Add support for visualizing v8 profile gathered by CpuProfiler::Start…

…Profling

cmd.js

@@ -58,6 +58,7 @@ async function cmd (argv, banner = defaultBanner) {
       version: 'v',
       help: 'h',
       visualizeOnly: 'visualize-only',
+      visualizeV8Profile: 'visualize-v8-profile',
       collectOnly: 'collect-only',
       kernelTracing: 'kernel-tracing',
       kernelTracingDebug: 'kernel-tracing-debug',
@@ -89,6 +90,10 @@ async function cmd (argv, banner = defaultBanner) {
     status(`Creating flamegraph from ${args.visualizeOnly}`)
   }
 
+  if (args.visualizeV8Profile) {
+    status(`Creating flamegraph from v8 profile ${args.visualizeV8Profile}`)
+  }
+
   const assetPath = await zeroEks(args)
 
   if (args.collectOnly) {

index.js

@@ -2,7 +2,7 @@
 
 const { sun, linux, windows, v8 } = require('./platform')
 const debug = require('debug')('0x')
-const { join, isAbsolute, relative } = require('path')
+const { join, isAbsolute, relative, dirname } = require('path')
 const fs = require('fs')
 const validate = require('./lib/validate')(require('./schema.json'))
 const traceStacksToTicks = require('./lib/trace-stacks-to-ticks')
@@ -26,11 +26,18 @@ async function zeroEks (args) {
 
   validate(args)
   const { collectOnly, visualizeOnly, writeTicks, treeDebug, mapFrames } = args
-  if (collectOnly && visualizeOnly) {
-    throw Error('"collect only" and "visualize only" cannot be used together')
+
+  let incompatibleOptions = 0
+  if (collectOnly) incompatibleOptions += 1
+  if (visualizeOnly) incompatibleOptions += 1
+  if (visualizeV8Profile) incompatibleOptions += 1
+
+  if (incompatibleOptions > 1) {
+    throw Error('Only one of "collect only", "visualize only", "visualize v8 profile" can be used')
   }
 
   if (visualizeOnly) return visualize(args)
+  if (visualizeV8Profile) return visualizeV8Profile(args)
 
   args.title = args.title || `node ${args.argv.join(' ')}`
   var { ticks, pid, folder, inlined } = await startProcessAndCollectTraceData(args)
@@ -97,11 +104,21 @@ async function generateFlamegraph (opts) {
   return file
 }
 
+function getFolder (file, workingDir) {
+  return isAbsolute(file)
+    ? relative(workingDir, file)
+    : file
+}
+
+async function visualizeV8Profile (opts) {
+  const folder = dirname(opts.visualizeV8Profile)
+  const file = await render({ ...opts, folder })
+  return file
+}
+
 async function visualize ({ visualizeOnly, treeDebug, workingDir, title, mapFrames, open, name, pathToNodeBinary }) {
   try {
-    const folder = isAbsolute(visualizeOnly)
-      ? relative(workingDir, visualizeOnly)
-      : visualizeOnly
+    const folder = getFolder(visualizeOnly, workingDir)
     const ls = fs.readdirSync(folder)
     const traceFile = /^stacks\.(.*)\.out$/
     const isolateLog = /^isolate-((0x)?[0-9A-Fa-f]{2,16})-(.*)-v8\.(log|json)$/

lib/convert-v8-profile-to-tree.js

@@ -0,0 +1,28 @@
+function convert (profile) {
+  const converted = {
+    children: new Array(profile.children.length),
+    name: `${profile.functionName} ${profile.url}:${profile.lineNumber}`,
+    top: profile.hitCount,
+    value: profile.hitCount,
+    S: 0,
+  }
+
+  for (let i = 0; i < profile.children.length; i++) {
+    converted.children[i] = convert(profile.children[i]);
+    converted.value += converted.children[i].value;
+  }
+
+  return converted;
+}
+
+function convertV8Profile (profile) {
+  const converted = convert(profile)
+  return {
+    merged: converted,
+    unmerged: converted,
+  }
+}
+
+module.exports = {
+  convertV8Profile,
+}

lib/render.js

@@ -7,16 +7,25 @@ const pump = require('pump')
 const debug = require('debug')('0x:render')
 const ticksToTree = require('./ticks-to-tree')
 const html = require('../visualizer/html')
+const { convertV8Profile } = require('./convert-v8-profile-to-tree')
 
 module.exports = render
 
 async function render (opts) {
   const {
     name, title, kernelTracing, outputHtml, pid,
-    workingDir, mapFrames, ticks, inlined, folder, pathToNodeBinary
+    workingDir, mapFrames, ticks, inlined, folder, pathToNodeBinary,
+    visualizeV8Profile
   } = opts
   debug('converted stacks to intermediate format')
-  const trees = ticksToTree(ticks, { mapFrames, inlined, pathToNodeBinary })
+
+  let trees
+  if (visualizeV8Profile) {
+    const v8Profile = require(path.resolve(workingDir, visualizeV8Profile))
+    trees = convertV8Profile(v8Profile.head)
+  } else {
+    trees = ticksToTree(ticks, { mapFrames, inlined, pathToNodeBinary })
+  }
 
   const script = `
     ${await createBundle()}

schema.json

@@ -80,6 +80,12 @@
     "visualizeOnly": {
       "type": "string"
     },
+    "visualize-v8-profile": {
+      "type": "string"
+    },
+    "visualizeV8Profile": {
+      "type": "string"
+    },
     "collect-only": {
       "type": "boolean"
     },
@@ -94,7 +100,7 @@
     },
     "P": {
       "type": "string"
-    },    
+    },
      "kernelTracing": {
       "type": "boolean"
     },