githaven-fork/vendor/github.com/couchbase/gomemcached/client/upr_feed.go
2019-02-05 11:52:51 -05:00

1006 lines
30 KiB
Go

// go implementation of upr client.
// See https://github.com/couchbaselabs/cbupr/blob/master/transport-spec.md
// TODO
// 1. Use a pool allocator to avoid garbage
package memcached
import (
"encoding/binary"
"errors"
"fmt"
"github.com/couchbase/gomemcached"
"github.com/couchbase/goutils/logging"
"strconv"
"sync"
"sync/atomic"
)
const uprMutationExtraLen = 30
const uprDeletetionExtraLen = 18
const uprDeletetionWithDeletionTimeExtraLen = 21
const uprSnapshotExtraLen = 20
const bufferAckThreshold = 0.2
const opaqueOpen = 0xBEAF0001
const opaqueFailover = 0xDEADBEEF
const uprDefaultNoopInterval = 120
// Counter on top of opaqueOpen that others can draw from for open and control msgs
var opaqueOpenCtrlWell uint32 = opaqueOpen
// UprEvent memcached events for UPR streams.
type UprEvent struct {
Opcode gomemcached.CommandCode // Type of event
Status gomemcached.Status // Response status
VBucket uint16 // VBucket this event applies to
DataType uint8 // data type
Opaque uint16 // 16 MSB of opaque
VBuuid uint64 // This field is set by downstream
Flags uint32 // Item flags
Expiry uint32 // Item expiration time
Key, Value []byte // Item key/value
OldValue []byte // TODO: TBD: old document value
Cas uint64 // CAS value of the item
Seqno uint64 // sequence number of the mutation
RevSeqno uint64 // rev sequence number : deletions
LockTime uint32 // Lock time
MetadataSize uint16 // Metadata size
SnapstartSeq uint64 // start sequence number of this snapshot
SnapendSeq uint64 // End sequence number of the snapshot
SnapshotType uint32 // 0: disk 1: memory
FailoverLog *FailoverLog // Failover log containing vvuid and sequnce number
Error error // Error value in case of a failure
ExtMeta []byte
AckSize uint32 // The number of bytes that can be Acked to DCP
}
// UprStream is per stream data structure over an UPR Connection.
type UprStream struct {
Vbucket uint16 // Vbucket id
Vbuuid uint64 // vbucket uuid
StartSeq uint64 // start sequence number
EndSeq uint64 // end sequence number
connected bool
}
const (
CompressionTypeStartMarker = iota // also means invalid
CompressionTypeNone = iota
CompressionTypeSnappy = iota
CompressionTypeEndMarker = iota // also means invalid
)
// kv_engine/include/mcbp/protocol/datatype.h
const (
JSONDataType uint8 = 1
SnappyDataType uint8 = 2
XattrDataType uint8 = 4
)
type UprFeatures struct {
Xattribute bool
CompressionType int
IncludeDeletionTime bool
}
/**
* Used to handle multiple concurrent calls UprRequestStream() by UprFeed clients
* It is expected that a client that calls UprRequestStream() more than once should issue
* different "opaque" (version) numbers
*/
type opaqueStreamMap map[uint16]*UprStream // opaque -> stream
type vbStreamNegotiator struct {
vbHandshakeMap map[uint16]opaqueStreamMap // vbno -> opaqueStreamMap
mutex sync.RWMutex
}
func (negotiator *vbStreamNegotiator) initialize() {
negotiator.mutex.Lock()
negotiator.vbHandshakeMap = make(map[uint16]opaqueStreamMap)
negotiator.mutex.Unlock()
}
func (negotiator *vbStreamNegotiator) registerRequest(vbno, opaque uint16, vbuuid, startSequence, endSequence uint64) {
negotiator.mutex.Lock()
defer negotiator.mutex.Unlock()
var osMap opaqueStreamMap
var ok bool
if osMap, ok = negotiator.vbHandshakeMap[vbno]; !ok {
osMap = make(opaqueStreamMap)
negotiator.vbHandshakeMap[vbno] = osMap
}
if _, ok = osMap[opaque]; !ok {
osMap[opaque] = &UprStream{
Vbucket: vbno,
Vbuuid: vbuuid,
