A database server made for the Recurse Center's pairing interview.

DatabaseServer.go

//Before your interview, write a program that runs a server that is accessible on http://localhost:4000/.
//When your server receives a request on http://localhost:4000/set?somekey=somevalue it should store the
//passed key and value in memory. When it receives a request on http://localhost:4000/get?key=somekey it
//should return the value stored at somekey.

//During your interview, you will pair on saving the data to a file. You can start with simply appending
//each write to the file, and work on making it more efficient if you have time.

package main

import (
	"fmt"
	"log"
	"net/http"
)

//setHandler handles the "/set" pattern by storing the key-value pair given in the URL query string in a map.
func setHandler(w http.ResponseWriter, r *http.Request, m map[string]string) {
	fmt.Printf("Set query: %v\n", r.URL.RawQuery)
	for k, v := range r.URL.Query() {
		m[k] = v[0]
		fmt.Fprintf(w, "Key/value pair stored!\n %v = %v\n", k, v[0])
	}
}

//getHandler handles the "/get" pattern by printing the value corresponding to "key" in the URL query string.
func getHandler(w http.ResponseWriter, r *http.Request, m map[string]string) {
	fmt.Printf("Get query: %v\n", r.URL.RawQuery)
	for _, k := range r.URL.Query()["key"] {
		fmt.Fprintf(w, "<h1> Key: %s  Value: %s </h1>\n", k, m[k])
		fmt.Printf("Value: %s\n", m[k])
	}
}

//makeHandler wraps a handler function with a map as an argument and returns a function of type http.HandlerFunc
//that can be passed to http.HandleFunc.
func makeHandler(fn func(http.ResponseWriter, *http.Request, map[string]string), m map[string]string) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		fn(w, r, m)
	}
}

func main() {
	m := map[string]string{
		"apple":  "red",
		"banana": "yellow",
		"lime":   "green",
	}
	http.HandleFunc("/set", makeHandler(setHandler, m))
	http.HandleFunc("/get", makeHandler(getHandler, m))
	fmt.Println("Serving . . .")
	log.Fatal(http.ListenAndServe(":4000", nil))
}