156 lines
3.1 KiB
Go
156 lines
3.1 KiB
Go
package api
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import (
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"fmt"
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"time"
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)
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type pollingHandler func() (exit bool, state interface{}, err error)
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func poll(handler pollingHandler, timeout time.Duration) (chan (interface{}), chan (interface{}), chan (error)) {
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compChan := make(chan interface{})
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progChan := make(chan interface{})
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errChan := make(chan error)
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tick := time.Tick(5 * time.Second)
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bomb := time.After(timeout)
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go func() {
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for {
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select {
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case <-tick:
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exit, state, err := handler()
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if state != nil {
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progChan <- state
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}
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if err != nil {
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errChan <- fmt.Errorf("Failed: poll: %s", err)
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return
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}
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if exit {
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compChan <- state
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return
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}
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case <-bomb:
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errChan <- fmt.Errorf("Timeout")
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return
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}
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}
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}()
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return compChan, progChan, errChan
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}
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func blockingPoll(handler pollingHandler, timeout time.Duration) error {
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c, p, e := poll(handler, timeout)
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for {
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select {
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case <-c:
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return nil
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case <-p:
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// noop
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case err := <-e:
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return err
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}
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}
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}
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type hasAvailable interface {
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IsAvailable() bool
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}
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type hasFailed interface {
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IsFailed() bool
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}
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func waitingForAvailableFunc(readFunc func() (hasAvailable, error), maxRetry int) func() (bool, interface{}, error) {
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counter := 0
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return func() (bool, interface{}, error) {
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v, err := readFunc()
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if err != nil {
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counter++
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if maxRetry > 0 && counter < maxRetry {
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return false, nil, nil
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}
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return false, nil, err
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}
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if v == nil {
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return false, nil, fmt.Errorf("readFunc returns nil")
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}
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if v.IsAvailable() {
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return true, v, nil
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}
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if f, ok := v.(hasFailed); ok && f.IsFailed() {
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return false, v, fmt.Errorf("InstanceState is failed: %#v", v)
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}
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return false, v, nil
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}
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}
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type hasUpDown interface {
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IsUp() bool
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IsDown() bool
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}
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func waitingForUpFunc(readFunc func() (hasUpDown, error), maxRetry int) func() (bool, interface{}, error) {
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counter := 0
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return func() (bool, interface{}, error) {
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v, err := readFunc()
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if err != nil {
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counter++
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if maxRetry > 0 && counter < maxRetry {
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return false, nil, nil
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}
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return false, nil, err
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}
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if v == nil {
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return false, nil, fmt.Errorf("readFunc returns nil")
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}
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if v.IsUp() {
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return true, v, nil
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}
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return false, v, nil
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}
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}
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func waitingForDownFunc(readFunc func() (hasUpDown, error), maxRetry int) func() (bool, interface{}, error) {
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counter := 0
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return func() (bool, interface{}, error) {
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v, err := readFunc()
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if err != nil {
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counter++
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if maxRetry > 0 && counter < maxRetry {
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return false, nil, nil
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}
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return false, nil, err
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}
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if v == nil {
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return false, nil, fmt.Errorf("readFunc returns nil")
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}
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if v.IsDown() {
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return true, v, nil
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}
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return false, v, nil
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}
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}
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func waitingForReadFunc(readFunc func() (interface{}, error), maxRetry int) func() (bool, interface{}, error) {
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counter := 0
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return func() (bool, interface{}, error) {
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v, err := readFunc()
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if err != nil {
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counter++
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if maxRetry > 0 && counter < maxRetry {
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return false, nil, nil
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}
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return false, nil, err
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}
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if v != nil {
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return true, v, nil
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}
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return false, v, nil
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}
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}
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