StartSeq: startSequence,
EndSeq: endSequence,
}
}
}
func (negotiator *vbStreamNegotiator) getStreamsCntFromMap(vbno uint16) int {
negotiator.mutex.RLock()
defer negotiator.mutex.RUnlock()
osmap, ok := negotiator.vbHandshakeMap[vbno]
if !ok {
return 0
} else {
return len(osmap)
}
}
func (negotiator *vbStreamNegotiator) getStreamFromMap(vbno, opaque uint16) (*UprStream, error) {
negotiator.mutex.RLock()
defer negotiator.mutex.RUnlock()
osmap, ok := negotiator.vbHandshakeMap[vbno]
if !ok {
return nil, fmt.Errorf("Error: stream for vb: %v does not exist", vbno)
}
stream, ok := osmap[opaque]
if !ok {
return nil, fmt.Errorf("Error: stream for vb: %v opaque: %v does not exist", vbno, opaque)
}
return stream, nil
}
func (negotiator *vbStreamNegotiator) deleteStreamFromMap(vbno, opaque uint16) {
negotiator.mutex.Lock()
defer negotiator.mutex.Unlock()
osmap, ok := negotiator.vbHandshakeMap[vbno]
if !ok {
return
}
delete(osmap, opaque)
if len(osmap) == 0 {
delete(negotiator.vbHandshakeMap, vbno)
}
}
func (negotiator *vbStreamNegotiator) handleStreamRequest(feed *UprFeed,
headerBuf [gomemcached.HDR_LEN]byte, pktPtr *gomemcached.MCRequest, bytesReceivedFromDCP int,
response *gomemcached.MCResponse) (*UprEvent, error) {
var event *UprEvent
if feed == nil || response == nil || pktPtr == nil {
return nil, errors.New("Invalid inputs")
}
// Get Stream from negotiator map
vbno := vbOpaque(response.Opaque)
opaque := appOpaque(response.Opaque)
stream, err := negotiator.getStreamFromMap(vbno, opaque)
if err != nil {
err = fmt.Errorf("Stream not found for vb %d appOpaque %v: %#v", vbno, appOpaque, *pktPtr)
logging.Errorf(err.Error())
return nil, err
}
status, rb, flog, err := handleStreamRequest(response, headerBuf[:])
if status == gomemcached.ROLLBACK {
event = makeUprEvent(*pktPtr, stream, bytesReceivedFromDCP)
event.Status = status
// rollback stream
logging.Infof("UPR_STREAMREQ with rollback %d for vb %d Failed: %v", rb, vbno, err)
negotiator.deleteStreamFromMap(vbno, opaque)
} else if status == gomemcached.SUCCESS {
event = makeUprEvent(*pktPtr, stream, bytesReceivedFromDCP)
event.Seqno = stream.StartSeq
event.FailoverLog = flog
event.Status = status
feed.activateStream(vbno, opaque, stream)
feed.negotiator.deleteStreamFromMap(vbno, opaque)
logging.Infof("UPR_STREAMREQ for vb %d successful", vbno)
} else if err != nil {
logging.Errorf("UPR_STREAMREQ for vbucket %d erro %s", vbno, err.Error())
event = &UprEvent{
Opcode: gomemcached.UPR_STREAMREQ,
Status: status,
VBucket: vbno,
Error: err,
}
negotiator.deleteStreamFromMap(vbno, opaque)
}
return event, nil
}
func (negotiator *vbStreamNegotiator) cleanUpVbStreams(vbno uint16) {
negotiator.mutex.Lock()
defer negotiator.mutex.Unlock()
delete(negotiator.vbHandshakeMap, vbno)
}
// UprFeed represents an UPR feed. A feed contains a connection to a single
// host and multiple vBuckets
type UprFeed struct {
// lock for feed.vbstreams
muVbstreams sync.RWMutex
// lock for feed.closed
muClosed sync.RWMutex
C <-chan *UprEvent // Exported channel for receiving UPR events
negotiator vbStreamNegotiator // Used for pre-vbstreams, concurrent vb stream negotiation
vbstreams map[uint16]*UprStream // official live vb->stream mapping
closer chan bool // closer
conn *Client // connection to UPR producer
Error error // error
bytesRead uint64 // total bytes read on this connection
toAckBytes uint32 // bytes client has read
maxAckBytes uint32 // Max buffer control ack bytes
stats UprStats // Stats for upr client
transmitCh chan *gomemcached.MCRequest // transmit command channel
