Add fixed axes, color-coded lines, summary stats, and >1000ms clamping

- Fixed Y-axis (0-1000ms) with tick labels
- Fixed X-axis showing seconds ago (-0s to -300s)
- Sparkline segments color-coded by latency value
- Summary line showing reachable count, min/max/avg across hosts
- Latencies >1000ms now clamped to unreachable/timeout
- Canvas height increased to 80px for axis labels
This commit is contained in:
Jeffrey Paul 2026-01-31 14:22:35 -08:00
parent ed602fdb5f
commit 3069b4692d

View File

@ -53,6 +53,10 @@ async function measureLatency(url) {
const latency = Math.round(performance.now() - start)
clearTimeout(timeoutId)
// Clamp >1000ms to unreachable
if (latency > 1000) {
return { latency: null, error: 'timeout' }
}
return { latency, error: null }
} catch (err) {
clearTimeout(timeoutId)
@ -65,16 +69,14 @@ async function measureLatency(url) {
}
}
// Get latency color based on value
function getLatencyColor(latency, status) {
if (status === 'offline' || status === 'error' || latency === null) {
return 'var(--color-latency-offline)'
}
if (latency < 50) return 'var(--color-latency-excellent)'
if (latency < 100) return 'var(--color-latency-good)'
if (latency < 200) return 'var(--color-latency-moderate)'
if (latency < 500) return 'var(--color-latency-poor)'
return 'var(--color-latency-bad)'
// Get latency color (raw hex for canvas)
function getLatencyColor(latency) {
if (latency === null) return '#6b7280' // gray
if (latency < 50) return '#22c55e' // green
if (latency < 100) return '#84cc16' // lime
if (latency < 200) return '#eab308' // yellow
if (latency < 500) return '#f97316' // orange
return '#ef4444' // red
}
// Get Tailwind class for latency
@ -89,95 +91,73 @@ function getLatencyClass(latency, status) {
return 'text-red-500'
}
// Fixed axis constants
const Y_AXIS_MAX = 1000 // ms
const Y_AXIS_TICKS = [0, 250, 500, 750, 1000]
const X_AXIS_TICKS = [0, 60, 120, 180, 240, 300] // seconds ago
// Draw sparkline on canvas - latest point at right edge, growing left
function drawSparkline(canvas, history, hostColor) {
function drawSparkline(canvas, history) {
const ctx = canvas.getContext('2d')
const width = canvas.width
const height = canvas.height
const padding = 4
const dpr = window.devicePixelRatio || 1
const width = canvas.width / dpr
const height = canvas.height / dpr
// Margins for axis labels
const marginLeft = 35
const marginRight = 10
const marginTop = 5
const marginBottom = 18
const chartWidth = width - marginLeft - marginRight
const chartHeight = height - marginTop - marginBottom
// Clear canvas
ctx.clearRect(0, 0, width, height)
// Filter valid latency points
const validPoints = history.filter(p => p.latency !== null)
// Draw Y-axis labels and grid lines
ctx.font = '9px monospace'
ctx.textAlign = 'right'
ctx.textBaseline = 'middle'
if (validPoints.length < 2) {
// Draw placeholder line
Y_AXIS_TICKS.forEach(tick => {
const y = marginTop + chartHeight - (tick / Y_AXIS_MAX) * chartHeight
// Grid line
ctx.strokeStyle = 'rgba(255,255,255,0.1)'
ctx.lineWidth = 1
ctx.beginPath()
ctx.moveTo(padding, height / 2)
ctx.lineTo(width - padding, height / 2)
ctx.moveTo(marginLeft, y)
ctx.lineTo(width - marginRight, y)
ctx.stroke()
return
}
// Calculate min/max for scaling
const latencies = validPoints.map(p => p.latency)
const minLatency = Math.min(...latencies)
const maxLatency = Math.max(...latencies)
const range = maxLatency - minLatency || 1
// Draw background grid lines
ctx.strokeStyle = 'rgba(255,255,255,0.05)'
ctx.lineWidth = 1
for (let i = 0; i <= 4; i++) {
const y = padding + (i / 4) * (height - 2 * padding)
ctx.beginPath()
ctx.moveTo(0, y)
ctx.lineTo(width, y)
ctx.stroke()
}
// Draw the sparkline - right-aligned (latest at right edge)
