ios - NSURLSession - 使用带有 AWS IOS 开发工具包的 uploadTaskWithStreamedRequest

Question

我已经搜索了几天来上传IOS Assets 而不在临时目录中创建文件副本的方法，但运气不好。我得到了使用临时副本的代码，但是复制可能从 10MB 到 4GB 的视频文件是不现实的。
我最接近以只读模式读取 Assets 的是下面的代码。根据苹果文档，这应该可以工作 - 请参阅以下链接:

https://developer.apple.com/library/ios/documentation/Miscellaneous/Reference/EntitlementKeyReference/Chapters/EnablingAppSandbox.html

我已启用这些键:

<key>com.apple.security.assets.movies.read-write</key>
<string>YES</string>
<key>com.apple.security.assets.music.read-write</key>
<string>YES</string>
<key>com.apple.security.assets.pictures.read-write</key>
<string>YES</string>
<key>com.apple.security.files.downloads.read-write</key>
<string>YES</string>

这是代码:

//  QueueController.h
#import <AVFoundation/AVFoundation.h>
#import <AWSS3.h>
#import <Foundation/Foundation.h>
#import <MobileCoreServices/MobileCoreServices.h>
#import "Reachability1.h"
#import "TransferType.h"
#import "TransferModel.h"
#import "Util.h"

@interface QueueController : NSObject<NSURLSessionDelegate>

@property(atomic, strong) NSURLSession* session;
@property(atomic, strong) NSNumber* sessionCount;
@property(atomic, strong) NSURLSessionConfiguration* configuration;

+ (QueueController*)sharedInstance;
- (void)transferMediaViaQueue:(MediaItem*)mediaItem
             withTransferType:(TransferType)transferType;
@end

@implementation QueueController {
  NSOperationQueue* copyQueue;
  NSOperationQueue* transferQueue;
  NSMutableArray* inProcessTransferArray;
  NSMutableArray* pendingTransferArray;
  bool isTransferring;
}

static QueueController* sharedInstance = nil;

// Get the shared instance and create it if necessary.
+ (QueueController*)sharedInstance {
  @synchronized(self) {
    if (sharedInstance == nil) {
      sharedInstance = [[QueueController alloc] init];
    }
  }
  return sharedInstance;
}

- (id)init {
  if (self = [super init]) {
    appDelegate =
        (RootViewControllerAppDelegate*)[UIApplication sharedApplication]
            .delegate;
    copyQueue = [[NSOperationQueue alloc] init];
    transferQueue = [[NSOperationQueue alloc] init];
    transferQueue.maxConcurrentOperationCount = MAX_CONCURRENT_TRANSFERS;
    inProcessTransferArray = [[NSMutableArray alloc] init];
    pendingTransferArray = [[NSMutableArray alloc] init];
    isTransferring = false;
    if (self.session == nil) {
      self.configuration = [NSURLSessionConfiguration
          backgroundSessionConfigurationWithIdentifier:@"transferQueue"];
      self.session = [NSURLSession sessionWithConfiguration:self.configuration
                                                   delegate:self
                                              delegateQueue:transferQueue];
    }
  }
  return self;
}

- (void)transferMediaViaQueue:(MediaItem*)mediaItem
             withTransferType:(TransferType)transferType {
  // Create a transfer model
  NSUserDefaults* defaultUser = [NSUserDefaults standardUserDefaults];
  NSString* user_id = [defaultUser valueForKey:@"UserId"];
  TransferModel* transferModel = [[TransferModel alloc] init];
  transferModel.mediaItem = mediaItem;
  transferModel.transferType = transferType;
  transferModel.s3Path = user_id;
  transferModel.s3file_name = mediaItem.mediaName;
  transferModel.assetURL =
      [[mediaItem.mediaLocalAsset defaultRepresentation] url];

  ALAssetRepresentation* mediaRep =
      [mediaItem.mediaLocalAsset defaultRepresentation];
  transferModel.content_type =
      (__bridge_transfer NSString*)UTTypeCopyPreferredTagWithClass(
          (__bridge CFStringRef)[mediaRep UTI], kUTTagClassMIMEType);

  @synchronized(pendingTransferArray) {
    if ((!isTransferring) &&
        (transferQueue.operationCount < MAX_CONCURRENT_TRANSFERS)) {
      isTransferring = true;
      if (transferModel.transferType == UPLOAD) {
        /**
         * Read ALAsset from NSURLRequestStream
         */
        NSInvocationOperation* uploadOP = [[NSInvocationOperation alloc]
            initWithTarget:self
                  selector:@selector(uploadMediaViaLocalPath:)
                    object:transferModel];
        [transferQueue addOperation:uploadOP];
        [inProcessTransferArray addObject:transferModel];
      }

    } else {
      // Add to pending
      [pendingTransferArray addObject:transferModel];
    }
  }
}

- (void)uploadMediaViaLocalPath:(TransferModel*)transferModel {
  @try {
    /**
     * Fetch readable asset 
     */
    NSURL* assetURL =
        [[transferModel.mediaItem.mediaLocalAsset defaultRepresentation] url];
    NSData* fileToUpload = [[NSData alloc] initWithContentsOfURL:assetURL];
    NSURLRequest* assetAsRequest =
        [NSURLRequest requestWithURL:assetURL
                      cachePolicy:NSURLRequestUseProtocolCachePolicy
                      timeoutInterval:60.0];
    /**
     * Fetch signed URL
     */
    AWSS3GetPreSignedURLRequest* getPreSignedURLRequest =
        [AWSS3GetPreSignedURLRequest new];
    getPreSignedURLRequest.bucket = BUCKET_NAME;
    NSString* s3Key = [NSString stringWithFormat:@"%@/%@", transferModel.s3Path, transferModel.s3file_name];
    getPreSignedURLRequest.key = s3Key;
    getPreSignedURLRequest.HTTPMethod = AWSHTTPMethodPUT;
    getPreSignedURLRequest.expires = [NSDate dateWithTimeIntervalSinceNow:3600];

