158 lines
2.6 KiB
Go
158 lines
2.6 KiB
Go
package wallet
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import (
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"context"
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"sync"
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"time"
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)
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type Command func(context.Context) error
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// FiniteCommand terminates when error is nil.
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type FiniteCommand struct {
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Interval time.Duration
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Runable func(context.Context) error
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}
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func (c FiniteCommand) Run(ctx context.Context) error {
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err := c.Runable(ctx)
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if err == nil {
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return nil
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}
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ticker := time.NewTicker(c.Interval)
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for {
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select {
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case <-ctx.Done():
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return ctx.Err()
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case <-ticker.C:
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err := c.Runable(ctx)
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if err == nil {
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return nil
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}
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}
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}
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}
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// InfiniteCommand runs until context is closed.
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type InfiniteCommand struct {
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Interval time.Duration
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Runable func(context.Context) error
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}
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func (c InfiniteCommand) Run(ctx context.Context) error {
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_ = c.Runable(ctx)
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ticker := time.NewTicker(c.Interval)
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for {
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select {
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case <-ctx.Done():
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return ctx.Err()
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case <-ticker.C:
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_ = c.Runable(ctx)
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}
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}
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}
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func NewGroup(parent context.Context) *Group {
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ctx, cancel := context.WithCancel(parent)
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return &Group{
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ctx: ctx,
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cancel: cancel,
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}
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}
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type Group struct {
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ctx context.Context
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cancel func()
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wg sync.WaitGroup
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}
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func (g *Group) Add(cmd Command) {
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g.wg.Add(1)
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go func() {
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_ = cmd(g.ctx)
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g.wg.Done()
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}()
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}
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func (g *Group) Stop() {
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g.cancel()
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}
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func (g *Group) Wait() {
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g.wg.Wait()
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}
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func (g *Group) WaitAsync() <-chan struct{} {
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ch := make(chan struct{})
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go func() {
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g.Wait()
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close(ch)
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}()
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return ch
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}
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func NewAtomicGroup(parent context.Context) *AtomicGroup {
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ctx, cancel := context.WithCancel(parent)
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return &AtomicGroup{ctx: ctx, cancel: cancel}
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}
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// AtomicGroup terminates as soon as first goroutine terminates..
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type AtomicGroup struct {
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ctx context.Context
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cancel func()
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wg sync.WaitGroup
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mu sync.Mutex
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error error
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}
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// Go spawns function in a goroutine and stores results or errors.
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func (d *AtomicGroup) Add(cmd Command) {
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d.wg.Add(1)
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go func() {
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defer d.wg.Done()
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err := cmd(d.ctx)
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d.mu.Lock()
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defer d.mu.Unlock()
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if err != nil {
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// do not overwrite original error by context errors
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if d.error != nil {
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return
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}
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d.error = err
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d.cancel()
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return
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}
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}()
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}
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// Wait for all downloaders to finish.
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func (d *AtomicGroup) Wait() {
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d.wg.Wait()
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if d.Error() == nil {
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d.mu.Lock()
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defer d.mu.Unlock()
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d.cancel()
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}
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}
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func (d *AtomicGroup) WaitAsync() <-chan struct{} {
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ch := make(chan struct{})
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go func() {
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d.Wait()
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close(ch)
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}()
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return ch
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}
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// Error stores an error that was reported by any of the downloader. Should be called after Wait.
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func (d *AtomicGroup) Error() error {
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d.mu.Lock()
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defer d.mu.Unlock()
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return d.error
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}
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func (d *AtomicGroup) Stop() {
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d.cancel()
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}
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