transmitCl chan bool // closer channel for transmit go-routine
closed bool // flag indicating whether the feed has been closed
// flag indicating whether client of upr feed will send ack to upr feed
// if flag is true, upr feed will use ack from client to determine whether/when to send ack to DCP
// if flag is false, upr feed will track how many bytes it has sent to client
// and use that to determine whether/when to send ack to DCP
ackByClient bool
}
// Exported interface - to allow for mocking
type UprFeedIface interface {
Close()
Closed() bool
CloseStream(vbno, opaqueMSB uint16) error
GetError() error
GetUprStats() *UprStats
ClientAck(event *UprEvent) error
GetUprEventCh() <-chan *UprEvent
StartFeed() error
StartFeedWithConfig(datachan_len int) error
UprOpen(name string, sequence uint32, bufSize uint32) error
UprOpenWithXATTR(name string, sequence uint32, bufSize uint32) error
UprOpenWithFeatures(name string, sequence uint32, bufSize uint32, features UprFeatures) (error, UprFeatures)
UprRequestStream(vbno, opaqueMSB uint16, flags uint32, vuuid, startSequence, endSequence, snapStart, snapEnd uint64) error
}
type UprStats struct {
TotalBytes uint64
TotalMutation uint64
TotalBufferAckSent uint64
TotalSnapShot uint64
}
// FailoverLog containing vvuid and sequnce number
type FailoverLog [][2]uint64
// error codes
var ErrorInvalidLog = errors.New("couchbase.errorInvalidLog")
func (flogp *FailoverLog) Latest() (vbuuid, seqno uint64, err error) {
if flogp != nil {
flog := *flogp
latest := flog[len(flog)-1]
return latest[0], latest[1], nil
}
return vbuuid, seqno, ErrorInvalidLog
}
func makeUprEvent(rq gomemcached.MCRequest, stream *UprStream, bytesReceivedFromDCP int) *UprEvent {
event := &UprEvent{
Opcode: rq.Opcode,
VBucket: stream.Vbucket,
VBuuid: stream.Vbuuid,
Key: rq.Key,
Value: rq.Body,
Cas: rq.Cas,
ExtMeta: rq.ExtMeta,
DataType: rq.DataType,
}
// set AckSize for events that need to be acked to DCP,
// i.e., events with CommandCodes that need to be buffered in DCP
if _, ok := gomemcached.BufferedCommandCodeMap[rq.Opcode]; ok {
event.AckSize = uint32(bytesReceivedFromDCP)
}
// 16 LSBits are used by client library to encode vbucket number.
// 16 MSBits are left for application to multiplex on opaque value.
event.Opaque = appOpaque(rq.Opaque)
if len(rq.Extras) >= uprMutationExtraLen &&
event.Opcode == gomemcached.UPR_MUTATION {
event.Seqno = binary.BigEndian.Uint64(rq.Extras[:8])
event.RevSeqno = binary.BigEndian.Uint64(rq.Extras[8:16])
event.Flags = binary.BigEndian.Uint32(rq.Extras[16:20])
event.Expiry = binary.BigEndian.Uint32(rq.Extras[20:24])
event.LockTime = binary.BigEndian.Uint32(rq.Extras[24:28])
event.MetadataSize = binary.BigEndian.Uint16(rq.Extras[28:30])
} else if len(rq.Extras) >= uprDeletetionWithDeletionTimeExtraLen &&
event.Opcode == gomemcached.UPR_DELETION {
event.Seqno = binary.BigEndian.Uint64(rq.Extras[:8])
event.RevSeqno = binary.BigEndian.Uint64(rq.Extras[8:16])
event.Expiry = binary.BigEndian.Uint32(rq.Extras[16:20])
} else if len(rq.Extras) >= uprDeletetionExtraLen &&
event.Opcode == gomemcached.UPR_DELETION ||
event.Opcode == gomemcached.UPR_EXPIRATION {
event.Seqno = binary.BigEndian.Uint64(rq.Extras[:8])
event.RevSeqno = binary.BigEndian.Uint64(rq.Extras[8:16])
event.MetadataSize = binary.BigEndian.Uint16(rq.Extras[16:18])
} else if len(rq.Extras) >= uprSnapshotExtraLen &&
event.Opcode == gomemcached.UPR_SNAPSHOT {
event.SnapstartSeq = binary.BigEndian.Uint64(rq.Extras[:8])
event.SnapendSeq = binary.BigEndian.Uint64(rq.Extras[8:16])
