Avoid deoptimizations in expression evaluation (#7334)

* avoid some JS deopts in expression evaluation * update deopt fix * update deopt fix 2
mapbox · Sep 26, 2018 · c612e07 · c612e07
1 parent 6ad95cb
commit c612e07
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Showing 2 changed files with 8 additions and 14 deletions.
diff --git a/src/style-spec/expression/evaluation_context.js b/src/style-spec/expression/evaluation_context.js
@@ -14,6 +14,9 @@ class EvaluationContext {
     _parseColorCache: {[string]: ?Color};
 
     constructor() {
+        this.globals = (null: any);
+        this.feature = null;
+        this.featureState = null;
         this._parseColorCache = {};
     }
 

diff --git a/src/style-spec/expression/index.js b/src/style-spec/expression/index.js
@@ -47,22 +47,17 @@ export class StyleExpression {
     _evaluator: EvaluationContext;
     _defaultValue: Value;
     _warningHistory: {[key: string]: boolean};
-    _enumValues: {[string]: any};
+    _enumValues: ?{[string]: any};
 
     constructor(expression: Expression, propertySpec: StylePropertySpecification) {
         this.expression = expression;
         this._warningHistory = {};
+        this._evaluator = new EvaluationContext();
         this._defaultValue = getDefaultValue(propertySpec);
-        if (propertySpec.type === 'enum') {
-            this._enumValues = propertySpec.values;
-        }
+        this._enumValues = propertySpec.type === 'enum' ? propertySpec.values : null;
     }
 
     evaluateWithoutErrorHandling(globals: GlobalProperties, feature?: Feature, featureState?: FeatureState): any {
-        if (!this._evaluator) {
-            this._evaluator = new EvaluationContext();
-        }
-
         this._evaluator.globals = globals;
         this._evaluator.feature = feature;
         this._evaluator.featureState = featureState;
@@ -71,13 +66,9 @@ export class StyleExpression {
     }
 
     evaluate(globals: GlobalProperties, feature?: Feature, featureState?: FeatureState): any {
-        if (!this._evaluator) {
-            this._evaluator = new EvaluationContext();
-        }
-
         this._evaluator.globals = globals;
-        this._evaluator.feature = feature;
-        this._evaluator.featureState = featureState;
+        this._evaluator.feature = feature || null;
+        this._evaluator.featureState = featureState || null;
 
         try {
             const val = this.expression.evaluate(this._evaluator);