Added HTTP retry, fixed async JSON body corrupting

api/rate/rate.go

@@ -171,22 +171,13 @@ func (l *Limiter) Release(path string, headers http.Header) error {
 		}
 
 	case reset != "":
-		date := headers.Get("Date")
-
-		t, err := http.ParseTime(date)
-		if err != nil {
-			return errors.Wrap(err, "Invalid date "+date)
-		}
-
 		unix, err := strconv.ParseFloat(reset, 64)
 		if err != nil {
 			return errors.Wrap(err, "Invalid reset "+reset)
 		}
 
-		reset := time.Unix(0, int64(unix*float64(time.Second)))
-		delta := reset.Sub(t) + ExtraDelay
-
-		b.reset = time.Now().Add(delta)
+		b.reset = time.Unix(0, int64(unix*float64(time.Second))).
+			Add(ExtraDelay)
 	}
 
 	if remaining != "" {

go.mod

@@ -4,6 +4,7 @@ go 1.13
 
 require (
 	github.com/bwmarrin/discordgo v0.20.2
+	github.com/davecgh/go-spew v1.1.1
 	github.com/gorilla/schema v1.1.0
 	github.com/gorilla/websocket v1.4.1
 	github.com/k0kubun/pp v3.0.1+incompatible

go.sum

@@ -1,6 +1,7 @@
 github.com/bwmarrin/discordgo v0.20.2 h1:nA7jiTtqUA9lT93WL2jPjUp8ZTEInRujBdx1C9gkr20=
 github.com/bwmarrin/discordgo v0.20.2/go.mod h1:O9S4p+ofTFwB02em7jkpkV8M3R0/PUVOwN61zSZ0r4Q=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/gobwas/httphead v0.0.0-20180130184737-2c6c146eadee h1:s+21KNqlpePfkah2I+gwHF8xmJWRjooY+5248k6m4A0=
 github.com/gobwas/httphead v0.0.0-20180130184737-2c6c146eadee/go.mod h1:L0fX3K22YWvt/FAX9NnzrNzcI4wNYi9Yku4O0LKYflo=

internal/httputil/client.go

@@ -6,7 +6,6 @@ import (
 	"context"
 	"io"
 	"io/ioutil"
-	"log"
 	"mime/multipart"
 	"net/http"
 	"time"
@@ -14,10 +13,16 @@ import (
 	"github.com/diamondburned/arikawa/internal/json"
 )
 
+// Retries is the default attempts to retry if the API returns an error before
+// giving up.
+var Retries uint = 5
+
 type Client struct {
 	http.Client
 	json.Driver
 	SchemaEncoder
+
+	Retries uint
 }
 
 var DefaultClient = NewClient()
@@ -29,6 +34,7 @@ func NewClient() Client {
 		},
 		Driver:        json.Default{},
 		SchemaEncoder: &DefaultSchema{},
+		Retries:       Retries,
 	}
 }
 
@@ -97,12 +103,27 @@ func (c *Client) RequestCtx(ctx context.Context,
 		}
 	}
 
-	r, err := c.Client.Do(req)
+	var r *http.Response
+
+	for i := uint(0); i < c.Retries; i++ {
+		r, err = c.Client.Do(req)
+		if err != nil {
+			continue
+		}
+
+		if r.StatusCode < 200 || r.StatusCode > 299 {
+			continue
+		}
+
+		break
+	}
+
+	// If all retries failed:
 	if err != nil {
-		log.Println("Do error", url, err)
 		return nil, RequestError{err}
 	}
 
+	// Response received, but with a failure status code:
 	if r.StatusCode < 200 || r.StatusCode > 299 {
 		httpErr := &HTTPError{
 			Status: r.StatusCode,

internal/httputil/http.go

@@ -5,18 +5,18 @@ import (
 )
 
 type TransportWrapper struct {
-	http.RoundTripper
-
-	Pre  func(*http.Request) error
-	Post func(*http.Response) error
+	Default http.RoundTripper
+	Pre     func(*http.Request) error
+	Post    func(*http.Response) error
 }
 
+var _ http.RoundTripper = (*TransportWrapper)(nil)
+
 func NewTransportWrapper() *TransportWrapper {
 	return &TransportWrapper{
-		RoundTripper: http.DefaultTransport,
-
-		Pre:  func(*http.Request) error { return nil },
-		Post: func(*http.Response) error { return nil },
+		Default: http.DefaultTransport,
+		Pre:     func(*http.Request) error { return nil },
+		Post:    func(*http.Response) error { return nil },
 	}
 }
 
@@ -25,7 +25,7 @@ func (c *TransportWrapper) RoundTrip(req *http.Request) (*http.Response, error)
 		return nil, err
 	}
 
-	r, err := c.RoundTripper.RoundTrip(req)
+	r, err := c.Default.RoundTrip(req)
 	if err != nil {
 		return nil, err
 	}

internal/httputil/options.go

@@ -1,9 +1,7 @@
 package httputil
 
 import (
-	"bytes"
 	"io"
-	"io/ioutil"
 	"net/http"
 
 	"github.com/diamondburned/arikawa/internal/json"
@@ -62,11 +60,12 @@ func WithJSONBody(json json.Driver, v interface{}) RequestOption {
 		}
 	}
 
-	var buf bytes.Buffer
 	var err error
+	var rp, wp = io.Pipe()
 
 	go func() {
-		err = json.EncodeStream(&buf, v)
+		err = json.EncodeStream(wp, v)
+		wp.Close()
 	}()
 
 	return func(r *http.Request) error {
@@ -75,7 +74,7 @@ func WithJSONBody(json json.Driver, v interface{}) RequestOption {
 		}
 
 		r.Header.Set("Content-Type", "application/json")
-		r.Body = ioutil.NopCloser(&buf)
+		r.Body = rp
 		return nil
 	}
 }