ctx.strokeStyle = hostColor
ctx.lineWidth = 1.5
ctx.lineCap = 'round'
ctx.lineJoin = 'round'
ctx.beginPath()
const pointWidth = (width - 2 * padding) / (MAX_HISTORY_POINTS - 1)
const historyLen = history.length
// Calculate x position: latest point at right edge
const getX = (i) => width - padding - (historyLen - 1 - i) * pointWidth
// Map all history points to x positions
let firstPoint = true
history.forEach((point, i) => {
if (point.latency === null) return
const x = getX(i)
const normalizedY = (point.latency - minLatency) / range
const y = height - padding - normalizedY * (height - 2 * padding)
if (firstPoint) {
ctx.moveTo(x, y)
firstPoint = false
} else {
ctx.lineTo(x, y)
}
// Label
ctx.fillStyle = 'rgba(255,255,255,0.5)'
ctx.fillText(`${tick}`, marginLeft - 4, y)
})
ctx.stroke()
// Draw X-axis labels
ctx.textAlign = 'center'
ctx.textBaseline = 'top'
// Draw latest point indicator (always at right edge)
const lastValidPoint = [...history].reverse().find(p => p.latency !== null)
if (lastValidPoint) {
const lastIndex = history.lastIndexOf(lastValidPoint)
const x = getX(lastIndex)
const normalizedY = (lastValidPoint.latency - minLatency) / range
const y = height - padding - normalizedY * (height - 2 * padding)
X_AXIS_TICKS.forEach(tick => {
// tick is seconds ago, 0 = now (right edge), 300 = 5min ago (left edge)
const x = marginLeft + chartWidth - (tick / HISTORY_DURATION) * chartWidth
ctx.fillStyle = hostColor
ctx.beginPath()
ctx.arc(x, y, 3, 0, Math.PI * 2)
ctx.fill()
}
// Label
ctx.fillStyle = 'rgba(255,255,255,0.5)'
ctx.fillText(`-${tick}s`, x, height - marginBottom + 4)
})
// Draw error regions (red zones where connectivity was lost)
ctx.fillStyle = 'rgba(239, 68, 68, 0.3)'
// Helper functions for chart coordinates
const historyLen = history.length
const pointWidth = chartWidth / (MAX_HISTORY_POINTS - 1)
const getX = (i) => marginLeft + chartWidth - (historyLen - 1 - i) * pointWidth
const getY = (latency) => marginTop + chartHeight - (latency / Y_AXIS_MAX) * chartHeight
// Draw error regions first (behind the line)
ctx.fillStyle = 'rgba(239, 68, 68, 0.2)'
let inErrorRegion = false
let errorStart = 0
@ -189,13 +169,57 @@ function drawSparkline(canvas, history, hostColor) {
errorStart = x
} else if (point.latency !== null && inErrorRegion) {
inErrorRegion = false
ctx.fillRect(errorStart, 0, x - errorStart, height)
ctx.fillRect(errorStart, marginTop, x - errorStart, chartHeight)
}
})
if (inErrorRegion) {
const lastX = getX(historyLen - 1)
ctx.fillRect(errorStart, 0, lastX - errorStart + padding, height)
ctx.fillRect(errorStart, marginTop, lastX - errorStart + 5, chartHeight)
}
// Draw the sparkline segments - color coded by latency
ctx.lineWidth = 2
ctx.lineCap = 'round'
ctx.lineJoin = 'round'
let prevPoint = null
let prevX = 0
let prevY = 0
history.forEach((point, i) => {
if (point.latency === null) {
prevPoint = null
return
}
const x = getX(i)
const y = getY(point.latency)
if (prevPoint !== null) {
ctx.strokeStyle = getLatencyColor(point.latency)
ctx.beginPath()
ctx.moveTo(prevX, prevY)
ctx.lineTo(x, y)
ctx.stroke()
}
prevPoint = point
prevX = x
prevY = y
})
// Draw latest point indicator
const lastValidPoint = [...history].reverse().find(p => p.latency !== null)
if (lastValidPoint) {
const lastIndex = history.lastIndexOf(lastValidPoint)
const x = getX(lastIndex)
const y = getY(lastValidPoint.latency)
ctx.fillStyle = getLatencyColor(lastValidPoint.latency)
ctx.beginPath()
ctx.arc(x, y, 3, 0, Math.PI * 2)
ctx.fill()
}
}
@ -228,6 +252,15 @@ function createUI() {
<span class="text-gray-500">History: ${HISTORY_DURATION}s</span> |
<span id="status-indicator" class="text-green-400">Running</span>
</p>
