ios - 使用缓冲区 iOS 7 上传

我正在尝试使用随机数据实现上传并测量速度。现在我正在像这样生成我的随机 NSData:

void * bytes = malloc("");
NSData * myData = [NSData dataWithBytes:bytes length:"bytes"];
free("bytes");

但是如果我想上传一个大文件会出现内存问题...

我的上传过程是这样的:

NSURLSessionConfiguration *sessionConfig =
[NSURLSessionConfiguration defaultSessionConfiguration];

NSURLSession *session =
[NSURLSession sessionWithConfiguration:sessionConfig
                              delegate:self
                         delegateQueue:nil];

NSURL * urll = [NSURL URLWithString:UPLOAD_SERVER];
NSMutableURLRequest * urlRequest = [NSMutableURLRequest requestWithURL:urll];
[urlRequest setHTTPMethod"OST"];
[urlRequest addValue"Keep-Alive" forHTTPHeaderField"Connection"];

NSString *boundary = @"*****";
NSString *contentType = [NSString stringWithFormat"multipart/form-data; boundary=%@",boundary];
[urlRequest addValue:contentType forHTTPHeaderField: @"Content-Type"];

NSMutableData *body = [NSMutableData data];
[body appendData:[[NSString stringWithFormat"\r\n--%@\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[@"Content-Type: application/octet-stream\r\n\r\n" dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[[NSString stringWithFormat"\r\n--%@--\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]];
// setting the body of the post to the reqeust
[urlRequest setHTTPBody:body];

void * bytes = malloc(250000000);
NSData * uploadData = [NSData dataWithBytes:bytes length:250000000];
free(bytes);

ulTask = [session uploadTaskWithRequest:urlRequest fromData:uploadData];

[ulTask resume];

有没有办法用缓冲区或其他东西上传？!比如生成小数据，上传这个然后生成一个新的再上传？!

---

Best Answer-推荐答案

我建议开始上传并继续发送数据。您还可以避免创建 250mb 缓冲区，方法是使用 uploadTaskWithStreamedRequest 然后创建一个 NSInputStream 子类，该子类一直提供更多数据，直到您告诉它停止。您可以实现 URLSession:task:didSendBodyData:totalBytesSent:totalBytesExpectedToSend: 来监控上传进度(因此您可以大概监控数据发送的速度)。

无论如何，创建上传请求:

@interface ViewController () <NSURLSessionDelegate, NSURLSessionTaskDelegate>

@property (nonatomic, strong) CustomStream *inputStream;

@end

@implementation ViewController

- (void)viewDidLoad
{
    [super viewDidLoad];

    self.inputStream = [[CustomStream alloc] init];

    NSURL *url = [NSURL URLWithString:kURLString];
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
    [request setHTTPMethod"OST"];

    NSURLSessionConfiguration *configuration = [NSURLSessionConfiguration defaultSessionConfiguration];
    NSURLSession *session = [NSURLSession sessionWithConfiguration:configuration delegate:self delegateQueue:nil];

    NSURLSessionUploadTask *task = [session uploadTaskWithStreamedRequest:request];

    [task resume];

    // I don't know how you want to finish the upload, but I'm just going 
    // to stop it after 10 seconds

    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(10.0 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
        self.inputStream.finished = YES;
    });
}

您显然必须实现适当的委托(delegate)方法:

#pragma mark - NSURLSessionTaskDelegate

- (void)URLSessionNSURLSession *)session taskNSURLSessionTask *)task didSendBodyDataint64_t)bytesSent totalBytesSentint64_t)totalBytesSent totalBytesExpectedToSendint64_t)totalBytesExpectedToSend
{
    NSLog(@"%lld %lld %lld", bytesSent, totalBytesSent, totalBytesExpectedToSend);
}

- (void)URLSessionNSURLSession *)session taskNSURLSessionTask *)task needNewBodyStreamvoid (^)(NSInputStream *bodyStream))completionHandler
{
    completionHandler(self.inputStream);
}

- (void)URLSessionNSURLSession *)session taskNSURLSessionTask *)task didCompleteWithError:(NSError *)error
{
    NSLog(@"%s: error = %@; data = %@", __PRETTY_FUNCTION__, error, [[NSString alloc] initWithData:self.responseData encoding:NSUTF8StringEncoding]);
}

#pragma mark - NSURLSessionDataDelegate

- (void)URLSession:(NSURLSession *)session dataTask:(NSURLSessionDataTask *)dataTask didReceiveResponse:(NSURLResponse *)response completionHandler:(void (^)(NSURLSessionResponseDisposition disposition))completionHandler
{
    self.responseData = [NSMutableData data];
    completionHandler(NSURLSessionResponseAllow);
}

- (void)URLSession:(NSURLSession *)session dataTask:(NSURLSessionDataTask *)dataTask didReceiveData:(NSData *)data
{
    [self.responseData appendData:data];
}

还有CustomStream:

static NSInteger const kBufferSize = 32768;

@interface CustomStream : NSInputStream

@property (nonatomic, readonly) NSStreamStatus streamStatus;
@property (nonatomic, getter = isFinished) BOOL finished;

@end

@interface CustomStream ()

@property (nonatomic) NSStreamStatus streamStatus;
@property (nonatomic) void *buffer;

@end

@implementation CustomStream

- (instancetype)init
{
    self = [super init];
    if (self) {
        _buffer = malloc(kBufferSize);
        NSAssert(_buffer, @"Unable to create buffer");
        memset(_buffer, 0, kBufferSize);
    }
    return self;
}

- (void)dealloc
{
    if (_buffer) {
        free(_buffer);
        self.buffer = NULL;
    }
}

- (void)open
{
    self.streamStatus = NSStreamStatusOpen;
}

- (void)close
{
    self.streamStatus = NSStreamStatusClosed;
}

- (NSInteger)read:(uint8_t *)buffer maxLength:(NSUInteger)len
{
    if ([self isFinished]) {
        if (self.streamStatus == NSStreamStatusOpen) {
            self.streamStatus = NSStreamStatusAtEnd;
        }
        return 0;
    }

    NSUInteger bytesToCopy = MIN(len, kBufferSize);
    memcpy(buffer, _buffer, bytesToCopy);

    return bytesToCopy;
}

- (BOOL)getBuffer:(uint8_t **)buffer length:(NSUInteger *)len
{
    return NO;
}

- (BOOL)hasBytesAvailable
{
    return self.streamStatus == NSStreamStatusOpen;
}

- (void)scheduleInRunLoop:(__unused NSRunLoop *)aRunLoop
                  forMode:(__unused NSString *)mode
{}

- (void)removeFromRunLoop:(__unused NSRunLoop *)aRunLoop
                  forMode:(__unused NSString *)mode
{}

#pragma mark Undocumented CFReadStream Bridged Methods

- (void)_scheduleInCFRunLoop:(__unused CFRunLoopRef)aRunLoop
                     forMode:(__unused CFStringRef)aMode
{}

- (void)_unscheduleFromCFRunLoop:(__unused CFRunLoopRef)aRunLoop
                         forMode:(__unused CFStringRef)aMode
{}

- (BOOL)_setCFClientFlags:(__unused CFOptionFlags)inFlags
                 callback:(__unused CFReadStreamClientCallBack)inCallback
                  context:(__unused CFStreamClientContext *)inContext {
    return NO;
}

@end

我建议你引用 BJ Homer 的文章 Subclassing NSInputStream关于这个 NSInputStream 子类中一些神秘方法的一些背景知识。

关于ios - 使用缓冲区 iOS 7 上传，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/22864565/