Use JSStringCreateWithUTF8CString and skip NSString decoding when loa…

…ding the bundle Summary: public Benchmarking our startup path has shown we spend a lot of time decoding strings (iPhone 4S / iPhone 5): * reading a 2MB JS bundle: 35ms / 15ms * decoding is to an `NSString`: 186ms / 78ms * transforming that to a `JSString`: 29ms / 10ms Instead of going through an `NSString` transformation, we generate a null-terminated bundle (0.1ms / 0.05ms to copy the data) and use `JSStringCreateWithUTF8CString` (121ms / 53ms) to generate the string. That makes decoding 70% faster. Reviewed By: javache Differential Revision: D2541140 fb-gh-sync-id: 09a016b8edfd46a9b62682c76705564d2024e75e
facebook · Oct 16, 2015 · 4a3857ef1dc073f4a58274b77e7f775ca81b39dd · 4a3857e
1 parent 8e2ec64
commit 4a3857ef1dc073f4a58274b77e7f775ca81b39dd
diff --git a/Examples/UIExplorer/UIExplorerUnitTests/RCTContextExecutorTests.m b/Examples/UIExplorer/UIExplorerUnitTests/RCTContextExecutorTests.m
@@ -40,7 +40,7 @@ - (void)setUp
 - (void)testNativeLoggingHookExceptionBehavior
 {
  dispatch_semaphore_t doneSem = dispatch_semaphore_create(0);
-  [_executor executeApplicationScript:@"var x = {toString: function() { throw 1; }}; nativeLoggingHook(x);"
+  [_executor executeApplicationScript:[@"var x = {toString: function() { throw 1; }}; nativeLoggingHook(x);" dataUsingEncoding:NSUTF8StringEncoding]
                           sourceURL:[NSURL URLWithString:@"file://"]
                          onComplete:^(__unused id error){
                            dispatch_semaphore_signal(doneSem);
@@ -128,7 +128,7 @@ function require(module) { \
    } \
  ";

-  [_executor executeApplicationScript:script sourceURL:[NSURL URLWithString:@"http://localhost:8081/"] onComplete:^(__unused NSError *error) {
+  [_executor executeApplicationScript:[script dataUsingEncoding:NSUTF8StringEncoding] sourceURL:[NSURL URLWithString:@"http://localhost:8081/"] onComplete:^(__unused NSError *error) {
    NSMutableArray *params = [NSMutableArray new];
    id data = @1;
    for (int i = 0; i < 4; i++) {
diff --git a/Libraries/WebSocket/RCTWebSocketExecutor.m b/Libraries/WebSocket/RCTWebSocketExecutor.m
@@ -148,7 +148,7 @@ - (void)sendMessage:(NSDictionary *)message waitForReply:(RCTWSMessageCallback)c
  });
 }

- (void)executeApplicationScript:(NSString *)script sourceURL:(NSURL *)URL onComplete:(RCTJavaScriptCompleteBlock)onComplete
+- (void)executeApplicationScript:(NSData *)script sourceURL:(NSURL *)URL onComplete:(RCTJavaScriptCompleteBlock)onComplete
 {
  NSDictionary *message = @{
    @"method": @"executeApplicationScript",
diff --git a/React/Base/RCTBatchedBridge.m b/React/Base/RCTBatchedBridge.m
@@ -116,8 +116,8 @@ - (void)start
  dispatch_group_t initModulesAndLoadSource = dispatch_group_create();
  dispatch_group_enter(initModulesAndLoadSource);
  __weak RCTBatchedBridge *weakSelf = self;
-  __block NSString *sourceCode;
-  [self loadSource:^(NSError *error, NSString *source) {
+  __block NSData *sourceCode;
+  [self loadSource:^(NSError *error, NSData *source) {
    if (error) {
      dispatch_async(dispatch_get_main_queue(), ^{
        [weakSelf stopLoadingWithError:error];
@@ -184,7 +184,7 @@ - (void)loadSource:(RCTSourceLoadBlock)_onSourceLoad
  RCTPerformanceLoggerStart(RCTPLScriptDownload);
  int cookie = RCTProfileBeginAsyncEvent(0, @"JavaScript download", nil);

-  RCTSourceLoadBlock onSourceLoad = ^(NSError *error, NSString *source) {
+  RCTSourceLoadBlock onSourceLoad = ^(NSError *error, NSData *source) {
    RCTProfileEndAsyncEvent(0, @"init,download", cookie, @"JavaScript download", nil);
    RCTPerformanceLoggerEnd(RCTPLScriptDownload);

