Question

早上好，我正在开发一个上传一些文件的应用程序;没有真正的问题，但只有一个大问题：如果我尝试上传1GB的文件，它会分配1GB的内存，你可以理解这不是一件好事。

这是我的代码：我将数据分配为NSData，然后使用NSMutableURLRequest + NSURLConnection上传它们;我的问题是：有没有办法做到这一点，而无需分配整个内存？我搜索过了，但我一无所获......

_uploadDataFile是之前分配的NSData子类实例。

NSMutableURLRequest *request = [[[NSMutableURLRequest alloc] initWithURL:[NSURL URLWithString:@"http://my.server/page"]
                                                            cachePolicy:NSURLRequestReloadIgnoringCacheData
                                                        timeoutInterval:60.0] autorelease];

NSData *dataFile;

if (_uploadDataFile == nil) {
    NSError *error = nil;
    dataFile = [[[NSData alloc] initWithContentsOfFile:@"pathToFile" options:NSDataReadingUncached error:&error] autorelease];

    if (error) {
        NSLog(@"Error %i: %@", [error code], [error localizedDescription]);
        [self fermaUpload]; //Stop Upload
        return;
    }
}

else 
    dataFile = [_uploadDataFile file];

NSMutableDictionary *dictPost = [[[NSMutableDictionary alloc] init] autorelease];
[dictPost setValue:dataFile forKey:@"uploads[]"];

NSData *mutData = [self dataForPOSTWithDictionary:dictPost boundary:@"0194784892923" nomeFile:[@"pathToFile" lastPathComponent]];

NSString *postLength = [NSString stringWithFormat:@"%d", [mutData length]];

[request setHTTPMethod:@"POST"];
[request setValue:postLength forHTTPHeaderField:@"Content-Length"];
[request setValue:@"multipart/form-data; boundary=0194784892923" forHTTPHeaderField:@"Content-Type"];
[request setHTTPBody:mutData];
[request setHTTPShouldHandleCookies:YES];

theConnection = [[NSURLConnection alloc] initWithRequest:request delegate:self];

以及如何 - （NSData *）dataForPOSTWithDictionary：boundary：nomeFile：方法如下：

- (NSData *)dataForPOSTWithDictionary:(NSDictionary *)aDictionary boundary:(NSString *)aBoundary nomeFile:(NSString *)nomeFile {
NSArray *myDictKeys = [aDictionary allKeys];
NSMutableData *myData = [NSMutableData dataWithCapacity:1];
NSString *myBoundary = [NSString stringWithFormat:@"--%@\r\n", aBoundary];

for(int i = 0;i < [myDictKeys count];i++) {
    id myValue = [aDictionary valueForKey:[myDictKeys objectAtIndex:i]];
    [myData appendData:[myBoundary dataUsingEncoding:NSUTF8StringEncoding]];
    //if ([myValue class] == [NSString class]) {
    if ([myValue isKindOfClass:[NSString class]]) {
        [myData appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name=\"%@\"\r\n\r\n", [myDictKeys objectAtIndex:i]] dataUsingEncoding:NSUTF8StringEncoding]];
        [myData appendData:[[NSString stringWithFormat:@"%@", myValue] dataUsingEncoding:NSUTF8StringEncoding]];
    } else if(([myValue isKindOfClass:[NSURL class]]) && ([myValue isFileURL])) {
        [myData appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name=\"%@\"; filename=\"%@\"\r\n", [myDictKeys objectAtIndex:i], [[myValue path] lastPathComponent]] dataUsingEncoding:NSUTF8StringEncoding]];
        [myData appendData:[[NSString stringWithFormat:@"Content-Type: application/octet-stream\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];
        [myData appendData:[NSData dataWithContentsOfFile:[myValue path]]];
    } else if(([myValue isKindOfClass:[NSData class]])) {
        [myData appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name=\"%@\"; filename=\"%@\"\r\n", [myDictKeys objectAtIndex:i], nomeFile] dataUsingEncoding:NSUTF8StringEncoding]];
        [myData appendData:[[NSString stringWithFormat:@"Content-Type: application/octet-stream\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];
        [myData appendData:myValue];
    } // eof if()

    [myData appendData:[[NSString stringWithString:@"\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];
} // eof for()
[myData appendData:[[NSString stringWithFormat:@"--%@--\r\n", aBoundary] dataUsingEncoding:NSUTF8StringEncoding]];

return myData; } // eof dataForPOSTWithDictionary:boundary:

谢谢你，对不起我的英语。

Answer 1

一个最有趣的问题！有两种方法可以将身体数据输入NSURLConnection/Request：

NSData
NSInputStream

不幸的是，既不想开箱即用，也不想上传文件+某些表单数据。理想情况下，您可以将NSInputStream子类化，以根据需要提供格式化的数据。但是，我上次检查时，NSURLConnection无法处理此类子类。相反，做一些像：

使用CFStreamCreateBoundPair()创建一对流。这会返回CFWriteStream和CFReadStream，它们分别免费桥接到NSOutputStream和NSInputStream
将自己设置为输出流的委托
-setHTTPBodyStream:
开始连接

现在应该定期调用输出流的委托，请求数据。您需要输入POST数据，然后输入大量文件数据。因此，整个文件永远不会完全在内存中。

NSMutableURLRequest和内存问题

1 个答案: