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55 lines
1.1 KiB
55 lines
1.1 KiB
// Package group provides a sample lazy load container.
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// The group only creating a new object not until the object is needed by user.
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// And it will cache all the objects to reduce the creation of object.
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package group
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import "sync"
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// Group is a lazy load container.
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type Group struct {
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new func() interface{}
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objs sync.Map
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sync.RWMutex
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}
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// NewGroup news a group container.
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func NewGroup(new func() interface{}) *Group {
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if new == nil {
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panic("container.group: can't assign a nil to the new function")
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}
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return &Group{
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new: new,
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}
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}
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// Get gets the object by the given key.
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func (g *Group) Get(key string) interface{} {
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g.RLock()
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new := g.new
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g.RUnlock()
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obj, ok := g.objs.Load(key)
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if !ok {
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obj = new()
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g.objs.Store(key, obj)
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}
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return obj
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}
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// Reset resets the new function and deletes all existing objects.
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func (g *Group) Reset(new func() interface{}) {
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if new == nil {
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panic("container.group: can't assign a nil to the new function")
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}
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g.Lock()
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g.new = new
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g.Unlock()
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g.Clear()
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}
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// Clear deletes all objects.
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func (g *Group) Clear() {
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g.objs.Range(func(key, value interface{}) bool {
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g.objs.Delete(key)
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return true
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})
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}
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