event.SnapshotType = binary.BigEndian.Uint32(rq.Extras[16:20])
}
return event
}
func (event *UprEvent) String() string {
name := gomemcached.CommandNames[event.Opcode]
if name == "" {
name = fmt.Sprintf("#%d", event.Opcode)
}
return name
}
func (event *UprEvent) IsSnappyDataType() bool {
return event.Opcode == gomemcached.UPR_MUTATION && (event.DataType&SnappyDataType > 0)
}
func (feed *UprFeed) sendCommands(mc *Client) {
transmitCh := feed.transmitCh
transmitCl := feed.transmitCl
loop:
for {
select {
case command := <-transmitCh:
if err := mc.Transmit(command); err != nil {
logging.Errorf("Failed to transmit command %s. Error %s", command.Opcode.String(), err.Error())
// get feed to close and runFeed routine to exit
feed.Close()
break loop
}
case <-transmitCl:
break loop
}
}
// After sendCommands exits, write to transmitCh will block forever
// when we write to transmitCh, e.g., at CloseStream(), we need to check feed closure to have an exit route
logging.Infof("sendCommands exiting")
}
// Sets the specified stream as the connected stream for this vbno, and also cleans up negotiator
func (feed *UprFeed) activateStream(vbno, opaque uint16, stream *UprStream) error {
feed.muVbstreams.Lock()
defer feed.muVbstreams.Unlock()
// Set this stream as the officially connected stream for this vb
stream.connected = true
feed.vbstreams[vbno] = stream
return nil
}
func (feed *UprFeed) cleanUpVbStream(vbno uint16) {
feed.muVbstreams.Lock()
defer feed.muVbstreams.Unlock()
delete(feed.vbstreams, vbno)
}
// NewUprFeed creates a new UPR Feed.
// TODO: Describe side-effects on bucket instance and its connection pool.
func (mc *Client) NewUprFeed() (*UprFeed, error) {
return mc.NewUprFeedWithConfig(false /*ackByClient*/)
}
func (mc *Client) NewUprFeedWithConfig(ackByClient bool) (*UprFeed, error) {
feed := &UprFeed{
conn: mc,
closer: make(chan bool, 1),
vbstreams: make(map[uint16]*UprStream),
transmitCh: make(chan *gomemcached.MCRequest),
transmitCl: make(chan bool),
ackByClient: ackByClient,
}
feed.negotiator.initialize()
go feed.sendCommands(mc)
return feed, nil
}
func (mc *Client) NewUprFeedIface() (UprFeedIface, error) {
return mc.NewUprFeed()
}
func (mc *Client) NewUprFeedWithConfigIface(ackByClient bool) (UprFeedIface, error) {
return mc.NewUprFeedWithConfig(ackByClient)
}
func doUprOpen(mc *Client, name string, sequence uint32, features UprFeatures) error {
rq := &gomemcached.MCRequest{
Opcode: gomemcached.UPR_OPEN,
Key: []byte(name),
Opaque: getUprOpenCtrlOpaque(),
}
rq.Extras = make([]byte, 8)
binary.BigEndian.PutUint32(rq.Extras[:4], sequence)
// opens a producer type connection
flags := gomemcached.DCP_PRODUCER
if features.Xattribute {
flags = flags | gomemcached.DCP_OPEN_INCLUDE_XATTRS
}
if features.IncludeDeletionTime {
flags = flags | gomemcached.DCP_OPEN_INCLUDE_DELETE_TIMES
}
binary.BigEndian.PutUint32(rq.Extras[4:], flags)
return sendMcRequestSync(mc, rq)
}
// Synchronously send a memcached request and wait for the response
func sendMcRequestSync(mc *Client, req *gomemcached.MCRequest) error {
if err := mc.Transmit(req); err != nil {
return err
}
if res, err := mc.Receive(); err != nil {
return err
} else if req.Opcode != res.Opcode {
return fmt.Errorf("unexpected #opcode sent %v received %v", req.Opcode, res.Opaque)
} else if req.Opaque != res.Opaque {
return fmt.Errorf("opaque mismatch, sent %v received %v", req.Opaque, res.Opaque)
} else if res.Status != gomemcached.SUCCESS {
return fmt.Errorf("error %v", res.Status)
}
return nil
}
// UprOpen to connect with a UPR producer.
