解析指針類(lèi)型結(jié)構(gòu)值中的值，該值將存儲(chǔ)指針指向的結(jié)構(gòu)中的值。然后 Create 方法接收所有你想從中獲取結(jié)構(gòu)內(nèi)應(yīng)用程序或服務(wù)值的方法。
在所有方法中使用指針接收器，您將能夠訪問(wèn)在解析 yaml 時(shí)更新的原始結(jié)構(gòu)。
創(chuàng)建一個(gè)指向該結(jié)構(gòu)的空實(shí)例的指針并將其作為方法接收器傳遞。然后在解組中訪問(wèn)該結(jié)構(gòu)以更新原始結(jié)構(gòu)中的 yaml 數(shù)據(jù)。通過(guò)使用指向方法的指針接收器訪問(wèn)原始結(jié)構(gòu)的值來(lái)訪問(wèn)每個(gè)函數(shù)中更新的結(jié)構(gòu)。
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(lè)場(chǎng)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(guò)從 parse 函數(shù)返回的結(jié)構(gòu)。由于我們正在傳遞一個(gè)指針類(lèi)型的接收器并將原始結(jié)構(gòu)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(shù)將變得更加干凈，因?yàn)槲覀儧](méi)有從它返回任何東西，我們只是使用方法 receiver 更新原始結(jié)構(gòu)，這是實(shí)現(xiàn)您一直試圖實(shí)現(xiàn)的目標(biāo)的更好方法。
您還可以選擇通過(guò)將 struct 中的方法定義為您嘗試為其實(shí)現(xiàn)接口的接收器來(lái)實(shí)現(xiàn)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(jià)是類(lèi)型系統(tǒng)和運(yùn)行時(shí)的復(fù)雜性。我們還沒(méi)有找到一種設(shè)計(jì)，讓價(jià)值與復(fù)雜性成正比，盡管我們繼續(xù)考慮它。同時(shí)，Go 的內(nèi)置映射和切片，加上使用空接口構(gòu)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(xiě)實(shí)現(xiàn)泛型能夠?qū)崿F(xiàn)的功能的代碼。
