janus/lib/RequestHandler.go

package lib

import (
	producer_module "com.navi.medici.janus/producer"

	"log"
    "net/http"  
	"encoding/binary"
	"github.com/Shopify/sarama"

)

var (
	RequestChannel = make(chan *RequestObject)
)

type RequestObject struct {
	Body     []byte
	Header   http.Header
}

func ProcessRequestChannel(topic string) {
    for {
        request := <- RequestChannel
        ClickstreamProtobufEventHandler(*request, topic)
    }
}

func ClickstreamProtobufEventHandler(request RequestObject, topic string) {

    messageBytes := request.Body

    // to be of the format [magicByte] + [schemaID] + [messageIndex] + [value]
	recordValue := []byte{}

    // add [magicByte]
    recordValue = append(recordValue, byte(0))

    // add schemaID]
    schemaIDBytes := make([]byte, 4)
    binary.BigEndian.PutUint32(schemaIDBytes, uint32(producer_module.SchemaVersionMap[topic]))
    recordValue = append(recordValue, schemaIDBytes...)

    // add [messageIndex]
    messageIndexBytes := []byte{byte(2), byte(0)}
    recordValue = append(recordValue, messageIndexBytes...)

    // Now write the bytes from the actual message...
    recordValue = append(recordValue, messageBytes...)

	message := &sarama.ProducerMessage{
        Topic: topic,
        Value: sarama.ByteEncoder(recordValue),
    }

    producer_module.WriteMessageToKafkaAsync(message)
    
}