add other session providers (#5963)

vendor/github.com/couchbase/gomemcached/LICENSE

@@ -0,0 +1,19 @@
+Copyright (c) 2013 Dustin Sallings
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.

vendor/github.com/couchbase/gomemcached/client/tap_feed.go

@@ -0,0 +1,333 @@
+package memcached
+
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+	"io"
+	"math"
+
+	"github.com/couchbase/gomemcached"
+	"github.com/couchbase/goutils/logging"
+)
+
+// TAP protocol docs: <http://www.couchbase.com/wiki/display/couchbase/TAP+Protocol>
+
+// TapOpcode is the tap operation type (found in TapEvent)
+type TapOpcode uint8
+
+// Tap opcode values.
+const (
+	TapBeginBackfill = TapOpcode(iota)
+	TapEndBackfill
+	TapMutation
+	TapDeletion
+	TapCheckpointStart
+	TapCheckpointEnd
+	tapEndStream
+)
+
+const tapMutationExtraLen = 16
+
+var tapOpcodeNames map[TapOpcode]string
+
+func init() {
+	tapOpcodeNames = map[TapOpcode]string{
+		TapBeginBackfill:   "BeginBackfill",
+		TapEndBackfill:     "EndBackfill",
+		TapMutation:        "Mutation",
+		TapDeletion:        "Deletion",
+		TapCheckpointStart: "TapCheckpointStart",
+		TapCheckpointEnd:   "TapCheckpointEnd",
+		tapEndStream:       "EndStream",
+	}
+}
+
+func (opcode TapOpcode) String() string {
+	name := tapOpcodeNames[opcode]
+	if name == "" {
+		name = fmt.Sprintf("#%d", opcode)
+	}
+	return name
+}
+
+// TapEvent is a TAP notification of an operation on the server.
+type TapEvent struct {
+	Opcode     TapOpcode // Type of event
+	VBucket    uint16    // VBucket this event applies to
+	Flags      uint32    // Item flags
+	Expiry     uint32    // Item expiration time
+	Key, Value []byte    // Item key/value
+	Cas        uint64
+}
+
+func makeTapEvent(req gomemcached.MCRequest) *TapEvent {
+	event := TapEvent{
+		VBucket: req.VBucket,
+	}
+	switch req.Opcode {
+	case gomemcached.TAP_MUTATION:
+		event.Opcode = TapMutation
+		event.Key = req.Key
+		event.Value = req.Body
+		event.Cas = req.Cas
+	case gomemcached.TAP_DELETE:
+		event.Opcode = TapDeletion
+		event.Key = req.Key
+		event.Cas = req.Cas
+	case gomemcached.TAP_CHECKPOINT_START:
+		event.Opcode = TapCheckpointStart
+	case gomemcached.TAP_CHECKPOINT_END:
+		event.Opcode = TapCheckpointEnd
+	case gomemcached.TAP_OPAQUE:
+		if len(req.Extras) < 8+4 {
+			return nil
+		}
+		switch op := int(binary.BigEndian.Uint32(req.Extras[8:])); op {
+		case gomemcached.TAP_OPAQUE_INITIAL_VBUCKET_STREAM:
+			event.Opcode = TapBeginBackfill
+		case gomemcached.TAP_OPAQUE_CLOSE_BACKFILL:
+			event.Opcode = TapEndBackfill
+		case gomemcached.TAP_OPAQUE_CLOSE_TAP_STREAM:
+			event.Opcode = tapEndStream
+		case gomemcached.TAP_OPAQUE_ENABLE_AUTO_NACK:
+			return nil
+		case gomemcached.TAP_OPAQUE_ENABLE_CHECKPOINT_SYNC:
+			return nil
+		default:
+			logging.Infof("TapFeed: Ignoring TAP_OPAQUE/%d", op)
+			return nil // unknown opaque event
+		}
+	case gomemcached.NOOP:
+		return nil // ignore
+	default:
+		logging.Infof("TapFeed: Ignoring %s", req.Opcode)
+		return nil // unknown event
+	}
+
+	if len(req.Extras) >= tapMutationExtraLen &&
+		(event.Opcode == TapMutation || event.Opcode == TapDeletion) {
+
+		event.Flags = binary.BigEndian.Uint32(req.Extras[8:])
+		event.Expiry = binary.BigEndian.Uint32(req.Extras[12:])
+	}
+
+	return &event
+}
+
+func (event TapEvent) String() string {
+	switch event.Opcode {
+	case TapBeginBackfill, TapEndBackfill, TapCheckpointStart, TapCheckpointEnd:
+		return fmt.Sprintf("<TapEvent %s, vbucket=%d>",
+			event.Opcode, event.VBucket)
+	default:
+		return fmt.Sprintf("<TapEvent %s, key=%q (%d bytes) flags=%x, exp=%d>",
+			event.Opcode, event.Key, len(event.Value),
+			event.Flags, event.Expiry)
+	}
+}
+
+// TapArguments are parameters for requesting a TAP feed.
+//
+// Call DefaultTapArguments to get a default one.
+type TapArguments struct {
+	// Timestamp of oldest item to send.
+	//
+	// Use TapNoBackfill to suppress all past items.
+	Backfill uint64
+	// If set, server will disconnect after sending existing items.
+	Dump bool
+	// The indices of the vbuckets to watch; empty/nil to watch all.
+	VBuckets []uint16
+	// Transfers ownership of vbuckets during cluster rebalance.
+	Takeover bool
+	// If true, server will wait for client ACK after every notification.
+	SupportAck bool
+	// If true, client doesn't want values so server shouldn't send them.
+	KeysOnly bool
+	// If true, client wants the server to send checkpoint events.
+	Checkpoint bool
+	// Optional identifier to use for this client, to allow reconnects
+	ClientName string
+	// Registers this client (by name) till explicitly deregistered.
+	RegisteredClient bool
+}
+
+// Value for TapArguments.Backfill denoting that no past events at all
+// should be sent.
+const TapNoBackfill = math.MaxUint64
+
+// DefaultTapArguments returns a default set of parameter values to
+// pass to StartTapFeed.
