/
server.go
165 lines (137 loc) · 3.28 KB
/
server.go
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package api
import (
"encoding/gob"
"encoding/json"
"errors"
"io"
"log"
"net/http"
"sync"
"github.com/barnex/bruteray/imagef"
"github.com/barnex/bruteray/tracer"
//. "github.com/barnex/bruteray/tracer/types"
)
//TODO: cancel bakery only, not preview
func Serve(addr string, spec Spec) error {
s := newServer(addr, spec)
return s.listenAndServe()
}
type server struct {
spec Spec
mux *http.ServeMux
httpServer http.Server
mu sync.Mutex
cancel chan struct{}
smplr *tracer.Sampler
smplrView View // View currently being rendred by smplr
smplrNum int
}
func newServer(addr string, spec Spec) *server {
mux := http.NewServeMux()
s := &server{
spec: spec,
mux: mux,
httpServer: http.Server{
Addr: addr,
Handler: mux,
},
}
s.handle("/preview", s.handlePreview)
s.handle("/bake", s.handleBake)
s.handle("/cancel", s.handleCancel)
return s
}
func (s *server) handlePreview(w http.ResponseWriter, r *http.Request) error {
// (1) Read view settings from request body (JSON)
v, err := decodeView(r.Body)
if err != nil {
return err
}
img := s.renderPreview(v)
return gob.NewEncoder(w).Encode(img)
}
func (s *server) handleBake(w http.ResponseWriter, r *http.Request) error {
defer r.Body.Close()
// (1) Read view settings from request body (JSON)
v, err := decodeView(r.Body)
if err != nil {
return err
}
// (2) Render (may return "canceled" error)
img, err := s.renderView(v)
if err != nil {
return err
}
// (3) Send encoded image as response
return gob.NewEncoder(w).Encode(img)
}
func decodeView(r io.ReadCloser) (View, error) {
var v View
err := json.NewDecoder(r).Decode(&v)
r.Close()
return v, err
}
func (s *server) renderPreview(v View) imagef.Image {
spec := v.ApplyTo(s.spec)
nPass := 1
img := tracer.Uniform(spec.ImageFunc(), nPass, v.Width, v.Height, v.AntiAlias)
return img
}
func (s *server) renderView(v View) (imagef.Image, error) {
cancel, err := s.prepareBakery(v)
if err != nil {
return nil, err
}
defer func() { // wrong
s.mu.Lock()
defer s.mu.Unlock()
s.cancel = nil
s.smplrNum++
}()
s.smplr.SampleWithCancel(s.smplrNum, cancel)
img := s.smplr.Image()
if img == nil {
return nil, errors.New("baking cancelled")
}
return img, nil
}
func (s *server) prepareBakery(v View) (chan struct{}, error) {
s.mu.Lock()
defer s.mu.Unlock()
if s.cancel != nil {
return nil, errors.New("already baking")
}
s.cancel = make(chan struct{})
if s.smplr == nil || s.smplrView != v {
spec := v.ApplyTo(s.spec)
s.smplr = tracer.NewSampler(spec.ImageFunc(), v.Width, v.Height, v.AntiAlias)
s.smplrView = v
s.smplrNum = 1
}
return s.cancel, nil
}
func (s *server) handleCancel(w http.ResponseWriter, r *http.Request) error {
s.mu.Lock()
defer s.mu.Unlock()
if s.cancel == nil {
return nil // already done
}
close(s.cancel)
s.cancel = nil
return nil
}
func (s *server) handle(prefix string, h handler) {
s.mux.Handle(prefix, h)
}
func (s *server) listenAndServe() error {
return s.httpServer.ListenAndServe()
}
type handler func(w http.ResponseWriter, r *http.Request) error
func (f handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
log.Println(r.Method, r.URL.Path)
err := f(w, r)
if err != nil {
log.Println(err)
http.Error(w, err.Error(), http.StatusInternalServerError)
}
}