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_test.go

@@ -0,0 +1,62 @@
+package stringutils2
+
+import (
+	"testing"
+)
+
+func TestSortedString(t *testing.T) {
+	input := []string{"Go", "Bravo", "Gopher", "Alpha", "Grin", "Delta"}
+	// Alpha Bravo Delta Go Gopher Grin
+	// 0     1     2     3  4      5
+	ss := NewSortedStrings(input)
+	cases := []struct {
+		Needle string
+		Index  int
+		Want   bool
+	}{
+		{"Go", 3, true},
+		{"Bravo", 1, true},
+		{"Gopher", 4, true},
+		{"Alpha", 0, true},
+		{"Grin", 5, true},
+		{"Delta", 2, true},
+		{"Go1", 4, false},
+		{"G", 3, false},
+		{"A", 0, false},
+		{"T", 6, false},
+	}
+	for _, c := range cases {
+		idx, find := ss.Index(c.Needle)
+		if idx != c.Index || find != c.Want {
+			t.Errorf("%s: want: %d %v got: %d %v", c.Needle, c.Index, c.Want, idx, find)
+		}
+	}
+}
+
+func TestSplitStrings(t *testing.T) {
+	input := []string{"Go", "Bravo", "Gopher", "Alpha", "Grin", "Delta"}
+	input2 := []string{"Go2", "Bravo", "Gopher", "Alpha1", "Grin", "Delt"}
+
+	ss1 := NewSortedStrings(input)
+	ss2 := NewSortedStrings(input2)
+
+	a, b, c := Split(ss1, ss2)
+	t.Logf("A: %s", ss1)
+	t.Logf("B: %s", ss2)
+	t.Logf("A-B: %s", a)
+	t.Logf("AnB: %s", b)
+	t.Logf("B-A: %s", c)
+}
+
+func TestMergeStrings(t *testing.T) {
+	input := []string{"Go", "Bravo", "Gopher", "Alpha", "Grin", "Delta"}
+	input2 := []string{"Go2", "Bravo", "Gopher", "Alpha1", "Grin", "Delt"}
+
+	ss1 := NewSortedStrings(input)
+	ss2 := NewSortedStrings(input2)
+
+	m := Merge(ss1, ss2)
+	t.Logf("A: %s", ss1)
+	t.Logf("B: %s", ss2)
+	t.Logf("%s", m)
+}