@@ -195,12 +195,13 @@ - (void)loadSource:(RCTSourceLoadBlock)_onSourceLoad

    // Force JS __DEV__ value to match RCT_DEBUG
    if (shouldOverrideDev) {
-      NSRange range = [source rangeOfString:@"__DEV__="];
+      NSString *sourceString = [[NSString alloc] initWithData:source encoding:NSUTF8StringEncoding];
+      NSRange range = [sourceString rangeOfString:@"__DEV__="];
      RCTAssert(range.location != NSNotFound, @"It looks like the implementation"
                "of __DEV__ has changed. Update -[RCTBatchedBridge loadSource:].");
      NSRange valueRange = {range.location + range.length, 2};
-      if ([[source substringWithRange:valueRange] isEqualToString:@"!1"]) {
-        source = [source stringByReplacingCharactersInRange:valueRange withString:@" 1"];
+      if ([[sourceString substringWithRange:valueRange] isEqualToString:@"!1"]) {
+        source = [[sourceString stringByReplacingCharactersInRange:valueRange withString:@" 1"] dataUsingEncoding:NSUTF8StringEncoding];
      }
    }

@@ -355,15 +356,15 @@ - (void)injectJSONConfiguration:(NSString *)configJSON
                             callback:onComplete];
 }

- (void)executeSourceCode:(NSString *)sourceCode
+- (void)executeSourceCode:(NSData *)sourceCode
 {
  if (!self.valid || !_javaScriptExecutor) {
    return;
  }

  RCTSourceCode *sourceCodeModule = self.modules[RCTBridgeModuleNameForClass([RCTSourceCode class])];
  sourceCodeModule.scriptURL = self.bundleURL;
-  sourceCodeModule.scriptText = sourceCode;
+  sourceCodeModule.scriptData = sourceCode;

  [self enqueueApplicationScript:sourceCode url:self.bundleURL onComplete:^(NSError *loadError) {
    if (!self.isValid) {
@@ -585,7 +586,7 @@ - (void)_immediatelyCallTimer:(NSNumber *)timer
  }
 }

- (void)enqueueApplicationScript:(NSString *)script
+- (void)enqueueApplicationScript:(NSData *)script
                             url:(NSURL *)url
                      onComplete:(RCTJavaScriptCompleteBlock)onComplete
 {
diff --git a/React/Base/RCTBridgeDelegate.h b/React/Base/RCTBridgeDelegate.h
@@ -7,7 +7,7 @@
 * of patent rights can be found in the PATENTS file in the same directory.
 */

-typedef void (^RCTSourceLoadBlock)(NSError *error, NSString *source);
+typedef void (^RCTSourceLoadBlock)(NSError *error, NSData *source);

 @class RCTBridge;

diff --git a/React/Base/RCTJavaScriptExecutor.h b/React/Base/RCTJavaScriptExecutor.h
@@ -46,7 +46,7 @@ typedef void (^RCTJavaScriptCallback)(id json, NSError *error);
 /**
 * Runs an application script, and notifies of the script load being complete via `onComplete`.
 */
- (void)executeApplicationScript:(NSString *)script
+- (void)executeApplicationScript:(NSData *)script
                       sourceURL:(NSURL *)sourceURL
                      onComplete:(RCTJavaScriptCompleteBlock)onComplete;

diff --git a/React/Base/RCTJavaScriptLoader.m b/React/Base/RCTJavaScriptLoader.m
@@ -36,8 +36,10 @@ + (void)loadBundleAtURL:(NSURL *)scriptURL onComplete:(RCTSourceLoadBlock)onComp
    NSString *filePath = scriptURL.path;
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
      NSError *error = nil;
-      NSString *rawText = [NSString stringWithContentsOfFile:filePath usedEncoding:NULL error:&error];
-      onComplete(error, rawText);
+      NSData *source = [NSData dataWithContentsOfFile:filePath
+                                              options:NSDataReadingMappedIfSafe
+                                                error:&error];
+      onComplete(error, source);
    });
    return;
  }
@@ -71,10 +73,10 @@ + (void)loadBundleAtURL:(NSURL *)scriptURL onComplete:(RCTSourceLoadBlock)onComp
        encoding = CFStringConvertEncodingToNSStringEncoding(cfEncoding);
      }
    }
-    NSString *rawText = [[NSString alloc] initWithData:data encoding:encoding];

    // Handle HTTP errors
    if ([response isKindOfClass:[NSHTTPURLResponse class]] && ((NSHTTPURLResponse *)response).statusCode != 200) {
+      NSString *rawText = [[NSString alloc] initWithData:data encoding:encoding];
      NSDictionary *userInfo;
      NSDictionary *errorDetails = RCTJSONParse(rawText, nil);
      if ([errorDetails isKindOfClass:[NSDictionary class]] &&
@@ -101,7 +103,7 @@ + (void)loadBundleAtURL:(NSURL *)scriptURL onComplete:(RCTSourceLoadBlock)onComp
      onComplete(error, nil);
      return;
    }
-    onComplete(nil, rawText);
+    onComplete(nil, data);
  }];

  [task resume];
diff --git a/React/Executors/RCTContextExecutor.m b/React/Executors/RCTContextExecutor.m
@@ -494,7 +494,7 @@ - (void)executeJSCall:(NSString *)name
  }), 0, @"js_call", (@{@"module":name, @"method": method, @"args": arguments}))];
 }

