diff options
Diffstat (limited to 'vendor/github.com/aws/aws-sdk-go/aws/request/waiter.go')
-rw-r--r-- | vendor/github.com/aws/aws-sdk-go/aws/request/waiter.go | 287 |
1 files changed, 287 insertions, 0 deletions
diff --git a/vendor/github.com/aws/aws-sdk-go/aws/request/waiter.go b/vendor/github.com/aws/aws-sdk-go/aws/request/waiter.go new file mode 100644 index 00000000..854b0854 --- /dev/null +++ b/vendor/github.com/aws/aws-sdk-go/aws/request/waiter.go @@ -0,0 +1,287 @@ +package request + +import ( + "fmt" + "time" + + "github.com/aws/aws-sdk-go/aws" + "github.com/aws/aws-sdk-go/aws/awserr" + "github.com/aws/aws-sdk-go/aws/awsutil" +) + +// WaiterResourceNotReadyErrorCode is the error code returned by a waiter when +// the waiter's max attempts have been exhausted. +const WaiterResourceNotReadyErrorCode = "ResourceNotReady" + +// A WaiterOption is a function that will update the Waiter value's fields to +// configure the waiter. +type WaiterOption func(*Waiter) + +// WithWaiterMaxAttempts returns the maximum number of times the waiter should +// attempt to check the resource for the target state. +func WithWaiterMaxAttempts(max int) WaiterOption { + return func(w *Waiter) { + w.MaxAttempts = max + } +} + +// WaiterDelay will return a delay the waiter should pause between attempts to +// check the resource state. The passed in attempt is the number of times the +// Waiter has checked the resource state. +// +// Attempt is the number of attempts the Waiter has made checking the resource +// state. +type WaiterDelay func(attempt int) time.Duration + +// ConstantWaiterDelay returns a WaiterDelay that will always return a constant +// delay the waiter should use between attempts. It ignores the number of +// attempts made. +func ConstantWaiterDelay(delay time.Duration) WaiterDelay { + return func(attempt int) time.Duration { + return delay + } +} + +// WithWaiterDelay will set the Waiter to use the WaiterDelay passed in. +func WithWaiterDelay(delayer WaiterDelay) WaiterOption { + return func(w *Waiter) { + w.Delay = delayer + } +} + +// WithWaiterLogger returns a waiter option to set the logger a waiter +// should use to log warnings and errors to. +func WithWaiterLogger(logger aws.Logger) WaiterOption { + return func(w *Waiter) { + w.Logger = logger + } +} + +// WithWaiterRequestOptions returns a waiter option setting the request +// options for each request the waiter makes. Appends to waiter's request +// options already set. +func WithWaiterRequestOptions(opts ...Option) WaiterOption { + return func(w *Waiter) { + w.RequestOptions = append(w.RequestOptions, opts...) + } +} + +// A Waiter provides the functionality to performing blocking call which will +// wait for an resource state to be satisfied a service. +// +// This type should not be used directly. The API operations provided in the +// service packages prefixed with "WaitUntil" should be used instead. +type Waiter struct { + Name string + Acceptors []WaiterAcceptor + Logger aws.Logger + + MaxAttempts int + Delay WaiterDelay + + RequestOptions []Option + NewRequest func([]Option) (*Request, error) +} + +// ApplyOptions updates the waiter with the list of waiter options provided. +func (w *Waiter) ApplyOptions(opts ...WaiterOption) { + for _, fn := range opts { + fn(w) + } +} + +// WaiterState are states the waiter uses based on WaiterAcceptor definitions +// to identify if the resource state the waiter is waiting on has occurred. +type WaiterState int + +// String returns the string representation of the waiter state. +func (s WaiterState) String() string { + switch s { + case SuccessWaiterState: + return "success" + case FailureWaiterState: + return "failure" + case RetryWaiterState: + return "retry" + default: + return "unknown waiter state" + } +} + +// States the waiter acceptors will use to identify target resource states. +const ( + SuccessWaiterState WaiterState = iota // waiter successful + FailureWaiterState // waiter failed + RetryWaiterState // waiter needs to be retried +) + +// WaiterMatchMode is the mode that the waiter will use to match the WaiterAcceptor +// definition's Expected attribute. +type WaiterMatchMode int + +// Modes the waiter will use when inspecting API response to identify target +// resource states. +const ( + PathAllWaiterMatch WaiterMatchMode = iota // match on all paths + PathWaiterMatch // match on specific path + PathAnyWaiterMatch // match on any path + PathListWaiterMatch // match on list of paths + StatusWaiterMatch // match on status code + ErrorWaiterMatch // match on error +) + +// String returns the string representation of the waiter match mode. +func (m WaiterMatchMode) String() string { + switch m { + case PathAllWaiterMatch: + return "pathAll" + case PathWaiterMatch: + return "path" + case PathAnyWaiterMatch: + return "pathAny" + case PathListWaiterMatch: + return "pathList" + case StatusWaiterMatch: + return "status" + case ErrorWaiterMatch: + return "error" + default: + return "unknown waiter match mode" + } +} + +// WaitWithContext will make requests for the API operation using NewRequest to +// build API requests. The request's response will be compared against the +// Waiter's Acceptors to determine the successful state of the resource the +// waiter is inspecting. +// +// The passed in context must not be nil. If it is nil a panic will occur. The +// Context will be used to cancel the waiter's pending requests and retry delays. +// Use aws.BackgroundContext if no context is available. +// +// The waiter will continue until the target state defined by the Acceptors, +// or the max attempts expires. +// +// Will return the WaiterResourceNotReadyErrorCode error code if the waiter's +// retryer ShouldRetry returns false. This normally will happen when the max +// wait attempts expires. +func (w Waiter) WaitWithContext(ctx aws.Context) error { + + for attempt := 1; ; attempt++ { + req, err := w.NewRequest(w.RequestOptions) + if err != nil { + waiterLogf(w.Logger, "unable to create request %v", err) + return err + } + req.Handlers.Build.PushBack(MakeAddToUserAgentFreeFormHandler("Waiter")) + err = req.Send() + + // See if any of the acceptors match the request's response, or error + for _, a := range w.Acceptors { + if matched, matchErr := a.match(w.Name, w.Logger, req, err); matched { + return matchErr + } + } + + // The Waiter should only check the resource state MaxAttempts times + // This is here instead of in the for loop above to prevent delaying + // unnecessary when the waiter will not retry. + if attempt == w.MaxAttempts { + break + } + + // Delay to wait before inspecting the resource again + delay := w.Delay(attempt) + if sleepFn := req.Config.SleepDelay; sleepFn != nil { + // Support SleepDelay for backwards compatibility and testing + sleepFn(delay) + } else if err := aws.SleepWithContext(ctx, delay); err != nil { + return awserr.New(CanceledErrorCode, "waiter context canceled", err) + } + } + + return awserr.New(WaiterResourceNotReadyErrorCode, "exceeded wait attempts", nil) +} + +// A WaiterAcceptor provides the information needed to wait for an API operation +// to complete. +type WaiterAcceptor struct { + State WaiterState + Matcher WaiterMatchMode + Argument string + Expected interface{} +} + +// match returns if the acceptor found a match with the passed in request +// or error. True is returned if the acceptor made a match, error is returned +// if there was an error attempting to perform the match. +func (a *WaiterAcceptor) match(name string, l aws.Logger, req *Request, err error) (bool, error) { + result := false + var vals []interface{} + + switch a.Matcher { + case PathAllWaiterMatch, PathWaiterMatch: + // Require all matches to be equal for result to match + vals, _ = awsutil.ValuesAtPath(req.Data, a.Argument) + if len(vals) == 0 { + break + } + result = true + for _, val := range vals { + if !awsutil.DeepEqual(val, a.Expected) { + result = false + break + } + } + case PathAnyWaiterMatch: + // Only a single match needs to equal for the result to match + vals, _ = awsutil.ValuesAtPath(req.Data, a.Argument) + for _, val := range vals { + if awsutil.DeepEqual(val, a.Expected) { + result = true + break + } + } + case PathListWaiterMatch: + // ignored matcher + case StatusWaiterMatch: + s := a.Expected.(int) + result = s == req.HTTPResponse.StatusCode + case ErrorWaiterMatch: + if aerr, ok := err.(awserr.Error); ok { + result = aerr.Code() == a.Expected.(string) + } + default: + waiterLogf(l, "WARNING: Waiter %s encountered unexpected matcher: %s", + name, a.Matcher) + } + + if !result { + // If there was no matching result found there is nothing more to do + // for this response, retry the request. + return false, nil + } + + switch a.State { + case SuccessWaiterState: + // waiter completed + return true, nil + case FailureWaiterState: + // Waiter failure state triggered + return true, awserr.New(WaiterResourceNotReadyErrorCode, + "failed waiting for successful resource state", err) + case RetryWaiterState: + // clear the error and retry the operation + return false, nil + default: + waiterLogf(l, "WARNING: Waiter %s encountered unexpected state: %s", + name, a.State) + return false, nil + } +} + +func waiterLogf(logger aws.Logger, msg string, args ...interface{}) { + if logger != nil { + logger.Log(fmt.Sprintf(msg, args...)) + } +} |