1.2.0

This adds support for importing heap profiles from Chrome: https://developers.google.com/web/tools/chrome-devtools/memory-problems/#allocation-profile

CHANGELOG.md

@@ -1,16 +1,36 @@
 ## Unreleased
 
+## [1.2.0] - 2018-10-08
+
+### Added
+
+* Add import of v8 heap allocation profile [#170] (by @vmarchaud)
+
+## [1.1.0] - 2018-09-26
+
+### Added
+
+* Add go tool pprof import support [#165]
+
+## [1.0.4] - 2018-09-12
+
+### Fixed
+
+* Fix import from Chrome < 69 when there are multiple profiles [#161]
+
 ## [1.0.3] - 2018-09-10
 
 ### Fixed
 
+* Fix import for Chrome 69, support leading idle time before first call [#160]
+
 ## [1.0.2] - 2018-09-04
 
 ### Fixed
 
 * Allow optional CR before LF when probing collapsed stacks files [#154]
 * Fix import for Firefox 63 [#156]
-* Change time formatting for minutes from 1.50min to 1:30 [#153]
+* Change time formatting for minutes from 1.50min to 1:30 [#153] (by @Alex-Diez)
 
 ## [1.0.1] - 2018-08-23
 

README.md

@@ -40,6 +40,8 @@ speedscope is designed to ingest profiles from a variety of different profilers
 - Ruby
   - [Importing from stackprof](https://github.com/jlfwong/speedscope/wiki/Importing-from-stackprof-(ruby))
   - [Importing from rbspy](https://github.com/jlfwong/speedscope/wiki/Importing-from-rbspy-(ruby))
+- Go
+  - [Importing from pprof](https://github.com/jlfwong/speedscope/wiki/Importing-from-pprof-(go))  
 - Native code
   - [Importing from Instruments.app](https://github.com/jlfwong/speedscope/wiki/Importing-from-Instruments.app) (macOS)
   - [Importing from `perf`](https://github.com/jlfwong/speedscope/wiki/Importing-from-perf-(linux)) (linux)

package.json

@@ -1,6 +1,6 @@
 {
   "name": "speedscope",
-  "version": "1.0.3",
+  "version": "1.2.0",
   "description": "",
   "repository": "jlfwong/speedscope",
   "main": "index.js",
@@ -38,6 +38,7 @@
     "preact": "8.2.7",
     "preact-redux": "jlfwong/preact-redux#a56dcc4",
     "prettier": "1.12.0",
+    "protobufjs": "6.8.8",
     "quicktype": "15.0.45",
     "redux": "^4.0.0",
     "ts-jest": "22.4.6",

sample/programs/go/.gitignore

@@ -0,0 +1,2 @@
+simple
+server

sample/programs/go/Makefile

@@ -0,0 +1,15 @@
+.PHONY: all clean linux-perf
+
+all: simple server
+
+clean:
+	rm -f simple server
+
+simple: simple.go
+	go build $<
+
+server: server.go
+	go build $<
+
+simple.prof: simple
+	./$< -cpuprofile=$@

sample/programs/go/server.go

@@ -0,0 +1,71 @@
+package main
+
+import (
+	"log"
+	"fmt"
+	"sync"
+	"time"
+	"net/http"
+)
+
+import _ "net/http/pprof"
+
+// See https://golang.org/pkg/net/http/pprof/ for details
+
+func alpha() {
+	z := 3
+	for i := 0; i < 100000; i++ {
+		z *= 3
+	}
+}
+
+func beta() {
+	z := 3
+	for i := 0; i < 100000; i++ {
+		z *= 3
+	}
+}
+
+func delta() {
+	z := 3
+	for i := 0; i < 100000; i++ {
+		z *= 3
+	}
+	alpha()
+	beta()
+}
+
+func gamma() {
+	z := 3
+	for i := 0; i < 100000; i++ {
+		z *= 3
+	}
+}
+
+
+func main() {
+    // we need a webserver to get the pprof webserver
+    go func() {
+        log.Println(http.ListenAndServe("localhost:6060", nil))
+    }()
+    fmt.Println("hello world")
+    var wg sync.WaitGroup
+    wg.Add(1)
+    go leakyFunction(wg)
+    wg.Wait()
+}
+
+func leakyFunction(wg sync.WaitGroup) {
+    defer wg.Done()
+    s := make([]string, 3)
+    for i:= 0; i < 10000000; i++{
+        alpha()
+        beta()
+        delta()
+        gamma()
+        s = append(s, "magical pandas")
+        if (i % 100000) == 0 {
+            time.Sleep(50 * time.Millisecond)
+        }
+    }
+}

sample/programs/go/simple.go

@@ -0,0 +1,53 @@
+package main
+
+import "flag"
+import "runtime/pprof"
+import "os"
+
+var cpuprofile = flag.String("cpuprofile", "", "write cpu profile to file")
+
+func alpha() {
+	z := 3
+	for i := 0; i < 100000; i++ {
+		z *= 3
+	}
+}
+
+func beta() {
+	z := 3
+	for i := 0; i < 100000; i++ {
+		z *= 3
+	}
+}
+
+func delta() {
+	z := 3
+	for i := 0; i < 100000; i++ {
+		z *= 3
+	}
+	alpha()
+	beta()
+}
+
+func gamma() {
+	z := 3
+	for i := 0; i < 100000; i++ {
+		z *= 3
+	}
+}
+
+func main() {
+	flag.Parse()
+	if *cpuprofile != "" {
+		f, _ := os.Create(*cpuprofile)
+		pprof.StartCPUProfile(f)
+		defer pprof.StopCPUProfile()
+	}
+
+	for i := 0; i < 10000; i++ {
+		alpha()
+		beta()
+		delta()
+		gamma()
+	}
+}

