JSC Pre-Parsing cache

Reviewed By: mikearmstrong001

Differential Revision: D2840411

fb-gh-sync-id: d238e10b9a859185e6011c4685229cedbcc57a3e

ReactAndroid/src/main/jni/react/JSCExecutor.cpp

@@ -138,6 +138,29 @@ JSCExecutor::~JSCExecutor() {
   JSGlobalContextRelease(m_context);
 }
 
+std::string JSCExecutor::getDeviceCacheDir(){
+  // Get the Application Context object
+  auto getApplicationClass = findClassLocal(
+                              "com/facebook/react/common/ApplicationHolder");
+  auto getApplicationMethod = getApplicationClass->getStaticMethod<jobject()>(
+                              "getApplication",
+                              "()Landroid/app/Application;"
+                              );
+  auto application = getApplicationMethod(getApplicationClass);
+
+  // Get getCacheDir() from the context
+  auto getCacheDirMethod = findClassLocal("android/app/Application")
+                            ->getMethod<jobject()>("getCacheDir",
+                                                   "()Ljava/io/File;"
+                                                  );
+  auto cacheDirObj = getCacheDirMethod(application);
+
+  // Call getAbsolutePath() on the returned File object
+  auto getAbsolutePathMethod = findClassLocal("java/io/File")
+                                ->getMethod<jstring()>("getAbsolutePath");
+  return getAbsolutePathMethod(cacheDirObj)->toStdString();
+}
+
 void JSCExecutor::executeApplicationScript(
     const std::string& script,
     const std::string& sourceURL) {
@@ -153,11 +176,18 @@ void JSCExecutor::executeApplicationScript(
   env->DeleteLocalRef(startStringMarker);
   env->DeleteLocalRef(endStringMarker);
 
+  String jsSourceURL(sourceURL.c_str());
   #ifdef WITH_FBSYSTRACE
   FbSystraceSection s(TRACE_TAG_REACT_CXX_BRIDGE, "JSCExecutor::executeApplicationScript",
     "sourceURL", sourceURL);
   #endif
-  evaluateScript(m_context, jsScript, String(sourceURL.c_str()));
+  if (!jsSourceURL) {
+    evaluateScript(m_context, jsScript, jsSourceURL);
+  } else {
+    // If we're evaluating a script, get the device's cache dir 
+    //  in which a cache file for that script will be stored.
+    evaluateScript(m_context, jsScript, jsSourceURL, getDeviceCacheDir().c_str());
+  }
 }
 
 void JSCExecutor::loadApplicationUnbundle(

ReactAndroid/src/main/jni/react/JSCExecutor.h

@@ -71,6 +71,7 @@ private:
   void postMessageToWebWorker(int worker, JSValueRef message, JSValueRef *exn);
   void terminateWebWorker(int worker);
   void loadModule(uint32_t moduleId);
+  std::string getDeviceCacheDir();
 
   static JSValueRef nativeStartWorker(
       JSContextRef ctx,

ReactAndroid/src/main/jni/react/JSCHelpers.cpp

@@ -8,6 +8,10 @@
 
 #include "Value.h"
 
+#if WITH_FBJSCEXTENSIONS
+#include <jsc_function_info_cache.h>
+#endif
+
 namespace facebook {
 namespace react {
 
@@ -32,9 +36,19 @@ JSValueRef makeJSCException(
   return JSValueToObject(ctx, exceptionString, NULL);
 }
 
-JSValueRef evaluateScript(JSContextRef context, JSStringRef script, JSStringRef source) {
-  JSValueRef exn;
-  auto result = JSEvaluateScript(context, script, NULL, source, 0, &exn);
+JSValueRef evaluateScript(JSContextRef context, JSStringRef script, JSStringRef source, const char *cachePath) {
+  JSValueRef exn, result;
+#if WITH_FBJSCEXTENSIONS
+  if (source){
+    // If evaluating an application script, send it through `JSEvaluateScriptWithCache()`
+    //  to add cache support.
+    result = JSEvaluateScriptWithCache(context, script, NULL, source, 0, &exn, cachePath);
+  } else {
+    result = JSEvaluateScript(context, script, NULL, source, 0, &exn);
+  }
+#else
+  result = JSEvaluateScript(context, script, NULL, source, 0, &exn);
+#endif
   if (result == nullptr) {
     Value exception = Value(context, exn);
     std::string exceptionText = exception.toString().str();

ReactAndroid/src/main/jni/react/JSCHelpers.h

@@ -20,6 +20,6 @@ JSValueRef makeJSCException(
     JSContextRef ctx,
     const char* exception_text);
 
-JSValueRef evaluateScript(JSContextRef context, JSStringRef script, JSStringRef source);
+JSValueRef evaluateScript(JSContextRef context, JSStringRef script, JSStringRef source, const char *cachePath = nullptr);
 
 } }