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:])
+}