Traverse performance (#10480)

* perf: remove this.inList assignment

* perf: convert NodePath.parentKey into accessor function

* perf: compress shouldSkip/shouldStop/removed traverse flags

* perf: lazy initialize this.skipKeys

* perf: lazily initialize NodePath.data

* add code comments before bit operations

* remove unused typeAnnotation property

# Conflicts:
#	packages/babel-traverse/src/path/index.js

* early return when visitor keys are empty

packages/babel-traverse/src/index.js

@@ -31,6 +31,10 @@ export default function traverse(
     }
   }
 
+  if (!t.VISITOR_KEYS[parent.type]) {
+    return;
+  }
+
   visitors.explode(opts);
 
   traverse.node(parent, opts, scope, state, parentPath);

packages/babel-traverse/src/path/context.js

@@ -1,6 +1,7 @@
 // This file contains methods responsible for maintaining a TraversalContext.
 
 import traverse from "../index";
+import { SHOULD_SKIP, SHOULD_STOP } from "./index";
 
 export function call(key): boolean {
   const opts = this.opts;
@@ -43,7 +44,8 @@ export function _call(fns?: Array<Function>): boolean {
     // node has been replaced, it will have been requeued
     if (this.node !== node) return true;
 
-    if (this.shouldStop || this.shouldSkip || this.removed) return true;
+    // this.shouldSkip || this.shouldStop || this.removed
+    if (this._traverseFlags > 0) return true;
   }
 
   return false;
@@ -97,12 +99,15 @@ export function skip() {
 }
 
 export function skipKey(key) {
+  if (this.skipKeys == null) {
+    this.skipKeys = {};
+  }
   this.skipKeys[key] = true;
 }
 
 export function stop() {
-  this.shouldStop = true;
+  // this.shouldSkip = true; this.shouldStop = true;
-  this.shouldSkip = true;
+  this._traverseFlags |= SHOULD_SKIP | SHOULD_STOP;
 }
 
 export function setScope() {
@@ -122,10 +127,11 @@ export function setScope() {
 }
 
 export function setContext(context) {
-  this.shouldSkip = false;
+  if (this.skipKeys != null) {
-  this.shouldStop = false;
-  this.removed = false;
     this.skipKeys = {};
+  }
+  // this.shouldSkip = false; this.shouldStop = false; this.removed = false;
+  this._traverseFlags = 0;
 
   if (context) {
     this.context = context;
@@ -220,9 +226,7 @@ export function pushContext(context) {
 }
 
 export function setup(parentPath, container, listKey, key) {
-  this.inList = !!listKey;
   this.listKey = listKey;
-  this.parentKey = listKey || key;
   this.container = container;
 
   this.parentPath = parentPath || this.parentPath;

packages/babel-traverse/src/path/index.js

@@ -23,15 +23,18 @@ import * as NodePath_comments from "./comments";
 
 const debug = buildDebug("babel");
 
+export const REMOVED = 1 << 0;
+export const SHOULD_STOP = 1 << 1;
+export const SHOULD_SKIP = 1 << 2;
+
 export default class NodePath {
   constructor(hub: HubInterface, parent: Object) {
     this.parent = parent;
     this.hub = hub;
     this.contexts = [];
-    this.data = Object.create(null);
+    this.data = null;
-    this.shouldSkip = false;
+    // this.shouldSkip = false; this.shouldStop = false; this.removed = false;
-    this.shouldStop = false;
+    this._traverseFlags = 0;
-    this.removed = false;
     this.state = null;
     this.opts = null;
     this.skipKeys = null;
@@ -39,13 +42,10 @@ export default class NodePath {
     this.context = null;
     this.container = null;
     this.listKey = null;
-    this.inList = false;
-    this.parentKey = null;
     this.key = null;
     this.node = null;
     this.scope = null;
     this.type = null;
-    this.typeAnnotation = null;
   }
 
   parent: Object;
@@ -57,18 +57,16 @@ export default class NodePath {
   removed: boolean;
   state: any;
   opts: ?Object;
+  _traverseFlags: number;
   skipKeys: ?Object;
   parentPath: ?NodePath;
   context: TraversalContext;
   container: ?Object | Array<Object>;
   listKey: ?string;
-  inList: boolean;
-  parentKey: ?string;
   key: ?string;
   node: ?Object;
   scope: Scope;
   type: ?string;
-  typeAnnotation: ?Object;
 
   static get({ hub, parentPath, parent, container, listKey, key }): NodePath {
     if (!hub && parentPath) {
@@ -111,10 +109,16 @@ export default class NodePath {
   }
 
   setData(key: string, val: any): any {
+    if (this.data == null) {
+      this.data = Object.create(null);
+    }
     return (this.data[key] = val);
   }
 
   getData(key: string, def?: any): any {
+    if (this.data == null) {
+      this.data = Object.create(null);
+    }
     let val = this.data[key];
     if (val === undefined && def !== undefined) val = this.data[key] = def;
     return val;
@@ -152,6 +156,49 @@ export default class NodePath {
   toString() {
     return generator(this.node).code;
   }
+
+  get inList() {
+    return !!this.listKey;
+  }
+
+  get parentKey() {
+    return this.listKey || this.key;
+  }
+
+  get shouldSkip() {
+    return !!(this._traverseFlags & SHOULD_SKIP);
+  }
+
+  set shouldSkip(v) {
+    if (v) {
+      this._traverseFlags |= SHOULD_SKIP;
+    } else {
+      this._traverseFlags &= ~SHOULD_SKIP;
+    }
+  }
+
+  get shouldStop() {
+    return !!(this._traverseFlags & SHOULD_STOP);
+  }
+
+  set shouldStop(v) {
+    if (v) {
+      this._traverseFlags |= SHOULD_STOP;
+    } else {
+      this._traverseFlags &= ~SHOULD_STOP;
+    }
+  }
+
+  get removed() {
+    return !!(this._traverseFlags & REMOVED);
+  }
+  set removed(v) {
+    if (v) {
+      this._traverseFlags |= REMOVED;
+    } else {
+      this._traverseFlags &= ~REMOVED;
+    }
+  }
 }
 
 Object.assign(

packages/babel-traverse/src/path/removal.js

@@ -1,6 +1,7 @@
 // This file contains methods responsible for removing a node.
 
 import { hooks } from "./lib/removal-hooks";
+import { REMOVED, SHOULD_SKIP } from "./index";
 
 export function remove() {
   this._assertUnremoved();
@@ -39,8 +40,8 @@ export function _remove() {
 }
 
 export function _markRemoved() {
-  this.shouldSkip = true;
+  // this.shouldSkip = true; this.removed = true;
-  this.removed = true;
+  this._traverseFlags |= SHOULD_SKIP | REMOVED;
   this.node = null;
 }