Upload a file to FTP - swift

Question

I'm trying to upload a file with Swift.
I found this (poorly written) tutorial from Apple for Objective-C:
I tried to implement it in Swift, but got stuck on dereferencing the pointer in the callback function:
func upload(filepath:String, url:String){
do {
let attr:NSDictionary? = try FileManager.default.attributesOfItem(atPath: filepath) as NSDictionary;
if attr == nil { return; }
let size:UInt64? = attr?.fileSize();
if size==nil { return; }
var info = MyStreamInfo(writeStream: CFWriteStreamCreateWithFTPURL(nil, CFURLCreateWithString(nil,url as CFString, nil)) as! CFWriteStream,
readStream: CFReadStreamCreateWithFile(nil, CFURLCreateWithString(nil, filepath as CFString, nil)),
/*proxyDict: CFDictionary(), */fileSize: size!, totalBytesWritten: 0, leftOverByteCount: 0, buffer: UnsafeMutablePointer<UInt8>.allocate(capacity: bSize));
var myContext=CFStreamClientContext(version: 0, info: &info, retain: nil, release: nil, copyDescription: nil);
//myContext.info = info;
CFReadStreamOpen(info.readStream);
CFWriteStreamSetProperty(info.writeStream, CFStreamPropertyKey(kCFStreamPropertyFTPUserName), username as CFTypeRef);
CFWriteStreamSetProperty(info.writeStream, CFStreamPropertyKey(kCFStreamPropertyFTPPassword), password as CFTypeRef);
CFWriteStreamSetProperty(info.writeStream, CFStreamPropertyKey(kCFStreamPropertyFTPProxyHost), hostname as CFTypeRef);
CFWriteStreamSetProperty(info.writeStream, CFStreamPropertyKey(kCFStreamPropertyFTPProxyPort), port as CFTypeRef);
CFWriteStreamSetClient(info.writeStream, CFStreamEventType.canAcceptBytes.rawValue, writeCB as! CFWriteStreamClientCallBack, &myContext);
} catch let error as NSError {
print(error);
}
}
func writeCB(stream:CFWriteStream, event:CFStreamEventType, myptr: UnsafeMutableRawPointer) {
var info:MyStreamInfo;
var totalBytesRead:Int32 = 0;
repeat {
var bytesRead:Int32 = 0;
var bytesWritten:Int32 = 0;
if info.leftOverByteCount>0 {
bytesRead = Int32(info.leftOverByteCount);
} else {
bytesRead = Int32(CFReadStreamRead(info.readStream, info.buffer, bSize));
if (bytesRead < 0){
print("error");
return;
}
totalBytesRead += bytesRead;
}
bytesWritten = Int32(CFWriteStreamWrite(info.writeStream, info.buffer, CFIndex(bytesRead)));
if bytesWritten > 0 {
info.totalBytesWritten += UInt32(bytesWritten);
if bytesWritten < bytesRead {
info.leftOverByteCount = UInt32(bytesRead - bytesWritten);
memmove(info.buffer, info.buffer.advanced(by: Int(bytesWritten)), Int(info.leftOverByteCount));
} else {
info.leftOverByteCount = 0;
}
} else {
if bytesWritten < 0 {
print("error");
break;
}
}
} while(CFWriteStreamCanAcceptBytes(info.writeStream));
}
How can I get the MyStreamInfo object out of the pointer?
Am I doing the rest right?
username, password, etc are of course members of my class that I set elsewhere.

Answer 1

You can use FilesProvider library to deal with FTP. It doesn't use deprecated CFWriteStreamCreateWithFTPURL API and implements FTP protocol from scratch and provides a high level, FileManager like API to deal with FTP/FTPS.
You can see a sample implementation here.