From 5a4dca76452906d5bd6903ba00c683504de084cb Mon Sep 17 00:00:00 2001
From: Xavier Sandal <sandalwing@sandalwing.com>
Date: Mon, 19 Dec 2016 22:36:13 -0500
Subject: [PATCH] Compile regexp ahead of time

Signed-off-by: Xavier Sandal <sandalwing@sandalwing.com>
---
 scope.go | 17 ++++++++++-------
 utils.go |  5 ++++-
 2 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/scope.go b/scope.go
index 484164ad..097c2243 100644
--- a/scope.go
+++ b/scope.go
@@ -447,7 +447,12 @@ func (scope *Scope) callMethod(methodName string, reflectValue reflect.Value) {
 	}
 }
 
-var columnRegexp = regexp.MustCompile("^[a-zA-Z]+(\\.[a-zA-Z]+)*$") // only match string like `name`, `users.name`
+var (
+	columnRegexp        = regexp.MustCompile("^[a-zA-Z]+(\\.[a-zA-Z]+)*$") // only match string like `name`, `users.name`
+	isNumberRegexp      = regexp.MustCompile("^\\s*\\d+\\s*$")             // match if string is number
+	comparisonRegexp    = regexp.MustCompile("(?i) (=|<>|>|<|LIKE|IS|IN) ")
+	countingQueryRegexp = regexp.MustCompile("(?i)^count(.+)$")
+)
 
 func (scope *Scope) quoteIfPossible(str string) string {
 	if columnRegexp.MatchString(str) {
@@ -509,8 +514,7 @@ func (scope *Scope) primaryCondition(value interface{}) string {
 func (scope *Scope) buildWhereCondition(clause map[string]interface{}) (str string) {
 	switch value := clause["query"].(type) {
 	case string:
-		// if string is number
-		if regexp.MustCompile("^\\s*\\d+\\s*$").MatchString(value) {
+		if isNumberRegexp.MatchString(value) {
 			return scope.primaryCondition(scope.AddToVars(value))
 		} else if value != "" {
 			str = fmt.Sprintf("(%v)", value)
@@ -573,11 +577,10 @@ func (scope *Scope) buildNotCondition(clause map[string]interface{}) (str string
 
 	switch value := clause["query"].(type) {
 	case string:
-		// is number
-		if regexp.MustCompile("^\\s*\\d+\\s*$").MatchString(value) {
+		if isNumberRegexp.MatchString(value) {
 			id, _ := strconv.Atoi(value)
 			return fmt.Sprintf("(%v <> %v)", scope.Quote(primaryKey), id)
-		} else if regexp.MustCompile("(?i) (=|<>|>|<|LIKE|IS|IN) ").MatchString(value) {
+		} else if comparisonRegexp.MatchString(value) {
 			str = fmt.Sprintf(" NOT (%v) ", value)
 			notEqualSQL = fmt.Sprintf("NOT (%v)", value)
 		} else {
@@ -924,7 +927,7 @@ func (scope *Scope) pluck(column string, value interface{}) *Scope {
 }
 
 func (scope *Scope) count(value interface{}) *Scope {
-	if query, ok := scope.Search.selects["query"]; !ok || !regexp.MustCompile("(?i)^count(.+)$").MatchString(fmt.Sprint(query)) {
+	if query, ok := scope.Search.selects["query"]; !ok || !countingQueryRegexp.MatchString(fmt.Sprint(query)) {
 		scope.Search.Select("count(*)")
 	}
 	scope.Search.ignoreOrderQuery = true
diff --git a/utils.go b/utils.go
index 8f3d0f38..bf1e5666 100644
--- a/utils.go
+++ b/utils.go
@@ -26,6 +26,9 @@ var NowFunc = func() time.Time {
 var commonInitialisms = []string{"API", "ASCII", "CPU", "CSS", "DNS", "EOF", "GUID", "HTML", "HTTP", "HTTPS", "ID", "IP", "JSON", "LHS", "QPS", "RAM", "RHS", "RPC", "SLA", "SMTP", "SSH", "TLS", "TTL", "UI", "UID", "UUID", "URI", "URL", "UTF8", "VM", "XML", "XSRF", "XSS"}
 var commonInitialismsReplacer *strings.Replacer
 
+var goSrcRegexp = regexp.MustCompile(`jinzhu/gorm/.*.go`)
+var goTestRegexp = regexp.MustCompile(`jinzhu/gorm/.*test.go`)
+
 func init() {
 	var commonInitialismsForReplacer []string
 	for _, initialism := range commonInitialisms {
@@ -171,7 +174,7 @@ func toQueryValues(values [][]interface{}) (results []interface{}) {
 func fileWithLineNum() string {
 	for i := 2; i < 15; i++ {
 		_, file, line, ok := runtime.Caller(i)
-		if ok && (!regexp.MustCompile(`jinzhu/gorm/.*.go`).MatchString(file) || regexp.MustCompile(`jinzhu/gorm/.*test.go`).MatchString(file)) {
+		if ok && (!goSrcRegexp.MatchString(file) || goTestRegexp.MatchString(file)) {
 			return fmt.Sprintf("%v:%v", file, line)
 		}
 	}