Курнат Андрей
84 lines
2.2 KiB
Go
84 lines
2.2 KiB
Go
package syncs
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import (
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"context"
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"fmt"
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"golang.org/x/sync/errgroup"
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)
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// ErrGroup is a collection of goroutines working on subtasks that
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// are part of the same overall task.
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//
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// Refers:
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//
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// https://github.com/neilotoole/errgroup
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// https://github.com/fatih/semgroup
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type ErrGroup struct {
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*errgroup.Group
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}
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// NewCtxErrGroup instance
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func NewCtxErrGroup(ctx context.Context, limit ...int) (*ErrGroup, context.Context) {
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egg, ctx1 := errgroup.WithContext(ctx)
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if len(limit) > 0 && limit[0] > 0 {
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egg.SetLimit(limit[0])
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}
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eg := &ErrGroup{Group: egg}
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return eg, ctx1
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}
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// NewErrGroup instance
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func NewErrGroup(limit ...int) *ErrGroup {
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eg := &ErrGroup{Group: new(errgroup.Group)}
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if len(limit) > 0 && limit[0] > 0 {
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eg.SetLimit(limit[0])
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}
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return eg
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}
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// Add one or more handler at once
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func (g *ErrGroup) Add(handlers ...func() error) {
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for _, handler := range handlers {
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g.Go(handler)
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}
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}
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// Go add a handler function. if panic occurs, will catch it and return as error
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func (g *ErrGroup) Go(fn func() error) {
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// Group.Go: 调用给定函数的新流程。
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// 第一次“离开”的调用必须在等待之前发生。它会一直阻塞，直到新 goroutine 能够被添加，而该组中活跃 goroutine 数量不超过配置限制。
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// 第一次返回非零错误的调用会取消该组的上下文，如果该组是由调用 WithContext 创建的。错误将由等待返回。
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g.Group.Go(func() (err error) {
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defer func() {
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if r := recover(); r != nil {
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err = fmt.Errorf("panic recover: %v", r)
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}
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}()
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err = fn()
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return
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})
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}
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// TryGo calls the given function in a new goroutine only if the number of
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// active goroutines in the group is currently below the configured limit.
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//
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// The return value reports whether the goroutine was started.
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//
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// If panic occurs, will catch it and return as error
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func (g *ErrGroup) TryGo(fn func() error) bool {
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// 只有当组中当前活跃的 goroutine 数量低于配置限制时，才会在新的 Goroutine 中调用该函数。
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// 返回值报告是否启动了goroutine。
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return g.Group.TryGo(func() (err error) {
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defer func() {
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if r := recover(); r != nil {
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err = fmt.Errorf("panic recover: %v", r)
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}
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}()
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err = fn()
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return
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})
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}
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