- (void)executeApplicationScript:(NSString *)script
+- (void)executeApplicationScript:(NSData *)script
                       sourceURL:(NSURL *)sourceURL
                      onComplete:(RCTJavaScriptCompleteBlock)onComplete
 {
@@ -508,9 +508,15 @@ - (void)executeApplicationScript:(NSString *)script
      return;
    }

+    // JSStringCreateWithUTF8CString expects a null terminated C string
+    NSMutableData *nullTerminatedScript = [NSMutableData dataWithCapacity:script.length + 1];
+
+    [nullTerminatedScript appendData:script];
+    [nullTerminatedScript appendBytes:"" length:1];
+
    RCTPerformanceLoggerStart(RCTPLScriptExecution);
    JSValueRef jsError = NULL;
-    JSStringRef execJSString = JSStringCreateWithCFString((__bridge CFStringRef)script);
+    JSStringRef execJSString = JSStringCreateWithUTF8CString(nullTerminatedScript.bytes);
    JSStringRef jsURL = JSStringCreateWithCFString((__bridge CFStringRef)sourceURL.absoluteString);
    JSValueRef result = JSEvaluateScript(strongSelf->_context.ctx, execJSString, NULL, jsURL, 0, &jsError);
    JSStringRelease(jsURL);
diff --git a/React/Executors/RCTWebViewExecutor.m b/React/Executors/RCTWebViewExecutor.m
@@ -130,7 +130,7 @@ - (void)executeJSCall:(NSString *)name
 * debugger. So we have to use this (essentially) async API - and register
 * ourselves as the webview delegate to be notified when load is complete.
 */
- (void)executeApplicationScript:(NSString *)script
+- (void)executeApplicationScript:(NSData *)script
                       sourceURL:(NSURL *)url
                      onComplete:(RCTJavaScriptCompleteBlock)onComplete
 {
@@ -142,6 +142,7 @@ - (void)executeApplicationScript:(NSString *)script
  }

  RCTAssert(onComplete != nil, @"");
+  NSString *scriptString = [[NSString alloc] initWithData:script encoding:NSUTF8StringEncoding];
  __weak RCTWebViewExecutor *weakSelf = self;
  _onApplicationScriptLoaded = ^(NSError *error){
    RCTWebViewExecutor *strongSelf = weakSelf;
@@ -163,23 +164,23 @@ - (void)executeApplicationScript:(NSString *)script
    }];
    [_objectsToInject removeAllObjects];
    [scriptWithInjections appendString:@"/* END NATIVELY INJECTED OBJECTS */\n"];
-    [scriptWithInjections appendString:script];
-    script = scriptWithInjections;
+    [scriptWithInjections appendString:scriptString];
+    scriptString = scriptWithInjections;
  }

-  script = [_commentsRegex stringByReplacingMatchesInString:script
-                                                    options:0
-                                                      range:NSMakeRange(0, script.length)
-                                               withTemplate:@""];
-  script = [_scriptTagsRegex stringByReplacingMatchesInString:script
-                                                      options:0
-                                                        range:NSMakeRange(0, script.length)
-                                                 withTemplate:@"\\\\<$1\\\\>"];
+  scriptString = [_commentsRegex stringByReplacingMatchesInString:scriptString
+                                                          options:0
+                                                            range:NSMakeRange(0, script.length)
+                                                     withTemplate:@""];
+  scriptString = [_scriptTagsRegex stringByReplacingMatchesInString:scriptString
+                                                            options:0
+                                                              range:NSMakeRange(0, script.length)
+                                                       withTemplate:@"\\\\<$1\\\\>"];

  NSString *runScript =
    [NSString
      stringWithFormat:@"<html><head></head><body><script type='text/javascript'>%@</script></body></html>",
-      script
+      scriptString
    ];
  [_webView loadHTMLString:runScript baseURL:url];
 }
diff --git a/React/Modules/RCTSourceCode.h b/React/Modules/RCTSourceCode.h
@@ -13,7 +13,7 @@

 @interface RCTSourceCode : NSObject <RCTBridgeModule>

-@property (nonatomic, copy) NSString *scriptText;
+@property (nonatomic, copy) NSData *scriptData;
 @property (nonatomic, copy) NSURL *scriptURL;

 @end
diff --git a/React/Modules/RCTSourceCode.m b/React/Modules/RCTSourceCode.m
@@ -27,8 +27,10 @@ - (void)setScriptText:(NSString *)scriptText {}
 RCT_EXPORT_METHOD(getScriptText:(RCTResponseSenderBlock)successCallback
                  failureCallback:(RCTResponseErrorBlock)failureCallback)
 {
-  if (RCT_DEV && self.scriptText && self.scriptURL) {
-    successCallback(@[@{@"text": self.scriptText, @"url": self.scriptURL.absoluteString}]);
+  if (RCT_DEV && self.scriptData && self.scriptURL) {
+    NSString *scriptText = [[NSString alloc] initWithData:self.scriptData encoding:NSUTF8StringEncoding];
+
+    successCallback(@[@{@"text": scriptText, @"url": self.scriptURL.absoluteString}]);
  } else {
    failureCallback(RCTErrorWithMessage(@"Source code is not available"));
  }