a7624a2bf9
Done with: ack '2022+' -l | xargs sed -i -e 's/2022+/2023+/g' Checked manually with: git add -p Hello to future James from 2024, and Happy Hacking!
65 lines
2.2 KiB
Go
65 lines
2.2 KiB
Go
// Mgmt
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// Copyright (C) 2013-2023+ James Shubin and the project contributors
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// Written by James Shubin <james@shubin.ca> and the project contributors
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//
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// This program is free software: you can redistribute it and/or modify
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// it under the terms of the GNU General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// This program is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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//
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// You should have received a copy of the GNU General Public License
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// along with this program. If not, see <http://www.gnu.org/licenses/>.
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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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)
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// ContextWithCloser wraps a context and returns a new one exactly like the
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// other context.With* functions, except that it takes a channel as an alternate
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// cancel signal.
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// TODO: switch to interface{} instead of <-chan struct to allow any chan type.
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func ContextWithCloser(ctx context.Context, ch <-chan struct{}) (context.Context, context.CancelFunc) {
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newCtx, cancel := context.WithCancel(ctx)
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go func() {
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defer cancel()
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select {
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case <-ch: // what we're waiting for
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case <-newCtx.Done(): // parent ctx was canceled
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}
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}()
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return newCtx, cancel
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}
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// ctxKeyWg is the context value key used by CtxWithWg and WgFromCtx.
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type ctxKeyWg struct{}
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// CtxWithWg takes a context and a wait group, and returns a new context that is
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// embedded with the wait group. You must use WgFromCtx to extract it.
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func CtxWithWg(ctx context.Context, wg *sync.WaitGroup) context.Context {
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//if wg == nil {
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// return ctx // return the parent?
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//}
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key := ctxKeyWg(struct{}{})
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return context.WithValue(ctx, key, wg)
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}
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// WgFromCtx takes a context and returns the stored wait group. You must use
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// CtxWithWg to store it.
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func WgFromCtx(ctx context.Context) *sync.WaitGroup {
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key := ctxKeyWg(struct{}{})
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if val := ctx.Value(key); val != nil {
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return val.(*sync.WaitGroup) // panic's if assertion fails
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}
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//return &sync.WaitGroup{} // return a dud?
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return nil
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}
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