src/import/__snapshots__/pprof.test.ts.snap

@@ -0,0 +1,249 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`importAsPprofProfile 1`] = `
+Object {
+  "frames": Array [
+    Frame {
+      "col": undefined,
+      "file": "/usr/local/Cellar/go/1.10.1/libexec/src/runtime/proc.go",
+      "key": "runtime.main:/usr/local/Cellar/go/1.10.1/libexec/src/runtime/proc.go:0",
+      "line": 0,
+      "name": "runtime.main",
+      "selfWeight": 0,
+      "totalWeight": 136,
+    },
+    Frame {
+      "col": undefined,
+      "file": "/Users/jlfwong/code/speedscope/sample/programs/go/simple.go",
+      "key": "main.main:/Users/jlfwong/code/speedscope/sample/programs/go/simple.go:0",
+      "line": 0,
+      "name": "main.main",
+      "selfWeight": 0,
+      "totalWeight": 136,
+    },
+    Frame {
+      "col": undefined,
+      "file": "/Users/jlfwong/code/speedscope/sample/programs/go/simple.go",
+      "key": "main.delta:/Users/jlfwong/code/speedscope/sample/programs/go/simple.go:0",
+      "line": 0,
+      "name": "main.delta",
+      "selfWeight": 22,
+      "totalWeight": 58,
+    },
+    Frame {
+      "col": undefined,
+      "file": "/Users/jlfwong/code/speedscope/sample/programs/go/simple.go",
+      "key": "main.beta:/Users/jlfwong/code/speedscope/sample/programs/go/simple.go:0",
+      "line": 0,
+      "name": "main.beta",
+      "selfWeight": 39,
+      "totalWeight": 39,
+    },
+    Frame {
+      "col": undefined,
+      "file": "/Users/jlfwong/code/speedscope/sample/programs/go/simple.go",
+      "key": "main.alpha:/Users/jlfwong/code/speedscope/sample/programs/go/simple.go:0",
+      "line": 0,
+      "name": "main.alpha",
+      "selfWeight": 48,
+      "totalWeight": 48,
+    },
+    Frame {
+      "col": undefined,
+      "file": "/Users/jlfwong/code/speedscope/sample/programs/go/simple.go",
+      "key": "main.gamma:/Users/jlfwong/code/speedscope/sample/programs/go/simple.go:0",
+      "line": 0,
+      "name": "main.gamma",
+      "selfWeight": 27,
+      "totalWeight": 27,
+    },
+    Frame {
+      "col": undefined,
+      "file": "/usr/local/Cellar/go/1.10.1/libexec/src/runtime/asm_amd64.s",
+      "key": "runtime.morestack:/usr/local/Cellar/go/1.10.1/libexec/src/runtime/asm_amd64.s:0",
+      "line": 0,
+      "name": "runtime.morestack",
+      "selfWeight": 0,
+      "totalWeight": 11,
+    },
+    Frame {
+      "col": undefined,
+      "file": "/usr/local/Cellar/go/1.10.1/libexec/src/runtime/stack.go",
+      "key": "runtime.newstack:/usr/local/Cellar/go/1.10.1/libexec/src/runtime/stack.go:0",
+      "line": 0,
+      "name": "runtime.newstack",
+      "selfWeight": 0,
+      "totalWeight": 11,
+    },
+    Frame {
+      "col": undefined,
+      "file": "/usr/local/Cellar/go/1.10.1/libexec/src/runtime/duff_amd64.s",
+      "key": "runtime.duffcopy:/usr/local/Cellar/go/1.10.1/libexec/src/runtime/duff_amd64.s:0",
+      "line": 0,
+      "name": "runtime.duffcopy",
+      "selfWeight": 11,
+      "totalWeight": 11,
+    },
+    Frame {
+      "col": undefined,
+      "file": "/usr/local/Cellar/go/1.10.1/libexec/src/runtime/time.go",
+      "key": "runtime.timerproc:/usr/local/Cellar/go/1.10.1/libexec/src/runtime/time.go:0",
+      "line": 0,
+      "name": "runtime.timerproc",
+      "selfWeight": 0,
+      "totalWeight": 1,
+    },
+    Frame {
+      "col": undefined,
+      "file": "/usr/local/Cellar/go/1.10.1/libexec/src/runtime/time.go",
+      "key": "runtime.goroutineReady:/usr/local/Cellar/go/1.10.1/libexec/src/runtime/time.go:0",
+      "line": 0,
+      "name": "runtime.goroutineReady",
+      "selfWeight": 0,
+      "totalWeight": 1,
+    },
+    Frame {
+      "col": undefined,
+      "file": "/usr/local/Cellar/go/1.10.1/libexec/src/runtime/proc.go",
+      "key": "runtime.goready:/usr/local/Cellar/go/1.10.1/libexec/src/runtime/proc.go:0",
+      "line": 0,
+      "name": "runtime.goready",
+      "selfWeight": 0,
+      "totalWeight": 1,
+    },
+    Frame {
+      "col": undefined,
+      "file": "/usr/local/Cellar/go/1.10.1/libexec/src/runtime/asm_amd64.s",
+      "key": "runtime.systemstack:/usr/local/Cellar/go/1.10.1/libexec/src/runtime/asm_amd64.s:0",
+      "line": 0,
+      "name": "runtime.systemstack",
+      "selfWeight": 0,
+      "totalWeight": 1,
+    },
+    Frame {
+      "col": undefined,
+      "file": "/usr/local/Cellar/go/1.10.1/libexec/src/runtime/proc.go",
+      "key": "runtime.goready.func1:/usr/local/Cellar/go/1.10.1/libexec/src/runtime/proc.go:0",
+      "line": 0,
+      "name": "runtime.goready.func1",
+      "selfWeight": 0,
+      "totalWeight": 1,
+    },
+    Frame {
+      "col": undefined,
+      "file": "/usr/local/Cellar/go/1.10.1/libexec/src/runtime/proc.go",
+      "key": "runtime.ready:/usr/local/Cellar/go/1.10.1/libexec/src/runtime/proc.go:0",
+      "line": 0,
+      "name": "runtime.ready",
+      "selfWeight": 0,
+      "totalWeight": 1,
+    },
+    Frame {
+      "col": undefined,
+      "file": "/usr/local/Cellar/go/1.10.1/libexec/src/runtime/proc.go",
+      "key": "runtime.wakep:/usr/local/Cellar/go/1.10.1/libexec/src/runtime/proc.go:0",
+      "line": 0,
+      "name": "runtime.wakep",
+      "selfWeight": 0,
+      "totalWeight": 1,
+    },
+    Frame {
+      "col": undefined,
+      "file": "/usr/local/Cellar/go/1.10.1/libexec/src/runtime/proc.go",
+      "key": "runtime.startm:/usr/local/Cellar/go/1.10.1/libexec/src/runtime/proc.go:0",
+      "line": 0,
+      "name": "runtime.startm",
+      "selfWeight": 0,
+      "totalWeight": 1,
+    },
+    Frame {
+      "col": undefined,
+      "file": "/usr/local/Cellar/go/1.10.1/libexec/src/runtime/lock_sema.go",
+      "key": "runtime.notewakeup:/usr/local/Cellar/go/1.10.1/libexec/src/runtime/lock_sema.go:0",
+      "line": 0,
+      "name": "runtime.notewakeup",
+      "selfWeight": 0,
+      "totalWeight": 1,
+    },
+    Frame {
+      "col": undefined,
+      "file": "/usr/local/Cellar/go/1.10.1/libexec/src/runtime/os_darwin.go",
+      "key": "runtime.semawakeup:/usr/local/Cellar/go/1.10.1/libexec/src/runtime/os_darwin.go:0",
+      "line": 0,
+      "name": "runtime.semawakeup",
+      "selfWeight": 0,
+      "totalWeight": 1,
+    },
+    Frame {
+      "col": undefined,
+      "file": "/usr/local/Cellar/go/1.10.1/libexec/src/runtime/os_darwin.go",
+      "key": "runtime.mach_semrelease:/usr/local/Cellar/go/1.10.1/libexec/src/runtime/os_darwin.go:0",
+      "line": 0,
+      "name": "runtime.mach_semrelease",
+      "selfWeight": 0,
+      "totalWeight": 1,
+    },
+    Frame {
+      "col": undefined,
+      "file": "/usr/local/Cellar/go/1.10.1/libexec/src/runtime/sys_darwin_amd64.s",
+      "key": "runtime.mach_semaphore_signal:/usr/local/Cellar/go/1.10.1/libexec/src/runtime/sys_darwin_amd64.s:0",
+      "line": 0,
+      "name": "runtime.mach_semaphore_signal",
+      "selfWeight": 1,
+      "totalWeight": 1,
+    },
+    Frame {
+      "col": undefined,
+      "file": "/usr/local/Cellar/go/1.10.1/libexec/src/runtime/proc.go",
+      "key": "runtime.mstart:/usr/local/Cellar/go/1.10.1/libexec/src/runtime/proc.go:0",
+      "line": 0,
+      "name": "runtime.mstart",
+      "selfWeight": 0,
+      "totalWeight": 2,
+    },
+    Frame {
+      "col": undefined,
+      "file": "/usr/local/Cellar/go/1.10.1/libexec/src/runtime/proc.go",
+      "key": "runtime.mstart1:/usr/local/Cellar/go/1.10.1/libexec/src/runtime/proc.go:0",
+      "line": 0,
+      "name": "runtime.mstart1",
+      "selfWeight": 0,
+      "totalWeight": 2,
+    },
+    Frame {
+      "col": undefined,
+      "file": "/usr/local/Cellar/go/1.10.1/libexec/src/runtime/proc.go",
+      "key": "runtime.sysmon:/usr/local/Cellar/go/1.10.1/libexec/src/runtime/proc.go:0",
+      "line": 0,
+      "name": "runtime.sysmon",
+      "selfWeight": 0,
+      "totalWeight": 2,
+    },
+    Frame {
+      "col": undefined,
+      "file": "/usr/local/Cellar/go/1.10.1/libexec/src/runtime/sys_darwin_amd64.s",
+      "key": "runtime.usleep:/usr/local/Cellar/go/1.10.1/libexec/src/runtime/sys_darwin_amd64.s:0",
+      "line": 0,
+      "name": "runtime.usleep",
+      "selfWeight": 2,
+      "totalWeight": 2,
+    },
+  ],
+  "name": "simple.prof",
+  "stacks": Array [
+    "runtime.main;main.main;main.delta;main.beta 14",
+    "runtime.main;main.main;main.alpha 26",
+    "runtime.main;main.main;main.gamma 27",
+    "runtime.morestack;runtime.newstack;runtime.duffcopy 11",
+    "runtime.main;main.main;main.beta 25",
+    "runtime.main;main.main;main.delta 22",
+    "runtime.main;main.main;main.delta;main.alpha 22",
+    "runtime.timerproc;runtime.goroutineReady;runtime.goready;runtime.systemstack;runtime.goready.func1;runtime.ready;runtime.wakep;runtime.startm;runtime.notewakeup;runtime.semawakeup;runtime.mach_semrelease;runtime.mach_semaphore_signal 1",
+    "runtime.mstart;runtime.mstart1;runtime.sysmon;runtime.usleep 2",
+  ],
+}
+`;
+
+exports[`importAsPprofProfile: indexToView 1`] = `0`;
+
+exports[`importAsPprofProfile: profileGroup.name 1`] = `"simple.prof"`;

