90 lines
1.9 KiB
Go
90 lines
1.9 KiB
Go
package main
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import (
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"fmt"
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"log"
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"time"
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)
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type GrainPool interface {
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GetOrSpawn(id string) (Grain, error)
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Get(id string) (Grain, error)
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}
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type Ttl struct {
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Expires time.Time
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Item Grain
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}
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type GrainLocalPool struct {
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grains map[string]Grain
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expiry []Ttl
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Ttl time.Duration
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PoolSize int
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}
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func NewGrainLocalPool(size int, ttl time.Duration) *GrainLocalPool {
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ret := &GrainLocalPool{
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grains: make(map[string]Grain),
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expiry: make([]Ttl, 0),
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Ttl: ttl,
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PoolSize: size,
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}
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cartPurge := time.NewTicker(time.Minute)
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go func() {
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<-cartPurge.C
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ret.Purge()
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}()
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return ret
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}
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func (p *GrainLocalPool) Purge() {
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lastChangeTime := time.Now().Add(-p.Ttl)
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keepChanged := lastChangeTime.Unix()
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for i := 0; i < len(p.expiry); i++ {
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item := p.expiry[i]
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if item.Expires.Before(time.Now()) {
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if item.Item.GetLastChange() > keepChanged {
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log.Printf("Changed item %s expired, keeping", item.Item.GetId())
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p.expiry = append(p.expiry[:i], p.expiry[i+1:]...)
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p.expiry = append(p.expiry, item)
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} else {
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log.Printf("Item %s expired", item.Item.GetId())
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delete(p.grains, item.Item.GetId())
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p.expiry = append(p.expiry[:i], p.expiry[i+1:]...)
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}
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} else {
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break
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}
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}
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}
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func (p *GrainLocalPool) GetGrains() map[string]Grain {
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return p.grains
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}
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func (p *GrainLocalPool) GetOrSpawn(id string, generator func(id string) Grain) (Grain, error) {
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grain, ok := p.grains[id]
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if !ok {
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if len(p.grains) >= p.PoolSize {
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if p.expiry[0].Expires.Before(time.Now()) {
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delete(p.grains, p.expiry[0].Item.GetId())
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p.expiry = p.expiry[1:]
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} else {
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return nil, fmt.Errorf("pool is full")
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}
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}
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grain = generator(id)
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p.grains[id] = grain
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}
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return grain, nil
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}
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func (p *GrainLocalPool) Get(id string) (Grain, error) {
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grain, ok := p.grains[id]
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if !ok {
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return nil, fmt.Errorf("grain not found")
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}
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return grain, nil
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}
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