diff options
Diffstat (limited to 'vendor/github.com/aws/aws-sdk-go/aws/request/handlers.go')
-rw-r--r-- | vendor/github.com/aws/aws-sdk-go/aws/request/handlers.go | 274 |
1 files changed, 274 insertions, 0 deletions
diff --git a/vendor/github.com/aws/aws-sdk-go/aws/request/handlers.go b/vendor/github.com/aws/aws-sdk-go/aws/request/handlers.go new file mode 100644 index 000000000..605a72d3c --- /dev/null +++ b/vendor/github.com/aws/aws-sdk-go/aws/request/handlers.go @@ -0,0 +1,274 @@ +package request + +import ( + "fmt" + "strings" +) + +// A Handlers provides a collection of request handlers for various +// stages of handling requests. +type Handlers struct { + Validate HandlerList + Build HandlerList + Sign HandlerList + Send HandlerList + ValidateResponse HandlerList + Unmarshal HandlerList + UnmarshalStream HandlerList + UnmarshalMeta HandlerList + UnmarshalError HandlerList + Retry HandlerList + AfterRetry HandlerList + Complete HandlerList +} + +// Copy returns of this handler's lists. +func (h *Handlers) Copy() Handlers { + return Handlers{ + Validate: h.Validate.copy(), + Build: h.Build.copy(), + Sign: h.Sign.copy(), + Send: h.Send.copy(), + ValidateResponse: h.ValidateResponse.copy(), + Unmarshal: h.Unmarshal.copy(), + UnmarshalStream: h.UnmarshalStream.copy(), + UnmarshalError: h.UnmarshalError.copy(), + UnmarshalMeta: h.UnmarshalMeta.copy(), + Retry: h.Retry.copy(), + AfterRetry: h.AfterRetry.copy(), + Complete: h.Complete.copy(), + } +} + +// Clear removes callback functions for all handlers +func (h *Handlers) Clear() { + h.Validate.Clear() + h.Build.Clear() + h.Send.Clear() + h.Sign.Clear() + h.Unmarshal.Clear() + h.UnmarshalStream.Clear() + h.UnmarshalMeta.Clear() + h.UnmarshalError.Clear() + h.ValidateResponse.Clear() + h.Retry.Clear() + h.AfterRetry.Clear() + h.Complete.Clear() +} + +// A HandlerListRunItem represents an entry in the HandlerList which +// is being run. +type HandlerListRunItem struct { + Index int + Handler NamedHandler + Request *Request +} + +// A HandlerList manages zero or more handlers in a list. +type HandlerList struct { + list []NamedHandler + + // Called after each request handler in the list is called. If set + // and the func returns true the HandlerList will continue to iterate + // over the request handlers. If false is returned the HandlerList + // will stop iterating. + // + // Should be used if extra logic to be performed between each handler + // in the list. This can be used to terminate a list's iteration + // based on a condition such as error like, HandlerListStopOnError. + // Or for logging like HandlerListLogItem. + AfterEachFn func(item HandlerListRunItem) bool +} + +// A NamedHandler is a struct that contains a name and function callback. +type NamedHandler struct { + Name string + Fn func(*Request) +} + +// copy creates a copy of the handler list. +func (l *HandlerList) copy() HandlerList { + n := HandlerList{ + AfterEachFn: l.AfterEachFn, + } + if len(l.list) == 0 { + return n + } + + n.list = append(make([]NamedHandler, 0, len(l.list)), l.list...) + return n +} + +// Clear clears the handler list. +func (l *HandlerList) Clear() { + l.list = l.list[0:0] +} + +// Len returns the number of handlers in the list. +func (l *HandlerList) Len() int { + return len(l.list) +} + +// PushBack pushes handler f to the back of the handler list. +func (l *HandlerList) PushBack(f func(*Request)) { + l.PushBackNamed(NamedHandler{"__anonymous", f}) +} + +// PushBackNamed pushes named handler f to the back of the handler list. +func (l *HandlerList) PushBackNamed(n NamedHandler) { + if cap(l.list) == 0 { + l.list = make([]NamedHandler, 0, 5) + } + l.list = append(l.list, n) +} + +// PushFront pushes handler f to the front of the handler list. +func (l *HandlerList) PushFront(f func(*Request)) { + l.PushFrontNamed(NamedHandler{"__anonymous", f}) +} + +// PushFrontNamed pushes named handler f to the front of the handler list. +func (l *HandlerList) PushFrontNamed(n NamedHandler) { + if cap(l.list) == len(l.list) { + // Allocating new list required + l.list = append([]NamedHandler{n}, l.list...) + } else { + // Enough room to prepend