// Name: name of te UPR connection
// sequence: sequence number for the connection
// bufsize: max size of the application
func (feed *UprFeed) UprOpen(name string, sequence uint32, bufSize uint32) error {
var allFeaturesDisabled UprFeatures
err, _ := feed.uprOpen(name, sequence, bufSize, allFeaturesDisabled)
return err
}
// UprOpen with XATTR enabled.
func (feed *UprFeed) UprOpenWithXATTR(name string, sequence uint32, bufSize uint32) error {
var onlyXattrEnabled UprFeatures
onlyXattrEnabled.Xattribute = true
err, _ := feed.uprOpen(name, sequence, bufSize, onlyXattrEnabled)
return err
}
func (feed *UprFeed) UprOpenWithFeatures(name string, sequence uint32, bufSize uint32, features UprFeatures) (error, UprFeatures) {
return feed.uprOpen(name, sequence, bufSize, features)
}
func (feed *UprFeed) uprOpen(name string, sequence uint32, bufSize uint32, features UprFeatures) (err error, activatedFeatures UprFeatures) {
mc := feed.conn
// First set this to an invalid value to state that the method hasn't gotten to executing this control yet
activatedFeatures.CompressionType = CompressionTypeEndMarker
if err = doUprOpen(mc, name, sequence, features); err != nil {
return
}
activatedFeatures.Xattribute = features.Xattribute
// send a UPR control message to set the window size for the this connection
if bufSize > 0 {
rq := &gomemcached.MCRequest{
Opcode: gomemcached.UPR_CONTROL,
Key: []byte("connection_buffer_size"),
Body: []byte(strconv.Itoa(int(bufSize))),
Opaque: getUprOpenCtrlOpaque(),
}
err = sendMcRequestSync(feed.conn, rq)
if err != nil {
return
}
feed.maxAckBytes = uint32(bufferAckThreshold * float32(bufSize))
}
// enable noop and set noop interval
rq := &gomemcached.MCRequest{
Opcode: gomemcached.UPR_CONTROL,
Key: []byte("enable_noop"),
Body: []byte("true"),
Opaque: getUprOpenCtrlOpaque(),
}
err = sendMcRequestSync(feed.conn, rq)
if err != nil {
return
}
rq = &gomemcached.MCRequest{
Opcode: gomemcached.UPR_CONTROL,
Key: []byte("set_noop_interval"),
Body: []byte(strconv.Itoa(int(uprDefaultNoopInterval))),
Opaque: getUprOpenCtrlOpaque(),
}
err = sendMcRequestSync(feed.conn, rq)
if err != nil {
return
}
if features.CompressionType == CompressionTypeSnappy {
activatedFeatures.CompressionType = CompressionTypeNone
rq = &gomemcached.MCRequest{
Opcode: gomemcached.UPR_CONTROL,
Key: []byte("force_value_compression"),
Body: []byte("true"),
Opaque: getUprOpenCtrlOpaque(),
}
err = sendMcRequestSync(feed.conn, rq)
} else if features.CompressionType == CompressionTypeEndMarker {
err = fmt.Errorf("UPR_CONTROL Failed - Invalid CompressionType: %v", features.CompressionType)
}
if err != nil {
return
}
activatedFeatures.CompressionType = features.CompressionType
return
}
// UprGetFailoverLog for given list of vbuckets.