src/import/chrome.ts

@@ -74,7 +74,6 @@ export function importFromChromeTimeline(events: TimelineEvent[]): Profile {
   for (let event of events) {
     if (event.name == 'CpuProfile') {
       cpuProfile = event.args.data.cpuProfile as CPUProfile
-      break
     }
 
     if (event.name == 'Profile') {

src/import/index.test.ts

@@ -1,8 +1,8 @@
-import {importProfileGroup} from '.'
+import {importProfileGroupFromText} from '.'
 
 test('importProfileGroup', async () => {
   // Importing garbage should return null
-  expect(await importProfileGroup('unknown', '')).toBe(null)
-  expect(await importProfileGroup('unknown', 'Hello world')).toBe(null)
-  expect(await importProfileGroup('unknown', 'Hello\n\nWorld')).toBe(null)
+  expect(await importProfileGroupFromText('unknown', '')).toBe(null)
+  expect(await importProfileGroupFromText('unknown', 'Hello world')).toBe(null)
+  expect(await importProfileGroupFromText('unknown', 'Hello\n\nWorld')).toBe(null)
 })

src/import/index.ts

@@ -9,12 +9,42 @@ import {importFromFirefox} from './firefox'
 import {importSpeedscopeProfiles} from '../lib/file-format'
 import {importFromV8ProfLog} from './v8proflog'
 import {importFromLinuxPerf} from './linux-tools-perf'
+import {ProfileDataSource, TextProfileDataSource, MaybeCompressedDataReader} from './utils'
+import {importAsPprofProfile} from './pprof'
+import {decodeBase64} from '../lib/utils'
+import {importFromChromeHeapProfile} from './v8heapalloc'
 
-export async function importProfileGroup(
+export async function importProfileGroupFromText(
   fileName: string,
   contents: string,
 ): Promise<ProfileGroup | null> {
-  const profileGroup = await _importProfileGroup(fileName, contents)
+  return await importProfileGroup(new TextProfileDataSource(fileName, contents))
+}
+
+export async function importProfileGroupFromBase64(
+  fileName: string,
+  b64contents: string,
+): Promise<ProfileGroup | null> {
+  return await importProfileGroup(
+    MaybeCompressedDataReader.fromArrayBuffer(fileName, decodeBase64(b64contents).buffer),
+  )
+}
+
+export async function importProfilesFromFile(file: File): Promise<ProfileGroup | null> {
+  return importProfileGroup(MaybeCompressedDataReader.fromFile(file))
+}
+
+export async function importProfilesFromArrayBuffer(
+  fileName: string,
+  buffer: ArrayBuffer,
+): Promise<ProfileGroup | null> {
+  return importProfileGroup(MaybeCompressedDataReader.fromArrayBuffer(fileName, buffer))
+}
+
+async function importProfileGroup(dataSource: ProfileDataSource): Promise<ProfileGroup | null> {
+  const fileName = await dataSource.name()
+
+  const profileGroup = await _importProfileGroup(dataSource)
   if (profileGroup) {
     if (!profileGroup.name) {
       profileGroup.name = fileName
@@ -34,10 +64,21 @@ function toGroup(profile: Profile | null): ProfileGroup | null {
   return {name: profile.getName(), indexToView: 0, profiles: [profile]}
 }
 
-async function _importProfileGroup(
-  fileName: string,
-  contents: string,
-): Promise<ProfileGroup | null> {
+async function _importProfileGroup(dataSource: ProfileDataSource): Promise<ProfileGroup | null> {
+  const fileName = await dataSource.name()
+
+  const buffer = await dataSource.readAsArrayBuffer()
+
+  {
+    const profile = importAsPprofProfile(buffer)
+    if (profile) {
+      console.log('Importing as protobuf encoded pprof file')
+      return toGroup(profile)
+    }
+  }
+
+  const contents = await dataSource.readAsText()
+
   // First pass: Check known file format names to infer the file type
   if (fileName.endsWith('.speedscope.json')) {
     console.log('Importing as speedscope json file')
@@ -63,6 +104,9 @@ async function _importProfileGroup(
   } else if (fileName.endsWith('.v8log.json')) {
     console.log('Importing as --prof-process v8 log')
     return toGroup(importFromV8ProfLog(JSON.parse(contents)))
+  } else if (fileName.endsWith('.heapprofile')) {
+    console.log('Importing as Chrome Heap Profile')
+    return toGroup(importFromChromeHeapProfile(JSON.parse(contents)))
   }
 
