rclone/vendor/github.com/aws/aws-sdk-go/private/protocol/rest/build.go
2016-12-04 16:25:30 +00:00

273 lines
6.6 KiB
Go

// Package rest provides RESTful serialization of AWS requests and responses.
package rest
import (
"bytes"
"encoding/base64"
"fmt"
"io"
"net/http"
"net/url"
"path"
"reflect"
"strconv"
"strings"
"time"
"github.com/aws/aws-sdk-go/aws"
"github.com/aws/aws-sdk-go/aws/awserr"
"github.com/aws/aws-sdk-go/aws/request"
)
// RFC822 returns an RFC822 formatted timestamp for AWS protocols
const RFC822 = "Mon, 2 Jan 2006 15:04:05 GMT"
// Whether the byte value can be sent without escaping in AWS URLs
var noEscape [256]bool
var errValueNotSet = fmt.Errorf("value not set")
func init() {
for i := 0; i < len(noEscape); i++ {
// AWS expects every character except these to be escaped
noEscape[i] = (i >= 'A' && i <= 'Z') ||
(i >= 'a' && i <= 'z') ||
(i >= '0' && i <= '9') ||
i == '-' ||
i == '.' ||
i == '_' ||
i == '~'
}
}
// BuildHandler is a named request handler for building rest protocol requests
var BuildHandler = request.NamedHandler{Name: "awssdk.rest.Build", Fn: Build}
// Build builds the REST component of a service request.
func Build(r *request.Request) {
if r.ParamsFilled() {
v := reflect.ValueOf(r.Params).Elem()
buildLocationElements(r, v, false)
buildBody(r, v)
}
}
// BuildAsGET builds the REST component of a service request with the ability to hoist
// data from the body.
func BuildAsGET(r *request.Request) {
if r.ParamsFilled() {
v := reflect.ValueOf(r.Params).Elem()
buildLocationElements(r, v, true)
buildBody(r, v)
}
}
func buildLocationElements(r *request.Request, v reflect.Value, buildGETQuery bool) {
query := r.HTTPRequest.URL.Query()
for i := 0; i < v.NumField(); i++ {
m := v.Field(i)
if n := v.Type().Field(i).Name; n[0:1] == strings.ToLower(n[0:1]) {
continue
}
if m.IsValid() {
field := v.Type().Field(i)
name := field.Tag.Get("locationName")
if name == "" {
name = field.Name
}
if m.Kind() == reflect.Ptr {
m = m.Elem()
}
if !m.IsValid() {
continue
}
var err error
switch field.Tag.Get("location") {
case "headers": // header maps
err = buildHeaderMap(&r.HTTPRequest.Header, m, field.Tag.Get("locationName"))
case "header":
err = buildHeader(&r.HTTPRequest.Header, m, name)
case "uri":
err = buildURI(r.HTTPRequest.URL, m, name)
case "querystring":
err = buildQueryString(query, m, name)
default:
if buildGETQuery {
err = buildQueryString(query, m, name)
}
}
r.Error = err
}
if r.Error != nil {
return
}
}
r.HTTPRequest.URL.RawQuery = query.Encode()
updatePath(r.HTTPRequest.URL, r.HTTPRequest.URL.Path, aws.BoolValue(r.Config.DisableRestProtocolURICleaning))
}
func buildBody(r *request.Request, v reflect.Value) {
if field, ok := v.Type().FieldByName("_"); ok {
if payloadName := field.Tag.Get("payload"); payloadName != "" {
pfield, _ := v.Type().FieldByName(payloadName)
if ptag := pfield.Tag.Get("type"); ptag != "" && ptag != "structure" {
payload := reflect.Indirect(v.FieldByName(payloadName))
if payload.IsValid() && payload.Interface() != nil {
switch reader := payload.Interface().(type) {
case io.ReadSeeker:
r.SetReaderBody(reader)
case []byte:
r.SetBufferBody(reader)
case string:
r.SetStringBody(reader)
default:
r.Error = awserr.New("SerializationError",
"failed to encode REST request",
fmt.Errorf("unknown payload type %s", payload.Type()))
}
}
}
}
}
}
func buildHeader(header *http.Header, v reflect.Value, name string) error {
str, err := convertType(v)
if err == errValueNotSet {
return nil
} else if err != nil {
return awserr.New("SerializationError", "failed to encode REST request", err)
}
header.Add(name, str)
return nil
}
func buildHeaderMap(header *http.Header, v reflect.Value, prefix string) error {
for _, key := range v.MapKeys() {
str, err := convertType(v.MapIndex(key))
if err == errValueNotSet {
continue
} else if err != nil {
return awserr.New("SerializationError", "failed to encode REST request", err)
}
header.Add(prefix+key.String(), str)
}
return nil
}
func buildURI(u *url.URL, v reflect.Value, name string) error {
value, err := convertType(v)
if err == errValueNotSet {
return nil
} else if err != nil {
return awserr.New("SerializationError", "failed to encode REST request", err)
}
uri := u.Path
uri = strings.Replace(uri, "{"+name+"}", EscapePath(value, true), -1)
uri = strings.Replace(uri, "{"+name+"+}", EscapePath(value, false), -1)
u.Path = uri
return nil
}
func buildQueryString(query url.Values, v reflect.Value, name string) error {
switch value := v.Interface().(type) {
case []*string:
for _, item := range value {
query.Add(name, *item)
}
case map[string]*string:
for key, item := range value {
query.Add(key, *item)
}
case map[string][]*string:
for key, items := range value {
for _, item := range items {
query.Add(key, *item)
}
}
default:
str, err := convertType(v)
if err == errValueNotSet {
return nil
} else if err != nil {
return awserr.New("SerializationError", "failed to encode REST request", err)
}
query.Set(name, str)
}
return nil
}
func updatePath(url *url.URL, urlPath string, disableRestProtocolURICleaning bool) {
scheme, query := url.Scheme, url.RawQuery
hasSlash := strings.HasSuffix(urlPath, "/")
// clean up path
if !disableRestProtocolURICleaning {
urlPath = path.Clean(urlPath)
}
if hasSlash && !strings.HasSuffix(urlPath, "/") {
urlPath += "/"
}
// get formatted URL minus scheme so we can build this into Opaque
url.Scheme, url.Path, url.RawQuery = "", "", ""
s := url.String()
url.Scheme = scheme
url.RawQuery = query
// build opaque URI
url.Opaque = s + urlPath
}
// EscapePath escapes part of a URL path in Amazon style
func EscapePath(path string, encodeSep bool) string {
var buf bytes.Buffer
for i := 0; i < len(path); i++ {
c := path[i]
if noEscape[c] || (c == '/' && !encodeSep) {
buf.WriteByte(c)
} else {
fmt.Fprintf(&buf, "%%%02X", c)
}
}
return buf.String()
}
func convertType(v reflect.Value) (string, error) {
v = reflect.Indirect(v)
if !v.IsValid() {
return "", errValueNotSet
}
var str string
switch value := v.Interface().(type) {
case string:
str = value
case []byte:
str = base64.StdEncoding.EncodeToString(value)
case bool:
str = strconv.FormatBool(value)
case int64:
str = strconv.FormatInt(value, 10)
case float64:
str = strconv.FormatFloat(value, 'f', -1, 64)
case time.Time:
str = value.UTC().Format(RFC822)
default:
err := fmt.Errorf("Unsupported value for param %v (%s)", v.Interface(), v.Type())
return "", err
}
return str, nil
}