func (mc *Client) UprGetFailoverLog(
vb []uint16) (map[uint16]*FailoverLog, error) {
rq := &gomemcached.MCRequest{
Opcode: gomemcached.UPR_FAILOVERLOG,
Opaque: opaqueFailover,
}
var allFeaturesDisabled UprFeatures
if err := doUprOpen(mc, "FailoverLog", 0, allFeaturesDisabled); err != nil {
return nil, fmt.Errorf("UPR_OPEN Failed %s", err.Error())
}
failoverLogs := make(map[uint16]*FailoverLog)
for _, vBucket := range vb {
rq.VBucket = vBucket
if err := mc.Transmit(rq); err != nil {
return nil, err
}
res, err := mc.Receive()
if err != nil {
return nil, fmt.Errorf("failed to receive %s", err.Error())
} else if res.Opcode != gomemcached.UPR_FAILOVERLOG || res.Status != gomemcached.SUCCESS {
return nil, fmt.Errorf("unexpected #opcode %v", res.Opcode)
}
flog, err := parseFailoverLog(res.Body)
if err != nil {
return nil, fmt.Errorf("unable to parse failover logs for vb %d", vb)
}
failoverLogs[vBucket] = flog
}
return failoverLogs, nil
}
// UprRequestStream for a single vbucket.
func (feed *UprFeed) UprRequestStream(vbno, opaqueMSB uint16, flags uint32,
vuuid, startSequence, endSequence, snapStart, snapEnd uint64) error {
rq := &gomemcached.MCRequest{
Opcode: gomemcached.UPR_STREAMREQ,
VBucket: vbno,
Opaque: composeOpaque(vbno, opaqueMSB),
}
rq.Extras = make([]byte, 48) // #Extras
binary.BigEndian.PutUint32(rq.Extras[:4], flags)
binary.BigEndian.PutUint32(rq.Extras[4:8], uint32(0))
binary.BigEndian.PutUint64(rq.Extras[8:16], startSequence)
binary.BigEndian.PutUint64(rq.Extras[16:24], endSequence)
binary.BigEndian.PutUint64(rq.Extras[24:32], vuuid)
binary.BigEndian.PutUint64(rq.Extras[32:40], snapStart)
binary.BigEndian.PutUint64(rq.Extras[40:48], snapEnd)
feed.negotiator.registerRequest(vbno, opaqueMSB, vuuid, startSequence, endSequence)
// Any client that has ever called this method, regardless of return code,
// should expect a potential UPR_CLOSESTREAM message due to this new map entry prior to Transmit.
if err := feed.conn.Transmit(rq); err != nil {
logging.Errorf("Error in StreamRequest %s", err.Error())
// If an error occurs during transmit, then the UPRFeed will keep the stream
// in the vbstreams map. This is to prevent nil lookup from any previously
// sent stream requests.
return err
}
return nil
}
// CloseStream for specified vbucket.
func (feed *UprFeed) CloseStream(vbno, opaqueMSB uint16) error {
err := feed.validateCloseStream(vbno)
if err != nil {
logging.Infof("CloseStream for %v has been skipped because of error %v", vbno, err)
return err
}
closeStream := &gomemcached.MCRequest{
Opcode: gomemcached.UPR_CLOSESTREAM,
VBucket: vbno,
Opaque: composeOpaque(vbno, opaqueMSB),
}
feed.writeToTransmitCh(closeStream)
return nil
}
func (feed *UprFeed) GetUprEventCh() <-chan *UprEvent {
return feed.C
}
func (feed *UprFeed) GetError() error {
return feed.Error
}
func (feed *UprFeed) validateCloseStream(vbno uint16) error {
feed.muVbstreams.RLock()
nilVbStream := feed.vbstreams[vbno] == nil
feed.muVbstreams.RUnlock()
if nilVbStream && (feed.negotiator.getStreamsCntFromMap(vbno) == 0) {
return fmt.Errorf("Stream for vb %d has not been requested", vbno)
}
return nil
}
func (feed *UprFeed) writeToTransmitCh(rq *gomemcached.MCRequest) error {
// write to transmitCh may block forever if sendCommands has exited
// check for feed closure to have an exit route in this case
select {
case <-feed.closer:
errMsg := fmt.Sprintf("Abort sending request to transmitCh because feed has been closed. request=%v", rq)
logging.Infof(errMsg)
return errors.New(errMsg)
case feed.transmitCh <- rq:
}
return nil
}
// StartFeed to start the upper feed.
