server/control.go

347 lines
9.0 KiB
Go

package server
import (
"encoding/json"
"errors"
"fmt"
"io/ioutil"
"log"
"net/http"
"os"
"runtime/pprof"
"strings"
"sync"
"golang.org/x/net/websocket"
"mcquay.me/idg"
)
// JsonHandler is a function type that allows setting the Content-Type
// appropriately for views destined to serve JSON
type JsonHandler func(http.ResponseWriter, *http.Request)
// ServeHTTP is JsonHandler's http.Handler implementation.
func (h JsonHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
w.Header().Set("Content-Type", "application/json")
h(w, req)
}
// Controller is the shepherd of a collection of games. The main package in
// server simply populates one of these and starts an http server.
type Controller struct {
Idg *idg.Generator
Conf Config
Games MapLock
Memprofile string
Profile string
}
// NewController takes a populated Config, and some parameters to determine
// what sorts of profiling to deal with and returns a freshly populated
// Controller.
func NewController(conf Config, mprof, pprof string) *http.ServeMux {
c := &Controller{
Idg: idg.NewGenerator(),
Conf: conf,
Games: MapLock{
M: make(map[string]*Game),
},
Memprofile: mprof,
Profile: pprof,
}
go c.Run()
sm := http.NewServeMux()
sm.Handle("/", JsonHandler(c.Info))
sm.Handle("/ws/", websocket.Handler(c.AddPlayer))
sm.Handle("/api/v0/game/start/", JsonHandler(c.StartGame))
sm.Handle("/api/v0/game/list/", JsonHandler(c.ListGames))
sm.Handle("/api/v0/game/stats/", JsonHandler(c.GameStats))
sm.Handle("/api/v0/game/bw/", JsonHandler(c.BW))
sm.Handle("/api/v0/game/stop/", JsonHandler(c.StopGame))
sm.HandleFunc("/api/v0/fsu/", c.KillServer)
sm.HandleFunc("/api/v0/info/", c.Info)
return sm
}
// TODO Eventually this thing will have a select loop for dealing with game
// access in a more lock-free manner?
func (c *Controller) Run() {
c.Idg.Run()
}
// StartGame is the http route responsible for responding to requests to start
// games under this controller. Creates a default Config object, and populates
// it according to data POSTed.
func (c *Controller) StartGame(w http.ResponseWriter, req *http.Request) {
log.Println("asked to create a game")
requested_game_name := c.Idg.Hash()
width, height := float64(c.Conf.Width), float64(c.Conf.Height)
obstacleCount := 0
obstacles := []Obstacle{}
maxPoints := c.Conf.MaxPoints
mode := "deathmatch"
// here we determine if we are going to run with defaults or pick them off
// a posted json blob
if req.Method == "POST" {
body, err := ioutil.ReadAll(req.Body)
if err != nil {
log.Printf("unable to read request body: %v", err)
}
req.Body.Close()
cfg := struct {
Name string `json:"name"`
Config
}{}
err = json.Unmarshal(body, &cfg)
if err != nil {
if err := json.NewEncoder(w).Encode(NewFailure(err.Error())); err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
}
return
}
requested_game_name = cfg.Name
width = float64(cfg.Width)
height = float64(cfg.Height)
obstacleCount = cfg.ObstacleCount
obstacles = cfg.Obstacles
maxPoints = cfg.MaxPoints
mode = cfg.Mode
}
g := c.Games.Get(requested_game_name)
if g == nil {
log.Printf("Game '%s' non-existant; making it now", requested_game_name)
var err error
g, err = NewGame(
requested_game_name,
width,
height,
c.Conf.Tick,
maxPoints,
mode,
)
g.obstacleCount = obstacleCount
g.obstacles = obstacles
g.defaultObstacles = obstacles
if len(g.defaultObstacles) == 0 {
g.obstacles = GenerateObstacles(
g.obstacleCount,
g.width,
g.height,
)
} else {
g.obstacles = c.Conf.Obstacles
}
if err != nil {
log.Printf("problem creating game: %s: %s", requested_game_name, err)
b, _ := json.Marshal(NewFailure("game creation failure"))
http.Error(w, string(b), http.StatusConflict)
return
}
go g.run()
c.Games.Add(g)
} else {
log.Printf("Game '%s' already exists: %p", requested_game_name, g)
b, _ := json.Marshal(NewFailure("game already exists"))
http.Error(w, string(b), http.StatusConflict)
return
}
game_json := struct {
Id string `json:"id"`
}{
Id: g.id,
}
if err := json.NewEncoder(w).Encode(game_json); err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
}
}
// ListGames makes a reasonable JSON response based on the games currently
// being run.
func (c *Controller) ListGames(w http.ResponseWriter, req *http.Request) {
log.Println("games list requested")
c.Games.RLock()
defer c.Games.RUnlock()
type pout struct {
Name string `json:"name"`
Id string `json:"id"`
}
type gl struct {
Id string `json:"id"`
Players []pout `json:"players"`
}
ids := make([]gl, 0)
for id, g := range c.Games.M {
players := make([]pout, 0)
// TODO - players instead of robots?
for p := range g.players {
for _, r := range p.Robots {
players = append(players, pout{
Name: r.Name,
Id: r.Id,
})
}
}
ids = append(ids, gl{
Id: id,
Players: players,
})
}
if err := json.NewEncoder(w).Encode(ids); err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
}
}
// GameStats provides an control mechanism to query for the stats of a single
// game
func (c *Controller) GameStats(w http.ResponseWriter, req *http.Request) {
// TODO: wrap this up in something similar to the JsonHandler to verify the
// url? Look at gorilla routing?
key, err := c.getGameId(req.URL.Path)
if err != nil {
b, _ := json.Marshal(NewFailure(err.Error()))
http.Error(w, string(b), http.StatusBadRequest)
return
}
log.Printf("requested stats for game: %s", key)
c.Games.RLock()
g, ok := c.Games.M[key]
c.Games.RUnlock()
if !ok {
b, _ := json.Marshal(NewFailure("game not found"))
http.Error(w, string(b), http.StatusNotFound)
return
}
g.stats.RLock()
defer g.stats.RUnlock()
if err := json.NewEncoder(w).Encode(g.stats.PlayerStats); err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
}
}
// BW provides a route to query for current bandwidth utilization for a single
// game.
func (c *Controller) BW(w http.ResponseWriter, req *http.Request) {
// TODO: wrap this up in something similar to the JsonHandler to verify the
// url? Look at gorilla routing?
key, err := c.getGameId(req.URL.Path)
if err != nil {
b, _ := json.Marshal(NewFailure(err.Error()))
http.Error(w, string(b), http.StatusBadRequest)
return
}
log.Printf("requested bandwidth for game: %s", key)
c.Games.RLock()
g, ok := c.Games.M[key]
c.Games.RUnlock()
if !ok {
b, _ := json.Marshal(NewFailure("game not found"))
http.Error(w, string(b), http.StatusNotFound)
return
}
s := map[string][]float64{
"tx": <-g.bw.Tx,
"rx": <-g.bw.Rx,
}
if err := json.NewEncoder(w).Encode(s); err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
}
}
// StopGame is the only mechanism to decrease the number of running games in
// a Controller
func (c *Controller) StopGame(w http.ResponseWriter, req *http.Request) {
key, err := c.getGameId(req.URL.Path)
if err != nil {
b, _ := json.Marshal(NewFailure(err.Error()))
http.Error(w, string(b), http.StatusBadRequest)
return
}
c.Games.Lock()
g, ok := c.Games.M[key]
defer c.Games.Unlock()
if !ok {
http.NotFound(w, req)
return
}
g.kill <- true
delete(c.Games.M, key)
message := struct {
Ok bool `json:"ok"`
Message string `json:"message"`
}{
Ok: true,
Message: fmt.Sprintf("Successfully stopped game: %s", key),
}
if err := json.NewEncoder(w).Encode(message); err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
}
log.Printf("returning from StopGame")
}
// KillServer is my favorite method of all the methods in server: it shuts
// things down respecting profiling requests.
func (c *Controller) KillServer(w http.ResponseWriter, req *http.Request) {
if c.Profile != "" {
log.Print("trying to stop cpu profile")
pprof.StopCPUProfile()
log.Print("stopped cpu profile")
}
if c.Memprofile != "" {
log.Print("trying to dump memory profile")
f, err := os.Create(c.Memprofile)
if err != nil {
log.Fatal(err)
}
pprof.WriteHeapProfile(f)
f.Close()
log.Print("stopped memory profile dump")
}
log.Fatal("shit got fucked up")
}
// getGameId trims the gameid off of the url. This is hokey, and makes me miss
// django regex-specified routes.
func (c *Controller) getGameId(path string) (string, error) {
var err error
trimmed := strings.Trim(path, "/")
fullPath := strings.Split(trimmed, "/")
if len(fullPath) != 3 {
return "", errors.New("improperly formed url")
}
key := fullPath[2]
return key, err
}
// MapLock is simply a map and a RWMutex
// TODO: obviate the need for this in Controller.Run
type MapLock struct {
M map[string]*Game
sync.RWMutex
}
// get is a function that returns a game if found, and creates one if
// not found and force is true. In order to get a hash (rather than use
// the string you pass) send "" for id.
func (ml *MapLock) Get(id string) *Game {
ml.Lock()
g, _ := ml.M[id]
ml.Unlock()
return g
}
// add is used to insert a new game into this MapLock
func (ml *MapLock) Add(g *Game) {
ml.Lock()
ml.M[g.id] = g
ml.Unlock()
}