58 lines
1.4 KiB
Go
58 lines
1.4 KiB
Go
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package waiterr
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import (
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"errors"
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"sync"
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)
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// WaitErr wraps a sync.WaitGroup with error handling.
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type WaitErr struct {
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wg sync.WaitGroup
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errs []error
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mut sync.RWMutex
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}
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// Go runs f in its own goroutine. When f returns, its error is stored, and returned
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// with we.Wait()
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func (we *WaitErr) Go(f func() error) {
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wrap := func() {
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err := f()
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we.mut.Lock()
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defer we.mut.Unlock()
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we.errs = append(we.errs, err)
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}
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we.wg.Go(wrap)
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}
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// WaitForError waits for the first error to be returned by one of our go routines, and immediately returns
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// with that error. If all functions return successfully, a nil is returned.
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func (we *WaitErr) WaitForError() error {
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// Implement this
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// If we already have an error, return it immediately without waiting
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// If no error has yet been returned, wait for the very first error and return it
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return nil
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}
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// Wait for all current goroutines to finish. Return an error that combines all errors returned
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// in the group so far (if any).
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func (we *WaitErr) Wait() error {
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we.wg.Wait()
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we.mut.RLock()
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defer we.mut.RUnlock()
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return errors.Join(we.errs...)
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}
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// Unwrap returns all non-nil errors returned by our functions.
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// If we.errs is empty, or all errors are nil, just return nil.
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func (we *WaitErr) Unwrap() []error {
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errs := make([]error, 0, len(we.errs))
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for _, e := range we.errs {
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if e != nil {
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errs = append(errs, e)
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}
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}
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if len(errs) == 0 {
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return nil
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}
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return errs
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}
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