diff options
Diffstat (limited to 'vendor/github.com/Azure/go-autorest/autorest/responder.go')
-rw-r--r-- | vendor/github.com/Azure/go-autorest/autorest/responder.go | 236 |
1 files changed, 236 insertions, 0 deletions
diff --git a/vendor/github.com/Azure/go-autorest/autorest/responder.go b/vendor/github.com/Azure/go-autorest/autorest/responder.go new file mode 100644 index 000000000..87f71e585 --- /dev/null +++ b/vendor/github.com/Azure/go-autorest/autorest/responder.go @@ -0,0 +1,236 @@ +package autorest + +import ( + "bytes" + "encoding/json" + "encoding/xml" + "fmt" + "io" + "io/ioutil" + "net/http" + "strings" +) + +// Responder is the interface that wraps the Respond method. +// +// Respond accepts and reacts to an http.Response. Implementations must ensure to not share or hold +// state since Responders may be shared and re-used. +type Responder interface { + Respond(*http.Response) error +} + +// ResponderFunc is a method that implements the Responder interface. +type ResponderFunc func(*http.Response) error + +// Respond implements the Responder interface on ResponderFunc. +func (rf ResponderFunc) Respond(r *http.Response) error { + return rf(r) +} + +// RespondDecorator takes and possibly decorates, by wrapping, a Responder. Decorators may react to +// the http.Response and pass it along or, first, pass the http.Response along then react. +type RespondDecorator func(Responder) Responder + +// CreateResponder creates, decorates, and returns a Responder. Without decorators, the returned +// Responder returns the passed http.Response unmodified. Responders may or may not be safe to share +// and re-used: It depends on the applied decorators. For example, a standard decorator that closes +// the response body is fine to share whereas a decorator that reads the body into a passed struct +// is not. +// +// To prevent memory leaks, ensure that at least one Responder closes the response body. +func CreateResponder(decorators ...RespondDecorator) Responder { + return DecorateResponder( + Responder(ResponderFunc(func(r *http.Response) error { return nil })), + decorators...) +} + +// DecorateResponder accepts a Responder and a, possibly empty, set of RespondDecorators, which it +// applies to the Responder. Decorators are applied in the order received, but their affect upon the +// request depends on whether they are a pre-decorator (react to the http.Response and then pass it +// along) or a post-decorator (pass the http.Response along and then react). +func DecorateResponder(r Responder, decorators ...RespondDecorator) Responder { + for _, decorate := range decorators { + r = decorate(r) + } + return r +} + +// Respond accepts an http.Response and a, possibly empty, set of RespondDecorators. +// It creates a Responder from the decorators it then applies to the passed http.Response. +func Respond(r *http.Response, decorators ...RespondDecorator) error { + if r == nil { + return nil + } + return CreateResponder(decorators...).Respond(r) +} + +// ByIgnoring returns a RespondDecorator that ignores the passed http.Response passing it unexamined +// to the next RespondDecorator. +func ByIgnoring() RespondDecorator { + return func(r Responder) Responder { + return ResponderFunc(func(resp *http.Response) error { + return r.Respond(resp) + }) + } +} + +// ByCopying copies the contents of the http.Response Body into the passed bytes.Buffer as +// the Body is read. +func ByCopying(b *bytes.Buffer) RespondDecorator { + return func(r Responder) Responder { + return ResponderFunc(func(resp *http.Response) error { + err := r.Respond(resp) + if err == nil && resp != nil && resp.Body != nil { + resp.Body = TeeReadCloser(resp.Body, b) + } + return err + }) + } +} + +// ByDiscardingBody returns a RespondDecorator that first invokes the passed Responder after which +// it copies the remaining bytes (if any) in the response body to ioutil.Discard. Since the passed +// Responder is invoked prior to discarding the response body, the decorator may occur anywhere +// within the set. +func ByDiscardingBody() RespondDecorator { + return func(r Responder) Responder { + return ResponderFunc(func(resp *http.Response) error { + err := r.Respond(resp) + if err == nil && resp != nil && resp.Body != nil { + if _, err := io.Copy(ioutil.Discard, resp.Body); err != nil { + return fmt.Errorf("Error discarding the response body: %v", err) + } + } + return err + }) + } +} + +// ByClosing returns a RespondDecorator that first invokes the passed