提升json生成性能

builder.go

@@ -0,0 +1,51 @@
+package json_spanner
+
+import (
+	"encoding/json"
+	"reflect"
+	"strings"
+)
+
+type Builder struct {
+	jsonMap map[string]interface{}
+}
+
+func NewBuilder() *Builder {
+	return &Builder{jsonMap: make(map[string]interface{})}
+}
+
+func (b *Builder) Set(key string, value interface{}) {
+	b.jsonMap = b.setInternal(key, b.jsonMap, value)
+}
+
+func (b *Builder) setInternal(key string, p map[string]interface{}, value interface{}) map[string]interface{} {
+	keys := strings.Split(key, ".")
+	if p == nil {
+		p = make(map[string]interface{})
+	}
+	if len(keys) == 1 {
+		p[keys[0]] = value
+		return p
+	} else {
+		if _, ok := p[keys[0]]; ok {
+			if reflect.TypeOf(p[keys[0]]) == reflect.TypeOf(p) {
+				p[keys[0]] = b.setInternal(strings.Join(keys[1:], "."), p[keys[0]].(map[string]interface{}), value)
+				return p
+			} else {
+				p[keys[0]] = make(map[string]interface{})
+				p[keys[0]] = b.setInternal(strings.Join(keys[1:], "."), p[keys[0]].(map[string]interface{}), value)
+				return p
+			}
+
+		} else {
+			p[keys[0]] = make(map[string]interface{})
+			p[keys[0]] = b.setInternal(strings.Join(keys[1:], "."), p[keys[0]].(map[string]interface{}), value)
+			return p
+		}
+	}
+}
+
+func (b *Builder) ToJson() string {
+	jsonBytes, _ := json.Marshal(b.jsonMap)
+	return string(jsonBytes)
+}

builder_test.go

@@ -0,0 +1,17 @@
+package json_spanner
+
+import (
+	"fmt"
+	"testing"
+)
+
+func TestBuilder(t *testing.T) {
+	b := NewBuilder()
+	b.Set("a", 6)
+	b.Set("a.b", 3)
+	b.Set("a.d", 3)
+
+	b.Set("c", "xxx")
+	fmt.Println(b.ToJson())
+
+}

engine.go

@@ -4,7 +4,6 @@ import (
 	"errors"
 	"github.com/fuhongbo/json_spanner/parser"
 	"github.com/tidwall/gjson"
-	"github.com/tidwall/sjson"
 )
 
 type Engine struct {
@@ -63,26 +62,32 @@ func (e *Engine) Transform(json string) (match bool, result string, err error) {
 
 	if e.valid(&jsonPath) {
 
-		resultJson := `{}`
+		b := NewBuilder()
+		//resultJson := `{}`
 
 		for _, item := range e.selectStatement.Fields {
 			switch item.Type {
 			case "NAME":
 				if item.Alias != "" {
-					resultJson, _ = sjson.Set(resultJson, item.Alias, jsonPath.Get(item.Name).Value())
+					b.Set(item.Alias, jsonPath.Get(item.Name).Value())
+					//resultJson, _ = sjson.Set(resultJson, item.Alias, jsonPath.Get(item.Name).Value())
 				} else {
-					resultJson, _ = sjson.Set(resultJson, item.Name, jsonPath.Get(item.Name).Value())
+					b.Set(item.Name, jsonPath.Get(item.Name).Value())
+					//resultJson, _ = sjson.Set(resultJson, item.Name, jsonPath.Get(item.Name).Value())
 				}
 			case "STRING":
-				resultJson, _ = sjson.Set(resultJson, item.Alias, item.ValueString)
+				b.Set(item.Alias, item.ValueString)
+				//resultJson, _ = sjson.Set(resultJson, item.Alias, item.ValueString)
 			case "FLOAT":
-				resultJson, _ = sjson.Set(resultJson, item.Alias, item.ValueFloat)
+				b.Set(item.Alias, item.ValueFloat)
+				//resultJson, _ = sjson.Set(resultJson, item.Alias, item.ValueFloat)
 			case "INT":
-				resultJson, _ = sjson.Set(resultJson, item.Alias, item.ValueInt)
+				b.Set(item.Alias, item.ValueInt)
+				//resultJson, _ = sjson.Set(resultJson,)
 			}
 		}
 
-		return true, resultJson, nil
+		return true, b.ToJson(), nil
 
 	} else {
 		return false, "", errors.New("Data does not match filter criteria . ")