Question

我试图将一个大的本地文件拆分成单独的NSData部分，然后使用AFNetworking 2上传每个文件部分。在所有上传成功后，每个文件部分的数据仍在内存中。每次完成零件上传后如何释放内存？我错过了什么？

以下是代码：

-(void) uploadRequestWithPart:(FilePart*) part{
    // setup request
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:part.uploadURL];
    [request setHTTPMethod:@"PUT"];
    [request setValue:part.fileType forHTTPHeaderField:@"Content-Type"];
    [request setValue:@"private" forHTTPHeaderField:@"x-amz-acl"];

    if(!sessionManager) sessionManager = [[AFURLSessionManager alloc] initWithSessionConfiguration:[NSURLSessionConfiguration defaultSessionConfiguration]];
    NSProgress *progress = nil;

    // create Data from file part
    FILE *file = fopen([part.fileURL.path UTF8String], "rb");
    if(file == NULL) return;
    void *data = malloc(part.size);
    fseeko(file, part.offset, SEEK_SET);
    fread(data, 1, part.size, file);
    fclose(file);

    NSURLSessionUploadTask *upTask;
    upTask = [sessionManager uploadTaskWithRequest:request fromData:[NSData dataWithBytesNoCopy:data length:part.size] progress:&progress completionHandler:^(NSURLResponse *response, id responseObject, NSError *error) {
        if (error){
            NSLog(@"%@",error.localizedDescription);
            [upTask cancel]; // <- does cancelling this task release the NSData??
            upTask = nil;
        } else{
            NSLog(@"Upload complete");
            [upTask cancel];  // <- does cancelling this task release the NSData??
            upTask = nil;
        }
        [progress removeObserver:self forKeyPath:@"partCompleted" context:nil];
    }];
    // setup upload progress
    [progress setUserInfoObject:part forKey:@"part"];
    [progress addObserver:self forKeyPath:@"partCompleted" options:NSKeyValueObservingOptionNew context:nil];

    // start upload
    [upTask resume];
}

谢谢，托马斯

Answer 1

dataBytesNoCopy：length：在文件部分缓冲区周围创建一个NSData包装器。生成的NSData对象负责释放数据缓冲区。由于有多种方法可以从文件中获取一大块字节，我尝试了这个（这对我有用）：

...
NSData *fileData = [NSData dataWithContentsOfFile:part.fileURL.path options:NSDataReadingMappedIfSafe error:nil];
NSData *partData = [fileData subdataWithRange:NSMakeRange(part.offset, part.size)];
NSURLSessionUploadTask *upTask;
upTask = [sessionManager uploadTaskWithRequest:request fromData:partData progress:&progress completionHandler:^(NSURLResponse *response, id responseObject, NSError *error) {...

这样ARC可以解决释放字节数据的问题。我希望这有助于某人。

数据上传后AFURLSessionManager可用内存

1 个答案: