Merge pull request lightninglabs#177 from sputn1ck/precompile_regexes

proxy: precompile regexp

Author: guggero

proxy/proxy.go

@@ -8,7 +8,6 @@ import (
 	"net/http"
 	"net/http/httputil"
 	"os"
-	"regexp"
 	"strconv"
 	"strings"
 
@@ -366,21 +365,21 @@ func certPool(services []*Service) (*x509.CertPool, error) {
 // expression matching the host and path.
 func matchService(req *http.Request, services []*Service) (*Service, bool) {
 	for _, service := range services {
-		hostRegexp := regexp.MustCompile(service.HostRegexp)
+		hostRegexp := service.compiledHostRegexp
 		if !hostRegexp.MatchString(req.Host) {
 			log.Tracef("Req host [%s] doesn't match [%s].",
 				req.Host, hostRegexp)
 			continue
 		}
 
-		if service.PathRegexp == "" {
+		if service.compiledPathRegexp == nil {
 			log.Debugf("Host [%s] matched pattern [%s] and path "+
 				"expression is empty. Using service [%s].",
 				req.Host, hostRegexp, service.Address)
 			return service, true
 		}
 
-		pathRegexp := regexp.MustCompile(service.PathRegexp)
+		pathRegexp := service.compiledPathRegexp
 		if !pathRegexp.MatchString(req.URL.Path) {
 			log.Tracef("Req path [%s] doesn't match [%s].",
 				req.URL.Path, pathRegexp)

proxy/service.go

@@ -103,6 +103,15 @@ type Service struct {
 	// /package_name.ServiceName/MethodName
 	AuthWhitelistPaths []string `long:"authwhitelistpaths" description:"List of regular expressions for paths that don't require authentication'"`
 
+	// compiledHostRegexp is the compiled host regex.
+	compiledHostRegexp *regexp.Regexp
+
+	// compiledPathRegexp is the compiled path regex.
+	compiledPathRegexp *regexp.Regexp
+
+	// compiledAuthWhitelistPaths is the compiled auth whitelist paths.
+	compiledAuthWhitelistPaths []*regexp.Regexp
+
 	freebieDB freebie.DB
 	pricer    pricer.Pricer
 }
@@ -123,8 +132,7 @@ func (s *Service) ResourceName(resourcePath string) string {
 // AuthRequired determines the auth level required for a given request.
 func (s *Service) AuthRequired(r *http.Request) auth.Level {
 	// Does the request match any whitelist entry?
-	for _, pathRegexp := range s.AuthWhitelistPaths {
-		pathRegexp := regexp.MustCompile(pathRegexp)
+	for _, pathRegexp := range s.compiledAuthWhitelistPaths {
 		if pathRegexp.MatchString(r.URL.Path) {
 			log.Tracef("Req path [%s] matches whitelist entry "+
 				"[%s].", r.URL.Path, pathRegexp)
@@ -184,15 +192,41 @@ func prepareServices(services []*Service) error {
 			}
 		}
 
+		// Compile the host regex.
+		compiledHostRegexp, err := regexp.Compile(service.HostRegexp)
+		if err != nil {
+			return fmt.Errorf("error compiling host regex: %v", err)
+		}
+		service.compiledHostRegexp = compiledHostRegexp
+
+		// Compile the path regex.
+		if service.PathRegexp != "" {
+			compiledPathRegexp, err := regexp.Compile(
+				service.PathRegexp,
+			)
+			if err != nil {
+				return fmt.Errorf("error compiling path "+
+					"regex: %v", err)
+			}
+			service.compiledPathRegexp = compiledPathRegexp
+		}
+
+		service.compiledAuthWhitelistPaths = make(
+			[]*regexp.Regexp, 0, len(service.AuthWhitelistPaths),
+		)
+
 		// Make sure all whitelist regular expression entries actually
 		// compile so we run into an eventual panic during startup and
 		// not only when the request happens.
 		for _, entry := range service.AuthWhitelistPaths {
-			_, err := regexp.Compile(entry)
+			regExp, err := regexp.Compile(entry)
 			if err != nil {
 				return fmt.Errorf("error validating auth "+
 					"whitelist: %v", err)
 			}
+			service.compiledAuthWhitelistPaths = append(
+				service.compiledAuthWhitelistPaths, regExp,
+			)
 		}
 
 		// If dynamic prices are enabled then use the provided