aws/protocol/rest: V2 REST Encoder Implementation (#449)

Adds utility for encoding HTTP REST values. Will be used by SDK's generated marshalers.

aws/protocol/rest/encode.go

@@ -0,0 +1,79 @@
+package rest
+
+import (
+	"net/http"
+	"net/url"
+	"strings"
+)
+
+// An Encoder provides encoding of REST URI path, query, and header components
+// of an HTTP request. Can also encode a stream as the payload.
+//
+// Does not support SetFields.
+type Encoder struct {
+	req *http.Request
+
+	path, rawPath, pathBuffer []byte
+
+	query  url.Values
+	header http.Header
+}
+
+// NewEncoder creates a new encoder from the passed in request. All query and
+// header values will be added on top of the request's existing values. Overwriting
+// duplicate values.
+func NewEncoder(req *http.Request) *Encoder {
+	e := &Encoder{
+		req: req,
+
+		path:    []byte(req.URL.Path),
+		rawPath: []byte(req.URL.Path),
+		query:   req.URL.Query(),
+		header:  req.Header,
+	}
+
+	return e
+}
+
+// Encode returns a REST protocol encoder for encoding HTTP bindings
+// Returns any error if one occurred during encoding.
+func (e *Encoder) Encode() error {
+	e.req.URL.Path, e.req.URL.RawPath = string(e.path), string(e.rawPath)
+	e.req.URL.RawQuery = e.query.Encode()
+	e.req.Header = e.header
+
+	return nil
+}
+
+// AddHeader returns a HeaderValue for appending to the given header name
+func (e *Encoder) AddHeader(key string) HeaderValue {
+	return newHeaderValue(e.header, key, true)
+}
+
+// SetHeader returns a HeaderValue for setting the given header name
+func (e *Encoder) SetHeader(key string) HeaderValue {
+	return newHeaderValue(e.header, key, false)
+}
+
+// Headers returns a Header used encoding headers with the given prefix
+func (e *Encoder) Headers(prefix string) Headers {
+	return Headers{
+		header: e.header,
+		prefix: strings.TrimSpace(prefix),
+	}
+}
+
+// SetURI returns a URIValue used for setting the given path key
+func (e *Encoder) SetURI(key string) URIValue {
+	return newURIValue(&e.path, &e.rawPath, &e.pathBuffer, key)
+}
+
+// SetQuery returns a QueryValue used for setting the given query key
+func (e *Encoder) SetQuery(key string) QueryValue {
+	return newQueryValue(e.query, key, false)
+}
+
+// AddQuery returns a QueryValue used for appending the given query key
+func (e *Encoder) AddQuery(key string) QueryValue {
+	return newQueryValue(e.query, key, true)
+}

aws/protocol/rest/encode_test.go

@@ -0,0 +1,56 @@
+package rest
+
+import (
+	"net/http"
+	"net/url"
+	"reflect"
+	"testing"
+)
+
+func TestEncoder(t *testing.T) {
+	actual := http.Request{
+		Header: http.Header{
+			"custom-user-header": {"someValue"},
+		},
+		URL: &url.URL{
+			Path:     "/some/{pathKey}/path",
+			RawQuery: "someExistingKeys=foobar",
+		},
+	}
+
+	expected := http.Request{
+		Header: map[string][]string{
+			"custom-user-header": {"someValue"},
+			"x-amzn-header-foo":  {"someValue"},
+			"x-amzn-meta-foo":    {"someValue"},
+		},
+		URL: &url.URL{
+			Path:     "/some/someValue/path",
+			RawPath:  "/some/someValue/path",
+			RawQuery: "someExistingKeys=foobar&someKey=someValue&someKey=otherValue",
+		},
+	}
+
+	encoder := NewEncoder(&actual)
+
+	// Headers
+	encoder.AddHeader("x-amzn-header-foo").String("someValue")
+	encoder.Headers("x-amzn-meta-").AddHeader("foo").String("someValue")
+
+	// Query
+	encoder.SetQuery("someKey").String("someValue")
+	encoder.AddQuery("someKey").String("otherValue")
+
+	// URI
+	if err := encoder.SetURI("pathKey").String("someValue"); err != nil {
+		t.Errorf("expected no err, but got %v", err)
+	}
+
+	if err := encoder.Encode(); err != nil {
+		t.Errorf("expected no err, but got %v", err)
+	}
+
+	if !reflect.DeepEqual(expected, actual) {
+		t.Errorf("expected %v, but got %v", expected, actual)
+	}
+}

aws/protocol/rest/header.go

@@ -0,0 +1,103 @@
+package rest
+
+import (
+	"encoding/base64"
+	"net/http"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/aws/aws-sdk-go-v2/aws"
+	"github.com/aws/aws-sdk-go-v2/private/protocol"
+)
+
+// Headers is used to encode header keys using a provided prefix
+type Headers struct {
+	header http.Header
+	prefix string
+}
+
+// AddHeader returns a HeaderValue used to append values to prefix+key
+func (h Headers) AddHeader(key string) HeaderValue {
+	return h.newHeaderValue(key, true)
+}
+
+// SetHeader returns a HeaderValue used to set the value of prefix+key
+func (h Headers) SetHeader(key string) HeaderValue {
+	return h.newHeaderValue(key, false)
+}
+
+func (h Headers) newHeaderValue(key string, append bool) HeaderValue {
+	return newHeaderValue(h.header, h.prefix+strings.TrimSpace(key), append)
+}
+
+// HeaderValue is used to encode values to an HTTP header
+type HeaderValue struct {
+	header http.Header
+	key    string
+	append bool
+}
+
+func newHeaderValue(header http.Header, key string, append bool) HeaderValue {
+	return HeaderValue{header: header, key: strings.TrimSpace(key), append: append}
+}
+
+func (h HeaderValue) modifyHeader(value string) {
+	lk := strings.ToLower(h.key)
+
+	val := h.header[lk]
+
+	if h.append {
+		val = append(val, value)
+	} else {
+		val = append(val[:0], value)
+	}
+
+	h.header[lk] = val
+}
+
+// String encodes the value v as the header string value
+func (h HeaderValue) String(v string) {
+	h.modifyHeader(v)
+}
+
+// Integer encodes the value v as the header string value
+func (h HeaderValue) Integer(v int64) {
+	h.modifyHeader(strconv.FormatInt(v, 10))
+}
+
+// Boolean encodes the value v as a header string value
+func (h HeaderValue) Boolean(v bool) {
+	h.modifyHeader(strconv.FormatBool(v))
+}
+
+// Float encodes the value v as a header string value
+func (h HeaderValue) Float(v float64) {
+	h.modifyHeader(strconv.FormatFloat(v, 'f', -1, 64))
+}
+
+// Time encodes the value v using the format name as a header string value
+func (h HeaderValue) Time(t time.Time, format string) error {
+	value, err := protocol.FormatTime(format, t)
+	if err != nil {
+		return err
+	}
+	h.modifyHeader(value)
+	return nil
+}
+
+// ByteSlice encodes the value v as a base64 header string value
+func (h HeaderValue) ByteSlice(v []byte) {
+	encodeToString := base64.StdEncoding.EncodeToString(v)
+	h.modifyHeader(encodeToString)
+}
+
+// JSONValue encodes the value v as a base64 header string value
+func (h HeaderValue) JSONValue(v aws.JSONValue) error {
+	encodedValue, err := protocol.EncodeJSONValue(v, protocol.Base64Escape)
+	if err != nil {
+		return err
+	}
+	h.modifyHeader(encodedValue)
+	return nil
+}