Responder after which it +// closes the response body. Since the passed Responder is invoked prior to closing the response +// body, the decorator may occur anywhere within the set. +func ByClosing() RespondDecorator { + return func(r Responder) Responder { + return ResponderFunc(func(resp *http.Response) error { + err := r.Respond(resp) + if resp != nil && resp.Body != nil { + if err := resp.Body.Close(); err != nil { + return fmt.Errorf("Error closing the response body: %v", err) + } + } + return err + }) + } +} + +// ByClosingIfError returns a RespondDecorator that first invokes the passed Responder after which +// it closes the response if the passed Responder returns an error and the response body exists. +func ByClosingIfError() RespondDecorator { + return func(r Responder) Responder { + return ResponderFunc(func(resp *http.Response) error { + err := r.Respond(resp) + if err != nil && resp != nil && resp.Body != nil { + if err := resp.Body.Close(); err != nil { + return fmt.Errorf("Error closing the response body: %v", err) + } + } + return err + }) + } +} + +// ByUnmarshallingJSON returns a RespondDecorator that decodes a JSON document returned in the +// response Body into the value pointed to by v. +func ByUnmarshallingJSON(v interface{}) RespondDecorator { + return func(r Responder) Responder { + return ResponderFunc(func(resp *http.Response) error { + err := r.Respond(resp) + if err == nil { + b, errInner := ioutil.ReadAll(resp.Body) + // Some responses might include a BOM, remove for successful unmarshalling + b = bytes.TrimPrefix(b, []byte("\xef\xbb\xbf")) + if errInner != nil { + err = fmt.Errorf("Error occurred reading http.Response#Body - Error = '%v'", errInner) + } else if len(strings.Trim(string(b), " ")) > 0 { + errInner = json.Unmarshal(b, v) + if errInner != nil { + err = fmt.Errorf("Error occurred unmarshalling JSON - Error = '%v' JSON = '%s'", errInner, string(b)) + } + } + } + return err + }) + } +} + +// ByUnmarshallingXML returns a RespondDecorator that decodes a XML document returned in the +// response Body into the value pointed to by v. +func ByUnmarshallingXML(v interface{}) RespondDecorator { + return func(r Responder) Responder { + return ResponderFunc(func(resp *http.Response) error { + err := r.Respond(resp) + if err == nil { + b, errInner := ioutil.ReadAll(resp.Body) + if errInner != nil { + err = fmt.Errorf("Error occurred reading http.Response#Body - Error = '%v'", errInner) + } else { + errInner = xml.Unmarshal(b, v) + if errInner != nil { + err = fmt.Errorf("Error occurred unmarshalling Xml - Error = '%v' Xml = '%s'", errInner, string(b)) + } + } + } + return err + }) + } +} + +// WithErrorUnlessStatusCode returns a RespondDecorator that emits an error unless the response +// StatusCode is among the set passed. On error, response body is fully read into a buffer and +// presented in the returned error, as well as in the response body. +func WithErrorUnlessStatusCode(codes ...int) RespondDecorator { + return func(r Responder) Responder { + return ResponderFunc(func(resp *http.Response) error { + err := r.Respond(resp) + if err == nil && !ResponseHasStatusCode(resp, codes...) { + derr := NewErrorWithResponse("autorest", "WithErrorUnlessStatusCode", resp, "%v %v failed with %s", + resp.Request.Method, + resp.Request.URL, + resp.Status) + if resp.Body != nil { + defer resp.Body.Close() + b, _ := ioutil.ReadAll(resp.Body) + derr.ServiceError = b + resp.Body = ioutil.NopCloser(bytes.NewReader(b)) + } + err = derr + } + return err + }) + } +} + +// WithErrorUnlessOK returns a RespondDecorator that emits an error if the response StatusCode is +// anything other than HTTP 200. +func WithErrorUnlessOK() RespondDecorator { + return WithErrorUnlessStatusCode(http.StatusOK) +} + +// ExtractHeader extracts all values of the specified header from the http.Response. It returns an +// empty string slice if the passed http.Response is nil or the header does not exist. +func ExtractHeader(header string, resp *http.Response) []string { + if resp != nil && resp.Header != nil { + return resp.Header[http.CanonicalHeaderKey(header)] + } + return nil +} + +// ExtractHeaderValue extracts the first value of the specified header from the http.Response. It +// returns an empty string if the passed http.Response is nil or the header does not exist. +func ExtractHeaderValue(header string, resp *http.Response) string { + h := ExtractHeader(header, resp) + if len(h) > 0 { + return h[0] + } + return "" +} |