ios - 使用缓冲区 iOS 7 上传
<p><p>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:</p>
<pre><code>void * bytes = malloc("");
NSData * myData = ;
free("bytes");
</code></pre>
<p>但是如果我想上传一个大文件会出现内存问题...</p>
<p>我的上传过程是这样的:</p>
<pre><code>NSURLSessionConfiguration *sessionConfig =
;
NSURLSession *session =
[NSURLSession sessionWithConfiguration:sessionConfig
delegate:self
delegateQueue:nil];
NSURL * urll = ;
NSMutableURLRequest * urlRequest = ;
;
;
NSString *boundary = @"*****";
NSString *contentType = ;
;
NSMutableData *body = ;
dataUsingEncoding:NSUTF8StringEncoding]];
];
dataUsingEncoding:NSUTF8StringEncoding]];
// setting the body of the post to the reqeust
;
void * bytes = malloc(250000000);
NSData * uploadData = ;
free(bytes);
ulTask = ;
;
</code></pre>
<p>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？!</p></p>
<br><hr><h1><strong>Best Answer-推荐答案</ strong></h1><br>
<p><p>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 <code>uploadTaskWithStreamedRequest</code> 然后创建一个 <code>NSInputStream</code> 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 <code>URLSession:task:didSendBodyData:totalBytesSent:totalBytesExpectedToSend:</code> 来监控上传进度(因此您可以大概监控数据发送的速度)。</p>
<p>无论如何，创建上传请求:</p>
<pre><code>@interface ViewController () <NSURLSessionDelegate, NSURLSessionTaskDelegate>
@property (nonatomic, strong) CustomStream *inputStream;
@end
@implementation ViewController
- (void)viewDidLoad
{
;
self.inputStream = [ init];
NSURL *url = ;
NSMutableURLRequest *request = ;
;
NSURLSessionConfiguration *configuration = ;
NSURLSession *session = ;
NSURLSessionUploadTask *task = ;
;
// 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;
});
}
</code></pre>
<p>您显然必须实现适当的委托(delegate)方法:</p>
<pre><code>#pragma mark - NSURLSessionTaskDelegate
- (void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task didSendBodyData:(int64_t)bytesSent totalBytesSent:(int64_t)totalBytesSent totalBytesExpectedToSend:(int64_t)totalBytesExpectedToSend
{
NSLog(@"%lld %lld %lld", bytesSent, totalBytesSent, totalBytesExpectedToSend);
}
- (void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task needNewBodyStream:(void (^)(NSInputStream *bodyStream))completionHandler
{
completionHandler(self.inputStream);
}
- (void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task didCompleteWithError:(NSError *)error
{
NSLog(@"%s: error = %@; data = %@", __PRETTY_FUNCTION__, error, [ 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 = ;
completionHandler(NSURLSessionResponseAllow);
}
- (void)URLSession:(NSURLSession *)session dataTask:(NSURLSessionDataTask *)dataTask didReceiveData:(NSData *)data
{
;
}
</code></pre>
<p>还有<code>CustomStream</code>:</p>
<pre><code>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 = ;
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 () {
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
</code></pre>
<p>我建议你引用 BJ Homer 的文章 <a href="http://bjhomer.blogspot.com/2011/04/subclassing-nsinputstream.html" rel="noreferrer noopener nofollow">Subclassing NSInputStream</a>关于这个 <code>NSInputStream</code> 子类中一些神秘方法的一些背景知识。 </p></p>
<p style="font-size: 20px;">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：
<a href="https://stackoverflow.com/questions/22864565/" rel="noreferrer noopener nofollow" style="color: red;">
https://stackoverflow.com/questions/22864565/
</a>
</p>
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