   // Second pass: Try to guess what file format it is based on structure
@@ -89,6 +133,9 @@ async function _importProfileGroup(
     } else if ('code' in parsed && 'functions' in parsed && 'ticks' in parsed) {
       console.log('Importing as --prof-process v8 log')
       return toGroup(importFromV8ProfLog(parsed))
+    } else if ('head' in parsed && 'selfSize' in parsed['head']) {
+      console.log('Importing as Chrome Heap Profile')
+      return toGroup(importFromChromeHeapProfile(JSON.parse(contents)))
     }
   } else {
     // Format is not JSON

src/import/instruments.ts

@@ -9,9 +9,9 @@ import {
   ProfileGroup,
 } from '../lib/profile'
 import {sortBy, getOrThrow, getOrInsert, lastOf, getOrElse, zeroPad} from '../lib/utils'
-import * as pako from 'pako'
 import {ByteFormatter, TimeFormatter} from '../lib/value-formatters'
 import {FileSystemDirectoryEntry, FileSystemEntry, FileSystemFileEntry} from './file-system-entry'
+import {MaybeCompressedDataReader} from './utils'
 
 function parseTSV<T>(contents: string): T[] {
   const lines = contents.split('\n').map(l => l.split('\t'))
@@ -183,56 +183,12 @@ async function extractDirectoryTree(entry: FileSystemDirectoryEntry): Promise<Tr
   return node
 }
 
-class MaybeCompressedFileReader {
-  private fileData: Promise<ArrayBuffer>
-
-  constructor(file: File) {
-    this.fileData = new Promise(resolve => {
-      const reader = new FileReader()
-      reader.addEventListener('loadend', () => {
-        if (!(reader.result instanceof ArrayBuffer)) {
-          throw new Error('Expected reader.result to be an instance of ArrayBuffer')
-        }
-        resolve(reader.result)
-      })
-      reader.readAsArrayBuffer(file)
-    })
-  }
-
-  private async getUncompressed(): Promise<ArrayBuffer> {
-    const fileData = await this.fileData
-    try {
-      const result = pako.inflate(new Uint8Array(fileData)).buffer
-      return result
-    } catch (e) {
-      return fileData
-    }
-  }
-
-  async readAsArrayBuffer(): Promise<ArrayBuffer> {
-    return await this.getUncompressed()
-  }
-
-  async readAsText(): Promise<string> {
-    const buffer = await this.getUncompressed()
-    let ret: string = ''
-
-    // JavaScript strings are UTF-16 encoded, but this data is coming
-    // from a UTF-8 encoded file.
-    const array = new Uint8Array(buffer)
-    for (let i = 0; i < array.length; i++) {
-      ret += String.fromCharCode(array[i])
-    }
-    return ret
-  }
-}
-
 function readAsArrayBuffer(file: File): Promise<ArrayBuffer> {
-  return new MaybeCompressedFileReader(file).readAsArrayBuffer()
+  return MaybeCompressedDataReader.fromFile(file).readAsArrayBuffer()
 }
 
 function readAsText(file: File): Promise<string> {
-  return new MaybeCompressedFileReader(file).readAsText()
+  return MaybeCompressedDataReader.fromFile(file).readAsText()
 }
 
 function getCoreDirForRun(tree: TraceDirectoryTree, selectedRun: number): TraceDirectoryTree {

src/import/pprof.test.ts

@@ -0,0 +1,5 @@
+import {checkProfileSnapshot} from '../lib/test-utils'
+
+test('importAsPprofProfile', async () => {
+  await checkProfileSnapshot('./sample/profiles/pprof/simple.prof')
+})

src/import/pprof.ts

@@ -0,0 +1,134 @@
+import {perftools} from './profile.proto.js'
+import {FrameInfo, StackListProfileBuilder, Profile} from '../lib/profile'
+import {lastOf} from '../lib/utils'
+import {TimeFormatter, ByteFormatter} from '../lib/value-formatters'
+
+interface SampleType {
+  type: string
+  unit: string
+}
+
+export function importAsPprofProfile(rawProfile: ArrayBuffer): Profile | null {
+  if (rawProfile.byteLength === 0) return null
+
+  let protoProfile: perftools.profiles.Profile
+  try {
+    protoProfile = perftools.profiles.Profile.decode(new Uint8Array(rawProfile))
+  } catch (e) {
+    return null
+  }
+
+  function i32(n: number | Long): number {
+    return typeof n === 'number' ? n : (n as Long).low
+  }
+
+  function stringVal(key: number | Long): string | null {
+    return protoProfile.stringTable[i32(key)] || null
+  }
+
+  const frameInfoByFunctionID = new Map<number, FrameInfo>()
+
+  function frameInfoForFunction(f: perftools.profiles.IFunction): FrameInfo | null {
+    const {name, filename, startLine} = f
+
+    const nameString = (name != null && stringVal(name)) || '(unknown)'
+    const fileNameString = filename != null ? stringVal(filename) : null
+    const line = startLine != null ? +startLine : null
+
+    const key = `${nameString}:${fileNameString}:${line}`
+
+    const frameInfo: FrameInfo = {
+      key,
+      name: nameString,
+    }
+
+    if (fileNameString != null) {
+      frameInfo.file = fileNameString
+    }
+
+    if (line != null) {
+      frameInfo.line = line
+    }
+
+    return frameInfo
+  }
+
+  for (let f of protoProfile.function) {
+    if (f.id) {
+      const frameInfo = frameInfoForFunction(f)
+      if (frameInfo != null) {
+        frameInfoByFunctionID.set(i32(f.id), frameInfo)
+      }
+    }
+  }
+
+  function frameInfoForLocation(location: perftools.profiles.ILocation): FrameInfo | null {
+    const {line} = location
+    if (line == null) return null
+
+    // From a comment on profile.proto:
+    //
+    //   Multiple line indicates this location has inlined functions,
+    //   where the last entry represents the caller into which the
+    //   preceding entries were inlined.
+    //
+    //   E.g., if memcpy() is inlined into printf:
+    //      line[0].function_name == "memcpy"
+    //      line[1].function_name == "printf"
+    //
+    // Let's just take the last line then
+    const lastLine = lastOf(line)
+    if (lastLine == null) return null
+
+    if (lastLine.functionId) {
+      return frameInfoByFunctionID.get(i32(lastLine.functionId)) || null
+    } else {
+      return null
+    }
+  }
+
+  const frameByLocationID = new Map<number, FrameInfo>()
+
+  for (let l of protoProfile.location) {
+    if (l.id != null) {
+      const frameInfo = frameInfoForLocation(l)
+      if (frameInfo) {
+        frameByLocationID.set(i32(l.id), frameInfo)
+      }
+    }
+  }
+
+  const sampleTypes: SampleType[] = protoProfile.sampleType.map(type => ({
+    type: (type.type && stringVal(type.type)) || 'samples',
+    unit: (type.unit && stringVal(type.unit)) || 'count',
+  }))
+
+  const sampleTypeIndex = protoProfile.defaultSampleType
+    ? +protoProfile.defaultSampleType
+    : sampleTypes.length - 1
+  const sampleType = sampleTypes[sampleTypeIndex]
+
+  const profileBuilder = new StackListProfileBuilder()
+
+  switch (sampleType.unit) {
+    case 'nanoseconds':
+    case 'microseconds':
+    case 'milliseconds':
+    case 'seconds':
+      profileBuilder.setValueFormatter(new TimeFormatter(sampleType.unit))
+      break
+
+    case 'bytes':
+      profileBuilder.setValueFormatter(new ByteFormatter())
+      break
+  }
+
+  for (let s of protoProfile.sample) {
+    const stack = s.locationId ? s.locationId.map(l => frameByLocationID.get(i32(l))) : []
+    stack.reverse()
+    const value = s.value![sampleTypeIndex]
+    profileBuilder.appendSampleWithWeight(stack.filter(f => f != null) as FrameInfo[], +value)
+  }
+
+  return profileBuilder.build()
+}