+func DefaultTapArguments() TapArguments {
+	return TapArguments{
+		Backfill: TapNoBackfill,
+	}
+}
+
+func (args *TapArguments) flags() []byte {
+	var flags gomemcached.TapConnectFlag
+	if args.Backfill != 0 {
+		flags |= gomemcached.BACKFILL
+	}
+	if args.Dump {
+		flags |= gomemcached.DUMP
+	}
+	if len(args.VBuckets) > 0 {
+		flags |= gomemcached.LIST_VBUCKETS
+	}
+	if args.Takeover {
+		flags |= gomemcached.TAKEOVER_VBUCKETS
+	}
+	if args.SupportAck {
+		flags |= gomemcached.SUPPORT_ACK
+	}
+	if args.KeysOnly {
+		flags |= gomemcached.REQUEST_KEYS_ONLY
+	}
+	if args.Checkpoint {
+		flags |= gomemcached.CHECKPOINT
+	}
+	if args.RegisteredClient {
+		flags |= gomemcached.REGISTERED_CLIENT
+	}
+	encoded := make([]byte, 4)
+	binary.BigEndian.PutUint32(encoded, uint32(flags))
+	return encoded
+}
+
+func must(err error) {
+	if err != nil {
+		panic(err)
+	}
+}
+
+func (args *TapArguments) bytes() (rv []byte) {
+	buf := bytes.NewBuffer([]byte{})
+
+	if args.Backfill > 0 {
+		must(binary.Write(buf, binary.BigEndian, uint64(args.Backfill)))
+	}
+
+	if len(args.VBuckets) > 0 {
+		must(binary.Write(buf, binary.BigEndian, uint16(len(args.VBuckets))))
+		for i := 0; i < len(args.VBuckets); i++ {
+			must(binary.Write(buf, binary.BigEndian, uint16(args.VBuckets[i])))
+		}
+	}
+	return buf.Bytes()
+}
+
+// TapFeed represents a stream of events from a server.
+type TapFeed struct {
+	C      <-chan TapEvent
+	Error  error
+	closer chan bool
+}
+
+// StartTapFeed starts a TAP feed on a client connection.
+//
+// The events can be read from the returned channel.  The connection
+// can no longer be used for other purposes; it's now reserved for
+// receiving the TAP messages. To stop receiving events, close the
+// client connection.
+func (mc *Client) StartTapFeed(args TapArguments) (*TapFeed, error) {
+	rq := &gomemcached.MCRequest{
+		Opcode: gomemcached.TAP_CONNECT,
+		Key:    []byte(args.ClientName),
+		Extras: args.flags(),
+		Body:   args.bytes()}
+
+	err := mc.Transmit(rq)
+	if err != nil {
+		return nil, err
+	}
+
+	ch := make(chan TapEvent)
+	feed := &TapFeed{
+		C:      ch,
+		closer: make(chan bool),
+	}
+	go mc.runFeed(ch, feed)
+	return feed, nil
+}
+
+// TapRecvHook is called after every incoming tap packet is received.
+var TapRecvHook func(*gomemcached.MCRequest, int, error)
+
+// Internal goroutine that reads from the socket and writes events to
+// the channel
+func (mc *Client) runFeed(ch chan TapEvent, feed *TapFeed) {
+	defer close(ch)
+	var headerBuf [gomemcached.HDR_LEN]byte
+loop:
+	for {
+		// Read the next request from the server.
+		//
+		//  (Can't call mc.Receive() because it reads a
+		//  _response_ not a request.)
+		var pkt gomemcached.MCRequest
+		n, err := pkt.Receive(mc.conn, headerBuf[:])
+		if TapRecvHook != nil {
+			TapRecvHook(&pkt, n, err)
+		}
+
+		if err != nil {
+			if err != io.EOF {
+				feed.Error = err
+			}
+			break loop
+		}
+
+		//logging.Infof("** TapFeed received %#v : %q", pkt, pkt.Body)
+
+		if pkt.Opcode == gomemcached.TAP_CONNECT {
+			// This is not an event from the server; it's
+			// an error response to my connect request.
+			feed.Error = fmt.Errorf("tap connection failed: %s", pkt.Body)
+			break loop
+		}
+
+		event := makeTapEvent(pkt)
+		if event != nil {
+			if event.Opcode == tapEndStream {
+				break loop
+			}
+
+			select {
+			case ch <- *event:
+			case <-feed.closer:
+				break loop
+			}
+		}
+
+		if len(pkt.Extras) >= 4 {
+			reqFlags := binary.BigEndian.Uint16(pkt.Extras[2:])
+			if reqFlags&gomemcached.TAP_ACK != 0 {
+				if _, err := mc.sendAck(&pkt); err != nil {
+					feed.Error = err
+					break loop
+				}
+			}
+		}
+	}
+	if err := mc.Close(); err != nil {
+		logging.Errorf("Error closing memcached client:  %v", err)
+	}
+}
+
+func (mc *Client) sendAck(pkt *gomemcached.MCRequest) (int, error) {
+	res := gomemcached.MCResponse{
+		Opcode: pkt.Opcode,
+		Opaque: pkt.Opaque,
+		Status: gomemcached.SUCCESS,
+	}
+	return res.Transmit(mc.conn)
+}
+
+// Close terminates a TapFeed.
+//
+//  Call this if you stop using a TapFeed before its channel ends.
+func (feed *TapFeed) Close() {
+	close(feed.closer)
+}

vendor/github.com/couchbase/gomemcached/client/transport.go

@@ -0,0 +1,67 @@
+package memcached
+
+import (
+	"errors"
+	"io"
+
+	"github.com/couchbase/gomemcached"
+)
+
+var errNoConn = errors.New("no connection")
+
+// UnwrapMemcachedError converts memcached errors to normal responses.
+//
+// If the error is a memcached response, declare the error to be nil
+// so a client can handle the status without worrying about whether it
+// indicates success or failure.
+func UnwrapMemcachedError(rv *gomemcached.MCResponse,
+	err error) (*gomemcached.MCResponse, error) {
+
+	if rv == err {
+		return rv, nil
+	}
+	return rv, err
+}
+
+// ReceiveHook is called after every packet is received (or attempted to be)
+var ReceiveHook func(*gomemcached.MCResponse, int, error)
+
+func getResponse(s io.Reader, hdrBytes []byte) (rv *gomemcached.MCResponse, n int, err error) {
+	if s == nil {
+		return nil, 0, errNoConn
+	}
+
+	rv = &gomemcached.MCResponse{}
+	n, err = rv.Receive(s, hdrBytes)
+
+	if ReceiveHook != nil {
+		ReceiveHook(rv, n, err)
+	}
+
+	if err == nil && (rv.Status != gomemcached.SUCCESS && rv.Status != gomemcached.AUTH_CONTINUE) {
+		err = rv
+	}
+	return rv, n, err
+}
+
+// TransmitHook is called after each packet is transmitted.
