Encapsulate common logics into methods

TextureGroup · Mar 7, 2019 · 6a1f368 · 6a1f368
1 parent 3848174
commit 6a1f368
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Showing 2 changed files with 56 additions and 136 deletions.
diff --git a/Source/ASMultiplexImageNode.mm b/Source/ASMultiplexImageNode.mm
@@ -279,92 +279,31 @@ - (BOOL)placeholderShouldPersist
 - (void)displayWillStartAsynchronously:(BOOL)asynchronously
 {
   [super displayWillStartAsynchronously:asynchronously];
-
   [self didEnterPreloadState];
-
-  if (_downloaderFlags.downloaderImplementsSetPriority) {
-    id downloadIdentifier;
-    {
-      ASDN::MutexLocker l(_downloadIdentifierLock);
-      downloadIdentifier = _downloadIdentifier;
-    }
-
-    if (downloadIdentifier != nil) {
-      ASImageDownloaderPriority priority = ASImageDownloaderPriorityImminent;
-      if (_isInImageDownloaderPriorityExperiment) {
-        priority = ASImageDownloaderPriorityWithInterfaceState(self.interfaceState);
-      }
-
-      [_downloader setPriority:priority withDownloadIdentifier:downloadIdentifier];
-    }
-  }
+  [self _updatePriorityOnDownloaderIfNeededWithDefaultPriority:ASImageDownloaderPriorityImminent];
 }
 
 /* didEnterVisibleState / didExitVisibleState in ASNetworkImageNode has a very similar implementation. Changes here are likely necessary
  in ASNetworkImageNode as well. */
 - (void)didEnterVisibleState
 {
   [super didEnterVisibleState];
-
-  if (_downloaderFlags.downloaderImplementsSetPriority) {
-    id downloadIdentifier;
-    {
-      ASDN::MutexLocker l(_downloadIdentifierLock);
-      downloadIdentifier = _downloadIdentifier;
-    }
-
-    if (downloadIdentifier != nil) {
-      ASImageDownloaderPriority priority = ASImageDownloaderPriorityVisible;
-      if (_isInImageDownloaderPriorityExperiment) {
-        priority = ASImageDownloaderPriorityWithInterfaceState(self.interfaceState);
-      }
-
-      [_downloader setPriority:priority withDownloadIdentifier:downloadIdentifier];
-    }
-  }
-
+  [self _updatePriorityOnDownloaderIfNeededWithDefaultPriority:ASImageDownloaderPriorityVisible];
   [self _updateProgressImageBlockOnDownloaderIfNeeded];
 }
 
 - (void)didExitVisibleState
 {
   [super didExitVisibleState];
-
-  if (_downloaderFlags.downloaderImplementsSetPriority) {
-    id downloadIdentifier;
-    {
-      ASDN::MutexLocker l(_downloadIdentifierLock);
-      downloadIdentifier = _downloadIdentifier;
-    }
-
-    if (downloadIdentifier != nil) {
-      ASImageDownloaderPriority priority = ASImageDownloaderPriorityPreload;
-      if (_isInImageDownloaderPriorityExperiment) {
-        priority = ASImageDownloaderPriorityWithInterfaceState(self.interfaceState);
-      }
-
-      [_downloader setPriority:priority withDownloadIdentifier:downloadIdentifier];
-    }
-  }
-
+  [self _updatePriorityOnDownloaderIfNeededWithDefaultPriority:ASImageDownloaderPriorityPreload];
   [self _updateProgressImageBlockOnDownloaderIfNeeded];
 }
 
 - (void)didExitDisplayState
 {
   [super didExitDisplayState];
-
-  if (_downloaderFlags.downloaderImplementsSetPriority && _isInImageDownloaderPriorityExperiment) {
-    id downloadIdentifier;
-    {
-      ASDN::MutexLocker l(_downloadIdentifierLock);
-      downloadIdentifier = _downloadIdentifier;
-    }
-
-    if (downloadIdentifier != nil) {
-      ASImageDownloaderPriority priority = ASImageDownloaderPriorityWithInterfaceState(self.interfaceState);
-      [_downloader setPriority:priority withDownloadIdentifier:downloadIdentifier];
-    }
+  if (_isInImageDownloaderPriorityExperiment) {
+    [self _updatePriorityOnDownloaderIfNeededWithDefaultPriority:ASImageDownloaderPriorityPreload];
   }
 }
 
