77 lines
1.5 KiB
Go
77 lines
1.5 KiB
Go
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// Copyright (C) 2020 Storj Labs, Inc.
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// See LICENSE for copying information.
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// Package lifecycle allows controlling group of items.
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package lifecycle
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import (
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"context"
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"github.com/zeebo/errs"
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"go.uber.org/zap"
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"golang.org/x/sync/errgroup"
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"gopkg.in/spacemonkeygo/monkit.v2"
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"storj.io/common/errs2"
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)
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var mon = monkit.Package()
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// Group implements a collection of items that have a
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// concurrent start and are closed in reverse order.
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type Group struct {
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log *zap.Logger
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items []Item
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}
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// Item is the lifecycle item that group runs and closes.
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type Item struct {
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Name string
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Run func(ctx context.Context) error
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Close func() error
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}
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// NewGroup creates a new group.
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func NewGroup(log *zap.Logger) *Group {
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return &Group{log: log}
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}
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// Add adds item to the group.
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func (group *Group) Add(item Item) {
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group.items = append(group.items, item)
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}
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// Run starts all items concurrently under group g.
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func (group *Group) Run(ctx context.Context, g *errgroup.Group) {
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defer mon.Task()(&ctx)(nil)
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var started []string
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for _, item := range group.items {
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item := item
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started = append(started, item.Name)
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if item.Run == nil {
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continue
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}
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g.Go(func() error {
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return errs2.IgnoreCanceled(item.Run(ctx))
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})
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}
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group.log.Debug("started", zap.Strings("items", started))
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}
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// Close closes all items in reverse order.
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func (group *Group) Close() error {
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var errlist errs.Group
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for i := len(group.items) - 1; i >= 0; i-- {
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item := group.items[i]
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if item.Close == nil {
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continue
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}
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errlist.Add(item.Close())
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}
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return errlist.Err()
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}
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