src/import/profile.proto

@@ -0,0 +1,206 @@
+// THIS FILE WAS IMPORTED FROM AN EXTERNAL SOURCE. DO NOT MODIFY THIS FILE
+// MANUALLY.
+//
+// Original from: https://github.com/google/pprof/blob/e027b50/proto/profile.proto
+//
+// This file is licensed under the Apache License 2.0
+// (https://github.com/google/pprof/blob/e027b5/LICENSE)
+
+// Profile is a common stacktrace profile format.
+//
+// Measurements represented with this format should follow the
+// following conventions:
+//
+// - Consumers should treat unset optional fields as if they had been
+//   set with their default value.
+//
+// - When possible, measurements should be stored in "unsampled" form
+//   that is most useful to humans.  There should be enough
+//   information present to determine the original sampled values.
+//
+// - On-disk, the serialized proto must be gzip-compressed.
+//
+// - The profile is represented as a set of samples, where each sample
+//   references a sequence of locations, and where each location belongs
+//   to a mapping.
+// - There is a N->1 relationship from sample.location_id entries to
+//   locations. For every sample.location_id entry there must be a
+//   unique Location with that id.
+// - There is an optional N->1 relationship from locations to
+//   mappings. For every nonzero Location.mapping_id there must be a
+//   unique Mapping with that id.
+
+syntax = "proto3";
+
+package perftools.profiles;
+
+option java_package = "com.google.perftools.profiles";
+option java_outer_classname = "ProfileProto";
+
+message Profile {
+  // A description of the samples associated with each Sample.value.
+  // For a cpu profile this might be:
+  //   [["cpu","nanoseconds"]] or [["wall","seconds"]] or [["syscall","count"]]
+  // For a heap profile, this might be:
+  //   [["allocations","count"], ["space","bytes"]],
+  // If one of the values represents the number of events represented
+  // by the sample, by convention it should be at index 0 and use
+  // sample_type.unit == "count".
+  repeated ValueType sample_type = 1;
+  // The set of samples recorded in this profile.
+  repeated Sample sample = 2;
+  // Mapping from address ranges to the image/binary/library mapped
+  // into that address range.  mapping[0] will be the main binary.
+  repeated Mapping mapping = 3;
+  // Useful program location
+  repeated Location location = 4;
+  // Functions referenced by locations
+  repeated Function function = 5;
+  // A common table for strings referenced by various messages.
+  // string_table[0] must always be "".
+  repeated string string_table = 6;
+  // frames with Function.function_name fully matching the following
+  // regexp will be dropped from the samples, along with their successors.
+  int64 drop_frames = 7; // Index into string table.
+  // frames with Function.function_name fully matching the following
+  // regexp will be kept, even if it matches drop_functions.
+  int64 keep_frames = 8; // Index into string table.
+
+  // The following fields are informational, do not affect
+  // interpretation of results.
+
+  // Time of collection (UTC) represented as nanoseconds past the epoch.
+  int64 time_nanos = 9;
+  // Duration of the profile, if a duration makes sense.
+  int64 duration_nanos = 10;
+  // The kind of events between sampled ocurrences.
+  // e.g [ "cpu","cycles" ] or [ "heap","bytes" ]
+  ValueType period_type = 11;
+  // The number of events between sampled occurrences.
+  int64 period = 12;
+  // Freeform text associated to the profile.
+  repeated int64 comment = 13; // Indices into string table.
+  // Index into the string table of the type of the preferred sample
+  // value. If unset, clients should default to the last sample value.
+  int64 default_sample_type = 14;
+}
+
+// ValueType describes the semantics and measurement units of a value.
+message ValueType {
+  int64 type = 1; // Index into string table.
+  int64 unit = 2; // Index into string table.
+}
+
+// Each Sample records values encountered in some program
+// context. The program context is typically a stack trace, perhaps
+// augmented with auxiliary information like the thread-id, some
+// indicator of a higher level request being handled etc.
+message Sample {
+  // The ids recorded here correspond to a Profile.location.id.
+  // The leaf is at location_id[0].
+  repeated uint64 location_id = 1;
+  // The type and unit of each value is defined by the corresponding
+  // entry in Profile.sample_type. All samples must have the same
+  // number of values, the same as the length of Profile.sample_type.
+  // When aggregating multiple samples into a single sample, the
+  // result has a list of values that is the elemntwise sum of the
+  // lists of the originals.
+  repeated int64 value = 2;
+  // label includes additional context for this sample. It can include
+  // things like a thread id, allocation size, etc
+  repeated Label label = 3;
+}
+
+message Label {
+  int64 key = 1; // Index into string table
+
+  // At most one of the following must be present
+  int64 str = 2; // Index into string table
+  int64 num = 3;
+
+  // Should only be present when num is present.
+  // Specifies the units of num.
+  // Use arbitrary string (for example, "requests") as a custom count unit.
+  // If no unit is specified, consumer may apply heuristic to deduce the unit.
+  // Consumers may also  interpret units like "bytes" and "kilobytes" as memory
+  // units and units like "seconds" and "nanoseconds" as time units,
+  // and apply appropriate unit conversions to these.
+  int64 num_unit = 4; // Index into string table
+}
+
+message Mapping {
+  // Unique nonzero id for the mapping.
+  uint64 id = 1;
+  // Address at which the binary (or DLL) is loaded into memory.
+  uint64 memory_start = 2;
+  // The limit of the address range occupied by this mapping.
+  uint64 memory_limit = 3;
+  // Offset in the binary that corresponds to the first mapped address.
+  uint64 file_offset = 4;
+  // The object this entry is loaded from.  This can be a filename on
+  // disk for the main binary and shared libraries, or virtual
+  // abstractions like "[vdso]".
+  int64 filename = 5; // Index into string table
+  // A string that uniquely identifies a particular program version
+  // with high probability. E.g., for binaries generated by GNU tools,
+  // it could be the contents of the .note.gnu.build-id field.
+  int64 build_id = 6; // Index into string table
+
+  // The following fields indicate the resolution of symbolic info.
+  bool has_functions = 7;
+  bool has_filenames = 8;
+  bool has_line_numbers = 9;
+  bool has_inline_frames = 10;
+}
+
+// Describes function and line table debug information.
+message Location {
+  // Unique nonzero id for the location.  A profile could use
+  // instruction addresses or any integer sequence as ids.
+  uint64 id = 1;
+  // The id of the corresponding profile.Mapping for this location.
+  // It can be unset if the mapping is unknown or not applicable for
+  // this profile type.
+  uint64 mapping_id = 2;
+  // The instruction address for this location, if available.  It
+  // should be within [Mapping.memory_start...Mapping.memory_limit]
+  // for the corresponding mapping. A non-leaf address may be in the
+  // middle of a call instruction. It is up to display tools to find
+  // the beginning of the instruction if necessary.
+  uint64 address = 3;
+  // Multiple line indicates this location has inlined functions,
+  // where the last entry represents the caller into which the
+  // preceding entries were inlined.
+  //
+  // E.g., if memcpy() is inlined into printf:
+  //    line[0].function_name == "memcpy"
+  //    line[1].function_name == "printf"
+  repeated Line line = 4;
+  // Provides an indication that multiple symbols map to this location's
+  // address, for example due to identical code folding by the linker. In that
+  // case the line information above represents one of the multiple
+  // symbols. This field must be recomputed when the symbolization state of the
+  // profile changes.
+  bool is_folded = 5;
+}
+
+message Line {
+  // The id of the corresponding profile.Function for this line.
+  uint64 function_id = 1;
+  // Line number in source code.
+  int64 line = 2;
+}
+
+message Function {
+  // Unique nonzero id for the function.
+  uint64 id = 1;
+  // Name of the function, in human-readable form if available.
+  int64 name = 2; // Index into string table
+  // Name of the function, as identified by the system.
+  // For instance, it can be a C++ mangled name.
+  int64 system_name = 3; // Index into string table
+  // Source file containing the function.
+  int64 filename = 4; // Index into string table
+  // Line number in source file.
+  int64 start_line = 5;
+}

