解析指針類型結構值中的值，該值將存儲指針指向的結構中的值。然后 Create 方法接收所有你想從中獲取結構內應用程序或服務值的方法。
在所有方法中使用指針接收器，您將能夠訪問在解析 yaml 時更新的原始結構。
創建一個指向該結構的空實例的指針并將其作為方法接收器傳遞。然后在解組中訪問該結構以更新原始結構中的 yaml 數據。通過使用指向方法的指針接收器訪問原始結構的值來訪問每個函數中更新的結構。
package main
import (
"fmt"
"log"
yaml "gopkg.in/yaml.v2"
)
var dmz = []byte(`
applications:
- name: app1
type: php
src: /app1
host: us
use:
- redis
- mysql
- name: app2
type: rust
src: /app2
host: eu
use:
- mongo
- mysql
- name: app3
type: golang
src: /app3
host: us
use:
- postgress
- mysql
services:
- name: mongo
type: db
host: us
- name: mysql
type: db
host: eu
- name: postgress
type: db
host: us
- name: redis
type: db
host: us
`)
type DMZ struct {
Applications []*Applications `yaml:"applications,omitempty"`
Services []*Services `yaml:"services,omitempty"`
}
type Applications struct {
Name string
Type string
Src string `yaml:"src,omitempty"`
use []Use `yaml:"use,omitempty"`
}
type Services struct {
Name string
Type string
Host string `yaml:"host,omitempty"`
}
type Use struct {
Name string `yaml:"name,omitempty"`
host string `yaml:"host,omitempty"`
Type string `yaml:"type,omitempty"`
}
func main() {
dm := &DMZ{}
result, err := dm.Parse(dmz)
dm.getApp("app1")
if err != nil {
fmt.Println(err)
}
fmt.Println(result)
fmt.Println(dm.getApp("app2"))
fmt.Println(dm.GetServiceForApp("mongo"))
}
func (dmz *DMZ) getApps() []*Applications {
return dmz.Applications
}
func (dmz *DMZ) getServices() []*Services {
return dmz.Services
}
func (dmz *DMZ) getApp(appname string) *Applications {
for _, value := range dmz.Applications {
if appname == value.Name {
fmt.Println((*value).Name)
return value
}
}
return nil
}
func (dmz *DMZ) GetServiceForApp(appname string) *Services {
for _, value := range dmz.Services {
if appname == value.Name {
return value
}
}
return nil
}
// Parse file
func (dmz *DMZ) Parse(yamlContent []byte) (out *DMZ, err error) {
err = yaml.Unmarshal([]byte(yamlContent), &dmz)
if err != nil {
log.Fatal("Yaml file is not valid, Error: " + err.Error())
}
return dmz, err
}
游樂場上的工作代碼
如果你想讓你的代碼更干凈，那么你也可以跳過從 parse 函數返回的結構。由于我們正在傳遞一個指針類型的接收器并將原始結構更新為：
package main
import (
"fmt"
"log"
yaml "gopkg.in/yaml.v2"
)
var dmz = []byte(`
applications:
- name: app1
type: php
src: /app1
host: us
use:
- redis
- mysql
- name: app2
type: rust
src: /app2
host: eu
use:
- mongo
- mysql
- name: app3
type: golang
src: /app3
host: us
use:
- postgress
- mysql
services:
- name: mongo
type: db
host: us
- name: mysql
type: db
host: eu
- name: postgress
type: db
host: us
- name: redis
type: db
host: us
`)
type DMZ struct {
Applications []*Applications `yaml:"applications,omitempty"`
Services []*Services `yaml:"services,omitempty"`
}
type Applications struct {
Name string
Type string
Src string `yaml:"src,omitempty"`
use []Use `yaml:"use,omitempty"`
}
type Services struct {
Name string
Type string
Host string `yaml:"host,omitempty"`
}
type Use struct {