+var TransmitHook func(*gomemcached.MCRequest, int, error)
+
+func transmitRequest(o io.Writer, req *gomemcached.MCRequest) (int, error) {
+	if o == nil {
+		return 0, errNoConn
+	}
+	n, err := req.Transmit(o)
+	if TransmitHook != nil {
+		TransmitHook(req, n, err)
+	}
+	return n, err
+}
+
+func transmitResponse(o io.Writer, res *gomemcached.MCResponse) (int, error) {
+	if o == nil {
+		return 0, errNoConn
+	}
+	n, err := res.Transmit(o)
+	return n, err
+}

vendor/github.com/couchbase/gomemcached/mc_constants.go

@@ -0,0 +1,335 @@
+// Package gomemcached is binary protocol packet formats and constants.
+package gomemcached
+
+import (
+	"fmt"
+)
+
+const (
+	REQ_MAGIC = 0x80
+	RES_MAGIC = 0x81
+)
+
+// CommandCode for memcached packets.
+type CommandCode uint8
+
+const (
+	GET        = CommandCode(0x00)
+	SET        = CommandCode(0x01)
+	ADD        = CommandCode(0x02)
+	REPLACE    = CommandCode(0x03)
+	DELETE     = CommandCode(0x04)
+	INCREMENT  = CommandCode(0x05)
+	DECREMENT  = CommandCode(0x06)
+	QUIT       = CommandCode(0x07)
+	FLUSH      = CommandCode(0x08)
+	GETQ       = CommandCode(0x09)
+	NOOP       = CommandCode(0x0a)
+	VERSION    = CommandCode(0x0b)
+	GETK       = CommandCode(0x0c)
+	GETKQ      = CommandCode(0x0d)
+	APPEND     = CommandCode(0x0e)
+	PREPEND    = CommandCode(0x0f)
+	STAT       = CommandCode(0x10)
+	SETQ       = CommandCode(0x11)
+	ADDQ       = CommandCode(0x12)
+	REPLACEQ   = CommandCode(0x13)
+	DELETEQ    = CommandCode(0x14)
+	INCREMENTQ = CommandCode(0x15)
+	DECREMENTQ = CommandCode(0x16)
+	QUITQ      = CommandCode(0x17)
+	FLUSHQ     = CommandCode(0x18)
+	APPENDQ    = CommandCode(0x19)
+	AUDIT      = CommandCode(0x27)
+	PREPENDQ   = CommandCode(0x1a)
+	GAT        = CommandCode(0x1d)
+	HELLO      = CommandCode(0x1f)
+	RGET       = CommandCode(0x30)
+	RSET       = CommandCode(0x31)
+	RSETQ      = CommandCode(0x32)
+	RAPPEND    = CommandCode(0x33)
+	RAPPENDQ   = CommandCode(0x34)
+	RPREPEND   = CommandCode(0x35)
+	RPREPENDQ  = CommandCode(0x36)
+	RDELETE    = CommandCode(0x37)
+	RDELETEQ   = CommandCode(0x38)
+	RINCR      = CommandCode(0x39)
+	RINCRQ     = CommandCode(0x3a)
+	RDECR      = CommandCode(0x3b)
+	RDECRQ     = CommandCode(0x3c)
+
+	SASL_LIST_MECHS = CommandCode(0x20)
+	SASL_AUTH       = CommandCode(0x21)
+	SASL_STEP       = CommandCode(0x22)
+
+	SET_VBUCKET = CommandCode(0x3d)
+
+	TAP_CONNECT          = CommandCode(0x40) // Client-sent request to initiate Tap feed
+	TAP_MUTATION         = CommandCode(0x41) // Notification of a SET/ADD/REPLACE/etc. on the server
+	TAP_DELETE           = CommandCode(0x42) // Notification of a DELETE on the server
+	TAP_FLUSH            = CommandCode(0x43) // Replicates a flush_all command
+	TAP_OPAQUE           = CommandCode(0x44) // Opaque control data from the engine
+	TAP_VBUCKET_SET      = CommandCode(0x45) // Sets state of vbucket in receiver (used in takeover)
+	TAP_CHECKPOINT_START = CommandCode(0x46) // Notifies start of new checkpoint
+	TAP_CHECKPOINT_END   = CommandCode(0x47) // Notifies end of checkpoint
+
+	UPR_OPEN        = CommandCode(0x50) // Open a UPR connection with a name
+	UPR_ADDSTREAM   = CommandCode(0x51) // Sent by ebucketMigrator to UPR Consumer
+	UPR_CLOSESTREAM = CommandCode(0x52) // Sent by eBucketMigrator to UPR Consumer
+	UPR_FAILOVERLOG = CommandCode(0x54) // Request failover logs
+	UPR_STREAMREQ   = CommandCode(0x53) // Stream request from consumer to producer
+	UPR_STREAMEND   = CommandCode(0x55) // Sent by producer when it has no more messages to stream
+	UPR_SNAPSHOT    = CommandCode(0x56) // Start of a new snapshot
+	UPR_MUTATION    = CommandCode(0x57) // Key mutation
+	UPR_DELETION    = CommandCode(0x58) // Key deletion
+	UPR_EXPIRATION  = CommandCode(0x59) // Key expiration
+	UPR_FLUSH       = CommandCode(0x5a) // Delete all the data for a vbucket
+	UPR_NOOP        = CommandCode(0x5c) // UPR NOOP
+	UPR_BUFFERACK   = CommandCode(0x5d) // UPR Buffer Acknowledgement
+	UPR_CONTROL     = CommandCode(0x5e) // Set flow control params
+
+	SELECT_BUCKET = CommandCode(0x89) // Select bucket
+
+	OBSERVE_SEQNO = CommandCode(0x91) // Sequence Number based Observe
+	OBSERVE       = CommandCode(0x92)
+
+	GET_META            = CommandCode(0xA0) // Get meta. returns with expiry, flags, cas etc
+	SUBDOC_GET          = CommandCode(0xc5) // Get subdoc. Returns with xattrs
+	SUBDOC_MULTI_LOOKUP = CommandCode(0xd0) // Multi lookup. Doc xattrs and meta.