    // Important: must set contentType for PUT request
    // getPreSignedURLRequest.contentType = transferModel.mediaItem.mimeType;
    getPreSignedURLRequest.contentType = transferModel.content_type;
    NSLog(@"mimeType: %@", transferModel.content_type);

    /**
     * Upload the file
     */
    [[[AWSS3PreSignedURLBuilder defaultS3PreSignedURLBuilder]
        getPreSignedURL:getPreSignedURLRequest]
        continueWithBlock:^id(BFTask* task) {
          NSURLSessionUploadTask* uploadTask;
          transferModel.sessionTask = uploadTask;
          if (task.error) {
            NSLog(@"Error: %@", task.error);
          } else {
            NSURL* presignedURL = task.result;
            NSLog(@"upload presignedURL is: \n%@", presignedURL);

            NSMutableURLRequest* request =
                [NSMutableURLRequest requestWithURL:presignedURL];
            request.cachePolicy = NSURLRequestReloadIgnoringLocalCacheData;
            [request setHTTPMethod:@"PUT"];
            [request setValue:transferModel.content_type
                forHTTPHeaderField:@"Content-Type"];

            uploadTask =
                [self.session uploadTaskWithStreamedRequest:assetAsRequest];
            [uploadTask resume];
          }
          return nil;
        }];
  } @catch (NSException* exception) {
    NSLog(@"exception: %@", exception);
  } @finally {
  }
}

- (void)URLSession:(NSURLSession*)session
                        task:(NSURLSessionTask*)task
             didSendBodyData:(int64_t)bytesSent
              totalBytesSent:(int64_t)totalBytesSent
    totalBytesExpectedToSend:(int64_t)totalBytesExpectedToSend {
  // Calculate progress
  double progress = (double)totalBytesSent / (double)totalBytesExpectedToSend;
  NSLog(@"UploadTask progress: %lf", progress);
}

- (void)URLSession:(NSURLSession*)session
                    task:(NSURLSessionTask*)task
    didCompleteWithError:(NSError*)error {
  NSLog(@"(void)URLSession:session task:(NSURLSessionTask*)task "
        @"didCompleteWithError:error called...%@",
        error);
}

- (void)URLSessionDidFinishEventsForBackgroundURLSession:
    (NSURLSession*)session {
  NSLog(@"URLSessionDidFinishEventsForBackgroundURLSession called...");
}

// NSURLSessionDataDelegate
- (void)URLSession:(NSURLSession*)session
          dataTask:(NSURLSessionDataTask*)dataTask
didReceiveResponse:(NSURLResponse*)response
 completionHandler:
     (void (^)(NSURLSessionResponseDisposition disposition))completionHandler {
  //completionHandler(NSURLSessionResponseAllow);
}

@end

但我收到此错误:

(void)URLSession:session task:(NSURLSessionTask*)task didCompleteWithError:error called...Error Domain=NSURLErrorDomain Code=-999 "cancelled" UserInfo=0x17166f840 {NSErrorFailingURLStringKey=assets-library://asset/asset.MOV?id=94F90EEB-BB6A-4E9D-B77E-CDD60173B60C&ext=MOV, NSLocalizedDescription=cancelled, NSErrorFailingURLKey=assets-library://asset/asset.MOV?id=94F90EEB-BB6A-4E9D-B77E-CDD60173B60C&ext=MOV}
 userInfo: {
    NSErrorFailingURLKey = "assets-library://asset/asset.MOV?id=94F90EEB-BB6A-4E9D-B77E-CDD60173B60C&ext=MOV";
    NSErrorFailingURLStringKey = "assets-library://asset/asset.MOV?id=94F90EEB-BB6A-4E9D-B77E-CDD60173B60C&ext=MOV";
    NSLocalizedDescription = cancelled;
}

在此先感谢您的帮助。

问候，
-J

Answer 1

关于使用 NSURLSessionUploadTask 的一些评论:

如果您实现 didReceiveResponse ，您必须调用completionHandler .

如果您调用uploadTaskWithStreamedRequest ，request 的文档参数警告我们:

The body stream and body data in this request object are ignored, and NSURLSession calls its delegate’s URLSession:task:needNewBodyStream: method to provide the body data.

所以你必须执行needNewBodyStream如果实现 NSInputStream基于请求。

预先警告，但使用这样的基于流的请求会创建一个带有 "chunked" transfer encoding 的请求并不是所有的服务器都能处理。

在代码中的某一时刻，您似乎尝试将 Assets 的内容加载到 NSData 中。 .如果你有这么大的 Assets ，你不能合理地将它加载到 NSData 中。目的。此外，这与使用 uploadTaskWithStreamedRequest 不一致。 .

您要么需要创建 NSInputStream或从文件上传。

您似乎正在使用 NSURLRequest 的 Assets URL .该 URL 应该是您的 Web 服务的 URL。

使用图像选择器时，您可以访问两个 URL 键:媒体 URL(一个 file:// 用于电影的 URL，但不是图片)和资源库引用 URL(一个 assets-library:// URL)。如果您使用媒体 URL，则可以使用它来上传电影。但是您不能将 Assets 库引用 URL 用于上传目的。您只能将其与 ALAssetsLibrary 结合使用.