Name string `yaml:"name,omitempty"`
host string `yaml:"host,omitempty"`
Type string `yaml:"type,omitempty"`
}
func main() {
dm := &DMZ{}
dm.Parse(dmz)
fmt.Println(dm.getApp("app2"))
fmt.Println(dm.GetServiceForApp("mongo"))
}
func (dmz *DMZ) getApps() []*Applications {
return dmz.Applications
}
func (dmz *DMZ) getServices() []*Services {
return dmz.Services
}
func (dmz *DMZ) getApp(appname string) *Applications {
for _, value := range dmz.Applications {
if appname == value.Name {
fmt.Println((*value).Name)
return value
}
}
return nil
}
func (dmz *DMZ) GetServiceForApp(appname string) *Services {
for _, value := range dmz.Services {
if appname == value.Name {
return value
}
}
return nil
}
// Parse file
func (dmz *DMZ) Parse(yamlContent []byte) {
if err := yaml.Unmarshal([]byte(yamlContent), &dmz); err != nil {
log.Fatal("Yaml file is not valid, Error: " + err.Error())
}
}
我們可以注意到 Parse 函數將變得更加干凈，因為我們沒有從它返回任何東西，我們只是使用方法 receiver 更新原始結構，這是實現您一直試圖實現的目標的更好方法。
您還可以選擇通過將 struct 中的方法定義為您嘗試為其實現接口的接收器來實現接口：
package main
import (
"fmt"
"log"
yaml "gopkg.in/yaml.v2"
)
type DI interface {
GetApps() []*Applications
GetServices() *Services
}
var dmz = []byte(`
applications:
- name: app1
type: php
src: /app1
host: us
use:
- redis
- mysql
- name: app2
type: rust
src: /app2
host: eu
use:
- mongo
- mysql
- name: app3
type: golang
src: /app3
host: us
use:
- postgress
- mysql
services:
- name: mongo
type: db
host: us
- name: mysql
type: db
host: eu
- name: postgress
type: db
host: us
- name: redis
type: db
host: us
`)
type DMZ struct {
Applications []*Applications `yaml:"applications,omitempty"`
Services []*Services `yaml:"services,omitempty"`
}
type Applications struct {
Name string
Type string
Src string `yaml:"src,omitempty"`
use []Use `yaml:"use,omitempty"`
}
type Services struct {
Name string
Type string
Host string `yaml:"host,omitempty"`
}
type Use struct {
Name string `yaml:"name,omitempty"`
host string `yaml:"host,omitempty"`
Type string `yaml:"type,omitempty"`
}
func main() {
dm := &DMZ{}
dm.Parse(dmz)
fmt.Println(dm.getApp("app2"))
fmt.Println(dm.GetServiceForApp("mongo"))
}
func (dmz *DMZ) GetApps() []*Applications {
return dmz.Applications
}
func (dmz *DMZ) GetServices() []*Services {
return dmz.Services
}
func (dmz *DMZ) getApp(appname string) *Applications {
for _, value := range dmz.Applications {
if appname == value.Name {
fmt.Println((*value).Name)
return value
}
}
return nil
}
func (dmz *DMZ) GetServiceForApp(appname string) *Services {
for _, value := range dmz.Services {
if appname == value.Name {
return value
}
}
return nil
}
// Parse file
func (dmz *DMZ) Parse(yamlContent []byte) {
if err := yaml.Unmarshal([]byte(yamlContent), &dmz); err != nil {
log.Fatal("Yaml file is not valid, Error: " + err.Error())
}
}
筆記：
泛型很方便，但它們的代價是類型系統和運行時的復雜性。我們還沒有找到一種設計，讓價值與復雜性成正比，盡管我們繼續考慮它。同時，Go 的內置映射和切片，加上使用空接口構造容器（顯式拆箱）的能力，意味著在許多情況下，即使不那么流暢，也可以編寫實現泛型能夠實現的功能的代碼。