+)
+
+// command codes that are counted toward DCP control buffer
+// when DCP clients receive DCP messages with these command codes, they need to provide acknowledgement
+var BufferedCommandCodeMap = map[CommandCode]bool{
+	SET_VBUCKET:    true,
+	UPR_STREAMEND:  true,
+	UPR_SNAPSHOT:   true,
+	UPR_MUTATION:   true,
+	UPR_DELETION:   true,
+	UPR_EXPIRATION: true}
+
+// Status field for memcached response.
+type Status uint16
+
+// Matches with protocol_binary.h as source of truth
+const (
+	SUCCESS         = Status(0x00)
+	KEY_ENOENT      = Status(0x01)
+	KEY_EEXISTS     = Status(0x02)
+	E2BIG           = Status(0x03)
+	EINVAL          = Status(0x04)
+	NOT_STORED      = Status(0x05)
+	DELTA_BADVAL    = Status(0x06)
+	NOT_MY_VBUCKET  = Status(0x07)
+	NO_BUCKET       = Status(0x08)
+	LOCKED          = Status(0x09)
+	AUTH_STALE      = Status(0x1f)
+	AUTH_ERROR      = Status(0x20)
+	AUTH_CONTINUE   = Status(0x21)
+	ERANGE          = Status(0x22)
+	ROLLBACK        = Status(0x23)
+	EACCESS         = Status(0x24)
+	NOT_INITIALIZED = Status(0x25)
+	UNKNOWN_COMMAND = Status(0x81)
+	ENOMEM          = Status(0x82)
+	NOT_SUPPORTED   = Status(0x83)
+	EINTERNAL       = Status(0x84)
+	EBUSY           = Status(0x85)
+	TMPFAIL         = Status(0x86)
+
+	// SUBDOC
+	SUBDOC_PATH_NOT_FOUND             = Status(0xc0)
+	SUBDOC_BAD_MULTI                  = Status(0xcc)
+	SUBDOC_MULTI_PATH_FAILURE_DELETED = Status(0xd3)
+)
+
+// for log redaction
+const (
+	UdTagBegin = "<ud>"
+	UdTagEnd   = "</ud>"
+)
+
+var isFatal = map[Status]bool{
+	DELTA_BADVAL:  true,
+	NO_BUCKET:     true,
+	AUTH_STALE:    true,
+	AUTH_ERROR:    true,
+	ERANGE:        true,
+	ROLLBACK:      true,
+	EACCESS:       true,
+	ENOMEM:        true,
+	NOT_SUPPORTED: true,
+}
+
+// the producer/consumer bit in dcp flags
+var DCP_PRODUCER uint32 = 0x01
+
+// the include XATTRS bit in dcp flags
+var DCP_OPEN_INCLUDE_XATTRS uint32 = 0x04
+
+// the include deletion time bit in dcp flags
+var DCP_OPEN_INCLUDE_DELETE_TIMES uint32 = 0x20
+
+// Datatype to Include XATTRS in SUBDOC GET
+var SUBDOC_FLAG_XATTR uint8 = 0x04
+
+// MCItem is an internal representation of an item.
+type MCItem struct {
+	Cas               uint64
+	Flags, Expiration uint32
+	Data              []byte
+}
+
+// Number of bytes in a binary protocol header.
+const HDR_LEN = 24
+
+// Mapping of CommandCode -> name of command (not exhaustive)
+var CommandNames map[CommandCode]string
+
+// StatusNames human readable names for memcached response.
+var StatusNames map[Status]string
+
+func init() {
+	CommandNames = make(map[CommandCode]string)
+	CommandNames[GET] = "GET"
+	CommandNames[SET] = "SET"
+	CommandNames[ADD] = "ADD"
+	CommandNames[REPLACE] = "REPLACE"
+	CommandNames[DELETE] = "DELETE"
+	CommandNames[INCREMENT] = "INCREMENT"
+	CommandNames[DECREMENT] = "DECREMENT"
+	CommandNames[QUIT] = "QUIT"
+	CommandNames[FLUSH] = "FLUSH"
+	CommandNames[GETQ] = "GETQ"
+	CommandNames[NOOP] = "NOOP"
+	CommandNames[VERSION] = "VERSION"
+	CommandNames[GETK] = "GETK"
+	CommandNames[GETKQ] = "GETKQ"
+	CommandNames[APPEND] = "APPEND"
+	CommandNames[PREPEND] = "PREPEND"
+	CommandNames[STAT] = "STAT"
+	CommandNames[SETQ] = "SETQ"
+	CommandNames[ADDQ] = "ADDQ"
+	CommandNames[REPLACEQ] = "REPLACEQ"
+	CommandNames[DELETEQ] = "DELETEQ"
+	CommandNames[INCREMENTQ] = "INCREMENTQ"
+	CommandNames[DECREMENTQ] = "DECREMENTQ"
+	CommandNames[QUITQ] = "QUITQ"
+	CommandNames[FLUSHQ] = "FLUSHQ"
+	CommandNames[APPENDQ] = "APPENDQ"
+	CommandNames[PREPENDQ] = "PREPENDQ"
+	CommandNames[RGET] = "RGET"
+	CommandNames[RSET] = "RSET"
+	CommandNames[RSETQ] = "RSETQ"
+	CommandNames[RAPPEND] = "RAPPEND"
+	CommandNames[RAPPENDQ] = "RAPPENDQ"
+	CommandNames[RPREPEND] = "RPREPEND"
+	CommandNames[RPREPENDQ] = "RPREPENDQ"
+	CommandNames[RDELETE] = "RDELETE"
+	CommandNames[RDELETEQ] = "RDELETEQ"
+	CommandNames[RINCR] = "RINCR"
+	CommandNames[RINCRQ] = "RINCRQ"