into list. + l.list = append(l.list, NamedHandler{}) + copy(l.list[1:], l.list) + l.list[0] = n + } +} + +// Remove removes a NamedHandler n +func (l *HandlerList) Remove(n NamedHandler) { + l.RemoveByName(n.Name) +} + +// RemoveByName removes a NamedHandler by name. +func (l *HandlerList) RemoveByName(name string) { + for i := 0; i < len(l.list); i++ { + m := l.list[i] + if m.Name == name { + // Shift array preventing creating new arrays + copy(l.list[i:], l.list[i+1:]) + l.list[len(l.list)-1] = NamedHandler{} + l.list = l.list[:len(l.list)-1] + + // decrement list so next check to length is correct + i-- + } + } +} + +// SwapNamed will swap out any existing handlers with the same name as the +// passed in NamedHandler returning true if handlers were swapped. False is +// returned otherwise. +func (l *HandlerList) SwapNamed(n NamedHandler) (swapped bool) { + for i := 0; i < len(l.list); i++ { + if l.list[i].Name == n.Name { + l.list[i].Fn = n.Fn + swapped = true + } + } + + return swapped +} + +// Swap will swap out all handlers matching the name passed in. The matched +// handlers will be swapped in. True is returned if the handlers were swapped. +func (l *HandlerList) Swap(name string, replace NamedHandler) bool { + var swapped bool + + for i := 0; i < len(l.list); i++ { + if l.list[i].Name == name { + l.list[i] = replace + swapped = true + } + } + + return swapped +} + +// SetBackNamed will replace the named handler if it exists in the handler list. +// If the handler does not exist the handler will be added to the end of the list. +func (l *HandlerList) SetBackNamed(n NamedHandler) { + if !l.SwapNamed(n) { + l.PushBackNamed(n) + } +} + +// SetFrontNamed will replace the named handler if it exists in the handler list. +// If the handler does not exist the handler will be added to the beginning of +// the list. +func (l *HandlerList) SetFrontNamed(n NamedHandler) { + if !l.SwapNamed(n) { + l.PushFrontNamed(n) + } +} + +// Run executes all handlers in the list with a given request object. +func (l *HandlerList) Run(r *Request) { + for i, h := range l.list { + h.Fn(r) + item := HandlerListRunItem{ + Index: i, Handler: h, Request: r, + } + if l.AfterEachFn != nil && !l.AfterEachFn(item) { + return + } + } +} + +// HandlerListLogItem logs the request handler and the state of the +// request's Error value. Always returns true to continue iterating +// request handlers in a HandlerList. +func HandlerListLogItem(item HandlerListRunItem) bool { + if item.Request.Config.Logger == nil { + return true + } + item.Request.Config.Logger.Log("DEBUG: RequestHandler", + item.Index, item.Handler.Name, item.Request.Error) + + return true +} + +// HandlerListStopOnError returns false to stop the HandlerList iterating +// over request handlers if Request.Error is not nil. True otherwise +// to continue iterating. +func HandlerListStopOnError(item HandlerListRunItem) bool { + return item.Request.Error == nil +} + +// WithAppendUserAgent will add a string to the user agent prefixed with a +// single white space. +func WithAppendUserAgent(s string) Option { + return func(r *Request) { + r.Handlers.Build.PushBack(func(r2 *Request) { + AddToUserAgent(r, s) + }) + } +} + +// MakeAddToUserAgentHandler will add the name/version pair to the User-Agent request +// header. If the extra parameters are provided they will be added as metadata to the +// name/version pair resulting in the following format. +// "name/version (extra0; extra1; ...)" +// The user agent part will be concatenated with this current request's user agent string. +func MakeAddToUserAgentHandler(name, version string, extra ...string) func(*Request) { + ua := fmt.Sprintf("%s/%s", name, version) + if len(extra) > 0 { + ua += fmt.Sprintf(" (%s)", strings.Join(extra, "; ")) + } + return func(r *Request) { + AddToUserAgent(r, ua) + } +} + +// MakeAddToUserAgentFreeFormHandler adds the input to the User-Agent request header. +// The input string will be concatenated with the current request's user agent string. +func MakeAddToUserAgentFreeFormHandler(s string) func(*Request) { + return func(r *Request) { + AddToUserAgent(r, s) + } +} |