Allow image loaders to enable/disable image telemetry

Summary:
When shouldEnableLoggingForRequestUrl is false, ImageTelemetry is not initialized, and no logging is done.

* Replace `- (NSString *)loaderModuleNameForRequestUrl:(NSURL *)url` with `- (BOOL)shouldEnableLoggingForRequestUrl:(NSURL *)url`
* Rename RCTImageLoaderInstrumentableProtocol.h -> RCTImageLoaderLoggableProtocol.h

Reviewed By: fkgozali

Differential Revision: D24523984

fbshipit-source-id: a5463eceea1c40f9452b0ad2ee6bf047f71a02c1

Author: p-sun

Libraries/Image/RCTImageLoader.h

@@ -15,9 +15,9 @@
 #import <React/RCTImageURLLoader.h>
 #import <React/RCTImageCache.h>
 #import <React/RCTImageLoaderProtocol.h>
-#import <React/RCTImageLoaderInstrumentableProtocol.h>
+#import <React/RCTImageLoaderLoggable.h>
 
-@interface RCTImageLoader : NSObject <RCTBridgeModule, RCTImageLoaderProtocol, RCTImageLoaderInstrumentableProtocol>
+@interface RCTImageLoader : NSObject <RCTBridgeModule, RCTImageLoaderProtocol, RCTImageLoaderLoggableProtocol>
 - (instancetype)init;
 - (instancetype)initWithRedirectDelegate:(id<RCTImageRedirectProtocol>)redirectDelegate NS_DESIGNATED_INITIALIZER;
 - (instancetype)initWithRedirectDelegate:(id<RCTImageRedirectProtocol>)redirectDelegate

Libraries/Image/RCTImageLoader.mm

@@ -839,12 +839,12 @@ - (RCTImageURLLoaderRequest *)loadImageWithURLRequest:(NSURLRequest *)imageURLRe
   return [[RCTImageURLLoaderRequest alloc] initWithRequestId:loaderRequest.requestId imageURL:imageURLRequest.URL cancellationBlock:cancellationBlock];
 }
 
-- (NSString *)loaderModuleNameForRequestUrl:(NSURL *)url {
+- (BOOL)shouldEnablePerfLoggingForRequestUrl:(NSURL *)url {
   id<RCTImageURLLoader> loadHandler = [self imageURLLoaderForURL:url];
-  if ([loadHandler respondsToSelector:@selector(loaderModuleNameForRequestUrl:)]) {
-    return [(id<RCTImageURLLoaderWithAttribution>)loadHandler loaderModuleNameForRequestUrl:url];
+  if ([loadHandler respondsToSelector:@selector(shouldEnablePerfLogging)]) {
+    return [(id<RCTImageURLLoaderWithAttribution>)loadHandler shouldEnablePerfLogging];
   }
-  return nil;
+  return NO;
 }
 
 - (void)trackURLImageVisibilityForRequest:(RCTImageURLLoaderRequest *)loaderRequest imageView:(UIView *)imageView

Libraries/Image/RCTImageLoaderInstrumentableProtocol.h

@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+/**
+ * The image loader (i.e. RCTImageLoader) implement this to declare whether image performance should be logged.
+ */
+@protocol RCTImageLoaderLoggableProtocol
+
+/**
+ * Image instrumentation - declares whether its caller should log images
+ */
+- (BOOL)shouldEnablePerfLoggingForRequestUrl:(NSURL *)url;
+
+@end
+
+/**
+ * Image handlers in the image loader implement this to declare whether image performance should be logged.
+ */
+@protocol RCTImageLoaderLoggable
+
+/**
+ * Image instrumentation - declares whether its caller should log images
+ */
+- (BOOL)shouldEnablePerfLogging;
+
+@end

Libraries/Image/RCTImageLoaderLoggable.h

@@ -9,7 +9,6 @@
 
 #import <React/RCTImageLoaderProtocol.h>
 #import <React/RCTImageURLLoaderWithAttribution.h>
-#import <React/RCTImageLoaderInstrumentableProtocol.h>
 
 RCT_EXTERN BOOL RCTImageLoadingInstrumentationEnabled(void);
 RCT_EXTERN BOOL RCTImageLoadingPerfInstrumentationEnabled(void);
@@ -19,7 +18,7 @@ RCT_EXTERN void RCTEnableImageLoadingPerfInstrumentation(BOOL enabled);
 RCT_EXTERN BOOL RCTGetImageLoadingPerfInstrumentationForFabricEnabled();
 RCT_EXTERN void RCTSetImageLoadingPerfInstrumentationForFabricEnabledBlock(BOOL (^getEnabled)());
 