src/import/utils.ts

@@ -0,0 +1,83 @@
+import * as pako from 'pako'
+
+export interface ProfileDataSource {
+  name(): Promise<string>
+  readAsArrayBuffer(): Promise<ArrayBuffer>
+  readAsText(): Promise<string>
+}
+
+export class TextProfileDataSource implements ProfileDataSource {
+  constructor(private fileName: string, private contents: string) {}
+  async name() {
+    return this.fileName
+  }
+  async readAsArrayBuffer() {
+    // JavaScript strings are UTF-16 encoded, but if this string is
+    // constructed based on
+
+    // TODO(jlfwong): Might want to make this construct an array
+    // buffer based on the text
+    return new ArrayBuffer(0)
+  }
+  async readAsText() {
+    return this.contents
+  }
+}
+
+export class MaybeCompressedDataReader implements ProfileDataSource {
+  private uncompressedData: Promise<ArrayBuffer>
+
+  constructor(
+    private namePromise: Promise<string>,
+    maybeCompressedDataPromise: Promise<ArrayBuffer>,
+  ) {
+    this.uncompressedData = maybeCompressedDataPromise.then(async (fileData: ArrayBuffer) => {
+      try {
+        const result = pako.inflate(new Uint8Array(fileData)).buffer
+        return result
+      } catch (e) {
+        return fileData
+      }
+    })
+  }
+
+  async name(): Promise<string> {
+    return await this.namePromise
+  }
+
+  async readAsArrayBuffer(): Promise<ArrayBuffer> {
+    return await this.uncompressedData
+  }
+
+  async readAsText(): Promise<string> {
+    const buffer = await this.readAsArrayBuffer()
+    let ret: string = ''
+
+    // JavaScript strings are UTF-16 encoded, but we're reading data
+    // from disk that we're going to asusme is UTF-8 encoded.
+    const array = new Uint8Array(buffer)
+    for (let i = 0; i < array.length; i++) {
+      ret += String.fromCharCode(array[i])
+    }
+    return ret
+  }
+
+  static fromFile(file: File): MaybeCompressedDataReader {
+    const maybeCompressedDataPromise: Promise<ArrayBuffer> = new Promise(resolve => {
+      const reader = new FileReader()
+      reader.addEventListener('loadend', () => {
+        if (!(reader.result instanceof ArrayBuffer)) {
+          throw new Error('Expected reader.result to be an instance of ArrayBuffer')
+        }
+        resolve(reader.result)
+      })
+      reader.readAsArrayBuffer(file)
+    })
+
+    return new MaybeCompressedDataReader(Promise.resolve(file.name), maybeCompressedDataPromise)
+  }
+
+  static fromArrayBuffer(name: string, buffer: ArrayBuffer): MaybeCompressedDataReader {
+    return new MaybeCompressedDataReader(Promise.resolve(name), Promise.resolve(buffer))
+  }
+}

src/import/v8heapalloc.test.ts

@@ -0,0 +1,9 @@
+import {checkProfileSnapshot} from '../lib/test-utils'
+
+test('importV8HeapAlloc from Chrome', async () => {
+  await checkProfileSnapshot('./sample/profiles/Chrome/69/Heap-20181005T144546.heapprofile')
+})
+
+test('importV8HeapAlloc from NodeJS', async () => {
+  await checkProfileSnapshot('./sample/profiles/node/10.11.0/Heap-20181003T105432.heapprofile')
+})

