[翻译] TCBlobDownload

TCBlobDownload

TCBlobDownload uses NSOperations to download large files (typically videos, music... well: BLOBs) using NSURLConnection in background threads.

TCBlobDownload使用了NSOpreations来下载大文件(尤其是视频,音乐之类的),在子线程中用NSURLConnection作为下载用的类.

Tested with files from ~150MB to ~1.2GB, mostly videos.

本人测试过的下载文件大小介于150Mb到1.2G之间,大部分都是视频文件.

I've implemented TCBlobDownloader which extends NSOperation and useTCBlobDownloadManager to execute it. You can set a delegate or use blocks for each download to update your views etc…

我已经实现了TCBlobDownloader,它扩展了NSOperation,你可以用TCBlobDownloadManager来运行它.你可以设置一个代理或者是一个block来更新下载进度.   

Requires iOS 5.0 or later and ARC.

需要iOS5.0+以及ARC

• Features
• Documentation
• Installation
• Examples
• Roadmap

Features

1. Download files in background threads 在子线程中下载文件
2. Blocks or delegate style 支持block以及代理的方式
3. Pause and resume a download 支持断点续传
4. Set a maximum number of concurrent downloads 可以设置最大并发下载数目
5. Custom download path 自定义下载路径
6. Download speed and remaining time 可以查看到下载速度以及下载剩下的时间
7. Download cancellation 支持取消下载
8. Download dependencies 支持队列下载

Documentation 

Browse the documentation on Cocoadocs or add it directly to Xcode by downloading the docset and placing it into ~/Library/Developer/Shared/Documentation/DocSets/. (or use Dash)

你可以通过Cocoadocs来下载支持文档,或者是你直接下载好后放在~/Libaray/Developer/Shared/Documentation/DocSets/.下面(或者直接使用Dash)

Installation

CocoaPods

Add the following to your Podfile and run $ pod install:

你可以直接使用CocoaPods来安装,执行 $ pod install 即可:

pod 'TCBlobDownload'

If you don't have CocoaPods installed or integrated into your project, you can learn how to do so here.

(Also be sure the $(inherited) flag is set in your Project's Target -> Build Settings -> Other Linker Flags)

如果你没有CocoaPods,你可以用这个here

Import as a static library

1. Drag and drop TCBlobDownload.xcodeproj from Finder to your opened project. 将TCBlobDownload.xcodeproj拖到你的项目当中去.
2. Project's Target -> Build Phases -> Target Dependencies -> add TCBlobDownload. Then, click Link binary with libraries and add libTCBlobDownload.a (no worries if it's red).  Project's Target -> Build Phases -> Target Dependencies ->中添加TCBlobDownload,然后,点击Link binary with libraries 添加上libTCBlobDownload.a静态库(如果是红色的也不用紧张).  
3. Go to build settings, switch "always search user paths" to YES and add$(PROJECT_TEMP_DIR)/../UninstalledProducts/include to "User Header Search Paths". 到build settings中,将"always search user paths"切换到YES,然后添加$(PROJECT_TEMP_DIR)/../UninstalledProducts/include到"User Header Search Paths"
4. Project's Target -> Build Settings -> Other Linker Flags -> Add -ObjC  Target -> Build Settings -> Other Linker Flags ->添加上-Objc
5. Import the lib. (no worries if no autocomplete) 导入静态库

#import <TCBlobDownload/TCBlobDownload.h>

Examples 

1. Blocks

To immediately start a download in the default TCBlobDownloadManager directory (tmp/ by default):

你可以用block的方式来开始一个默认的下载任务(直接下载到tmp/目录下):

TCBlobDownloadManager *sharedManager = [TCBlobDownloadManager sharedInstance];

TCBlobDownloader *downloader = [sharedManager startDownloadWithURL:@"http://give.me/abigfile.avi"
                downloadPath:nil
               firstResponse:^(NSURLResponse *response) {

               }
               progress:^(uint64_t receivedLength, uint64_t totalLength, NSInteger remainingTime, float progress) {
                 // downloader.remainingTime
                 // downloader.speedRate
               }
               error:^(NSError *error) {

               }
               complete:^(BOOL downloadFinished, NSString *pathToFile) {

               }];

If you set a custom path:

你也可以自己设置路径:

NSString *customPath = [NSTemporaryDirectory() stringByAppendingPathComponent:@"My/Custom/Path/"];

TCBlobDownloader *downloader = [sharedManager startDownloadWithURL:@"http://give.me/abigfile.avi"
                                                        customPath:customPath // here we set the path
                                                       andDelegate:nil];

This will create the given path if needed and download the file in the Path/ directory. Please note that during the download process you have no control over the file name as explained with reasons why in the documentation. Remember that you should follow the iOS Data Storage Guidelines.

这将会根据你给出的路径来创建出下载文件.请注意,下载期间你无法控制文件命名,你可以看看苹果的文件存储规范.

2. Delegate

You can either set a delegate which can implement those optional methods if delegates have your preference over blocks:

你也可是设置代理来控制下载:

- (void)download:(TCBlobDownloader *)download didReceiveFirstResponse:(NSURLResponse *)response
{

}

- (void)download:(TCBlobDownloader *)download didReceiveData:(uint64_t)received onTotal:(uint64_t)total
{
  // download.remainingTime
  // download.speedRate
}

- (void)download:(TCBlobDownloader *)download didStopWithError:(NSError *)error
{

}

- (void)download:(TCBlobDownloader *)download didFinishWithSucces:(BOOL)downloadFinished atPath:(NSString *)pathToFile
{

}

3. Other features

• If a download has been stopped and the local file has not been deleted, when you will restart the download to the same local path, the download will start where it has stopped using the HTTPRange header (14.35). 如果你已经停止了下载,而且,本地的文件也没有被删除掉,下一次下载会直接从断点处下载.

• You can also set dependencies in your downloads using the addDependentDownload: method from TCBlobDownloader. 你可以设置下载依赖,使用addDependentDownload:来设置下载依赖问题.

See documentation for more details.

请看文档来了解更多的信息.

Roadmap 

If you have any idea or request, please suggest it! 

如果你有任何建议或者需求,提出来吧!

• Multi segmented downloads 多线程下载同一个文件.
• Dash XML feed for documentation versioning