHasBeenFound() {
-    let intervalTimer: any
-    if (!treeNode) {
-      intervalTimer = setInterval(() => {
-        const node = tree.findNode(path)
-        if (node) {
-          setTreeNode(node)
-          clearInterval(intervalTimer)
-        }
-      }, 500)
-    }
-    return function cleanup() {
-      intervalTimer && clearInterval(intervalTimer)
-    }
-  }
-
-  React.useEffect(pollUntilTreeNodeHasBeenFound, [])
-}
diff --git a/app/src/components/SettingsDrawer/BrokerStatistics.tsx b/app/src/components/SettingsDrawer/BrokerStatistics.tsx
index 9f5e716..637a60f 100644
--- a/app/src/components/SettingsDrawer/BrokerStatistics.tsx
+++ b/app/src/components/SettingsDrawer/BrokerStatistics.tsx
@@ -1,13 +1,12 @@
 import * as q from '../../../../backend/src/Model'
-import * as React from 'react'
+import React, { useMemo } from 'react'
 import { AppState } from '../../reducers'
+import { Base64Message } from '../../../../backend/src/Model/Base64Message'
 import { connect } from 'react-redux'
-import { StyleRulesCallback, withStyles, Theme } from '@material-ui/core/styles'
+import { Theme, withStyles } from '@material-ui/core/styles'
 import { TopicViewModel } from '../../model/TopicViewModel'
 import { Typography } from '@material-ui/core'
-import { Base64Message } from '../../../../backend/src/Model/Base64Message'
-import teal from '@material-ui/core/colors/teal'
-
+import { usePollingToFetchTreeNode } from '../helper/usePollingToFetchTreeNode'
 const abbreviate = require('number-abbreviate')
 
 interface Stats {
@@ -16,10 +15,6 @@ interface Stats {
 }
 
 const styles = (theme: Theme) => ({
-  flex: {
-    display: 'flex',
-    width: '100%',
-  },
   container: {
     width: '100%',
     height: '224px',
@@ -34,24 +29,12 @@ interface Props {
   tree?: q.Tree<TopicViewModel>
 }
 
-class BrokerStatistics extends React.Component<Props, {}> {
-  constructor(props: any) {
-    super(props)
-    this.state = {}
-  }
+function BrokerStatistics(props: Props) {
+  const { tree, classes } = props
+  const sysTopic = usePollingToFetchTreeNode(props.tree, '$SYS')
 
-  private renderPair(tree: q.Tree<TopicViewModel>, a: Stats, b: Stats) {
-    return (
-      <div className={this.props.classes.flex}>
-        <div style={{ flex: 1 }}>{this.renderStat(tree, a)}</div>
-        <div style={{ flex: 1 }}>{this.renderStat(tree, b)}</div>
-      </div>
-    )
-  }
-
-  public render() {
-    const { tree, classes } = this.props
-    if (!tree || !tree.findNode('$SYS/broker/clients/total')) {
+  return useMemo(() => {
+    if (!Boolean(sysTopic)) {
       return null
     }
 
@@ -94,38 +77,20 @@ class BrokerStatistics extends React.Component<Props, {}> {
       },
     }
 
-    return (
-      <div className={classes.container}>
-        {this.renderStat(tree, stats.broker)}
-        {this.renderPair(tree, stats.sent, stats.received)}
-        {this.renderPair(tree, stats.clients, stats.subscriptions)}
-        {this.renderPair(tree, stats.sent5m, stats.received5m)}
-        {this.renderPair(tree, stats.heap, stats.heapMax)}
-      </div>
-    )
-  }
-
-  public renderStat(tree: q.Tree<TopicViewModel>, stat: Stats) {
-    const node = tree.findNode(stat.topic)
-    if (!node || !node.message) {
+    if (!tree) {
       return null
     }
 
-    const str = node.message.value ? Base64Message.toUnicodeString(node.message.value) : ''
-    let value = node.message && node.message.value ? parseFloat(str) : NaN
-    value = !isNaN(value) ? abbreviate(value) : str
-
     return (
-      <div key={stat.title}>
-        <Typography>
-          <b>{stat.title}</b>
-        </Typography>
-        <Typography style={{ paddingLeft: '8px' }}>
-          <i>{value}</i>
-        </Typography>
+      <div className={classes.container}>
+        {renderStat(tree, stats.broker)}
+        {renderPair(tree, stats.sent, stats.received)}
+        {renderPair(tree, stats.clients, stats.subscriptions)}
+        {renderPair(tree, stats.sent5m, stats.received5m)}
+        {renderPair(tree, stats.heap, stats.heapMax)}
       </div>
     )
-  }
+  }, [sysTopic && sysTopic.lastUpdate])
 }
 
 const mapStateToProps = (state: AppState) => {
@@ -135,3 +100,39 @@ const mapStateToProps = (state: AppState) => {
 }
 
 export default withStyles(styles)(connect(mapStateToProps)(BrokerStatistics))
+
+function renderPair(tree: q.Tree<TopicViewModel>, a: Stats, b: Stats) {
+  return (
+    <div
+      style={{
+        display: 'flex',
+        width: '100%',
+      }}
+    >
+      <div style={{ flex: 1 }}>{renderStat(tree, a)}</div>
+      <div style={{ flex: 1 }}>{renderStat(tree, b)}</div>
+    </div>
+  )
+}
+
+function renderStat(tree: q.Tree<TopicViewModel>, stat: Stats) {
+  const node = tree.findNode(stat.topic)
+  if (!node || !node.message) {
+    return null
+  }
+
+  const str = node.message.value ? Base64Message.toUnicodeString(node.message.value) : ''
+  let value = node.message && node.message.value ? parseFloat(str) : NaN
+  value = !isNaN(value) ? abbreviate(value) : str
+
+  return (
+    <div key={stat.title}>
+      <Typography>
+        <b>{stat.title}</b>
+      </Typography>
+      <Typography style={{ paddingLeft: '8px' }}>
+        <i>{value}</i>
+      </Typography>
+    </div>
+  )
+}
diff --git a/app/src/components/helper/usePollingToFetchTreeNode.tsx b/app/src/components/helper/usePollingToFetchTreeNode.tsx
new file mode 100644
index 0000000..3cd8697
--- /dev/null
+++ b/app/src/components/helper/usePollingToFetchTreeNode.tsx
@@ -0,0 +1,38 @@
+import * as q from '../../../../backend/src/Model'
+import { useState, useEffect } from 'react'
+
+/**
+ * If a node is not available when the plot is shown, keep polling until it has been created
+ */
+export function usePollingToFetchTreeNode(tree: q.Tree<any> | undefined, path: string) {
+  const [treeNode, setTreeNode] = useState<q.TreeNode<any> | undefined>()
+
+  function pollUntilTreeNodeHasBeenFound() {
+    if (!tree) {
+      return
+    }
+
+    const initialTreeNode = tree.findNode(path)
+    if (initialTreeNode) {
+      setTreeNode(initialTreeNode)
+      return
+    }
+
+    let intervalTimer: any
+    if (!treeNode) {
+      intervalTimer = setInterval(() => {
+        const node = tree.findNode(path)
+        if (node) {
+          setTreeNode(node)
+          clearInterval(intervalTimer)
+        }
+      }, 500)
+    }
+    return function cleanup() {
+      intervalTimer && clearInterval(intervalTimer)
+    }
+  }
+
+  useEffect(pollUntilTreeNodeHasBeenFound, [tree])
+  return treeNode
+}