go-vise

main.go (4922B)

---

 // Example: HTTP server wrapper (to be used with manual client).
 package main
 
 import (
 	"context"
 	"flag"
 	"fmt"
 	"io/ioutil"
 	"net/http"
 	"os"
 	"path"
 
 	"git.defalsify.org/vise.git/engine"
 	"git.defalsify.org/vise.git/persist"
 	"git.defalsify.org/vise.git/resource"
 	"git.defalsify.org/vise.git/logging"
 	fsdb "git.defalsify.org/vise.git/db/fs"
 )
 
 var (
 	logg logging.Logger = logging.NewVanilla().WithDomain("http")
 )
 
 type LocalHandler struct {
 	sessionId string
 }	
 
 func NewLocalHandler() *LocalHandler {
 	return &LocalHandler{
 		sessionId: "",
 	}
 }
 
 func(h* LocalHandler) SetSession(sessionId string) {
 	h.sessionId = sessionId
 }
 
 func(h* LocalHandler) AddSession(ctx context.Context, sym string, input []byte) (resource.Result, error) {
 	return resource.Result{
 		Content: h.sessionId + ":" + string(input),
 	}, nil
 }
 
 type RequestParser interface {
 	GetSessionId(*http.Request) (string, error)
 	GetInput(*http.Request) ([]byte, error)
 }
 
 type DefaultRequestParser struct {
 }
 
 func(rp *DefaultRequestParser) GetSessionId(rq *http.Request) (string, error) {
 	v := rq.Header.Get("X-Vise-Session")
 	if v == "" {
 		return "", fmt.Errorf("no session found")
 	}
 	return v, nil
 }
 
 func(rp *DefaultRequestParser) GetInput(rq *http.Request) ([]byte, error) {
 	defer rq.Body.Close()
 	v, err := ioutil.ReadAll(rq.Body)
 	if err != nil {
 		return nil, err
 	}
 	return v, nil
 }
 
 type DefaultSessionHandler struct {
 	cfgTemplate engine.Config
 	rp RequestParser
 	rs resource.Resource
 	rh *LocalHandler
 	peBase string
 }
 
 func NewDefaultSessionHandler(ctx context.Context, persistBase string, resourceBase string, rp RequestParser, outputSize uint32, cacheSize uint32, flagCount uint32) *DefaultSessionHandler {
 	store := fsdb.NewFsDb()
 	err := store.Connect(ctx, resourceBase)
 	if err != nil {
 		panic(err)
 	}
 	rs := resource.NewDbResource(store)
 	rh := NewLocalHandler()
 	rs.AddLocalFunc("echo", rh.AddSession)
 	return &DefaultSessionHandler{
 		cfgTemplate: engine.Config{
 			OutputSize: outputSize,
 			Root: "root",
 			FlagCount: flagCount,
 			CacheSize: cacheSize,
 		},
 		rs: rs,
 		rh: rh,
 		rp: rp,
 	}
 }
 
 func(f *DefaultSessionHandler) GetEngine(ctx context.Context, sessionId string) (engine.Engine, error) {
 	cfg := f.cfgTemplate
 	cfg.SessionId = sessionId
 	
 	//persistPath := path.Join(f.peBase, sessionId)
 	persistPath := path.Join(f.peBase)
 	if persistPath == "" {
 		persistPath = ".state"
 	}
 	store := fsdb.NewFsDb()
 	err := store.Connect(ctx, persistPath)
 	if err != nil {
 		return nil, err
 	}
 	store.SetSession(cfg.SessionId)
 	f.rh.SetSession(cfg.SessionId)
 
 	pe := persist.NewPersister(store)
 	en := engine.NewEngine(cfg, f.rs)
 	en = en.WithPersister(pe)
 
 	return en, err
 }
 
 func(f *DefaultSessionHandler) writeError(w http.ResponseWriter, code int, msg string, err error) {
 	w.Header().Set("X-Vise", msg + ": " + err.Error())
 	w.Header().Set("Content-Length", "0")
 	w.WriteHeader(code)
 	_, err = w.Write([]byte{})
 	if err != nil {
 		w.WriteHeader(500)
 		w.Header().Set("X-Vise", err.Error())
 	}
 	return 
 }
 
 func(f *DefaultSessionHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 	var r bool
 	sessionId, err := f.rp.GetSessionId(req)
 	if err != nil {
 		f.writeError(w, 400, "Session missing", err)
 		return
 	}
 	input, err := f.rp.GetInput(req)
 	if err != nil {
 		f.writeError(w, 400, "Input read fail", err)
 		return
 	}
 	ctx := req.Context()
 	en, err := f.GetEngine(ctx, sessionId)
 	if err != nil {
 		f.writeError(w, 400, "Engine start fail", err)
 		return
 	}
 
 	//if len(input) == 0 {
 	//	r, err = en.Init(ctx)
 	//} else {
 	r, err = en.Exec(ctx, input)
 	//}
 	if err != nil {
 		f.writeError(w, 500, "Engine exec fail", err)
 		return
 	}
 	w.WriteHeader(200)
 	w.Header().Set("Content-Type", "text/plain")
 	_, err = en.Flush(ctx, w)
 	if err != nil {
 		f.writeError(w, 500, "Write result fail", err)
 		return
 	}
 	err = en.Finish()
 	if err != nil {
 		f.writeError(w, 500, "Engine finish fail", err)
 		return
 	}
 	_ = r
 }
 
 func main() {
 	var host string
 	var port string
 	var peDir string
 	var rsDir string
 	var outSize uint
 	var flagCount uint
 	var cacheSize uint
 	flag.StringVar(&rsDir, "r", ".", "resource dir")
 	flag.StringVar(&host, "h", "127.0.0.1", "http host")
 	flag.StringVar(&port, "p", "7123", "http port")
 	flag.StringVar(&peDir, "d", ".state", "persistance dir")
 	flag.UintVar(&flagCount, "f", 0, "flag count")
 	flag.UintVar(&cacheSize, "c", 1024 * 1024, "cache size")
 	flag.UintVar(&outSize, "s", 160, "max size of output")
 	flag.Parse()
 	fmt.Fprintf(os.Stderr, "starting server:\n\tpersistence dir: %s\n\tresource dir: %s\n", rsDir, peDir)
 
 	ctx := context.Background()
 	rp := &DefaultRequestParser{}
 	h := NewDefaultSessionHandler(ctx, peDir, rsDir, rp, uint32(outSize), uint32(cacheSize), uint32(flagCount))
 	s := &http.Server{
 		Addr: fmt.Sprintf("%s:%s", host, port),
 		Handler: h,
 	}
 	err := s.ListenAndServe()
 	if err != nil {
 		fmt.Fprintf(os.Stderr, "Server error: %s", err)
 		os.Exit(1)
 	}
 }