Database server that stores {key, value} in memory.

README.md

Database server, to compile and run, run ./run.sh

cache.go has the cache store. server.go creates the server and serves request. main.go is the driver file.

cache.go

package main

import (
	"log"
)

var store = make(map[string]string)

func setValue(key, value string) {
	store[key] = value
	log.Print("setValue: Key %s, Value %s:", key, value)
}

func getValue(key string) string {
	value := store[key]
	log.Print("getValue: Key %s, Value %s:", key, value)
	return value
}

main.go

package main

import "log"

const port = 4000

func main() {
	setRouter()
	err := setListeningPort(PORT)
	if err != nil {
		log.Fatal("Oops there was an error: ", err)
	}
}

run.sh

#!

go build main.go server.go cache.go

./main

server.go

package main

import (
	"bytes"
	"fmt"
	"log"
	"net/http"
	"strconv"
	"strings"
)

func setRouter() {
	http.HandleFunc("/", listen)
}

func getPortString(port int) string {
	var portBuffer bytes.Buffer
	portBuffer.WriteString(":")
	portBuffer.WriteString(strconv.Itoa(port))
	return portBuffer.String()
}

func setListeningPort(port int) error {
	err := http.ListenAndServe(getPortString(port), nil)
	return err
}

func requestDecoder(request http.Request) (string, string) {
	for k, v := range request.Form {
		return k, strings.Join(v, "")
	}
	return "", ""
}

func requestSelector(response http.ResponseWriter, request *http.Request) {

	key, value := requestDecoder(*request)

	if len(key) == 0 || len(value) == 0 {
		fmt.Fprintf(response, "Request is ill-formed")
	} else if request.URL.Path == "/set" {
		setValue(key, value)
		fmt.Fprintf(response, "Stored data in cache")
	} else if request.URL.Path == "/get" {
		storedValue := getValue(value)
		if len(storedValue) == 0 {
			fmt.Fprintf(response, "Key does not exist in cache")
		}
		log.Print("Response %s:", storedValue)
		fmt.Fprintf(response, storedValue)
	} else {
		log.Print("Request not supported")
		fmt.Fprintf(response, "Request not supported")
	}
}

func listen(response http.ResponseWriter, request *http.Request) {
	log.Print("Request: %T", request)
	request.ParseForm()
	requestSelector(response, request)
}