perf(proxy): optimize hot request paths

- Cache route handlers, simplify NoRoute path normalization, and reduce matcher/header allocations

- Honor configured transport pool limits in auto mode and add hotpath regression benchmarks/tests

proxy/handler.go

@@ -3,7 +3,6 @@ package proxy
 import (
 	"fmt"
 	"ghproxy/config"
-	"regexp"
 	"strings"
 
 	"github.com/infinite-iroha/touka"
@@ -31,29 +30,34 @@ func buildProxyPath(path, matcher string) string {
 	return sb.String()
 }
 
-var re = regexp.MustCompile(`^(http:|https:)?/?/?(.*)`) // 匹配http://或https://开头的路径
+func normalizeProxyPath(rawPath string) (string, bool) {
+	path := strings.TrimLeft(rawPath, "/")
+
+	switch {
+	case strings.HasPrefix(path, "https:"):
+		path = path[len("https:"):]
+	case strings.HasPrefix(path, "http:"):
+		path = path[len("http:"):]
+	}
+
+	path = strings.TrimLeft(path, "/")
+	return path, path != ""
+}
 
 func NoRouteHandler(cfg *config.Config) touka.HandlerFunc {
 	return func(c *touka.Context) {
 		var ctx = c.Request.Context()
 		var shoudBreak bool
 
-		var (
-			rawPath string
-			matches []string
-		)
-
-		rawPath = strings.TrimPrefix(c.GetRequestURI(), "/") // 去掉前缀/
-		matches = re.FindStringSubmatch(rawPath)             // 匹配路径
+		path, ok := normalizeProxyPath(c.GetRequestURI())
 
 		// 匹配路径错误处理
-		if len(matches) < 3 {
+		if !ok {
 			c.Warnf("%s %s %s %s %s Invalid URL", c.ClientIP(), c.Request.Method, c.Request.URL.Path, c.UserAgent(), c.Request.Proto)
 			ErrorPage(c, NewErrorWithStatusLookup(400, fmt.Sprintf("Invalid URL Format: %s", c.GetRequestURI())))
 			return
 		}
 
-		path := matches[2]
 		var matcherErr *GHProxyErrors
 		user, repo, matcher, matcherErr := Matcher("https://"+path, cfg)
 		if matcherErr != nil {
@@ -61,7 +65,7 @@ func NoRouteHandler(cfg *config.Config) touka.HandlerFunc {
 			return
 		}
 
-		rawPath = buildProxyPath(path, matcher)
+		rawPath := buildProxyPath(path, matcher)
 
 		shoudBreak = listCheck(cfg, c, user, repo, rawPath)
 		if shoudBreak {