@@ -503,7 +442,6 @@ - (void)_setDownloadIdentifier:(id)downloadIdentifier
   _downloadIdentifier = downloadIdentifier;
 }
 
-
 #pragma mark - Image Loading Machinery
 
 - (void)_loadImageIdentifiers
@@ -547,12 +485,31 @@ - (UIImage *)_bestImmediatelyAvailableImageFromDataSource:(id *)imageIdentifierO
 
 #pragma mark -
 
-/**
- @note: This should be called without _downloadIdentifierLock held. We will lock
- super to read our interface state and it's best to avoid acquiring both locks.
- */
+- (void)_updatePriorityOnDownloaderIfNeededWithDefaultPriority:(ASImageDownloaderPriority)defaultPriority
+{
+  ASAssertUnlocked(_downloadIdentifierLock);
+  if (_downloaderFlags.downloaderImplementsSetPriority) {
+    id downloadIdentifier;
+    {
+      ASDN::MutexLocker l(_downloadIdentifierLock);
+      downloadIdentifier = _downloadIdentifier;
+    }
+
+    if (downloadIdentifier != nil) {
+      ASImageDownloaderPriority priority = defaultPriority;
+      if (_isInImageDownloaderPriorityExperiment) {
+        priority = ASImageDownloaderPriorityWithInterfaceState(self.interfaceState);
+      }
+
+      [_downloader setPriority:priority withDownloadIdentifier:downloadIdentifier];
+    }
+  }
+}
+
 - (void)_updateProgressImageBlockOnDownloaderIfNeeded
 {
+  ASAssertUnlocked(_downloadIdentifierLock);
+
   BOOL shouldRenderProgressImages = self.shouldRenderProgressImages;
 
   // Read our interface state before locking so that we don't lock super while holding our lock.

diff --git a/Source/ASNetworkImageNode.mm b/Source/ASNetworkImageNode.mm
@@ -340,14 +340,10 @@ - (void)displayWillStartAsynchronously:(BOOL)asynchronously
 
   id<ASNetworkImageNodeDelegate> delegate;
   BOOL notifyDelegate;
-  ASInterfaceState interfaceState;
-  id downloadIdentifier;
   {
     ASLockScopeSelf();
     notifyDelegate = _delegateFlags.delegateWillStartDisplayAsynchronously;
     delegate = _delegate;
-    downloadIdentifier = _downloaderFlags.downloaderImplementsSetPriority ? _downloadIdentifier : nil;
-    interfaceState = _interfaceState;
   }
   if (notifyDelegate) {
     [delegate imageNodeWillStartDisplayAsynchronously:self];
@@ -377,13 +373,8 @@ - (void)displayWillStartAsynchronously:(BOOL)asynchronously
     }
   }
 
-  if (self.image == nil && downloadIdentifier != nil) {
-    ASImageDownloaderPriority priority = ASImageDownloaderPriorityImminent;
-    if (_isInImageDownloaderPriorityExperiment) {
-      priority = ASImageDownloaderPriorityWithInterfaceState(interfaceState);
-    }
-
-    [_downloader setPriority:priority withDownloadIdentifier:downloadIdentifier];
+  if (self.image == nil) {
+    [self _updatePriorityOnDownloaderIfNeededWithDefaultPriority:ASImageDownloaderPriorityImminent];
   }
 }
 
