More firefox import fixes (#128)

sample/programs/javascript/recursion.html

@@ -0,0 +1 @@
+<script src="./recursion.js"></script>

sample/programs/javascript/recursion.js

@@ -0,0 +1,41 @@
+function alpha(depth) {
+  if (depth > 15 * Math.random()) {
+    return
+  }
+  beta(depth + 1)
+  delta()
+  gamma()
+}
+
+function beta(depth) {
+  alpha(depth + 1)
+  for (let i = 0; i < 10; i++) {
+    gamma()
+  }
+}
+
+function delta() {
+  for (let i = 0; i < 10; i++) {
+    gamma()
+  }
+}
+
+function gamma() {
+  let prod = 1
+  for (let i = 1; i < 1000; i++) {
+    prod *= i
+  }
+  return prod
+}
+
+function main() {
+  for (let i = 0; i < 100; i++) {
+    alpha(0)
+  }
+}
+
+console.profile('recursion')
+main()
+setTimeout(() => {
+  console.profileEnd('recursion')
+}, 0)

sample/programs/javascript/simple.js

@@ -1,23 +1,23 @@
-function a() {
+function alpha() {
   for (let i = 0; i < 1000; i++) {
-    b()
-    c()
+    beta()
+    delta()
   }
 }
 
-function b() {
+function beta() {
   for (let i = 0; i < 10; i++) {
-    d()
+    gamma()
   }
 }
 
-function c() {
+function delta() {
   for (let i = 0; i < 10; i++) {
-    d()
+    gamma()
   }
 }
 
-function d() {
+function gamma() {
   let prod = 1
   for (let i = 1; i < 1000; i++) {
     prod *= i
@@ -25,10 +25,8 @@ function d() {
   return prod
 }
 
-console.profile('a')
-a()
+console.profile('simple')
+alpha()
 setTimeout(() => {
-  console.profileEnd('a')
+  console.profileEnd('simple')
 }, 0)
-
-window.addEventListener('click', a)

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

@@ -57,3 +57,66 @@ Object {
   ],
 }
 `;
+
+exports[`importFromFirefox recursion 1`] = `
+Object {
+  "frames": Array [
+    Frame {
+      "col": undefined,
+      "file": "file:///Users/jlfwong/code/speedscope/sample/programs/javascript/recursion.js",
+      "key": "main (file:///Users/jlfwong/code/speedscope/sample/programs/javascript/recursion.js:31)",
+      "line": 31,
+      "name": "main",
+      "selfWeight": 1.1944820000207983,
+      "totalWeight": 11.149112000013702,
+    },
+    Frame {
+      "col": undefined,
+      "file": "file:///Users/jlfwong/code/speedscope/sample/programs/javascript/recursion.js",
+      "key": "alpha (file:///Users/jlfwong/code/speedscope/sample/programs/javascript/recursion.js:1)",
+      "line": 1,
+      "name": "alpha",
+      "selfWeight": 0,
+      "totalWeight": 9.954629999992903,
+    },
+    Frame {
+      "col": undefined,
+      "file": "file:///Users/jlfwong/code/speedscope/sample/programs/javascript/recursion.js",
+      "key": "beta (file:///Users/jlfwong/code/speedscope/sample/programs/javascript/recursion.js:10)",
+      "line": 10,
+      "name": "beta",
+      "selfWeight": 0,
+      "totalWeight": 8.962158999987878,
+    },
+    Frame {
+      "col": undefined,
+      "file": "file:///Users/jlfwong/code/speedscope/sample/programs/javascript/recursion.js",
+      "key": "delta (file:///Users/jlfwong/code/speedscope/sample/programs/javascript/recursion.js:17)",
+      "line": 17,
+      "name": "delta",
+      "selfWeight": 0,
+      "totalWeight": 6.859736999962479,
+    },
+    Frame {
+      "col": undefined,
+      "file": "file:///Users/jlfwong/code/speedscope/sample/programs/javascript/recursion.js",
+      "key": "gamma (file:///Users/jlfwong/code/speedscope/sample/programs/javascript/recursion.js:23)",
+      "line": 23,
+      "name": "gamma",
+      "selfWeight": 9.954629999992903,
+      "totalWeight": 9.954629999992903,
+    },
+  ],
+  "stacks": Array [
+    "main;alpha;beta;alpha;beta;alpha;beta;alpha;delta;gamma 998.89µs",
+    "main 1.19ms",
+    "main;alpha;beta;alpha;delta;gamma 1.83ms",
+    "main;alpha;beta;alpha;beta;alpha;beta;gamma 1.16ms",
+    "main;alpha;beta;alpha;delta;gamma 1.84ms",
+    "main;alpha;beta;alpha;beta;alpha;beta;alpha;gamma 964.81µs",
+    "main;alpha;beta;alpha;beta;alpha;beta;alpha;delta;gamma 1.19ms",
+    "main;alpha;beta;gamma 965.25µs",
+    "main;alpha;delta;gamma 992.47µs",
+  ],
+}
+`;

src/import/firefox.test.ts

@@ -3,3 +3,7 @@ import {checkProfileSnapshot} from '../lib/test-utils'
 test('importFromFirefox', async () => {
   await checkProfileSnapshot('./sample/profiles/Firefox/59/simple-firefox.json')
 })
+
+test('importFromFirefox recursion', async () => {
+  await checkProfileSnapshot('./sample/profiles/Firefox/61/recursion.json')
+})

src/import/firefox.ts

@@ -1,5 +1,5 @@
 import {Profile, FrameInfo, CallTreeProfileBuilder} from '../lib/profile'
-import {getOrInsert, lastOf} from '../lib/utils'
+import {getOrInsert} from '../lib/utils'
 import {TimeFormatter} from '../lib/value-formatters'
 
 interface Allocations {
@@ -203,25 +203,22 @@ export function importFromFirefox(firefoxProfile: FirefoxProfile): Profile {
     const value = sample[1]
 
     // Find lowest common ancestor of the current stack and the previous one
-    let lca: FrameInfo | null = null
+    let lcaIndex = -1
 
     for (let i = 0; i < Math.min(stack.length, prevStack.length); i++) {
       if (prevStack[i] !== stack[i]) {
         break
       }
-      lca = stack[i]
+      lcaIndex = i
     }
 
     // Close frames that are no longer open
-    while (prevStack.length > 0 && (!lca || lastOf(prevStack) !== lca)) {
-      const closingFrame = prevStack.pop()!
-      profile.leaveFrame(closingFrame, value)
+    for (let i = prevStack.length - 1; i > lcaIndex; i--) {
+      profile.leaveFrame(prevStack[i], value)
     }
 
-    // Open frames that are now becoming open
-    for (let i = lca ? stack.indexOf(lca) + 1 : 0; i < stack.length; i++) {
-      const frame = stack[i]
-      profile.enterFrame(frame, value)
+    for (let i = lcaIndex + 1; i < stack.length; i++) {
+      profile.enterFrame(stack[i], value)
     }
 
     prevStack = stack

src/lib/profile.ts

@@ -586,6 +586,11 @@ export class CallTreeProfileBuilder extends Profile {
   }
 
   build(): Profile {
+    // Each stack is expected to contain a single node which we initialize to be
+    // the root node.
+    if (this.appendOrderStack.length > 1 || this.groupedOrderStack.length > 1) {
+      throw new Error('Tried to complete profile construction with a non-empty stack')
+    }
     return this
   }
 }