1 files changed, 199 insertions, 0 deletions
diff --git a/vendor/github.com/aws/aws-sdk-go/private/protocol/eventstream/decode.go b/vendor/github.com/aws/aws-sdk-go/private/protocol/eventstream/decode.go
new file mode 100644
index 0000000..4b972b2
--- /dev/null
+++ b/vendor/github.com/aws/aws-sdk-go/private/protocol/eventstream/decode.go
@@ -0,0 +1,199 @@
+package eventstream
+
+import (
+	"bytes"
+	"encoding/binary"
+	"encoding/hex"
+	"encoding/json"
+	"fmt"
+	"hash"
+	"hash/crc32"
+	"io"
+
+	"github.com/aws/aws-sdk-go/aws"
+)
+
+// Decoder provides decoding of an Event Stream messages.
+type Decoder struct {
+	r      io.Reader
+	logger aws.Logger
+}
+
+// NewDecoder initializes and returns a Decoder for decoding event
+// stream messages from the reader provided.
+func NewDecoder(r io.Reader) *Decoder {
+	return &Decoder{
+		r: r,
+	}
+}
+
+// Decode attempts to decode a single message from the event stream reader.
+// Will return the event stream message, or error if Decode fails to read
+// the message from the stream.
+func (d *Decoder) Decode(payloadBuf []byte) (m Message, err error) {
+	reader := d.r
+	if d.logger != nil {
+		debugMsgBuf := bytes.NewBuffer(nil)
+		reader = io.TeeReader(reader, debugMsgBuf)
+		defer func() {
+			logMessageDecode(d.logger, debugMsgBuf, m, err)
+		}()
+	}
+
+	crc := crc32.New(crc32IEEETable)
+	hashReader := io.TeeReader(reader, crc)
+
+	prelude, err := decodePrelude(hashReader, crc)
+	if err != nil {
+		return Message{}, err
+	}
+
+	if prelude.HeadersLen > 0 {
+		lr := io.LimitReader(hashReader, int64(prelude.HeadersLen))
+		m.Headers, err = decodeHeaders(lr)
+		if err != nil {
+			return Message{}, err
+		}
+	}
+
+	if payloadLen := prelude.PayloadLen(); payloadLen > 0 {
+		buf, err := decodePayload(payloadBuf, io.LimitReader(hashReader, int64(payloadLen)))
+		if err != nil {
+			return Message{}, err
+		}
+		m.Payload = buf
+	}
+
+	msgCRC := crc.Sum32()
+	if err := validateCRC(reader, msgCRC); err != nil {
+		return Message{}, err
+	}
+
+	return m, nil
+}
+
+// UseLogger specifies the Logger that that the decoder should use to log the
+// message decode to.
+func (d *Decoder) UseLogger(logger aws.Logger) {
+	d.logger = logger
+}
+
+func logMessageDecode(logger aws.Logger, msgBuf *bytes.Buffer, msg Message, decodeErr error) {
+	w := bytes.NewBuffer(nil)
+	defer func() { logger.Log(w.String()) }()
+
+	fmt.Fprintf(w, "Raw message:\n%s\n",
+		hex.Dump(msgBuf.Bytes()))
+
+	if decodeErr != nil {
+		fmt.Fprintf(w, "Decode error: %v\n", decodeErr)
+		return
+	}
+
+	rawMsg, err := msg.rawMessage()
+	if err != nil {
+		fmt.Fprintf(w, "failed to create raw message, %v\n", err)
+		return
+	}
+
+	decodedMsg := decodedMessage{
+		rawMessage: rawMsg,
+		Headers:    decodedHeaders(msg.Headers),
+	}
+
+	fmt.Fprintf(w, "Decoded message:\n")
+	encoder := json.NewEncoder(w)
+	if err := encoder.Encode(decodedMsg); err != nil {
+		fmt.Fprintf(w, "failed to generate decoded message, %v\n", err)
+	}
+}
+
+func decodePrelude(r io.Reader, crc hash.Hash32) (messagePrelude, error) {
+	var p messagePrelude
+
+	var err error
+	p.Length, err = decodeUint32(r)
+	if err != nil {
+		return messagePrelude{}, err
+	}
+
+	p.HeadersLen, err = decodeUint32(r)
+	if err != nil {
+		return messagePrelude{}, err
+	}
+
+	if err := p.ValidateLens(); err != nil {
+		return messagePrelude{}, err
+	}
+
+	preludeCRC := crc.Sum32()
+	if err := validateCRC(r, preludeCRC); err != nil {
+		return messagePrelude{}, err
+	}
+
+	p.PreludeCRC = preludeCRC
+
+	return p, nil
+}
+
+func decodePayload(buf []byte, r io.Reader) ([]byte, error) {
+	w := bytes.NewBuffer(buf[0:0])
+
+	_, err := io.Copy(w, r)
+	return w.Bytes(), err
+}
+
+func decodeUint8(r io.Reader) (uint8, error) {
+	type byteReader interface {
+		ReadByte() (byte, error)
+	}
+
+	if br, ok := r.(byteReader); ok {
+		v, err := br.ReadByte()
+		return uint8(v), err
+	}
+
+	var b [1]byte
+	_, err := io.ReadFull(r, b[:])
+	return uint8(b[0]), err
+}
+func decodeUint16(r io.Reader) (uint16, error) {
+	var b [2]byte
+	bs := b[:]
+	_, err := io.ReadFull(r, bs)
+	if err != nil {
+		return 0, err
+	}
+	return binary.BigEndian.Uint16(bs), nil
+}
+func decodeUint32(r io.Reader) (uint32, error) {
+	var b [4]byte
+	bs := b[:]
+	_, err := io.ReadFull(r, bs)
+	if err != nil {
+		return 0, err
+	}
+	return binary.BigEndian.Uint32(bs), nil
+}
+func decodeUint64(r io.Reader) (uint64, error) {
+	var b [8]byte
+	bs := b[:]
+	_, err := io.ReadFull(r, bs)
+	if err != nil {
+		return 0, err
+	}
+	return binary.BigEndian.Uint64(bs), nil
+}
+
+func validateCRC(r io.Reader, expect uint32) error {
+	msgCRC, err := decodeUint32(r)
+	if err != nil {
+		return err
+	}
+
+	if msgCRC != expect {
+		return ChecksumError{}
+	}
+
+	return nil
+}