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49 lines
1.1 KiB
Go
49 lines
1.1 KiB
Go
package syncx
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import "sync"
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// A ManagedResource is used to manage a resource that might be broken and refetched, like a connection.
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type ManagedResource struct {
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resource interface{}
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lock sync.RWMutex
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generate func() interface{}
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equals func(a, b interface{}) bool
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}
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// NewManagedResource returns a ManagedResource.
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func NewManagedResource(generate func() interface{}, equals func(a, b interface{}) bool) *ManagedResource {
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return &ManagedResource{
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generate: generate,
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equals: equals,
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}
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}
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// MarkBroken marks the resouce broken.
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func (mr *ManagedResource) MarkBroken(resource interface{}) {
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mr.lock.Lock()
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defer mr.lock.Unlock()
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if mr.equals(mr.resource, resource) {
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mr.resource = nil
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}
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}
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// Take takes the resource, if not loaded, generates it.
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func (mr *ManagedResource) Take() interface{} {
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mr.lock.RLock()
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resource := mr.resource
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mr.lock.RUnlock()
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if resource != nil {
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return resource
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}
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mr.lock.Lock()
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defer mr.lock.Unlock()
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// maybe another Take() call already generated the resource.
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if mr.resource == nil {
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mr.resource = mr.generate()
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}
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return mr.resource
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}
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