From a18a13fb09eac00cdacf1f74080524182b7243de Mon Sep 17 00:00:00 2001 From: Niall Sheridan Date: Mon, 6 Jun 2016 00:55:30 +0100 Subject: update vendor --- .../aws/aws-sdk-go/private/protocol/idempotency.go | 75 ++++++++++++++++++++++ 1 file changed, 75 insertions(+) create mode 100644 vendor/github.com/aws/aws-sdk-go/private/protocol/idempotency.go (limited to 'vendor/github.com/aws/aws-sdk-go/private/protocol/idempotency.go') 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:]) +} -- cgit v1.2.3