request

README

GoCryptoTrader package Request

This request package is part of the GoCryptoTrader codebase.

This is still in active development

You can track ideas, planned features and what's in progress on this Trello board: https://trello.com/b/ZAhMhpOy/gocryptotrader.

Join our slack to discuss all things related to GoCryptoTrader! GoCryptoTrader Slack

Current Features for request

• This package services the exchanges package with request handling.
  • Throttling of requests for an individual exchange

Please click GoDocs chevron above to view current GoDoc information for this package

Contribution

Please feel free to submit any pull requests or suggest any desired features to be added.

When submitting a PR, please abide by our coding guidelines:

• Code must adhere to the official Go formatting guidelines (i.e. uses gofmt).
• Code must be documented adhering to the official Go commentary guidelines.
• Code must adhere to our coding style.
• Pull requests need to be based on and opened against the master branch.

Donations

If this framework helped you in any way, or you would like to support the developers working on it, please donate Bitcoin to:

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Documentation

Index

• Constants
• Variables
• func DefaultRetryPolicy(resp *http.Response, err error) (bool, error)
• func NewRateLimit(interval time.Duration, actions int) *rate.Limiter
• func RetryAfter(resp *http.Response, now time.Time) time.Duration
• func SetupGlobalReporter(r Reporter)
• func WithVerbose(ctx context.Context) context.Context
• type AuthType
• type Backoff
  • func DefaultBackoff() Backoff
  • func LinearBackoff(base, max time.Duration) Backoff
• type BasicLimit
  • func (b *BasicLimit) Limit(ctx context.Context, _ EndpointLimit) error
• type EndpointLimit
• type Generate
• type Item
• type Limiter
  • func NewBasicRateLimit(interval time.Duration, actions int) Limiter
• type Reporter
• type Requester
  • func New(name string, httpRequester *http.Client, opts ...RequesterOption) (*Requester, error)
  • func (r *Requester) DisableRateLimiter() error
  • func (r *Requester) EnableRateLimiter() error
  • func (r *Requester) GetHTTPClientUserAgent() (string, error)
  • func (r *Requester) GetNonce(set nonce.Setter) nonce.Value
  • func (r *Requester) InitiateRateLimit(ctx context.Context, e EndpointLimit) error
  • func (r *Requester) SendPayload(ctx context.Context, ep EndpointLimit, newRequest Generate, ...) error
  • func (r *Requester) SetHTTPClient(newClient *http.Client) error
  • func (r *Requester) SetHTTPClientTimeout(timeout time.Duration) error
  • func (r *Requester) SetHTTPClientUserAgent(userAgent string) error
  • func (r *Requester) SetProxy(p *url.URL) error
  • func (r *Requester) Shutdown() error
• type RequesterOption
  • func WithBackoff(b Backoff) RequesterOption
  • func WithLimiter(l Limiter) RequesterOption
  • func WithReporter(rep Reporter) RequesterOption
  • func WithRetryPolicy(p RetryPolicy) RequesterOption
• type RetryPolicy

Constants

const (
	// UnsetRequest is an unset request authentication level
	UnsetRequest AuthType = 0
	// UnauthenticatedRequest denotes a request with no credentials
	UnauthenticatedRequest = iota << 1
	// AuthenticatedRequest denotes a request using API credentials
	AuthenticatedRequest
)

const (
	DefaultMaxRetryAttempts = 3
	DefaultMutexLockTimeout = 50 * time.Millisecond
)

Const vars for rate limiter

Variables

var (
	ErrRateLimiterAlreadyDisabled = errors.New("rate limiter already disabled")
	ErrRateLimiterAlreadyEnabled  = errors.New("rate limiter already enabled")
)

Defines rate limiting errors

var (
	// ErrRequestSystemIsNil defines and error if the request system has not
	// been set up yet.
	ErrRequestSystemIsNil = errors.New("request system is nil")
	// ErrAuthRequestFailed is a wrapping error to denote that it's an auth request that failed
	ErrAuthRequestFailed = errors.New("authenticated request failed")
	// ErrBadStatus is a wrapping error to denote that the HTTP status code was unsuccessful
	ErrBadStatus = errors.New("unsuccessful HTTP status code")
)

var (
	MaxRetryAttempts = DefaultMaxRetryAttempts
)

Vars for rate limiter

Functions

func DefaultRetryPolicy

func DefaultRetryPolicy(resp *http.Response, err error) (bool, error)

DefaultRetryPolicy determines whether the request should be retried, implemented with a default strategy.

func NewRateLimit

func NewRateLimit(interval time.Duration, actions int) *rate.Limiter

NewRateLimit creates a new RateLimit based of time interval and how many actions allowed and breaks it down to an actions-per-second basis -- Burst rate is kept as one as this is not supported for out-bound requests.

func RetryAfter

func RetryAfter(resp *http.Response, now time.Time) time.Duration

RetryAfter parses the Retry-After header in the response to determine the minimum duration needed to wait before retrying.

func SetupGlobalReporter

func SetupGlobalReporter(r Reporter)

SetupGlobalReporter sets a reporter interface to be used for all exchange requests

func WithVerbose

func WithVerbose(ctx context.Context) context.Context

WithVerbose adds verbosity to a request context so that specific requests can have distinct verbosity without impacting all requests.

Types

type AuthType

type AuthType uint8

AuthType helps distinguish the purpose of a HTTP request

type Backoff

type Backoff func(n int) time.Duration

Backoff determines how long to wait between request attempts.

func DefaultBackoff

func DefaultBackoff() Backoff

DefaultBackoff is a default strategy for backoff after a retryable request failure.

func LinearBackoff

func LinearBackoff(base, max time.Duration) Backoff

LinearBackoff applies a backoff increasing by a base amount with each retry capped at a maximum duration.

type BasicLimit

type BasicLimit struct {
	// contains filtered or unexported fields
}

BasicLimit denotes basic rate limit that implements the Limiter interface does not need to set endpoint functionality.

func (*BasicLimit) Limit

func (b *BasicLimit) Limit(ctx context.Context, _ EndpointLimit) error

Limit executes a single rate limit set by NewRateLimit

type EndpointLimit

type EndpointLimit int

EndpointLimit defines individual endpoint rate limits that are set when New is called.

const (
	Unset EndpointLimit = iota
	Auth
	UnAuth
)

Const here define individual functionality sub types for rate limiting

type Generate

type Generate func() (*Item, error)

Generate defines a closure for functionality outside the requester to generate a new *http.Request on every attempt. This minimizes the chance of being outside the receive window if application rate limiting reduces outbound requests.

type Item

type Item struct {
	Method        string
	Path          string
	Headers       map[string]string
	Body          io.Reader
	Result        interface{}
	NonceEnabled  bool
	Verbose       bool
	HTTPDebugging bool
	HTTPRecording bool
	IsReserved    bool
	// HeaderResponse for inspection of header contents package side useful for
	// pagination
	HeaderResponse *http.Header
}

Item is a temp item for requests

type Limiter

type Limiter interface {
	Limit(context.Context, EndpointLimit) error
}

Limiter interface groups rate limit functionality defined in the REST wrapper for extended rate limiting configuration i.e. Shells of rate limits with a global rate for sub rates.

func NewBasicRateLimit

func NewBasicRateLimit(interval time.Duration, actions int) Limiter

NewBasicRateLimit returns an object that implements the limiter interface for basic rate limit

type Reporter

type Reporter interface {
	Latency(name, method, path string, t time.Duration)
}

Reporter interface groups observability functionality over HTTP request latency.

type Requester

type Requester struct {
	Nonce nonce.Nonce
	// contains filtered or unexported fields
}

Requester struct for the request client

func New

func New(name string, httpRequester *http.Client, opts ...RequesterOption) (*Requester, error)

New returns a new Requester

func (*Requester) DisableRateLimiter

func (r *Requester) DisableRateLimiter() error

DisableRateLimiter disables the rate limiting system for the exchange

func (*Requester) EnableRateLimiter

func (r *Requester) EnableRateLimiter() error

EnableRateLimiter enables the rate limiting system for the exchange

func (*Requester) GetHTTPClientUserAgent

func (r *Requester) GetHTTPClientUserAgent() (string, error)

GetHTTPClientUserAgent gets the exchanges HTTP user agent

func (*Requester) GetNonce

func (r *Requester) GetNonce(set nonce.Setter) nonce.Value

GetNonce returns a nonce for requests. This locks and enforces concurrent nonce FIFO on the buffered job channel

func (*Requester) InitiateRateLimit

func (r *Requester) InitiateRateLimit(ctx context.Context, e EndpointLimit) error

InitiateRateLimit sleeps for designated end point rate limits

func (*Requester) SendPayload

func (r *Requester) SendPayload(ctx context.Context, ep EndpointLimit, newRequest Generate, requestType AuthType) error

SendPayload handles sending HTTP/HTTPS requests

func (*Requester) SetHTTPClient

func (r *Requester) SetHTTPClient(newClient *http.Client) error

SetHTTPClient sets exchanges HTTP client

func (*Requester) SetHTTPClientTimeout

func (r *Requester) SetHTTPClientTimeout(timeout time.Duration) error

SetHTTPClientTimeout sets the timeout value for the exchanges HTTP Client and also the underlying transports idle connection timeout

func (*Requester) SetHTTPClientUserAgent

func (r *Requester) SetHTTPClientUserAgent(userAgent string) error

SetHTTPClientUserAgent sets the exchanges HTTP user agent

func (*Requester) SetProxy

func (r *Requester) SetProxy(p *url.URL) error

SetProxy sets a proxy address for the client transport

func (*Requester) Shutdown

func (r *Requester) Shutdown() error

Shutdown releases persistent memory for garbage collection.

type RequesterOption

type RequesterOption func(*Requester)

RequesterOption is a function option that can be applied to configure a Requester when creating it.

func WithBackoff

func WithBackoff(b Backoff) RequesterOption

WithBackoff configures the backoff strategy for a Requester.

func WithLimiter

func WithLimiter(l Limiter) RequesterOption

WithLimiter configures the rate limiter for a Requester.

func WithReporter

func WithReporter(rep Reporter) RequesterOption

WithReporter configures the reporter for a Requester.

func WithRetryPolicy

func WithRetryPolicy(p RetryPolicy) RequesterOption

WithRetryPolicy configures the retry policy for a Requester.

type RetryPolicy

type RetryPolicy func(resp *http.Response, err error) (bool, error)

RetryPolicy determines whether the request should be retried.