iOS 快速计算目录的size
diskMode为YES时是指占用磁盘的空间（磁盘占用空间与文件的实际大小一般是不一样的）
+ (uint64_t)sizeAtPath:(NSString*)filePath diskMode:(BOOL)diskMode
{
uint64_t totalSize =0;
NSMutableArray*searchPaths = [NSMutableArrayarrayWithObject:filePath];
while([searchPaths count] >0)
{
@autoreleasepool
{
NSString*fullPath = [searchPaths objectAtIndex:0];
[searchPaths removeObjectAtIndex:0];
structstat fileStat;
if(lstat([fullPath fileSystemRepresentation], &fileStat) ==0)
{
if(fileStat.st_mode& S_IFDIR)
{
NSArray*childSubPaths = [[NSFileManagerdefaultManager] contentsOfDirectoryAtPath:fullPath error:nil];
for(NSString*childIteminchildSubPaths)
{
NSString*childPath = [fullPath stringByAppendingPathComponent:childItem];
[searchPaths insertObject:childPath atIndex:0];
}
}else
{
if(diskMode)
totalSize += fileStat.st_blocks*512;
else
totalSize += fileStat.st_size;
}
}
}
}
returntotalSize;
}
