Swift Byte Processor

akshansh_96_zerodha

For people who are looking to build iOS and Android apps, I've written a byte processor for the zerodha APIs for web socket streaming..

https://github.com/athakur3/swiftKiteConnect


example:


class ByteProcessor: NSObject {

/// Two bytes inside of a data packet are allocated to communicate the number of packets
let numberOfPacketsByteSize = 2

/// Two bytes are allocated in the data to communicate the length of each packet
let lengthOfPacketsByteSize = 2

/// 4 Bytes represent each node inside a packet
let packetSubDataLength = 4


/*

|--| |- -| |--||--||--| |- -| |--||--||--|
NP LP1 LP2
(No of packets) (P1 Length) (Packet 1) (P2 Length) (Packet 2) ....

*/

let data: Data

init(data: Data) {
self.data = data
}


func processByteData() -> [[UInt32]] {

var index = 1

// Get first two bytes.. This has the number of packets
// Index [0, 1]
let numberOfPacketsData = data[0...index]

let numberOfPackets = Int(getInt16Value(data: numberOfPacketsData))

var dataPackets = [[UInt32]]()

// Loop Through Each Packet
Array(0...(numberOfPackets - 1)).forEach { value in
index += 2

let packetLengthData = data[(index - 1)...index]

guard let scalarPacketLength = String(data: packetLengthData, encoding: .utf16)?.unicodeScalars else {
return
}
guard scalarPacketLength.count == 1, let packetLength = scalarPacketLength.first?.value else {
return
}

var packet = [UInt32]()

for value in stride(
from: 0,
to: packetLength - 1,
by: packetSubDataLength
) {
packet.append(
getInt32Value(
data: data[
(
value + UInt32(
index + 1
)
)...(
value + UInt32(
index + 4
)
)
]
)
)
}

dataPackets.append(packet)

index += Int(packetLength)

}

return dataPackets
}

func getInt32Value(data: Data) -> UInt32 {
return UInt32(bigEndian: data.withUnsafeBytes { $0.pointee })
}

func getInt16Value(data: Data) -> UInt16 {
return UInt16(bigEndian: data.withUnsafeBytes { $0.pointee })
}
}



*Cries to hire me*