New minor release after complete rewrite.

Brings neat and testable codebase with minimum allocations in mind.

utils/ordered_map/ordered_map.go

@@ -0,0 +1,64 @@
+package ordered_map
+
+import (
+	"bytes"
+
+	jsoniter "github.com/json-iterator/go"
+)
+
+var json = jsoniter.ConfigCompatibleWithStandardLibrary
+
+type OrderedMap struct {
+	values map[string]interface{}
+	keys   []string
+}
+
+func New() *OrderedMap {
+	o := OrderedMap{}
+	o.keys = []string{}
+	o.values = map[string]interface{}{}
+	return &o
+}
+
+func (o *OrderedMap) Set(key string, value interface{}) {
+	_, exists := o.values[key]
+	if !exists {
+		o.keys = append(o.keys, key)
+	}
+	o.values[key] = value
+}
+
+func (o OrderedMap) MarshalJSON() ([]byte, error) {
+	var buf bytes.Buffer
+	buf.WriteByte('{')
+	encoder := json.NewEncoder(&buf)
+	encoder.SetEscapeHTML(false)
+	encoder.SetIndent("", "")
+	for i, k := range o.keys {
+		if i > 0 {
+			buf.WriteByte(',')
+		}
+		buf.WriteByte('"')
+		buf.WriteString(k)
+		buf.WriteString(`":`)
+		customEncoder := &customJsonEncoder{buf: &buf}
+		if err := customEncoder.Encode(o.values[k]); err != nil {
+			return nil, err
+		}
+	}
+	buf.WriteByte('}')
+	return buf.Bytes(), nil
+}
+
+type customJsonEncoder struct {
+	buf *bytes.Buffer
+}
+
+func (e *customJsonEncoder) Encode(v interface{}) error {
+	data, err := json.Marshal(v)
+	if err != nil {
+		return err
+	}
+	e.buf.Write(data)
+	return nil
+}

utils/ordered_map/ordered_map_test.go

@@ -0,0 +1,164 @@
+package ordered_map
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestNew(t *testing.T) {
+	tests := []struct {
+		want *OrderedMap
+		name string
+	}{
+		{
+			name: "TestNew",
+			want: &OrderedMap{
+				keys:   []string{},
+				values: map[string]interface{}{},
+			},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := New(); !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("New() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+func TestOrderedMap_Set(t *testing.T) {
+	type fields struct {
+		values map[string]interface{}
+		keys   []string
+	}
+	type args struct {
+		value interface{}
+		key   string
+	}
+	tests := []struct {
+		args   args
+		name   string
+		fields fields
+	}{
+		{
+			name: "TestOrderedMap_Set",
+			fields: fields{
+				values: map[string]interface{}{},
+				keys:   []string{},
+			},
+			args: args{},
+		},
+		{
+			name: "TestOrderedMap_Set2",
+			fields: fields{
+				values: map[string]interface{}{
+					"hello": "world",
+				},
+				keys: []string{"hello"},
+			},
+			args: args{},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			o := &OrderedMap{
+				values: tt.fields.values,
+				keys:   tt.fields.keys,
+			}
+			o.Set(tt.args.key, tt.args.value)
+			for _, key := range o.keys {
+				if _, ok := o.values[key]; !ok {
+					t.Errorf("OrderedMap.Set() key not found in values map")
+				}
+			}
+		})
+	}
+}
+
+func TestOrderedMap_MarshalJSON(t *testing.T) {
+	type fields struct {
+		values map[string]interface{}
+		keys   []string
+	}
+	tests := []struct {
+		name    string
+		fields  fields
+		want    []byte
+		wantErr bool
+	}{
+		{
+			name: "TestOrderedMap_MarshalJSON",
+			fields: fields{
+				values: map[string]interface{}{
+					"hello": "world",
+				},
+				keys: []string{"hello"},
+			},
+			want:    []byte(`{"hello":"world"}`),
+			wantErr: false,
+		},
+		{
+			name: "TestOrderedMap_MarshalJSON2",
+			fields: fields{
+				values: map[string]interface{}{
+					"hello": "world",
+					"foo":   "bar",
+				},
+				keys: []string{"hello", "foo"},
+			},
+			want:    []byte(`{"hello":"world","foo":"bar"}`),
+			wantErr: false,
+		},
+		{
+			name: "TestOrderedMap_MarshalJSON_with_error",
+			fields: fields{
+				values: map[string]interface{}{
+					"hello": "world",
+					"foo":   make(chan int),
+				},
+				keys: []string{"hello", "foo"},
+			},
+			want:    nil,
+			wantErr: true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			o := OrderedMap{
+				values: tt.fields.values,
+				keys:   tt.fields.keys,
+			}
+			got, err := o.MarshalJSON()
+			if (err != nil) != tt.wantErr {
+				t.Errorf("OrderedMap.MarshalJSON() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("OrderedMap.MarshalJSON() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+func BenchmarkOrderedMapTest(b *testing.B) {
+	m := New()
+	for i := 0; i < b.N; i++ {
+		m.Set("hello", "world")
+	}
+}
+
+func BenchmarkOrderedMarshalJSON(b *testing.B) {
+	m := New()
+	for i := 0; i < b.N; i++ {
+		m.Set("hello", "world")
+		m.MarshalJSON()
+	}
+}
+
+func BenchmarkMapTest(b *testing.B) {
+	m := make(map[string]interface{})
+	for i := 0; i < b.N; i++ {
+		m["hello"] = "world"
+	}
+}