api/router: avoid unneeded loops and fix path match (#1594)

* api/router: avoid unneeded loops and fix path match

* if match found in google api path syntax, not try pcre loop
* if path is not ending via $ sign, append it to pcre to avoid matching other strings like
  /api/account/register can be matched to /api/account
* api: add tests and validations

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

static.go

@@ -110,11 +110,15 @@ func (r *staticRouter) Register(ep *api.Endpoint) error {
 
 	for _, p := range ep.Path {
 		var pcreok bool
+
+		// pcre only when we have start and end markers
+		if p[0] == '^' && p[len(p)-1] == '$' {
 			pcrereg, err := regexp.CompilePOSIX(p)
 			if err == nil {
 				pcreregs = append(pcreregs, pcrereg)
 				pcreok = true
 			}
+		}
 
 		rule, err := util.Parse(p)
 		if err != nil && !pcreok {
@@ -122,6 +126,7 @@ func (r *staticRouter) Register(ep *api.Endpoint) error {
 		} else if err != nil && pcreok {
 			continue
 		}
+
 		tpl := rule.Compile()
 		pathreg, err := util.NewPattern(tpl.Version, tpl.OpCodes, tpl.Pool, "")
 		if err != nil {
@@ -280,6 +285,9 @@ func (r *staticRouter) endpoint(req *http.Request) (*endpoint, error) {
 				}
 				continue
 			}
+			if logger.V(logger.DebugLevel, logger.DefaultLogger) {
+				logger.Debugf("api gpath match %s = %v", path, pathreg)
+			}
 			pMatch = true
 			ctx := req.Context()
 			md, ok := metadata.FromContext(ctx)
@@ -294,6 +302,7 @@ func (r *staticRouter) endpoint(req *http.Request) (*endpoint, error) {
 			break
 		}
 
+		if !pMatch {
 			// 4. try path via pcre path matching
 			for _, pathreg := range ep.pcreregs {
 				if !pathreg.MatchString(req.URL.Path) {
@@ -305,6 +314,7 @@ func (r *staticRouter) endpoint(req *http.Request) (*endpoint, error) {
 				pMatch = true
 				break
 			}
+		}
 
 		if !pMatch {
 			continue