mirror of https://github.com/grafana/grafana.git
45 lines
959 B
Go
45 lines
959 B
Go
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package util
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import (
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"context"
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"sync"
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"github.com/hashicorp/go-multierror"
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)
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// this is a decorator for a regular context that contains a custom error and returns the
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type contextWithCancellableReason struct {
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context.Context
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mtx sync.Mutex
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err error
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}
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func (c *contextWithCancellableReason) Err() error {
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c.mtx.Lock()
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defer c.mtx.Unlock()
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if c.err != nil {
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return multierror.Append(c.Context.Err(), c.err)
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}
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return c.Context.Err()
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}
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type CancelCauseFunc func(error)
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// WithCancelCause creates a cancellable context that can be cancelled with a custom reason
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func WithCancelCause(parent context.Context) (context.Context, CancelCauseFunc) {
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ctx, cancel := context.WithCancel(parent)
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errOnce := sync.Once{}
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result := &contextWithCancellableReason{
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Context: ctx,
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}
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cancelFn := func(reason error) {
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errOnce.Do(func() {
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result.mtx.Lock()
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result.err = reason
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result.mtx.Unlock()
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cancel()
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})
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}
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return result, cancelFn
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}
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