+	CommandNames[RDECR] = "RDECR"
+	CommandNames[RDECRQ] = "RDECRQ"
+
+	CommandNames[SASL_LIST_MECHS] = "SASL_LIST_MECHS"
+	CommandNames[SASL_AUTH] = "SASL_AUTH"
+	CommandNames[SASL_STEP] = "SASL_STEP"
+
+	CommandNames[TAP_CONNECT] = "TAP_CONNECT"
+	CommandNames[TAP_MUTATION] = "TAP_MUTATION"
+	CommandNames[TAP_DELETE] = "TAP_DELETE"
+	CommandNames[TAP_FLUSH] = "TAP_FLUSH"
+	CommandNames[TAP_OPAQUE] = "TAP_OPAQUE"
+	CommandNames[TAP_VBUCKET_SET] = "TAP_VBUCKET_SET"
+	CommandNames[TAP_CHECKPOINT_START] = "TAP_CHECKPOINT_START"
+	CommandNames[TAP_CHECKPOINT_END] = "TAP_CHECKPOINT_END"
+
+	CommandNames[UPR_OPEN] = "UPR_OPEN"
+	CommandNames[UPR_ADDSTREAM] = "UPR_ADDSTREAM"
+	CommandNames[UPR_CLOSESTREAM] = "UPR_CLOSESTREAM"
+	CommandNames[UPR_FAILOVERLOG] = "UPR_FAILOVERLOG"
+	CommandNames[UPR_STREAMREQ] = "UPR_STREAMREQ"
+	CommandNames[UPR_STREAMEND] = "UPR_STREAMEND"
+	CommandNames[UPR_SNAPSHOT] = "UPR_SNAPSHOT"
+	CommandNames[UPR_MUTATION] = "UPR_MUTATION"
+	CommandNames[UPR_DELETION] = "UPR_DELETION"
+	CommandNames[UPR_EXPIRATION] = "UPR_EXPIRATION"
+	CommandNames[UPR_FLUSH] = "UPR_FLUSH"
+	CommandNames[UPR_NOOP] = "UPR_NOOP"
+	CommandNames[UPR_BUFFERACK] = "UPR_BUFFERACK"
+	CommandNames[UPR_CONTROL] = "UPR_CONTROL"
+	CommandNames[SUBDOC_GET] = "SUBDOC_GET"
+	CommandNames[SUBDOC_MULTI_LOOKUP] = "SUBDOC_MULTI_LOOKUP"
+
+	StatusNames = make(map[Status]string)
+	StatusNames[SUCCESS] = "SUCCESS"
+	StatusNames[KEY_ENOENT] = "KEY_ENOENT"
+	StatusNames[KEY_EEXISTS] = "KEY_EEXISTS"
+	StatusNames[E2BIG] = "E2BIG"
+	StatusNames[EINVAL] = "EINVAL"
+	StatusNames[NOT_STORED] = "NOT_STORED"
+	StatusNames[DELTA_BADVAL] = "DELTA_BADVAL"
+	StatusNames[NOT_MY_VBUCKET] = "NOT_MY_VBUCKET"
+	StatusNames[NO_BUCKET] = "NO_BUCKET"
+	StatusNames[AUTH_STALE] = "AUTH_STALE"
+	StatusNames[AUTH_ERROR] = "AUTH_ERROR"
+	StatusNames[AUTH_CONTINUE] = "AUTH_CONTINUE"
+	StatusNames[ERANGE] = "ERANGE"
+	StatusNames[ROLLBACK] = "ROLLBACK"
+	StatusNames[EACCESS] = "EACCESS"
+	StatusNames[NOT_INITIALIZED] = "NOT_INITIALIZED"
+	StatusNames[UNKNOWN_COMMAND] = "UNKNOWN_COMMAND"
+	StatusNames[ENOMEM] = "ENOMEM"
+	StatusNames[NOT_SUPPORTED] = "NOT_SUPPORTED"
+	StatusNames[EINTERNAL] = "EINTERNAL"
+	StatusNames[EBUSY] = "EBUSY"
+	StatusNames[TMPFAIL] = "TMPFAIL"
+	StatusNames[SUBDOC_PATH_NOT_FOUND] = "SUBDOC_PATH_NOT_FOUND"
+	StatusNames[SUBDOC_BAD_MULTI] = "SUBDOC_BAD_MULTI"
+
+}
+
+// String an op code.
+func (o CommandCode) String() (rv string) {
+	rv = CommandNames[o]
+	if rv == "" {
+		rv = fmt.Sprintf("0x%02x", int(o))
+	}
+	return rv
+}
+
+// String an op code.
+func (s Status) String() (rv string) {
+	rv = StatusNames[s]
+	if rv == "" {
+		rv = fmt.Sprintf("0x%02x", int(s))
+	}
+	return rv
+}
+
+// IsQuiet will return true if a command is a "quiet" command.
+func (o CommandCode) IsQuiet() bool {
+	switch o {
+	case GETQ,
+		GETKQ,
+		SETQ,
+		ADDQ,
+		REPLACEQ,
+		DELETEQ,
+		INCREMENTQ,
+		DECREMENTQ,
+		QUITQ,
+		FLUSHQ,
+		APPENDQ,
+		PREPENDQ,
+		RSETQ,
+		RAPPENDQ,
+		RPREPENDQ,
+		RDELETEQ,
+		RINCRQ,
+		RDECRQ:
+		return true
+	}
+	return false
+}

vendor/github.com/couchbase/gomemcached/mc_req.go

@@ -0,0 +1,197 @@
+package gomemcached
+
+import (
+	"encoding/binary"
+	"fmt"
+	"io"
+)
+
+// The maximum reasonable body length to expect.
+// Anything larger than this will result in an error.
+// The current limit, 20MB, is the size limit supported by ep-engine.
+var MaxBodyLen = int(20 * 1024 * 1024)
+
+// MCRequest is memcached Request
+type MCRequest struct {
+	// The command being issued
+	Opcode CommandCode
+	// The CAS (if applicable, or 0)
+	Cas uint64
+	// An opaque value to be returned with this request
+	Opaque uint32
+	// The vbucket to which this command belongs
+	VBucket uint16
+	// Command extras, key, and body
+	Extras, Key, Body, ExtMeta []byte
+	// Datatype identifier
+	DataType uint8
+}
+
+// Size gives the number of bytes this request requires.
