corehandlers

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• Variables

Variables

var AddHostExecEnvUserAgentHandler = request.NamedHandler{
	Name: "core.AddHostExecEnvUserAgentHandler",
	Fn: func(r *request.Request) {
		v := os.Getenv(execEnvVar)
		if len(v) == 0 {
			return
		}

		request.AddToUserAgent(r, execEnvUAKey+"/"+v)
	},
}

AddHostExecEnvUserAgentHandler is a request handler appending the SDK's execution environment to the user agent.

If the environment variable VOLCSTACK_EXECUTION_ENV is set, its value will be appended to the user agent string.

var AfterRetryHandler = request.NamedHandler{
	Name: "core.AfterRetryHandler",
	Fn: func(r *request.Request) {

		if r.Retryable == nil || volcengine.BoolValue(r.Config.EnforceShouldRetryCheck) {
			r.Retryable = volcengine.Bool(r.ShouldRetry(r))
		}

		if r.WillRetry() {
			r.RetryDelay = r.RetryRules(r)

			if sleepFn := r.Config.SleepDelay; sleepFn != nil {

				sleepFn(r.RetryDelay)
			} else if err := volcengine.SleepWithContext(r.Context(), r.RetryDelay); err != nil {
				r.Error = volcengineerr.New(request.CanceledErrorCode,
					"request context canceled", err)
				r.Retryable = volcengine.Bool(false)
				return
			}

			if r.IsErrorExpired() {
				r.Config.Credentials.Expire()
			}

			r.RetryCount++
			r.Error = nil
		}
	}}

AfterRetryHandler performs final checks to determine if the request should be retried and how long to delay.

var BuildContentLengthHandler = request.NamedHandler{Name: "core.BuildContentLengthHandler", Fn: func(r *request.Request) {
	var length int64

	if slength := r.HTTPRequest.Header.Get("Content-Length"); slength != "" {
		length, _ = strconv.ParseInt(slength, 10, 64)
	} else {
		if r.Body != nil {
			var err error
			length, err = volcengine.SeekerLen(r.Body)
			if err != nil {
				r.Error = volcengineerr.New(request.ErrCodeSerialization, "failed to get request volcenginebody's length", err)
				return
			}
		}
	}

	if length > 0 {
		r.HTTPRequest.ContentLength = length
		r.HTTPRequest.Header.Set("Content-Length", fmt.Sprintf("%d", length))
	} else {
		r.HTTPRequest.ContentLength = 0
		r.HTTPRequest.Header.Del("Content-Length")
	}
}}

BuildContentLengthHandler builds the content length of a request based on the volcenginebody, or will use the HTTPRequest.Header's "Content-Length" if defined. If unable to determine request volcenginebody length and no "Content-Length" was specified it will panic.

The Content-Length will only be added to the request if the length of the volcenginebody is greater than 0. If the volcenginebody is empty or the current `Content-Length` header is <= 0, the header will also be stripped.

var CustomerRequestHandler = request.NamedHandler{
	Name: "core.CustomerRequestHandler",
	Fn: func(r *request.Request) {
		if r.Config.ExtendHttpRequest != nil {
			r.Config.ExtendHttpRequest(r.Context(), r.HTTPRequest)
		}

		if r.Config.ExtendHttpRequestWithMeta != nil {
			r.Config.ExtendHttpRequestWithMeta(r.Context(), r.HTTPRequest, custom.RequestMetadata{
				ServiceName: r.ClientInfo.ServiceName,
				Version:     r.ClientInfo.APIVersion,
				Action:      r.Operation.Name,
				HttpMethod:  r.Operation.HTTPMethod,
				Region:      *r.Config.Region,
			})
		}
	},
}

var SDKVersionUserAgentHandler = request.NamedHandler{
	Name: "core.SDKVersionUserAgentHandler",
	Fn: request.MakeAddToUserAgentHandler(volcengine.SDKName, volcengine.SDKVersion,
		runtime.Version(), runtime.GOOS, runtime.GOARCH),
}

SDKVersionUserAgentHandler is a request handler for adding the SDK Version to the user agent.

var SendHandler = request.NamedHandler{
	Name: "core.SendHandler",
	Fn: func(r *request.Request) {
		sender := sendFollowRedirects
		if r.DisableFollowRedirects {
			sender = sendWithoutFollowRedirects
		}

		if request.NoBody == r.HTTPRequest.Body {

			reqOrig, reqCopy := r.HTTPRequest, *r.HTTPRequest
			reqCopy.Body = nil
			r.HTTPRequest = &reqCopy
			defer func() {
				r.HTTPRequest = reqOrig
			}()
		}

		var err error
		r.HTTPResponse, err = sender(r)
		if err != nil {
			handleSendError(r, err)
		}
	},
}

SendHandler is a request handler to send service request using HTTP client.

var ValidateEndpointHandler = request.NamedHandler{Name: "core.ValidateEndpointHandler", Fn: func(r *request.Request) {
	if r.ClientInfo.SigningRegion == "" && volcengine.StringValue(r.Config.Region) == "" && r.Config.DynamicCredentials == nil {
		r.Error = volcengine.ErrMissingRegion
	} else if r.ClientInfo.Endpoint == "" {
		r.Error = volcengine.ErrMissingEndpoint
	}
}}

ValidateEndpointHandler is a request handler to validate a request had the appropriate Region and Endpoint set. Will set r.Error if the endpoint or region is not valid.

var ValidateParametersHandler = request.NamedHandler{Name: "core.ValidateParametersHandler", Fn: func(r *request.Request) {
	if !r.ParamsFilled() {
		return
	}

	if v, ok := r.Params.(request.Validator); ok {
		if err := v.Validate(); err != nil {
			r.Error = err
		}
	}
}}

ValidateParametersHandler is a request handler to validate the input parameters. Validating parameters only has meaning if done prior to the request being sent.

var ValidateReqSigHandler = request.NamedHandler{
	Name: "core.ValidateReqSigHandler",
	Fn: func(r *request.Request) {

		if r.Config.Credentials == credentials.AnonymousCredentials {
			return
		}

		signedTime := r.Time
		if !r.LastSignedAt.IsZero() {
			signedTime = r.LastSignedAt
		}

		if signedTime.Add(5 * time.Minute).After(time.Now()) {
			return
		}

		fmt.Println("request expired, resigning")
		r.Sign()
	},
}

ValidateReqSigHandler is a request handler to ensure that the request's signature doesn't expire before it is sent. This can happen when a request is built and signed significantly before it is sent. Or significant delays occur when retrying requests that would cause the signature to expire.

var ValidateResponseHandler = request.NamedHandler{Name: "core.ValidateResponseHandler", Fn: func(r *request.Request) {
	if r.HTTPResponse.StatusCode == 0 || r.HTTPResponse.StatusCode >= 300 {

		r.Error = volcengineerr.New("UnknownError", "unknown error", nil)
	}
}}

ValidateResponseHandler is a request handler to validate service response.