Add a cached parameter to the success block to tell the receiver if t…

…he image came from cache or network SDWebImage#181

Do not check request response status code when the protocol isn't HTTP (

fix SDWebImage#110)

Fix a bug in SDImageCache making first request to disk cache to alway…

…s return nil (fix SDWebImage#81)

Failsafe a very common usage error (passing URL as NSString instead o…

…f NSURL)

Perform disk cache out operations asynchronousely in order to prevent…

… from blocking the main runloop when a lot of cache queries are performed at the same time

Do not convert images to JPEG when stored to disk for caching

This saves CPU and memory in all cases and alpha channel / image clearness if orignal format was PNG or GIF.

Better nil url handling

Better nil url handling

Replace the NSOperation based downloader by a simple async NSURLConne…

…ction (read-on to understand why)

I finally found the reason behind the download not started while UITableView is manipulated: the default NSURLConnection runloop mode. Its default mode is NSEventTrackingRunLoopMode which is interrupted by UI events. Changing default NSURLConnection runloop mode to NSRunLoopCommonModes just fix this good old responsiveness issue.

I thus decided to replace the current NSOperation based implementation by this finding, as NSOperation is far more expensive than simple async connections. Additionally, moving aways from NSOperation here fix an odd lagging issue with iOS 4, an issue I can't explain at the moment.

Note that `SDWebImageDownloader`'s `setMaxConcurrentDownloads:` method is now a no-op as I didn't implemented the NSOperation queuing system with async connections. I don't think it still necessary as thread-less async connectaions are very lightweight. If you think there is a real need of this, I may reconsider and implement it in the future. In the meantime, this method does nothing and its usage is declared as deprecated.

Replace the NSOperation based downloader by a simple async NSURLConne…

…ction (read-on to understand why)

I finally found the reason behind the download not started while UITableView is manipulated: the default NSURLConnection runloop mode. Its default mode is NSEventTrackingRunLoopMode which is interrupted by UI events. Changing default NSURLConnection runloop mode to NSRunLoopCommonModes just fix this good old responsiveness issue.

I thus decided to replace the current NSOperation based implementation by this finding, as NSOperation is far more expensive than simple async connections. Additionally, moving aways from NSOperation here fix an odd lagging issue with iOS 4, an issue I can't explain at the moment.

Note that `SDWebImageDownloader`'s `setMaxConcurrentDownloads:` method is now a no-op as I didn't implemented the NSOperation queuing system with async connections. I don't think it still necessary as thread-less async connectaions are very lightweight. If you think there is a real need of this, I may reconsider and implement it in the future. In the meantime, this method does nothing and its usage is declared as deprecated.