+func (req *MCRequest) Size() int {
+	return HDR_LEN + len(req.Extras) + len(req.Key) + len(req.Body) + len(req.ExtMeta)
+}
+
+// A debugging string representation of this request
+func (req MCRequest) String() string {
+	return fmt.Sprintf("{MCRequest opcode=%s, bodylen=%d, key='%s'}",
+		req.Opcode, len(req.Body), req.Key)
+}
+
+func (req *MCRequest) fillHeaderBytes(data []byte) int {
+
+	pos := 0
+	data[pos] = REQ_MAGIC
+	pos++
+	data[pos] = byte(req.Opcode)
+	pos++
+	binary.BigEndian.PutUint16(data[pos:pos+2],
+		uint16(len(req.Key)))
+	pos += 2
+
+	// 4
+	data[pos] = byte(len(req.Extras))
+	pos++
+	// Data type
+	if req.DataType != 0 {
+		data[pos] = byte(req.DataType)
+	}
+	pos++
+	binary.BigEndian.PutUint16(data[pos:pos+2], req.VBucket)
+	pos += 2
+
+	// 8
+	binary.BigEndian.PutUint32(data[pos:pos+4],
+		uint32(len(req.Body)+len(req.Key)+len(req.Extras)+len(req.ExtMeta)))
+	pos += 4
+
+	// 12
+	binary.BigEndian.PutUint32(data[pos:pos+4], req.Opaque)
+	pos += 4
+
+	// 16
+	if req.Cas != 0 {
+		binary.BigEndian.PutUint64(data[pos:pos+8], req.Cas)
+	}
+	pos += 8
+
+	if len(req.Extras) > 0 {
+		copy(data[pos:pos+len(req.Extras)], req.Extras)
+		pos += len(req.Extras)
+	}
+
+	if len(req.Key) > 0 {
+		copy(data[pos:pos+len(req.Key)], req.Key)
+		pos += len(req.Key)
+	}
+
+	return pos
+}
+
+// HeaderBytes will return the wire representation of the request header
+// (with the extras and key).
+func (req *MCRequest) HeaderBytes() []byte {
+	data := make([]byte, HDR_LEN+len(req.Extras)+len(req.Key))
+
+	req.fillHeaderBytes(data)
+
+	return data
+}
+
+// Bytes will return the wire representation of this request.
+func (req *MCRequest) Bytes() []byte {
+	data := make([]byte, req.Size())
+
+	pos := req.fillHeaderBytes(data)
+
+	if len(req.Body) > 0 {
+		copy(data[pos:pos+len(req.Body)], req.Body)
+	}
+
+	if len(req.ExtMeta) > 0 {
+		copy(data[pos+len(req.Body):pos+len(req.Body)+len(req.ExtMeta)], req.ExtMeta)
+	}
+
+	return data
+}
+
+// Transmit will send this request message across a writer.
+func (req *MCRequest) Transmit(w io.Writer) (n int, err error) {
+	if len(req.Body) < 128 {
+		n, err = w.Write(req.Bytes())
+	} else {
+		n, err = w.Write(req.HeaderBytes())
+		if err == nil {
+			m := 0
+			m, err = w.Write(req.Body)
+			n += m
+		}
+	}
+	return
+}
+
+// Receive will fill this MCRequest with the data from a reader.
+func (req *MCRequest) Receive(r io.Reader, hdrBytes []byte) (int, error) {
+	if len(hdrBytes) < HDR_LEN {
+		hdrBytes = []byte{
+			0, 0, 0, 0, 0, 0, 0, 0,
+			0, 0, 0, 0, 0, 0, 0, 0,
+			0, 0, 0, 0, 0, 0, 0, 0}
+	}
+	n, err := io.ReadFull(r, hdrBytes)
+	if err != nil {
+		return n, err
+	}
+
+	if hdrBytes[0] != RES_MAGIC && hdrBytes[0] != REQ_MAGIC {
+		return n, fmt.Errorf("bad magic: 0x%02x", hdrBytes[0])
+	}
+
+	klen := int(binary.BigEndian.Uint16(hdrBytes[2:]))
+	elen := int(hdrBytes[4])
+	// Data type at 5
+	req.DataType = uint8(hdrBytes[5])
+
+	req.Opcode = CommandCode(hdrBytes[1])
+	// Vbucket at 6:7
+	req.VBucket = binary.BigEndian.Uint16(hdrBytes[6:])
+	totalBodyLen := int(binary.BigEndian.Uint32(hdrBytes[8:]))
+
+	req.Opaque = binary.BigEndian.Uint32(hdrBytes[12:])
+	req.Cas = binary.BigEndian.Uint64(hdrBytes[16:])
+
+	if totalBodyLen > 0 {
+		buf := make([]byte, totalBodyLen)
+		m, err := io.ReadFull(r, buf)
+		n += m
+		if err == nil {
+			if req.Opcode >= TAP_MUTATION &&
+				req.Opcode <= TAP_CHECKPOINT_END &&
+				len(buf) > 1 {
+				// In these commands there is "engine private"
+				// data at the end of the extras.  The first 2
+				// bytes of extra data give its length.
+				elen += int(binary.BigEndian.Uint16(buf))
+			}
+
+			req.Extras = buf[0:elen]
+			req.Key = buf[elen : klen+elen]
+
+			// get the length of extended metadata
+			extMetaLen := 0
+			if elen > 29 {
+				extMetaLen = int(binary.BigEndian.Uint16(req.Extras[28:30]))
+			}
+
+			bodyLen := totalBodyLen - klen - elen - extMetaLen
+			if bodyLen > MaxBodyLen {
+				return n, fmt.Errorf("%d is too big (max %d)",
+					bodyLen, MaxBodyLen)
+			}
+
+			req.Body = buf[klen+elen : klen+elen+bodyLen]
+			req.ExtMeta = buf[klen+elen+bodyLen:]
+		}
+	}
+	return n, err
+}

vendor/github.com/couchbase/gomemcached/mc_res.go

@@ -0,0 +1,267 @@
+package gomemcached
+
+import (
+	"encoding/binary"
+	"fmt"
+	"io"
+	"sync"
+)
+
+// MCResponse is memcached response
+type MCResponse struct {
+	// The command opcode of the command that sent the request
+	Opcode CommandCode
+	// The status of the response
+	Status Status
+	// The opaque sent in the request
+	Opaque uint32
+	// The CAS identifier (if applicable)
+	Cas uint64
+	// Extras, key, and body for this response
+	Extras, Key, Body []byte
+	// If true, this represents a fatal condition and we should hang up
+	Fatal bool
+	// Datatype identifier
+	DataType uint8
+}
+
+// A debugging string representation of this response
+func (res MCResponse) String() string {
+	return fmt.Sprintf("{MCResponse status=%v keylen=%d, extralen=%d, bodylen=%d}",
+		res.Status, len(res.Key), len(res.Extras), len(res.Body))
+}
+
+// Response as an error.