-@protocol RCTImageLoaderWithAttributionProtocol<RCTImageLoaderProtocol, RCTImageLoaderInstrumentableProtocol>
+@protocol RCTImageLoaderWithAttributionProtocol<RCTImageLoaderProtocol, RCTImageLoaderLoggableProtocol>
 
 // TODO (T61325135): Remove C++ checks
 #ifdef __cplusplus

Libraries/Image/RCTImageLoaderWithAttributionProtocol.h

@@ -7,7 +7,7 @@
 
 #import <React/RCTImageURLLoader.h>
 #import <React/RCTImageLoaderProtocol.h>
-#import <React/RCTImageLoaderInstrumentableProtocol.h>
+#import <React/RCTImageLoaderLoggable.h>
 
 // TODO (T61325135): Remove C++ checks
 #ifdef __cplusplus
@@ -39,7 +39,7 @@ struct ImageURLLoaderAttribution {
  * Same as the RCTImageURLLoader interface, but allows passing in optional `attribution` information.
  * This is useful for per-app logging and other instrumentation.
  */
-@protocol RCTImageURLLoaderWithAttribution <RCTImageURLLoader, RCTImageLoaderInstrumentableProtocol>
+@protocol RCTImageURLLoaderWithAttribution <RCTImageURLLoader, RCTImageLoaderLoggable>
 
 // TODO (T61325135): Remove C++ checks
 #ifdef __cplusplus

Libraries/Image/RCTImageURLLoaderWithAttribution.h

@@ -19,14 +19,6 @@ SurfaceId ImageTelemetry::getSurfaceId() const {
   return surfaceId_;
 }
 
-std::string ImageTelemetry::getLoaderModuleName() const {
-  return loaderModuleName_;
-}
-
-void ImageTelemetry::setLoaderModuleName(std::string const &loaderModuleName) {
-  loaderModuleName_ = loaderModuleName;
-}
-
 TelemetryTimePoint ImageTelemetry::getWillRequestUrlTime() const {
   assert(willRequestUrlTime_ != kTelemetryUndefinedTimePoint);
   return willRequestUrlTime_;

ReactCommon/react/renderer/imagemanager/ImageTelemetry.cpp

@@ -31,14 +31,11 @@ class ImageTelemetry final {
   TelemetryTimePoint getWillRequestUrlTime() const;
 
   SurfaceId getSurfaceId() const;
-  std::string getLoaderModuleName() const;
-  void setLoaderModuleName(std::string const &loaderModuleName);
 
  private:
   TelemetryTimePoint willRequestUrlTime_{kTelemetryUndefinedTimePoint};
 
   const SurfaceId surfaceId_;
-  std::string loaderModuleName_{""};
 };
 
 } // namespace react

ReactCommon/react/renderer/imagemanager/ImageTelemetry.h

@@ -40,22 +40,22 @@ - (ImageRequest)requestImage:(ImageSource)imageSource surfaceId:(SurfaceId)surfa
 {
   SystraceSection s("RCTImageManager::requestImage");
 
-  auto telemetry = std::make_shared<ImageTelemetry>(surfaceId);
-  telemetry->willRequestUrl();
+  NSURLRequest *request = NSURLRequestFromImageSource(imageSource);
+  std::shared_ptr<ImageTelemetry> telemetry;
+  if ([self->_imageLoader shouldEnablePerfLoggingForRequestUrl:request.URL]) {
+    telemetry = std::make_shared<ImageTelemetry>(surfaceId);
+    telemetry->willRequestUrl();
+  } else {
+    telemetry = nullptr;
+  }
+
   auto imageRequest = ImageRequest(imageSource, telemetry);
   auto weakObserverCoordinator =
       (std::weak_ptr<const ImageResponseObserverCoordinator>)imageRequest.getSharedObserverCoordinator();
 
   auto sharedCancelationFunction = SharedFunction<>();
   imageRequest.setCancelationFunction(sharedCancelationFunction);
 
-  NSURLRequest *request = NSURLRequestFromImageSource(imageSource);
-  BOOL hasModuleName = [self->_imageLoader respondsToSelector:@selector(loaderModuleNameForRequestUrl:)];
-  NSString *moduleName = hasModuleName ? [self->_imageLoader loaderModuleNameForRequestUrl:request.URL] : nil;
-  std::string moduleCString =
-      std::string([moduleName UTF8String], [moduleName lengthOfBytesUsingEncoding:NSUTF8StringEncoding]);
-  telemetry->setLoaderModuleName(moduleCString);
-
   /*
    * Even if an image is being loaded asynchronously on some other background thread, some other preparation
    * work (such as creating an `NSURLRequest` object and some obscure logic inside `RCTImageLoader`) can take a couple