@@ -392,72 +383,22 @@ - (void)displayWillStartAsynchronously:(BOOL)asynchronously
 - (void)didEnterVisibleState
 {
   [super didEnterVisibleState];
-
-  if (_downloaderFlags.downloaderImplementsSetPriority) {
-    id downloadIdentifier;
-    ASInterfaceState interfaceState;
-    {
-      ASLockScopeSelf();
-      downloadIdentifier = _downloadIdentifier;
-      interfaceState = _interfaceState;
-    }
-
-    if (downloadIdentifier != nil) {
-      ASImageDownloaderPriority priority = ASImageDownloaderPriorityVisible;
-      if (_isInImageDownloaderPriorityExperiment) {
-        priority = ASImageDownloaderPriorityWithInterfaceState(interfaceState);
-      }
-
-      [_downloader setPriority:priority withDownloadIdentifier:downloadIdentifier];
-    }
-  }
-
+  [self _updatePriorityOnDownloaderIfNeededWithDefaultPriority:ASImageDownloaderPriorityVisible];
   [self _updateProgressImageBlockOnDownloaderIfNeeded];
 }
 
 - (void)didExitVisibleState
 {
   [super didExitVisibleState];
-
-  if (_downloaderFlags.downloaderImplementsSetPriority) {
-    id downloadIdentifier;
-    ASInterfaceState interfaceState;
-    {
-      ASLockScopeSelf();
-      downloadIdentifier = _downloadIdentifier;
-      interfaceState = _interfaceState;
-    }
-
-    if (downloadIdentifier != nil) {
-      ASImageDownloaderPriority priority = ASImageDownloaderPriorityPreload;
-      if (_isInImageDownloaderPriorityExperiment) {
-        priority = ASImageDownloaderPriorityWithInterfaceState(interfaceState);
-      }
-
-      [_downloader setPriority:priority withDownloadIdentifier:downloadIdentifier];
-    }
-  }
-
+  [self _updatePriorityOnDownloaderIfNeededWithDefaultPriority:ASImageDownloaderPriorityPreload];
   [self _updateProgressImageBlockOnDownloaderIfNeeded];
 }
 
 - (void)didExitDisplayState
 {
   [super didExitDisplayState];
-
-  if (_downloaderFlags.downloaderImplementsSetPriority && _isInImageDownloaderPriorityExperiment) {
-    id downloadIdentifier;
-    ASInterfaceState interfaceState;
-    {
-      ASLockScopeSelf();
-      downloadIdentifier = _downloadIdentifier;
-      interfaceState = _interfaceState;
-    }
-
-    if (downloadIdentifier != nil) {
-      ASImageDownloaderPriority priority = ASImageDownloaderPriorityWithInterfaceState(interfaceState);
-      [_downloader setPriority:priority withDownloadIdentifier:downloadIdentifier];
-    }
+  if (_isInImageDownloaderPriorityExperiment) {
+    [self _updatePriorityOnDownloaderIfNeededWithDefaultPriority:ASImageDownloaderPriorityPreload];
   }
 }
 
@@ -507,6 +448,28 @@ - (void)handleProgressImage:(UIImage *)progressImage progress:(CGFloat)progress
   [self _locked__setImage:progressImage];
 }
 
+- (void)_updatePriorityOnDownloaderIfNeededWithDefaultPriority:(ASImageDownloaderPriority)defaultPriority
+{
+  if (_downloaderFlags.downloaderImplementsSetPriority) {
+    id downloadIdentifier;
+    ASInterfaceState interfaceState;
+    {
+      ASLockScopeSelf();
+      downloadIdentifier = _downloadIdentifier;
+      interfaceState = _interfaceState;
+    }
+
+    if (downloadIdentifier != nil) {
+      ASImageDownloaderPriority priority = defaultPriority;
+      if (_isInImageDownloaderPriorityExperiment) {
+        priority = ASImageDownloaderPriorityWithInterfaceState(interfaceState);
+      }
+
+      [_downloader setPriority:priority withDownloadIdentifier:downloadIdentifier];
+    }
+  }
+}
+
 - (void)_updateProgressImageBlockOnDownloaderIfNeeded
 {
   // If the downloader doesn't do progress, we are done.