packager: GlobalTransformCache: cache the transform options digest

Reviewed By: davidaurelio

Differential Revision: D4906974

fbshipit-source-id: b6cf83ba6a072400685948329070e171f65c837d

packager/src/lib/GlobalTransformCache.js

@@ -225,7 +225,7 @@ class URIBasedGlobalTransformCache {
   keyOf(props: FetchProps) {
     const hash = crypto.createHash('sha1');
     const {sourceCode, filePath, transformOptions} = props;
-    this._optionsHasher.hashTransformWorkerOptions(hash, transformOptions);
+    hash.update(this._optionsHasher.getTransformWorkerOptionsDigest(transformOptions));
     const cacheKey = props.getTransformCacheKey(sourceCode, filePath, transformOptions);
     hash.update(JSON.stringify(cacheKey));
     hash.update(crypto.createHash('sha1').update(sourceCode).digest('hex'));
@@ -313,9 +313,23 @@ class URIBasedGlobalTransformCache {
 
 class OptionsHasher {
   _rootPath: string;
+  _cache: WeakMap<TransformWorkerOptions, string>;
 
   constructor(rootPath: string) {
     this._rootPath = rootPath;
+    this._cache = new WeakMap();
+  }
+
+  getTransformWorkerOptionsDigest(options: TransformWorkerOptions): string {
+    const digest = this._cache.get(options);
+    if (digest != null) {
+      return digest;
+    }
+    const hash = crypto.createHash('sha1');
+    this.hashTransformWorkerOptions(hash, options);
+    const newDigest = hash.digest('hex');
+    this._cache.set(options, newDigest);
+    return newDigest;
   }
 
   /**

packager/src/lib/__tests__/__snapshots__/GlobalTransformCache-test.js.snap

@@ -19,12 +19,12 @@ Object {
 exports[`GlobalTransformCache fetches results 1`] = `
 Array [
   Object {
-    "code": "/* code from http://globalcache.com/fb94b11256237327e4eef5daa08bad33573b3781-foo.js */",
+    "code": "/* code from http://globalcache.com/43e279be6916de8be463ef98bd72ded391608371-foo.js */",
     "dependencies": Array [],
     "dependencyOffsets": Array [],
   },
   Object {
-    "code": "/* code from http://globalcache.com/b902b4a8841fcea2919c2fe9b21e68d96dff59c9-bar.js */",
+    "code": "/* code from http://globalcache.com/e09598ad4c807cb22b32d68cfc16e0cba7fdb85c-bar.js */",
     "dependencies": Array [],
     "dependencyOffsets": Array [],
   },