server.go

package main

import (
	"math/rand"
	"time"
)

// This file should only handle initialization of actors

func main() {
	go dataReadLoop() // Start our async read loop
	client.start()    // Start our client
	go dataSendLoop() // Start our loop to tell the client when to send

	select {} // Immortality
}

func dataSendLoop() {
	for {
		time.Sleep(time.Second * dataSendPeriod)
		client.sendData()
	}
}

// TODO: when we have a real modbus connection the next two funcs will be moved into a modbus manager
func dataReadLoop() { // Read data all day every day
	for {
		dataBuffer := make(map[string][]StampedReading)
		reading := readData()                // TODO: error handling
		for metric, value := range reading { // Put our data in the buffer
			if record, found := dataBuffer[metric]; !found {
				dataBuffer[metric] = []StampedReading{value}
			} else {
				dataBuffer[metric] = append(record, value)
			}
		}
		client.send <- dataBuffer
		time.Sleep(time.Second * dataReadPeriod)
	}
}

var oldReadings = map[string]StampedReading{}

func readData() map[string]StampedReading {
	newReadings := map[string]StampedReading{}
	for _, element := range metrics {
		newRead := StampedReading{
			int(time.Now().Unix()),
			0.875*oldReadings[element.Name].Value + 0.125*((rand.Float32()*(element.UBound-element.LBound))+element.LBound),
		}
		newReadings[element.Name] = newRead
	}
	oldReadings = newReadings
	return newReadings
}