micro-server-http/handler.go
Vasiliy Tolstov 3ec25548a8 fully working micro http server implementation
Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>
2021-02-05 18:31:51 +03:00

220 lines
5.1 KiB
Go

package http
import (
"context"
"fmt"
"net/http"
"reflect"
"strings"
"github.com/unistack-org/micro/v3/codec"
"github.com/unistack-org/micro/v3/logger"
"github.com/unistack-org/micro/v3/metadata"
"github.com/unistack-org/micro/v3/register"
"github.com/unistack-org/micro/v3/server"
"github.com/unistack-org/micro/v3/util/qson"
rflutil "github.com/unistack-org/micro/v3/util/reflect"
rutil "github.com/unistack-org/micro/v3/util/router"
)
var (
DefaultErrorHandler = func(ctx context.Context, s server.Handler, w http.ResponseWriter, r *http.Request, err error, status int) {
w.WriteHeader(status)
w.Write([]byte(err.Error()))
}
DefaultContentType = "application/json"
)
type patHandler struct {
pat rutil.Pattern
mtype *methodType
name string
rcvr reflect.Value
}
type httpHandler struct {
name string
opts server.HandlerOptions
sopts server.Options
eps []*register.Endpoint
hd interface{}
handlers map[string][]patHandler
errorHandler func(context.Context, server.Handler, http.ResponseWriter, *http.Request, error, int)
}
func (h *httpHandler) newCodec(ct string) (codec.Codec, error) {
if cf, ok := h.sopts.Codecs[ct]; ok {
return cf, nil
}
return nil, codec.ErrUnknownContentType
}
func (h *httpHandler) Name() string {
return h.name
}
func (h *httpHandler) Handler() interface{} {
return h.hd
}
func (h *httpHandler) Endpoints() []*register.Endpoint {
return h.eps
}
func (h *httpHandler) Options() server.HandlerOptions {
return h.opts
}
func (h *httpHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
ctx := r.Context()
path := r.URL.Path
if !strings.HasPrefix(path, "/") {
h.errorHandler(ctx, h, w, r, fmt.Errorf("path must contains /"), http.StatusBadRequest)
}
ct := DefaultContentType
if htype := r.Header.Get("Content-Type"); htype != "" {
ct = htype
}
cf, err := h.newCodec(ct)
if err != nil {
h.errorHandler(ctx, h, w, r, err, http.StatusBadRequest)
}
components := strings.Split(path[1:], "/")
l := len(components)
var verb string
idx := strings.LastIndex(components[l-1], ":")
if idx == 0 {
h.errorHandler(ctx, h, w, r, fmt.Errorf("not found"), http.StatusNotFound)
return
}
if idx > 0 {
c := components[l-1]
components[l-1], verb = c[:idx], c[idx+1:]
}
matches := make(map[string]interface{})
var match bool
var hldr patHandler
for _, hldr = range h.handlers[r.Method] {
mp, err := hldr.pat.Match(components, verb)
if err == nil {
match = true
for k, v := range mp {
matches[k] = v
}
break
}
}
if !match {
h.errorHandler(ctx, h, w, r, fmt.Errorf("not matching route found"), http.StatusNotFound)
return
}
md, ok := metadata.FromContext(ctx)
if !ok {
md = metadata.New(0)
}
for k, v := range r.Header {
md.Set(k, strings.Join(v, ", "))
}
// get fields from url values
if len(r.URL.RawQuery) > 0 {
umd := make(map[string]interface{})
err = qson.Unmarshal(&umd, r.URL.RawQuery)
if err != nil {
h.errorHandler(ctx, h, w, r, err, http.StatusBadRequest)
}
for k, v := range umd {
matches[k] = v
}
}
var argv, replyv reflect.Value
// Decode the argument value.
argIsValue := false // if true, need to indirect before calling.
if hldr.mtype.ArgType.Kind() == reflect.Ptr {
argv = reflect.New(hldr.mtype.ArgType.Elem())
} else {
argv = reflect.New(hldr.mtype.ArgType)
argIsValue = true
}
if argIsValue {
argv = argv.Elem()
}
// reply value
replyv = reflect.New(hldr.mtype.ReplyType.Elem())
function := hldr.mtype.method.Func
//function := hldr.rcvr
var returnValues []reflect.Value
if err = rflutil.MergeMap(argv.Interface(), matches); err != nil {
h.errorHandler(ctx, h, w, r, err, http.StatusBadRequest)
return
}
b, err := cf.Marshal(argv.Interface())
if err != nil {
h.errorHandler(ctx, h, w, r, err, http.StatusBadRequest)
return
}
hr := &rpcRequest{
codec: cf,
service: h.sopts.Name,
contentType: ct,
method: fmt.Sprintf("%s.%s", hldr.name, hldr.mtype.method.Name),
body: b,
payload: argv.Interface(),
}
var scode int
// define the handler func
fn := func(ctx context.Context, req server.Request, rsp interface{}) (err error) {
ctx = context.WithValue(ctx, rspCodeKey{}, &rspCodeVal{})
ctx = metadata.NewContext(ctx, md)
returnValues = function.Call([]reflect.Value{hldr.rcvr, hldr.mtype.prepareContext(ctx), reflect.ValueOf(argv.Interface()), reflect.ValueOf(rsp)})
scode = GetRspCode(ctx)
// The return value for the method is an error.
if rerr := returnValues[0].Interface(); rerr != nil {
err = rerr.(error)
}
return err
}
// wrap the handler func
for i := len(h.sopts.HdlrWrappers); i > 0; i-- {
fn = h.sopts.HdlrWrappers[i-1](fn)
}
if appErr := fn(ctx, hr, replyv.Interface()); appErr != nil {
b, err = cf.Marshal(appErr)
} else {
b, err = cf.Marshal(replyv.Interface())
}
if err != nil && h.sopts.Logger.V(logger.ErrorLevel) {
h.sopts.Logger.Errorf(h.sopts.Context, "XXXXX: %v", err)
return
}
w.Header().Set("content-Type", ct)
if scode != 0 {
w.WriteHeader(scode)
} else {
h.sopts.Logger.Warn(h.sopts.Context, "response code not set in handler via SetRspCode(ctx, http.StatusXXX)")
}
w.Write(b)
}