<div id="summary" class="mt-4 p-3 bg-gray-800/70 rounded-lg border border-gray-700/50 font-mono text-sm">
<span class="text-gray-400">Reachable:</span> <span id="summary-reachable" class="text-white">--/--</span>
<span class="text-gray-600 mx-3">|</span>
<span class="text-gray-400">Min:</span> <span id="summary-min" class="text-green-400">--ms</span>
<span class="text-gray-600 mx-3">|</span>
<span class="text-gray-400">Max:</span> <span id="summary-max" class="text-red-400">--ms</span>
<span class="text-gray-600 mx-3">|</span>
<span class="text-gray-400">Avg:</span> <span id="summary-avg" class="text-yellow-400">--ms</span>
</div>
</header>
<div id="hosts-container" class="space-y-4">
@ -258,7 +291,7 @@ function createUI() {
<canvas
class="sparkline-canvas w-full"
data-host="${index}"
height="60"
height="80"
></canvas>
</div>
</div>
@ -285,7 +318,7 @@ function createUI() {
document.querySelectorAll('.sparkline-canvas').forEach(canvas => {
const rect = canvas.getBoundingClientRect()
canvas.width = rect.width * window.devicePixelRatio
canvas.height = 60 * window.devicePixelRatio
canvas.height = 80 * window.devicePixelRatio
canvas.getContext('2d').scale(window.devicePixelRatio, window.devicePixelRatio)
})
})
@ -326,7 +359,7 @@ function updateHostDisplay(index) {
// Update sparkline
const canvasRect = canvas.getBoundingClientRect()
drawSparkline(canvas, host.history, host.color)
drawSparkline(canvas, host.history)
}
// Calculate average latency from history
@ -338,6 +371,45 @@ function calculateAverageLatency(history) {
return Math.round(sum / validPoints.length)
}
// Update summary line with current host stats
function updateSummary() {
const reachableHosts = hostState.filter(h => h.lastLatency !== null)
const reachableCount = reachableHosts.length
const totalCount = hostState.length
const reachableEl = document.getElementById('summary-reachable')
const minEl = document.getElementById('summary-min')
const maxEl = document.getElementById('summary-max')
const avgEl = document.getElementById('summary-avg')
if (!reachableEl) return
reachableEl.textContent = `${reachableCount}/${totalCount}`
reachableEl.className = reachableCount === totalCount ? 'text-green-400' :
reachableCount === 0 ? 'text-red-400' : 'text-yellow-400'
if (reachableCount > 0) {
const latencies = reachableHosts.map(h => h.lastLatency)
const min = Math.min(...latencies)
const max = Math.max(...latencies)
const avg = Math.round(latencies.reduce((a, b) => a + b, 0) / latencies.length)
minEl.textContent = `${min}ms`
minEl.className = getLatencyClass(min, 'online')
maxEl.textContent = `${max}ms`
maxEl.className = getLatencyClass(max, 'online')
avgEl.textContent = `${avg}ms`
avgEl.className = getLatencyClass(avg, 'online')
} else {
minEl.textContent = '--ms'
minEl.className = 'text-gray-500'
maxEl.textContent = '--ms'
maxEl.className = 'text-gray-500'
avgEl.textContent = '--ms'
avgEl.className = 'text-gray-500'
}
}
// Main measurement loop
async function measureAll() {
const timestamp = Date.now()
@ -376,6 +448,9 @@ async function measureAll() {
// Update display
updateHostDisplay(index)
})
// Update summary
updateSummary()
}
// Handle window resize
@ -383,14 +458,14 @@ function handleResize() {
document.querySelectorAll('.sparkline-canvas').forEach((canvas, index) => {
const rect = canvas.getBoundingClientRect()
canvas.width = rect.width * window.devicePixelRatio
canvas.height = 60 * window.devicePixelRatio
canvas.height = 80 * window.devicePixelRatio
const ctx = canvas.getContext('2d')
ctx.setTransform(1, 0, 0, 1, 0, 0)
ctx.scale(window.devicePixelRatio, window.devicePixelRatio)
// Redraw
if (hostState[index]) {
drawSparkline(canvas, hostState[index].history, hostState[index].color)
drawSparkline(canvas, hostState[index].history)
}
})
}