+func (res *MCResponse) Error() string {
+	return fmt.Sprintf("MCResponse status=%v, opcode=%v, opaque=%v, msg: %s",
+		res.Status, res.Opcode, res.Opaque, string(res.Body))
+}
+
+func errStatus(e error) Status {
+	status := Status(0xffff)
+	if res, ok := e.(*MCResponse); ok {
+		status = res.Status
+	}
+	return status
+}
+
+// IsNotFound is true if this error represents a "not found" response.
+func IsNotFound(e error) bool {
+	return errStatus(e) == KEY_ENOENT
+}
+
+// IsFatal is false if this error isn't believed to be fatal to a connection.
+func IsFatal(e error) bool {
+	if e == nil {
+		return false
+	}
+	_, ok := isFatal[errStatus(e)]
+	if ok {
+		return true
+	}
+	return false
+}
+
+// Size is number of bytes this response consumes on the wire.
+func (res *MCResponse) Size() int {
+	return HDR_LEN + len(res.Extras) + len(res.Key) + len(res.Body)
+}
+
+func (res *MCResponse) fillHeaderBytes(data []byte) int {
+	pos := 0
+	data[pos] = RES_MAGIC
+	pos++
+	data[pos] = byte(res.Opcode)
+	pos++
+	binary.BigEndian.PutUint16(data[pos:pos+2],
+		uint16(len(res.Key)))
+	pos += 2
+
+	// 4
+	data[pos] = byte(len(res.Extras))
+	pos++
+	// Data type
+	if res.DataType != 0 {
+		data[pos] = byte(res.DataType)
+	} else {
+		data[pos] = 0
+	}
+	pos++
+	binary.BigEndian.PutUint16(data[pos:pos+2], uint16(res.Status))
+	pos += 2
+
+	// 8
+	binary.BigEndian.PutUint32(data[pos:pos+4],
+		uint32(len(res.Body)+len(res.Key)+len(res.Extras)))
+	pos += 4
+
+	// 12
+	binary.BigEndian.PutUint32(data[pos:pos+4], res.Opaque)
+	pos += 4
+
+	// 16
+	binary.BigEndian.PutUint64(data[pos:pos+8], res.Cas)
+	pos += 8
+
+	if len(res.Extras) > 0 {
+		copy(data[pos:pos+len(res.Extras)], res.Extras)
+		pos += len(res.Extras)
+	}
+
+	if len(res.Key) > 0 {
+		copy(data[pos:pos+len(res.Key)], res.Key)
+		pos += len(res.Key)
+	}
+
+	return pos
+}
+
+// HeaderBytes will get just the header bytes for this response.
+func (res *MCResponse) HeaderBytes() []byte {
+	data := make([]byte, HDR_LEN+len(res.Extras)+len(res.Key))
+
+	res.fillHeaderBytes(data)
+
+	return data
+}
+
+// Bytes will return the actual bytes transmitted for this response.
+func (res *MCResponse) Bytes() []byte {
+	data := make([]byte, res.Size())
+
+	pos := res.fillHeaderBytes(data)
+
+	copy(data[pos:pos+len(res.Body)], res.Body)
+
+	return data
+}
+
+// Transmit will send this response message across a writer.
+func (res *MCResponse) Transmit(w io.Writer) (n int, err error) {
+	if len(res.Body) < 128 {
+		n, err = w.Write(res.Bytes())
+	} else {
+		n, err = w.Write(res.HeaderBytes())
+		if err == nil {
+			m := 0
+			m, err = w.Write(res.Body)
+			m += n
+		}
+	}
+	return
+}
+
+// Receive will fill this MCResponse with the data from this reader.
+func (res *MCResponse) Receive(r io.Reader, hdrBytes []byte) (n int, err error) {
+	if len(hdrBytes) < HDR_LEN {
+		hdrBytes = []byte{
+			0, 0, 0, 0, 0, 0, 0, 0,
+			0, 0, 0, 0, 0, 0, 0, 0,
+			0, 0, 0, 0, 0, 0, 0, 0}
+	}
+	n, err = io.ReadFull(r, hdrBytes)
+	if err != nil {
+		return n, err
+	}
+
+	if hdrBytes[0] != RES_MAGIC && hdrBytes[0] != REQ_MAGIC {
+		return n, fmt.Errorf("bad magic: 0x%02x", hdrBytes[0])
+	}
+
+	klen := int(binary.BigEndian.Uint16(hdrBytes[2:4]))
+	elen := int(hdrBytes[4])
+
+	res.Opcode = CommandCode(hdrBytes[1])
+	res.DataType = uint8(hdrBytes[5])
+	res.Status = Status(binary.BigEndian.Uint16(hdrBytes[6:8]))
+	res.Opaque = binary.BigEndian.Uint32(hdrBytes[12:16])
+	res.Cas = binary.BigEndian.Uint64(hdrBytes[16:24])
+
+	bodyLen := int(binary.BigEndian.Uint32(hdrBytes[8:12])) - (klen + elen)
+
+	//defer function to debug the panic seen with MB-15557
+	defer func() {
+		if e := recover(); e != nil {
+			err = fmt.Errorf(`Panic in Receive. Response %v \n
+                        key len %v extra len %v bodylen %v`, res, klen, elen, bodyLen)
+		}
+	}()
+
+	buf := make([]byte, klen+elen+bodyLen)
+	m, err := io.ReadFull(r, buf)
+	if err == nil {
+		res.Extras = buf[0:elen]
+		res.Key = buf[elen : klen+elen]
+		res.Body = buf[klen+elen:]
+	}
+
+	return n + m, err
+}
+
+type MCResponsePool struct {
+	pool *sync.Pool
+}
+
+func NewMCResponsePool() *MCResponsePool {
+	rv := &MCResponsePool{
+		pool: &sync.Pool{
+			New: func() interface{} {
+				return &MCResponse{}
+			},
+		},
+	}
+
+	return rv
+}
+
+func (this *MCResponsePool) Get() *MCResponse {
+	return this.pool.Get().(*MCResponse)
+}
+
+func (this *MCResponsePool) Put(r *MCResponse) {
+	if r == nil {
+		return
+	}
+
+	r.Extras = nil
+	r.Key = nil
+	r.Body = nil
+	r.Fatal = false
+
+	this.pool.Put(r)
+}
+
+type StringMCResponsePool struct {
+	pool *sync.Pool
+	size int
+}
+
+func NewStringMCResponsePool(size int) *StringMCResponsePool {
