From 3e4636c4547f1f8c07e2d3789265cd456cc0ca66 Mon Sep 17 00:00:00 2001
From: Denis Tarasov <denistarasov@users.noreply.github.com>
Date: Sun, 6 Sep 2020 21:07:18 +0300
Subject: [PATCH] Delete Unpacker type

---
 structtags/README.md          |  4 ++--
 structtags/structtags.go      | 15 ++++-----------
 structtags/structtags_test.go | 29 ++++++++++-------------------
 3 files changed, 16 insertions(+), 32 deletions(-)

diff --git a/structtags/README.md b/structtags/README.md
index bb0cf7d..67c9d27 100644
--- a/structtags/README.md
+++ b/structtags/README.md
@@ -7,7 +7,7 @@
 goos: linux
 goarch: amd64
 pkg: gitlab.com/slon/shad-go/structtags
-BenchmarkUnpacker/user-4                    3273            329346 ns/op
-BenchmarkUnpacker/user+good+order-4                  648           1721068 ns/op
+BenchmarkUnpacker/user-4                    3064            362500 ns/op
+BenchmarkUnpacker/user+good+order-4                  663           1799294 ns/op
 PASS
 ```
diff --git a/structtags/structtags.go b/structtags/structtags.go
index 7ef8fb0..d97dbfd 100644
--- a/structtags/structtags.go
+++ b/structtags/structtags.go
@@ -10,13 +10,6 @@ import (
 	"strings"
 )
 
-type Unpacker struct {
-}
-
-func NewUnpacker() *Unpacker {
-	return &Unpacker{}
-}
-
 // Функция Unpack присваивает значения параметров из url query в поля переданной структуры.
 
 // Для этого сначала в первом создается map,
@@ -25,7 +18,7 @@ func NewUnpacker() *Unpacker {
 
 // В следующем цикле поля структуры заполняются соответствующими
 // значениями из url query.
-func (u *Unpacker) Unpack(req *http.Request, ptr interface{}) error {
+func Unpack(req *http.Request, ptr interface{}) error {
 	if err := req.ParseForm(); err != nil {
 		return err
 	}
@@ -48,12 +41,12 @@ func (u *Unpacker) Unpack(req *http.Request, ptr interface{}) error {
 		for _, value := range values {
 			if f.Kind() == reflect.Slice {
 				elem := reflect.New(f.Type().Elem()).Elem()
-				if err := u.populate(elem, value); err != nil {
+				if err := populate(elem, value); err != nil {
 					return fmt.Errorf("%s: %v", name, err)
 				}
 				f.Set(reflect.Append(f, elem))
 			} else {
-				if err := u.populate(f, value); err != nil {
+				if err := populate(f, value); err != nil {
 					return fmt.Errorf("%s: %v", name, err)
 				}
 			}
@@ -62,7 +55,7 @@ func (u *Unpacker) Unpack(req *http.Request, ptr interface{}) error {
 	return nil
 }
 
-func (u *Unpacker) populate(v reflect.Value, value string) error {
+func populate(v reflect.Value, value string) error {
 	switch v.Kind() {
 	case reflect.String:
 		v.SetString(value)
diff --git a/structtags/structtags_test.go b/structtags/structtags_test.go
index 2d97931..6204622 100644
--- a/structtags/structtags_test.go
+++ b/structtags/structtags_test.go
@@ -75,8 +75,7 @@ type Order struct {
 func TestUnpack_User(t *testing.T) {
 	r, _ := http.NewRequest("GET", userURL, nil)
 	user := &User{}
-	u := NewUnpacker()
-	err := u.Unpack(r, user)
+	err := Unpack(r, user)
 	require.NoError(t, err)
 	require.Equal(t, expectedUser.ID, user.ID)
 	require.Equal(t, expectedUser.Name, user.Name)
@@ -88,8 +87,7 @@ func TestUnpack_User(t *testing.T) {
 func TestUnpack_Good(t *testing.T) {
 	r, _ := http.NewRequest("GET", goodURL, nil)
 	good := &Good{}
-	u := NewUnpacker()
-	err := u.Unpack(r, good)
+	err := Unpack(r, good)
 	require.NoError(t, err)
 	require.Equal(t, expectedGood.ID, good.ID)
 	require.Equal(t, expectedGood.Name, good.Name)
@@ -98,9 +96,7 @@ func TestUnpack_Good(t *testing.T) {
 func TestUnpack_Order(t *testing.T) {
 	r, _ := http.NewRequest("GET", orderURL, nil)
 	order := &Order{}
-	u := NewUnpacker()
-	err := u.Unpack(r, order)
-	fmt.Println(orderURL)
+	err := Unpack(r, order)
 	require.NoError(t, err)
 	require.Equal(t, expectedOrder.ID, order.ID)
 	require.Equal(t, expectedOrder.UserID, order.UserID)
@@ -111,8 +107,7 @@ func TestUnpack_Order(t *testing.T) {
 func TestUnpack_ParseFormError(t *testing.T) {
 	r, _ := http.NewRequest("POST", "localhost", nil)
 	user := &User{}
-	u := NewUnpacker()
-	err := u.Unpack(r, user)
+	err := Unpack(r, user)
 	require.Error(t, err)
 }
 
@@ -120,8 +115,7 @@ func TestUnpack_IncorrectBoolData(t *testing.T) {
 	url := "localhost/user?id=1&has_subscription=7"
 	r, _ := http.NewRequest("GET", url, nil)
 	user := &User{}
-	u := NewUnpacker()
-	err := u.Unpack(r, user)
+	err := Unpack(r, user)
 	require.Error(t, err)
 }
 
@@ -129,8 +123,7 @@ func TestUnpack_IncorrectIntData(t *testing.T) {
 	url := "localhost/user?id=abc"
 	r, _ := http.NewRequest("GET", url, nil)
 	user := &User{}
-	u := NewUnpacker()
-	err := u.Unpack(r, user)
+	err := Unpack(r, user)
 	require.Error(t, err)
 }
 
@@ -145,21 +138,19 @@ func BenchmarkUnpacker(b *testing.B) {
 	order := &Order{}
 
 	b.Run("user", func(b *testing.B) {
-		u := NewUnpacker()
 		for i := 0; i < b.N; i++ {
 			for j := 0; j < 1000; j++ {
-				_ = u.Unpack(userRequest, user)
+				_ = Unpack(userRequest, user)
 			}
 		}
 	})
 
 	b.Run("user+good+order", func(b *testing.B) {
-		u := NewUnpacker()
 		for i := 0; i < b.N; i++ {
 			for j := 0; j < 1000; j++ {
-				_ = u.Unpack(userRequest, user)
-				_ = u.Unpack(goodRequest, good)
-				_ = u.Unpack(orderRequest, order)
+				_ = Unpack(userRequest, user)
+				_ = Unpack(goodRequest, good)
+				_ = Unpack(orderRequest, order)
 			}
 		}
 	})