Merge branch 'master'

vendor/github.com/mcuadros/go-version/compare.go

@@ -11,16 +11,18 @@ var regexpDotBeforeDigit = regexp.MustCompile(`([^.\d]+)`)
 var regexpMultipleDots = regexp.MustCompile(`\.{2,}`)
 
 var specialForms = map[string]int{
-	"dev":   -6,
-	"alpha": -5,
-	"a":     -5,
-	"beta":  -4,
-	"b":     -4,
-	"RC":    -3,
-	"rc":    -3,
-	"#":     -2,
-	"p":     1,
-	"pl":    1,
+	"SNAPSHOT": -7,
+	"snapshot": -7,
+	"dev":      -6,
+	"alpha":    -5,
+	"a":        -5,
+	"beta":     -4,
+	"b":        -4,
+	"RC":       -3,
+	"rc":       -3,
+	"#":        -2,
+	"p":        1,
+	"pl":       1,
 }
 
 var unknownForm int = -7

vendor/github.com/mcuadros/go-version/group.go

@@ -4,6 +4,7 @@ import (
 	"regexp"
 	"strconv"
 	"strings"
+	"sync"
 )
 
 type ConstraintGroup struct {
@@ -241,8 +242,38 @@ func (self *ConstraintGroup) parseConstraint(constraint string) []*Constraint {
 	return []*Constraint{{constraint, stabilityModifier}}
 }
 
+// PCRegMap : PreCompiled Regex Map
+type PCRegMap struct {
+	sync.RWMutex
+	m map[string]*regexp.Regexp
+}
+
+// MustCompile : to replace regexp.MustCompile in RegFind.
+func (p *PCRegMap) MustCompile(pattern string) *regexp.Regexp {
+	p.RLock()
+	ret, exist := p.m[pattern]
+	p.RUnlock()
+	if exist {
+		return ret
+	}
+	ret = regexp.MustCompile(pattern)
+	p.Lock()
+	p.m[pattern] = ret
+	p.Unlock()
+	return ret
+}
+
+var (
+	regexpCache *PCRegMap
+)
+
+func init() {
+	regexpCache = new(PCRegMap)
+	regexpCache.m = make(map[string]*regexp.Regexp)
+}
+
 func RegFind(pattern, subject string) []string {
-	reg := regexp.MustCompile(pattern)
+	reg := regexpCache.MustCompile(pattern)
 	matched := reg.FindAllStringSubmatch(subject, -1)
 
 	if matched != nil {