//

// Socket+File.swift

// Swifter

//

// Created by Damian Kolakowski on 13/07/16.

//

import Foundation

#if os(iOS) || os(tvOS) || os (Linux)

// swiftlint:disable type_name function_parameter_count

struct sf_hdtr { }

private func sendfileImpl(_ source: UnsafeMutablePointer<FILE>, _ target: Int32, _: off_t, _: UnsafeMutablePointer<off_t>, _: UnsafeMutablePointer<sf_hdtr>, _: Int32) -> Int32 {

var buffer = [UInt8](repeating: 0, count: 1024)

while true {

let readResult = fread(&buffer, 1, buffer.count, source)

guard readResult > 0 else {

return Int32(readResult)

}

var writeCounter = 0

while writeCounter < readResult {

let writeResult = buffer.withUnsafeBytes { (ptr) -> Int in

let start = ptr.baseAddress! + writeCounter

let len = readResult - writeCounter

#if os(Linux)

return send(target, start, len, Int32(MSG_NOSIGNAL))

#else

return write(target, start, len)

#endif

}

guard writeResult > 0 else {

return Int32(writeResult)

}

writeCounter += writeResult

}

}

}

#endif

extension Socket {

public func writeFile(_ file: String.File) throws {

var offset: off_t = 0

var sf: sf_hdtr = sf_hdtr()

#if os(iOS) || os(tvOS) || os (Linux)

let result = sendfileImpl(file.pointer, self.socketFileDescriptor, 0, &offset, &sf, 0)

#else

let result = sendfile(fileno(file.pointer), self.socketFileDescriptor, 0, &offset, &sf, 0)

#endif

if result == -1 {

throw SocketError.writeFailed("sendfile: " + Errno.description())

}

}

}