src/import/v8heapalloc.ts

@@ -0,0 +1,109 @@
+import {Profile, FrameInfo, StackListProfileBuilder} from '../lib/profile'
+import {getOrInsert} from '../lib/utils'
+import {ByteFormatter} from '../lib/value-formatters'
+
+/**
+ * The V8 Heap Allocation profile is a way to represent heap allocation for each
+ * javascript function. The format is a simple tree where the weight of each node
+ * represent the memory allocated by the function and all its callee.
+ * You can find more information on how to get a profile there :
+ * https://developers.google.com/web/tools/chrome-devtools/memory-problems/#allocation-profile
+ * You need to scroll down to "Investigate memory allocation by function"
+ *
+ * Note that Node.JS can retrieve this kind of profile via the Inspector protocol.
+ */
+
+interface HeapProfileCallFrame {
+  columnNumber: number
+  functionName: string
+  lineNumber: number
+  scriptId: string
+  url: string
+}
+
+interface HeapProfileNode {
+  callFrame: HeapProfileCallFrame
+  selfSize: number
+  children: HeapProfileNode[]
+  id: number
+  parent?: number
+  totalSize: number
+}
+
+interface HeapProfile {
+  head: HeapProfileNode
+}
+
+const callFrameToFrameInfo = new Map<HeapProfileCallFrame, FrameInfo>()
+function frameInfoForCallFrame(callFrame: HeapProfileCallFrame) {
+  return getOrInsert(callFrameToFrameInfo, callFrame, callFrame => {
+    const name = callFrame.functionName || '(anonymous)'
+    const file = callFrame.url
+    const line = callFrame.lineNumber
+    const col = callFrame.columnNumber
+    return {
+      key: `${name}:${file}:${line}:${col}`,
+      name,
+      file,
+      line,
+      col,
+    }
+  })
+}
+
+export function importFromChromeHeapProfile(chromeProfile: HeapProfile): Profile {
+  const nodeById = new Map<number, HeapProfileNode>()
+  let currentId = 0
+  const computeId = (node: HeapProfileNode, parent?: HeapProfileNode) => {
+    node.id = currentId++
+    nodeById.set(node.id, node)
+    if (parent) {
+      node.parent = parent.id
+    }
+
+    node.children.forEach(children => computeId(children, node))
+  }
+  computeId(chromeProfile.head)
+
+  // Compute the total size
+  const computeTotalSize = (node: HeapProfileNode): number => {
+    if (node.children.length === 0) return node.selfSize || 0
+    const totalChild = node.children.reduce((total: number, children) => {
+      total += computeTotalSize(children)
+      return total
+    }, node.selfSize)
+    node.totalSize = totalChild
+    return totalChild
+  }
+  const total = computeTotalSize(chromeProfile.head)
+
+  // Compute all stacks by taking each last node and going upward
+  const stacks: HeapProfileNode[][] = []
+  for (let currentNode of nodeById.values()) {
+    let stack: HeapProfileNode[] = []
+    stack.push(currentNode)
+    // While we found a parent
+    while (true) {
+      if (currentNode.parent === undefined) break
+      const parent = nodeById.get(currentNode.parent)
+      if (parent === undefined) break
+      // Push the parent at the beginning of the stack
+      stack.unshift(parent)
+      currentNode = parent
+    }
+    stacks.push(stack)
+  }
+
+  const profile = new StackListProfileBuilder(total)
+
+  for (let stack of stacks) {
+    const lastFrame = stack[stack.length - 1]
+    profile.appendSampleWithWeight(
+      stack.map(frame => frameInfoForCallFrame(frame.callFrame)),
+      lastFrame.selfSize,
+    )
+  }
+
+  profile.setValueFormatter(new ByteFormatter())
+  return profile.build()
+}

src/lib/test-utils.ts

@@ -1,8 +1,8 @@
 import * as fs from 'fs'
 import * as path from 'path'
 import {Profile, CallTreeNode, Frame} from './profile'
-import {importProfileGroup} from '../import'
 import {exportProfileGroup, importSpeedscopeProfiles} from './file-format'
+import {importProfilesFromArrayBuffer} from '../import'
 
 interface DumpedProfile {
   name: string
@@ -47,9 +47,10 @@ export function dumpProfile(profile: Profile): any {
 }
 
 export async function checkProfileSnapshot(filepath: string) {
-  const input = fs.readFileSync(filepath, 'utf8')
+  const buffer = fs.readFileSync(filepath)
+  const arrayBuffer = buffer.buffer.slice(buffer.byteOffset, buffer.byteOffset + buffer.byteLength)
 
-  const profileGroup = await importProfileGroup(path.basename(filepath), input)
+  const profileGroup = await importProfilesFromArrayBuffer(path.basename(filepath), arrayBuffer)
   if (profileGroup) {
     expect(profileGroup.name).toMatchSnapshot('profileGroup.name')
     expect(profileGroup.indexToView).toMatchSnapshot('indexToView')
@@ -62,7 +63,7 @@ export async function checkProfileSnapshot(filepath: string) {
     return
   }
 
-  const profilesWithoutFilename = await importProfileGroup('unknown', input)
+  const profilesWithoutFilename = await importProfilesFromArrayBuffer('unknown', arrayBuffer)
   if (profilesWithoutFilename) {
     expect(profilesWithoutFilename.profiles.length).toEqual(profileGroup.profiles.length)
     profilesWithoutFilename.name = profileGroup.name

src/lib/utils.test.ts

@@ -13,8 +13,11 @@ import {
   memoizeByReference,
   memoizeByShallowEquality,
   objectsHaveShallowEquality,
+  decodeBase64,
 } from './utils'
 
+import * as jsc from 'jsverify'
+
 test('sortBy', () => {
   const ls = ['a3', 'b2', 'c1', 'd4']
   sortBy(ls, k => k.charCodeAt(1))
@@ -173,3 +176,19 @@ test('objectsHaveShallowEquality', () => {
   expect(objectsHaveShallowEquality([1], [1, 2])).toBe(false)
   expect(objectsHaveShallowEquality([1, 2], [1])).toBe(false)
 })
+
+test('decodeBase64', () => {
+  jsc.assertForall(jsc.array(jsc.uint8), byteArray => {
+    let binaryString = ''
+    for (let byte of byteArray) {
+      binaryString += String.fromCharCode(byte)
+    }
+    const b64string = btoa(binaryString)
+    const decoded = decodeBase64(b64string)
+
+    expect(Uint8Array.from(byteArray)).toEqual(decoded)
+
+    // If the above expect(...) assertion fails, we won't reach here.
+    return true
+  })
+})

