55 lines
1.2 KiB
Go
55 lines
1.2 KiB
Go
package singleton
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import (
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"github.com/hashicorp/nomad/helper/pluginutils/loader"
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"github.com/hashicorp/nomad/helper/uuid"
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)
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// future is a sharable future for retrieving a plugin instance or any error
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// that may have occurred during the creation.
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type future struct {
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waitCh chan struct{}
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id string
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err error
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instance loader.PluginInstance
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}
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// newFuture returns a new pull future
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func newFuture() *future {
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return &future{
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waitCh: make(chan struct{}),
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id: uuid.Generate(),
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}
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}
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func (f *future) equal(o *future) bool {
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if f == nil && o == nil {
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return true
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} else if f != nil && o != nil {
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return f.id == o.id
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} else {
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return false
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}
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}
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// wait waits till the future has a result
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func (f *future) wait() *future {
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<-f.waitCh
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return f
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}
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// result returns the results of the future and should only ever be called after
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// wait returns.
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func (f *future) result() (loader.PluginInstance, error) {
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return f.instance, f.err
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}
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// set is used to set the results and unblock any waiter. This may only be
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// called once.
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func (f *future) set(instance loader.PluginInstance, err error) {
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f.instance = instance
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f.err = err
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close(f.waitCh)
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}
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