+	rv := &StringMCResponsePool{
+		pool: &sync.Pool{
+			New: func() interface{} {
+				return make(map[string]*MCResponse, size)
+			},
+		},
+		size: size,
+	}
+
+	return rv
+}
+
+func (this *StringMCResponsePool) Get() map[string]*MCResponse {
+	return this.pool.Get().(map[string]*MCResponse)
+}
+
+func (this *StringMCResponsePool) Put(m map[string]*MCResponse) {
+	if m == nil || len(m) > 2*this.size {
+		return
+	}
+
+	for k := range m {
+		m[k] = nil
+		delete(m, k)
+	}
+
+	this.pool.Put(m)
+}

vendor/github.com/couchbase/gomemcached/tap.go

@@ -0,0 +1,168 @@
+package gomemcached
+
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"strings"
+)
+
+type TapConnectFlag uint32
+
+// Tap connect option flags
+const (
+	BACKFILL           = TapConnectFlag(0x01)
+	DUMP               = TapConnectFlag(0x02)
+	LIST_VBUCKETS      = TapConnectFlag(0x04)
+	TAKEOVER_VBUCKETS  = TapConnectFlag(0x08)
+	SUPPORT_ACK        = TapConnectFlag(0x10)
+	REQUEST_KEYS_ONLY  = TapConnectFlag(0x20)
+	CHECKPOINT         = TapConnectFlag(0x40)
+	REGISTERED_CLIENT  = TapConnectFlag(0x80)
+	FIX_FLAG_BYTEORDER = TapConnectFlag(0x100)
+)
+
+// Tap opaque event subtypes
+const (
+	TAP_OPAQUE_ENABLE_AUTO_NACK       = 0
+	TAP_OPAQUE_INITIAL_VBUCKET_STREAM = 1
+	TAP_OPAQUE_ENABLE_CHECKPOINT_SYNC = 2
+	TAP_OPAQUE_CLOSE_TAP_STREAM       = 7
+	TAP_OPAQUE_CLOSE_BACKFILL         = 8
+)
+
+// Tap item flags
+const (
+	TAP_ACK                     = 1
+	TAP_NO_VALUE                = 2
+	TAP_FLAG_NETWORK_BYTE_ORDER = 4
+)
+
+// TapConnectFlagNames for TapConnectFlag
+var TapConnectFlagNames = map[TapConnectFlag]string{
+	BACKFILL:           "BACKFILL",
+	DUMP:               "DUMP",
+	LIST_VBUCKETS:      "LIST_VBUCKETS",
+	TAKEOVER_VBUCKETS:  "TAKEOVER_VBUCKETS",
+	SUPPORT_ACK:        "SUPPORT_ACK",
+	REQUEST_KEYS_ONLY:  "REQUEST_KEYS_ONLY",
+	CHECKPOINT:         "CHECKPOINT",
+	REGISTERED_CLIENT:  "REGISTERED_CLIENT",
+	FIX_FLAG_BYTEORDER: "FIX_FLAG_BYTEORDER",
+}
+
+// TapItemParser is a function to parse a single tap extra.
+type TapItemParser func(io.Reader) (interface{}, error)
+
+// TapParseUint64 is a function to parse a single tap uint64.
+func TapParseUint64(r io.Reader) (interface{}, error) {
+	var rv uint64
+	err := binary.Read(r, binary.BigEndian, &rv)
+	return rv, err
+}
+
+// TapParseUint16 is a function to parse a single tap uint16.
+func TapParseUint16(r io.Reader) (interface{}, error) {
+	var rv uint16
+	err := binary.Read(r, binary.BigEndian, &rv)
+	return rv, err
+}
+
+// TapParseBool is a function to parse a single tap boolean.
+func TapParseBool(r io.Reader) (interface{}, error) {
+	return true, nil
+}
+
+// TapParseVBList parses a list of vBucket numbers as []uint16.
+func TapParseVBList(r io.Reader) (interface{}, error) {
+	num, err := TapParseUint16(r)
+	if err != nil {
+		return nil, err
+	}
+	n := int(num.(uint16))
+
+	rv := make([]uint16, n)
+	for i := 0; i < n; i++ {
+		x, err := TapParseUint16(r)
+		if err != nil {
+			return nil, err
+		}
+		rv[i] = x.(uint16)
+	}
+
+	return rv, err
+}
+
+// TapFlagParsers parser functions for TAP fields.
+var TapFlagParsers = map[TapConnectFlag]TapItemParser{
+	BACKFILL:      TapParseUint64,
+	LIST_VBUCKETS: TapParseVBList,
+}
+
+// SplitFlags will split the ORed flags into the individual bit flags.
+func (f TapConnectFlag) SplitFlags() []TapConnectFlag {
+	rv := []TapConnectFlag{}
+	for i := uint32(1); f != 0; i = i << 1 {
+		if uint32(f)&i == i {
+			rv = append(rv, TapConnectFlag(i))
+		}
+		f = TapConnectFlag(uint32(f) & (^i))
+	}
+	return rv
+}
+
+func (f TapConnectFlag) String() string {
+	parts := []string{}
+	for _, x := range f.SplitFlags() {
+		p := TapConnectFlagNames[x]
+		if p == "" {
+			p = fmt.Sprintf("0x%x", int(x))
+		}
+		parts = append(parts, p)
+	}
+	return strings.Join(parts, "|")
+}
+
+type TapConnect struct {
+	Flags         map[TapConnectFlag]interface{}
+	RemainingBody []byte
+	Name          string
+}
+
+// ParseTapCommands parse the tap request into the interesting bits we may
+// need to do something with.
+func (req *MCRequest) ParseTapCommands() (TapConnect, error) {
+	rv := TapConnect{
+		Flags: map[TapConnectFlag]interface{}{},
+		Name:  string(req.Key),
+	}
+
+	if len(req.Extras) < 4 {
+		return rv, fmt.Errorf("not enough extra bytes: %x", req.Extras)
+	}
+
+	flags := TapConnectFlag(binary.BigEndian.Uint32(req.Extras))
+
+	r := bytes.NewReader(req.Body)
+
+	for _, f := range flags.SplitFlags() {
+		fun := TapFlagParsers[f]
+		if fun == nil {
+			fun = TapParseBool
+		}
+
+		val, err := fun(r)
+		if err != nil {
+			return rv, err
+		}
+
+		rv.Flags[f] = val
+	}
+
+	var err error
+	rv.RemainingBody, err = ioutil.ReadAll(r)
+
+	return rv, err
+}