src/lib/utils.ts

@@ -167,3 +167,131 @@ export function memoizeByReference<T, U>(cb: (t: T) => U): (t: T) => U {
     }
   }
 }
+
+export function lazyStatic<T>(cb: () => T): () => T {
+  let last: {result: T} | null = null
+  return () => {
+    if (last == null) {
+      last = {result: cb()}
+    }
+    return last.result
+  }
+}
+
+const base64lookupTable = lazyStatic((): Map<string, number> => {
+  const alphabet = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'
+  const ret = new Map<string, number>()
+  for (let i = 0; i < alphabet.length; i++) {
+    ret.set(alphabet.charAt(i), i)
+  }
+  ret.set('=', -1)
+  return ret
+})
+
+// NOTE: There are probably simpler solutions to this problem, but I have this written already, so
+// until we run into problems with this, let's just use this.
+//
+// See: https://developer.mozilla.org/en-US/docs/Web/API/WindowBase64/Base64_encoding_and_decoding#The_Unicode_Problem#The_Unicode_Problem
+export function decodeBase64(encoded: string): Uint8Array {
+  // Reference: https://www.rfc-editor.org/rfc/rfc4648.txt
+
+  const lookupTable = base64lookupTable()
+
+  // 3 byte groups are represented as sequneces of 4 characters.
+  //
+  // "The encoding process represents 24-bit groups of input bits as output
+  //  strings of 4 encoded characters."
+  //
+  // "Special processing is performed if fewer than 24 bits are available
+  //  at the end of the data being encoded.  A full encoding quantum is
+  //  always completed at the end of a quantity.  When fewer than 24 input
+  //  bits are available in an input group bits with value zero are added
+  //  (on the right) to form an integral number of 6-bit groups."
+
+  if (encoded.length % 4 !== 0) {
+    throw new Error(
+      `Invalid length for base64 encoded string. Expected length % 4 = 0, got length = ${
+        encoded.length
+      }`,
+    )
+  }
+
+  const quartetCount = encoded.length / 4
+  let byteCount: number
+
+  // Special processing is performed if fewer than 24 bits are available
+  // at the end of the data being encoded.  A full encoding quantum is
+  // always completed at the end of a quantity.  When fewer than 24 input
+  // bits are available in an input group, bits with value zero are added
+  // (on the right) to form an integral number of 6-bit groups.  Padding
+  // at the end of the data is performed using the '=' character.  Since
+  // all base 64 input is an integral number of octets, only the following
+  // cases can arise:
+  //
+  // (1) The final quantum of encoding input is an integral multiple of 24
+  //     bits; here, the final unit of encoded output will be an integral
+  //     multiple of 4 characters with no "=" padding.
+  //
+  // (2) The final quantum of encoding input is exactly 8 bits; here, the
+  //     final unit of encoded output will be two characters followed by
+  //     two "=" padding characters.
+  //
+  // (3) The final quantum of encoding input is exactly 16 bits; here, the
+  //     final unit of encoded output will be three characters followed by
+  //     one "=" padding character.
+  if (encoded.length >= 4) {
+    if (encoded.charAt(encoded.length - 1) === '=') {
+      if (encoded.charAt(encoded.length - 2) === '=') {
+        // Case (2)
+        byteCount = quartetCount * 3 - 2
+      } else {
+        // Case (3)
+        byteCount = quartetCount * 3 - 1
+      }
+    } else {
+      // Case (1)
+      byteCount = quartetCount * 3
+    }
+  } else {
+    // Case (1)
+    byteCount = quartetCount * 3
+  }
+
+  const bytes = new Uint8Array(byteCount)
+  let offset = 0
+
+  for (let i = 0; i < quartetCount; i++) {
+    const enc1 = encoded.charAt(i * 4 + 0)
+    const enc2 = encoded.charAt(i * 4 + 1)
+    const enc3 = encoded.charAt(i * 4 + 2)
+    const enc4 = encoded.charAt(i * 4 + 3)
+
+    const sextet1 = lookupTable.get(enc1)
+    const sextet2 = lookupTable.get(enc2)
+    const sextet3 = lookupTable.get(enc3)
+    const sextet4 = lookupTable.get(enc4)
+
+    if (sextet1 == null || sextet2 == null || sextet3 == null || sextet4 == null) {
+      throw new Error(
+        `Invalid quartet at indices ${i * 4} .. ${i * 4 + 3}: ${encoded.substring(
+          i * 4,
+          i * 4 + 3,
+        )}`,
+      )
+    }
+
+    bytes[offset++] = (sextet1 << 2) | (sextet2 >> 4)
+    if (enc3 !== '=') {
+      bytes[offset++] = ((sextet2 & 15) << 4) | (sextet3 >> 2)
+    }
+    if (enc4 !== '=') {
+      bytes[offset++] = ((sextet3 & 7) << 6) | sextet4
+    }
+  }
+
+  if (offset !== byteCount) {
+    throw new Error(`Expected to decode ${byteCount} bytes, but only decoded ${offset})`)
+  }
+
+  return bytes
+}

src/views/application.tsx

@@ -18,8 +18,23 @@ import {Graphics} from '../gl/graphics'
 const importModule = import('../import')
 // Force eager loading of the module
 importModule.then(() => {})
-async function importProfiles(fileName: string, contents: string): Promise<ProfileGroup | null> {
-  return (await importModule).importProfileGroup(fileName, contents)
+
+async function importProfilesFromText(
+  fileName: string,
+  contents: string,
+): Promise<ProfileGroup | null> {
+  return (await importModule).importProfileGroupFromText(fileName, contents)
+}
+
+async function importProfilesFromBase64(
+  fileName: string,
+  contents: string,
+): Promise<ProfileGroup | null> {
+  return (await importModule).importProfileGroupFromBase64(fileName, contents)
+}
+
+async function importProfilesFromFile(file: File): Promise<ProfileGroup | null> {
+  return (await importModule).importProfilesFromFile(file)
 }
 async function importFromFileSystemDirectoryEntry(entry: FileSystemDirectoryEntry) {
   return (await importModule).importFromFileSystemDirectoryEntry(entry)
@@ -320,16 +335,7 @@ export class Application extends StatelessComponent<ApplicationProps> {
 
   loadFromFile(file: File) {
     this.loadProfile(async () => {
-      const reader = new FileReader()
-      const loadPromise = new Promise(resolve => reader.addEventListener('loadend', resolve))
-      reader.readAsText(file)
-      await loadPromise
-
-      if (typeof reader.result !== 'string') {
-        throw new Error('Expected ArrayBuffer')
-      }
-
-      const profiles = await importProfiles(file.name, reader.result)
+      const profiles = await importProfilesFromFile(file)
       if (profiles) {
         for (let profile of profiles.profiles) {
           if (!profile.getName()) {
@@ -344,7 +350,19 @@ export class Application extends StatelessComponent<ApplicationProps> {
         // a symbol map. If that's the case, we want to parse it, and apply the symbol
         // mapping to the already loaded profile. This can be use to take an opaque
         // profile and make it readable.
-        const map = importEmscriptenSymbolMap(reader.result)
+        const reader = new FileReader()
+        const fileContentsPromise = new Promise<string>(resolve => {
+          reader.addEventListener('loadend', () => {
+            if (typeof reader.result !== 'string') {
+              throw new Error('Expected reader.result to be a string')
+            }
+            resolve(reader.result)
+          })
+        })
+        reader.readAsText(file)
+        const fileContents = await fileContentsPromise
+
+        const map = importEmscriptenSymbolMap(fileContents)
         if (map) {
           const {profile, index} = this.props.activeProfileState
           console.log('Importing as emscripten symbol map')
@@ -365,7 +383,7 @@ export class Application extends StatelessComponent<ApplicationProps> {
     this.loadProfile(async () => {
       const filename = 'perf-vertx-stacks-01-collapsed-all.txt'
       const data = await fetch(exampleProfileURL).then(resp => resp.text())
-      return await importProfiles(filename, data)
+      return await importProfilesFromText(filename, data)
     })
   }
 
@@ -463,7 +481,7 @@ export class Application extends StatelessComponent<ApplicationProps> {
 
     const pasted = (ev as ClipboardEvent).clipboardData.getData('text')
     this.loadProfile(async () => {
-      return await importProfiles('From Clipboard', pasted)
+      return await importProfilesFromText('From Clipboard', pasted)
     })
   }
 
@@ -489,12 +507,12 @@ export class Application extends StatelessComponent<ApplicationProps> {
         return
       }
       this.loadProfile(async () => {
-        const response = await fetch(this.props.hashParams.profileURL!)
+        const response: Response = await fetch(this.props.hashParams.profileURL!)
         let filename = new URL(this.props.hashParams.profileURL!).pathname
         if (filename.includes('/')) {
           filename = filename.slice(filename.lastIndexOf('/') + 1)
         }
-        return await importProfiles(filename, await response.text())
+        return await importProfilesFromText(filename, await response.text())
       })
     } else if (this.props.hashParams.localProfilePath) {
       // There isn't good cross-browser support for XHR of local files, even from
@@ -502,8 +520,7 @@ export class Application extends StatelessComponent<ApplicationProps> {
       // as a JavaScript file which will invoke a global function.
       ;(window as any)['speedscope'] = {
         loadFileFromBase64: (filename: string, base64source: string) => {
-          const source = atob(base64source)
-          this.loadProfile(() => importProfiles(filename, source))
+          this.loadProfile(() => importProfilesFromBase64(filename, base64source))
         },
       }