improve server-list performance (#193)

* improve server-list performance

FetchCustomizeColumns that fetch extra fields for all rows 3. separate
read and write http request session

* update vendor

* update: optimize multi-column indexes

pkg/util/stringutils2/sortedstrings.go

@@ -0,0 +1,113 @@
+package stringutils2
+
+import (
+	"sort"
+)
+
+type SSortedStrings []string
+
+func NewSortedStrings(strs []string) SSortedStrings {
+	if strs == nil {
+		return nil
+	}
+	sort.Strings(strs)
+	return SSortedStrings(strs)
+}
+
+func (ss SSortedStrings) Index(needle string) (int, bool) {
+	i := 0
+	j := len(ss) - 1
+	for i <= j {
+		m := (i + j) / 2
+		if ss[m] < needle {
+			i = m + 1
+		} else if ss[m] > needle {
+			j = m - 1
+		} else {
+			return m, true
+		}
+	}
+	return j + 1, false
+}
+
+func (ss SSortedStrings) Contains(needle string) bool {
+	_, find := ss.Index(needle)
+	return find
+}
+
+func (ss SSortedStrings) ContainsAny(needles ...string) bool {
+	for i := range needles {
+		_, find := ss.Index(needles[i])
+		if find {
+			return true
+		}
+	}
+	return false
+}
+
+func (ss SSortedStrings) ContainsAll(needles ...string) bool {
+	for i := range needles {
+		_, find := ss.Index(needles[i])
+		if !find {
+			return false
+		}
+	}
+	return true
+}
+
+func Split(a, b SSortedStrings) (aNoB SSortedStrings, aAndB SSortedStrings, bNoA SSortedStrings) {
+	a_b := make([]string, 0)
+	b_a := make([]string, 0)
+	anb := make([]string, 0)
+	i := 0
+	j := 0
+	for i < len(a) && j < len(b) {
+		if a[i] == b[j] {
+			anb = append(anb, a[i])
+			i += 1
+			j += 1
+		} else if a[i] < b[j] {
+			a_b = append(a_b, a[i])
+			i += 1
+		} else if a[i] > b[j] {
+			b_a = append(b_a, b[j])
+			j += 1
+		}
+	}
+	if i < len(a) {
+		a_b = append(a_b, a[i:]...)
+	}
+	if j < len(b) {
+		b_a = append(b_a, b[j:]...)
+	}
+	aNoB = SSortedStrings(a_b)
+	aAndB = SSortedStrings(anb)
+	bNoA = SSortedStrings(b_a)
+	return
+}
+
+func Merge(a, b SSortedStrings) SSortedStrings {
+	ret := make([]string, 0)
+	i := 0
+	j := 0
+	for i < len(a) && j < len(b) {
+		if a[i] == b[j] {
+			ret = append(ret, a[i])
+			i += 1
+			j += 1
+		} else if a[i] < b[j] {
+			ret = append(ret, a[i])
+			i += 1
+		} else if a[i] > b[j] {
+			ret = append(ret, b[j])
+			j += 1
+		}
+	}
+	if i < len(a) {
+		ret = append(ret, a[i:]...)
+	}
+	if j < len(b) {
+		ret = append(ret, b[j:]...)
+	}
+	return SSortedStrings(ret)
+}