From 547345c7f5372d29172630c4df8d743491fe45ba Mon Sep 17 00:00:00 2001
From: Don <don.holly@gmail.com>
Date: Thu, 12 Sep 2013 11:58:43 -0700
Subject: [PATCH 1/2] Added and exposed some methods that allow to check if an
 image exists on disk without taking it off disk and decompressing it first.
 Makes for a nice performance boost when checking if many files exist in the
 disk cache already

---
 SDWebImage/SDImageCache.h      |  5 +++++
 SDWebImage/SDImageCache.m      | 18 +++++++++++++++++-
 SDWebImage/SDWebImageManager.h |  5 +++++
 SDWebImage/SDWebImageManager.m |  5 +++++
 4 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/SDWebImage/SDImageCache.h b/SDWebImage/SDImageCache.h
index 133af9d..4a571c1 100644
--- a/SDWebImage/SDImageCache.h
+++ b/SDWebImage/SDImageCache.h
@@ -159,4 +159,9 @@ typedef enum SDImageCacheType SDImageCacheType;
  */
 - (void)calculateSizeWithCompletionBlock:(void (^)(NSUInteger fileCount, unsigned long long totalSize))completionBlock;
 
+/**
+ * Check if image exists in cache already
+ */
+- (BOOL)diskImageExistsWithKey:(NSString *)key;
+
 @end
diff --git a/SDWebImage/SDImageCache.m b/SDWebImage/SDImageCache.m
index 0b86507..16b1e6c 100644
--- a/SDWebImage/SDImageCache.m
+++ b/SDWebImage/SDImageCache.m
@@ -25,7 +25,9 @@ static const NSInteger kDefaultCacheMaxCacheAge = 60 * 60 * 24 * 7; // 1 week
 @end
 
 
-@implementation SDImageCache
+@implementation SDImageCache {
+    NSFileManager *_fileManager;
+}
 
 + (SDImageCache *)sharedImageCache
 {
@@ -60,6 +62,10 @@ static const NSInteger kDefaultCacheMaxCacheAge = 60 * 60 * 24 * 7; // 1 week
         NSArray *paths = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES);
         _diskCachePath = [paths[0] stringByAppendingPathComponent:fullNamespace];
 
+        dispatch_sync(_ioQueue, ^{
+            _fileManager = NSFileManager.new;
+        });
+        
 #if TARGET_OS_IPHONE
         // Subscribe to app events
         [[NSNotificationCenter defaultCenter] addObserver:self
@@ -184,6 +190,16 @@ static const NSInteger kDefaultCacheMaxCacheAge = 60 * 60 * 24 * 7; // 1 week
     [self storeImage:image imageData:nil forKey:key toDisk:toDisk];
 }
 
+- (BOOL)diskImageExistsWithKey:(NSString *)key {
+    
+    __block BOOL exists = NO;
+    dispatch_sync(_ioQueue, ^{
+        exists = [_fileManager fileExistsAtPath:[self defaultCachePathForKey:key]];
+    });
+    
+    return exists;
+}
+
 - (UIImage *)imageFromMemoryCacheForKey:(NSString *)key
 {
     return [self.memCache objectForKey:key];
diff --git a/SDWebImage/SDWebImageManager.h b/SDWebImage/SDWebImageManager.h
index da8abce..4528dcf 100644
--- a/SDWebImage/SDWebImageManager.h
+++ b/SDWebImage/SDWebImageManager.h
@@ -171,4 +171,9 @@ SDWebImageManager *manager = [SDWebImageManager sharedManager];
  */
 - (BOOL)isRunning;
 
+/**
+ * Check if image has already been cached
+ */
+- (BOOL)diskImageExistsForURL:(NSURL *)url;
+
 @end
diff --git a/SDWebImage/SDWebImageManager.m b/SDWebImage/SDWebImageManager.m
index 8940d65..5c89fdf 100644
--- a/SDWebImage/SDWebImageManager.m
+++ b/SDWebImage/SDWebImageManager.m
@@ -66,6 +66,11 @@
     }
 }
 
+- (BOOL)diskImageExistsForURL:(NSURL *)url {
+    NSString *key = [self cacheKeyForURL:url];
+    return [self.imageCache diskImageExistsWithKey:key];
+}
+
 - (id<SDWebImageOperation>)downloadWithURL:(NSURL *)url options:(SDWebImageOptions)options progress:(SDWebImageDownloaderProgressBlock)progressBlock completed:(SDWebImageCompletedWithFinishedBlock)completedBlock
 {    
     // Invoking this method without a completedBlock is pointless

From 8a2ae7e5475640bbf36ae8d0944eb621811619f2 Mon Sep 17 00:00:00 2001
From: Don <don.holly@gmail.com>
Date: Thu, 12 Sep 2013 13:45:11 -0700
Subject: [PATCH 2/2] Fixed styling to match rs/SDWebImage repo

---
 SDWebImage/SDImageCache.m      | 10 ++++++----
 SDWebImage/SDWebImageManager.m |  3 ++-
 2 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/SDWebImage/SDImageCache.m b/SDWebImage/SDImageCache.m
index 16b1e6c..f520fe5 100644
--- a/SDWebImage/SDImageCache.m
+++ b/SDWebImage/SDImageCache.m
@@ -62,7 +62,8 @@ static const NSInteger kDefaultCacheMaxCacheAge = 60 * 60 * 24 * 7; // 1 week
         NSArray *paths = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES);
         _diskCachePath = [paths[0] stringByAppendingPathComponent:fullNamespace];
 
-        dispatch_sync(_ioQueue, ^{
+        dispatch_sync(_ioQueue, ^
+        {
             _fileManager = NSFileManager.new;
         });
         
@@ -190,10 +191,11 @@ static const NSInteger kDefaultCacheMaxCacheAge = 60 * 60 * 24 * 7; // 1 week
     [self storeImage:image imageData:nil forKey:key toDisk:toDisk];
 }
 
-- (BOOL)diskImageExistsWithKey:(NSString *)key {
-    
+- (BOOL)diskImageExistsWithKey:(NSString *)key
+{
     __block BOOL exists = NO;
-    dispatch_sync(_ioQueue, ^{
+    dispatch_sync(_ioQueue, ^
+    {
         exists = [_fileManager fileExistsAtPath:[self defaultCachePathForKey:key]];
     });
     
diff --git a/SDWebImage/SDWebImageManager.m b/SDWebImage/SDWebImageManager.m
index 5c89fdf..a3ecdec 100644
--- a/SDWebImage/SDWebImageManager.m
+++ b/SDWebImage/SDWebImageManager.m
@@ -66,7 +66,8 @@
     }
 }
 
-- (BOOL)diskImageExistsForURL:(NSURL *)url {
+- (BOOL)diskImageExistsForURL:(NSURL *)url
+{
     NSString *key = [self cacheKeyForURL:url];
     return [self.imageCache diskImageExistsWithKey:key];
 }