1 files changed, 75 insertions, 0 deletions
diff --git a/vendor/github.com/aws/aws-sdk-go/private/protocol/idempotency.go b/vendor/github.com/aws/aws-sdk-go/private/protocol/idempotency.go
new file mode 100644
index 0000000..53831df
--- /dev/null
+++ b/vendor/github.com/aws/aws-sdk-go/private/protocol/idempotency.go
@@ -0,0 +1,75 @@
+package protocol
+
+import (
+	"crypto/rand"
+	"fmt"
+	"reflect"
+)
+
+// RandReader is the random reader the protocol package will use to read
+// random bytes from. This is exported for testing, and should not be used.
+var RandReader = rand.Reader
+
+const idempotencyTokenFillTag = `idempotencyToken`
+
+// CanSetIdempotencyToken returns true if the struct field should be
+// automatically populated with a Idempotency token.
+//
+// Only *string and string type fields that are tagged with idempotencyToken
+// which are not already set can be auto filled.
+func CanSetIdempotencyToken(v reflect.Value, f reflect.StructField) bool {
+	switch u := v.Interface().(type) {
+	// To auto fill an Idempotency token the field must be a string,
+	// tagged for auto fill, and have a zero value.
+	case *string:
+		return u == nil && len(f.Tag.Get(idempotencyTokenFillTag)) != 0
+	case string:
+		return len(u) == 0 && len(f.Tag.Get(idempotencyTokenFillTag)) != 0
+	}
+
+	return false
+}
+
+// GetIdempotencyToken returns a randomly generated idempotency token.
+func GetIdempotencyToken() string {
+	b := make([]byte, 16)
+	RandReader.Read(b)
+
+	return UUIDVersion4(b)
+}
+
+// SetIdempotencyToken will set the value provided with a Idempotency Token.
+// Given that the value can be set. Will panic if value is not setable.
+func SetIdempotencyToken(v reflect.Value) {
+	if v.Kind() == reflect.Ptr {
+		if v.IsNil() && v.CanSet() {
+			v.Set(reflect.New(v.Type().Elem()))
+		}
+		v = v.Elem()
+	}
+	v = reflect.Indirect(v)
+
+	if !v.CanSet() {
+		panic(fmt.Sprintf("unable to set idempotnecy token %v", v))
+	}
+
+	b := make([]byte, 16)
+	_, err := rand.Read(b)
+	if err != nil {
+		// TODO handle error
+		return
+	}
+
+	v.Set(reflect.ValueOf(UUIDVersion4(b)))
+}
+
+// UUIDVersion4 returns a Version 4 random UUID from the byte slice provided
+func UUIDVersion4(u []byte) string {
+	// https://en.wikipedia.org/wiki/Universally_unique_identifier#Version_4_.28random.29
+	// 13th character is "4"
+	u[6] = (u[6] | 0x40) & 0x4F
+	// 17th character is "8", "9", "a", or "b"
+	u[8] = (u[8] | 0x80) & 0xBF
+
+	return fmt.Sprintf(`%X-%X-%X-%X-%X`, u[0:4], u[4:6], u[6:8], u[8:10], u[10:])
+}