From 18334bcc8f298125a67cf35f39c25bdcc155128f Mon Sep 17 00:00:00 2001
From: Jon Parise <jon@indelible.org>
Date: Tue, 25 Jun 2013 19:25:04 -0700
Subject: [PATCH] Add -calculateSizeWithCompletionBlock:.

This method provides a way to asynchronously calculate the size of the
disk cache, reporting both the number of files and the total file
size.

This is useful when querying large disk caches because the file system
enumeration operation can take some time.
---
 SDWebImage/SDImageCache.h |  5 +++++
 SDWebImage/SDImageCache.m | 33 +++++++++++++++++++++++++++++++++
 2 files changed, 38 insertions(+)

diff --git a/SDWebImage/SDImageCache.h b/SDWebImage/SDImageCache.h
index d3699b60..afe07f47 100644
--- a/SDWebImage/SDImageCache.h
+++ b/SDWebImage/SDImageCache.h
@@ -154,4 +154,9 @@ typedef enum SDImageCacheType SDImageCacheType;
  */
 - (int)getDiskCount;
 
+/**
+ * Asynchronously calculate the disk cache's size.
+ */
+- (void)calculateSizeWithCompletionBlock:(void (^)(NSUInteger fileCount, unsigned long long totalSize))completionBlock;
+
 @end
diff --git a/SDWebImage/SDImageCache.m b/SDWebImage/SDImageCache.m
index 22e37148..5fe3aae8 100644
--- a/SDWebImage/SDImageCache.m
+++ b/SDWebImage/SDImageCache.m
@@ -423,4 +423,37 @@ static const NSInteger kDefaultCacheMaxCacheAge = 60 * 60 * 24 * 7; // 1 week
     return count;
 }
 
+- (void)calculateSizeWithCompletionBlock:(void (^)(NSUInteger fileCount, unsigned long long totalSize))completionBlock
+{
+    NSURL *diskCacheURL = [NSURL fileURLWithPath:self.diskCachePath isDirectory:YES];
+
+    dispatch_async(self.ioQueue, ^
+    {
+        NSUInteger fileCount = 0;
+        unsigned long long totalSize = 0;
+
+        NSFileManager *fileManager = [NSFileManager defaultManager];
+        NSDirectoryEnumerator *fileEnumerator = [fileManager enumeratorAtURL:diskCacheURL
+                                                  includingPropertiesForKeys:@[ NSFileSize ]
+                                                                     options:NSDirectoryEnumerationSkipsHiddenFiles
+                                                                errorHandler:NULL];
+
+        for (NSURL *fileURL in fileEnumerator)
+        {
+            NSNumber *fileSize;
+            [fileURL getResourceValue:&fileSize forKey:NSURLFileSizeKey error:NULL];
+            totalSize += [fileSize unsignedLongLongValue];
+            fileCount += 1;
+        }
+
+        if (completionBlock)
+        {
+            dispatch_async(dispatch_get_main_queue(), ^
+            {
+                completionBlock(fileCount, totalSize);
+            });
+        }
+    });
+}
+
 @end