From cf1e4c87f56acf287b806428df1c228ea0cad61e Mon Sep 17 00:00:00 2001
From: Garrett Moon <garrett@pinterest.com>
Date: Fri, 12 Feb 2016 15:04:14 -0800
Subject: [PATCH 1/2] Add image loading delegate method / cache instead of
 respondsToSelector

---
 AsyncDisplayKit/ASNetworkImageNode.h  |  9 ++++++++
 AsyncDisplayKit/ASNetworkImageNode.mm | 32 ++++++++++++++++++++++-----
 2 files changed, 35 insertions(+), 6 deletions(-)

diff --git a/AsyncDisplayKit/ASNetworkImageNode.h b/AsyncDisplayKit/ASNetworkImageNode.h
index 82513a8c55..0579b0351a 100644
--- a/AsyncDisplayKit/ASNetworkImageNode.h
+++ b/AsyncDisplayKit/ASNetworkImageNode.h
@@ -95,6 +95,15 @@ NS_ASSUME_NONNULL_BEGIN
 
 @optional
 
+/**
+ * Notification that the image node started to load
+ *
+ * @param imageNode The sender.
+ *
+ * @discussion Called on a background queue.
+ */
+- (void)imageNodeDidStartLoading:(ASNetworkImageNode *)imageNode;
+
 /**
  * Notification that the image node failed to download the image.
  *
diff --git a/AsyncDisplayKit/ASNetworkImageNode.mm b/AsyncDisplayKit/ASNetworkImageNode.mm
index debeab01f7..6c152dd06b 100755
--- a/AsyncDisplayKit/ASNetworkImageNode.mm
+++ b/AsyncDisplayKit/ASNetworkImageNode.mm
@@ -35,10 +35,15 @@
 
   BOOL _imageLoaded;
   
+  BOOL _delegateSupportsDidStartLoading;
+  BOOL _delegateSupportsDidFailWithError;
+  BOOL _delegateSupportsImageNodeDidFinishDecoding;
+  
   //set on init only
   BOOL _downloaderSupportsNewProtocol;
   BOOL _downloaderImplementsSetProgress;
   BOOL _downloaderImplementsSetPriority;
+  
   BOOL _cacheSupportsNewProtocol;
   BOOL _cacheSupportsClearing;
 }
@@ -144,6 +149,10 @@
 {
   ASDN::MutexLocker l(_lock);
   _delegate = delegate;
+  
+  _delegateSupportsDidStartLoading = [delegate respondsToSelector:@selector(imageNodeDidStartLoading:)];
+  _delegateSupportsDidFailWithError = [delegate respondsToSelector:@selector(imageNode:didFailWithError:)];
+  _delegateSupportsImageNodeDidFinishDecoding = [delegate respondsToSelector:@selector(imageNodeDidFinishDecoding:)];
 }
 
 - (id<ASNetworkImageNodeDelegate>)delegate
@@ -278,6 +287,13 @@
 - (void)_lazilyLoadImageIfNecessary
 {
   if (!_imageLoaded && _URL != nil && _downloadIdentifier == nil) {
+    {
+      ASDN::MutexLocker l(_lock);
+      if (_delegateSupportsDidStartLoading) {
+        [_delegate imageNodeDidStartLoading:self];
+      }
+    }
+    
     if (_URL.isFileURL) {
       {
         ASDN::MutexLocker l(_lock);
@@ -329,11 +345,14 @@
           strongSelf->_cacheUUID = nil;
         }
 
-        if (responseImage != NULL) {
-          [strongSelf->_delegate imageNode:strongSelf didLoadImage:strongSelf.image];
-        }
-        else if (error && [strongSelf->_delegate respondsToSelector:@selector(imageNode:didFailWithError:)]) {
-          [strongSelf->_delegate imageNode:strongSelf didFailWithError:error];
+        {
+          ASDN::MutexLocker l(strongSelf->_lock);
+          if (responseImage != NULL) {
+            [strongSelf->_delegate imageNode:strongSelf didLoadImage:strongSelf.image];
+          }
+          else if (error && _delegateSupportsDidFailWithError) {
+            [strongSelf->_delegate imageNode:strongSelf didFailWithError:error];
+          }
         }
       };
 
