mirror of
https://github.com/teivah/100-go-mistakes.git
synced 2026-06-22 01:17:11 +08:00
61 lines
974 B
Go
61 lines
974 B
Go
package main
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import (
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"fmt"
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"sync"
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)
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func main() {
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customer := Customer{}
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_ = customer.UpdateAge1(-1)
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_ = customer.UpdateAge2(-1)
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_ = customer.UpdateAge3(-1)
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}
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type Customer struct {
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mutex sync.RWMutex
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id string
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age int
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}
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func (c *Customer) UpdateAge1(age int) error {
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c.mutex.Lock()
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defer c.mutex.Unlock()
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if age < 0 {
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return fmt.Errorf("age should be positive for customer %v", c)
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}
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c.age = age
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return nil
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}
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func (c *Customer) UpdateAge2(age int) error {
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if age < 0 {
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return fmt.Errorf("age should be positive for customer %v", c)
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}
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c.mutex.Lock()
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defer c.mutex.Unlock()
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c.age = age
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return nil
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}
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func (c *Customer) UpdateAge3(age int) error {
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c.mutex.Lock()
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defer c.mutex.Unlock()
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if age < 0 {
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return fmt.Errorf("age should be positive for customer id %s", c.id)
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}
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c.age = age
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return nil
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}
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func (c *Customer) String() string {
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c.mutex.RLock()
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defer c.mutex.RUnlock()
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return fmt.Sprintf("id %s, age %d", c.id, c.age)
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}
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