@@ -377,7 +396,8 @@
 - (void)asyncdisplaykit_asyncTransactionContainerStateDidChange
 {
   if (self.asyncdisplaykit_asyncTransactionContainerState == ASAsyncTransactionContainerStateNoTransactions) {
-    if (self.layer.contents != nil && [self.delegate respondsToSelector:@selector(imageNodeDidFinishDecoding:)]) {
+    ASDN::MutexLocker l(_lock);
+    if (self.layer.contents != nil && _delegateSupportsImageNodeDidFinishDecoding) {
       [self.delegate imageNodeDidFinishDecoding:self];
     }
   }

From 7d80fb31bd2f97c6f795697a721f78623d63fdc8 Mon Sep 17 00:00:00 2001
From: Garrett Moon <garrett@pinterest.com>
Date: Fri, 12 Feb 2016 15:10:58 -0800
Subject: [PATCH 2/2] rename imageNodeDidStartLoading to
 imageNodeDidStartFetchingData

---
 AsyncDisplayKit/ASNetworkImageNode.h  | 2 +-
 AsyncDisplayKit/ASNetworkImageNode.mm | 8 ++++----
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/AsyncDisplayKit/ASNetworkImageNode.h b/AsyncDisplayKit/ASNetworkImageNode.h
index 0579b0351a..79070aaccc 100644
--- a/AsyncDisplayKit/ASNetworkImageNode.h
+++ b/AsyncDisplayKit/ASNetworkImageNode.h
@@ -102,7 +102,7 @@ NS_ASSUME_NONNULL_BEGIN
  *
  * @discussion Called on a background queue.
  */
-- (void)imageNodeDidStartLoading:(ASNetworkImageNode *)imageNode;
+- (void)imageNodeDidStartFetchingData:(ASNetworkImageNode *)imageNode;
 
 /**
  * Notification that the image node failed to download the image.
diff --git a/AsyncDisplayKit/ASNetworkImageNode.mm b/AsyncDisplayKit/ASNetworkImageNode.mm
index 6c152dd06b..3b5eb75db9 100755
--- a/AsyncDisplayKit/ASNetworkImageNode.mm
+++ b/AsyncDisplayKit/ASNetworkImageNode.mm
@@ -35,7 +35,7 @@
 
   BOOL _imageLoaded;
   
-  BOOL _delegateSupportsDidStartLoading;
+  BOOL _delegateSupportsDidStartFetchingData;
   BOOL _delegateSupportsDidFailWithError;
   BOOL _delegateSupportsImageNodeDidFinishDecoding;
   
@@ -150,7 +150,7 @@
   ASDN::MutexLocker l(_lock);
   _delegate = delegate;
   
-  _delegateSupportsDidStartLoading = [delegate respondsToSelector:@selector(imageNodeDidStartLoading:)];
+  _delegateSupportsDidStartFetchingData = [delegate respondsToSelector:@selector(imageNodeDidStartFetchingData:)];
   _delegateSupportsDidFailWithError = [delegate respondsToSelector:@selector(imageNode:didFailWithError:)];
   _delegateSupportsImageNodeDidFinishDecoding = [delegate respondsToSelector:@selector(imageNodeDidFinishDecoding:)];
 }
@@ -289,8 +289,8 @@
   if (!_imageLoaded && _URL != nil && _downloadIdentifier == nil) {
     {
       ASDN::MutexLocker l(_lock);
-      if (_delegateSupportsDidStartLoading) {
-        [_delegate imageNodeDidStartLoading:self];
+      if (_delegateSupportsDidStartFetchingData) {
+        [_delegate imageNodeDidStartFetchingData:self];
       }
     }