func (feed *UprFeed) StartFeed() error {
return feed.StartFeedWithConfig(10)
}
func (feed *UprFeed) StartFeedWithConfig(datachan_len int) error {
ch := make(chan *UprEvent, datachan_len)
feed.C = ch
go feed.runFeed(ch)
return nil
}
func parseFailoverLog(body []byte) (*FailoverLog, error) {
if len(body)%16 != 0 {
err := fmt.Errorf("invalid body length %v, in failover-log", len(body))
return nil, err
}
log := make(FailoverLog, len(body)/16)
for i, j := 0, 0; i < len(body); i += 16 {
vuuid := binary.BigEndian.Uint64(body[i : i+8])
seqno := binary.BigEndian.Uint64(body[i+8 : i+16])
log[j] = [2]uint64{vuuid, seqno}
j++
}
return &log, nil
}
func handleStreamRequest(
res *gomemcached.MCResponse,
headerBuf []byte,
) (gomemcached.Status, uint64, *FailoverLog, error) {
var rollback uint64
var err error
switch {
case res.Status == gomemcached.ROLLBACK:
logging.Infof("Rollback response. body=%v, headerBuf=%v\n", res.Body, headerBuf)
rollback = binary.BigEndian.Uint64(res.Body)
logging.Infof("Rollback seqno is %v for response with opaque %v\n", rollback, res.Opaque)
return res.Status, rollback, nil, nil
case res.Status != gomemcached.SUCCESS:
err = fmt.Errorf("unexpected status %v for response with opaque %v", res.Status, res.Opaque)
return res.Status, 0, nil, err
}
flog, err := parseFailoverLog(res.Body[:])
return res.Status, rollback, flog, err
}
// generate stream end responses for all active vb streams
func (feed *UprFeed) doStreamClose(ch chan *UprEvent) {
feed.muVbstreams.RLock()
uprEvents := make([]*UprEvent, len(feed.vbstreams))
index := 0
for vbno, stream := range feed.vbstreams {
uprEvent := &UprEvent{
VBucket: vbno,
VBuuid: stream.Vbuuid,
Opcode: gomemcached.UPR_STREAMEND,
}
uprEvents[index] = uprEvent
index++
}
// release the lock before sending uprEvents to ch, which may block
feed.muVbstreams.RUnlock()
loop:
for _, uprEvent := range uprEvents {
select {
case ch <- uprEvent:
case <-feed.closer:
logging.Infof("Feed has been closed. Aborting doStreamClose.")
break loop
}
}
}
func (feed *UprFeed) runFeed(ch chan *UprEvent) {
defer close(ch)
var headerBuf [gomemcached.HDR_LEN]byte
var pkt gomemcached.MCRequest
var event *UprEvent
mc := feed.conn.Hijack()
uprStats := &feed.stats
loop:
for {
select {
case <-feed.closer:
logging.Infof("Feed has been closed. Exiting.")
break loop
default:
bytes, err := pkt.Receive(mc, headerBuf[:])
if err != nil {
logging.Errorf("Error in receive %s", err.Error())
feed.Error = err
// send all the stream close messages to the client
feed.doStreamClose(ch)
break loop
} else {
event = nil
res := &gomemcached.MCResponse{
Opcode: pkt.Opcode,
Cas: pkt.Cas,
Opaque: pkt.Opaque,
Status: gomemcached.Status(pkt.VBucket),
Extras: pkt.Extras,
Key: pkt.Key,
Body: pkt.Body,
}
vb := vbOpaque(pkt.Opaque)
appOpaque := appOpaque(pkt.Opaque)
uprStats.TotalBytes = uint64(bytes)
feed.muVbstreams.RLock()
stream := feed.vbstreams[vb]
feed.muVbstreams.RUnlock()
switch pkt.Opcode {
case gomemcached.UPR_STREAMREQ:
event, err = feed.negotiator.handleStreamRequest(feed, headerBuf, &pkt, bytes, res)
if err != nil {
logging.Infof(err.Error())
break loop
}
case gomemcached.UPR_MUTATION,
gomemcached.UPR_DELETION,
gomemcached.UPR_EXPIRATION:
if stream == nil {
logging.Infof("Stream not found for vb %d: %#v", vb, pkt)
break loop
}
event = makeUprEvent(pkt, stream, bytes)
uprStats.TotalMutation++
case gomemcached.UPR_STREAMEND:
if stream == nil {
logging.Infof("Stream not found for vb %d: %#v", vb, pkt)
break loop
}
//stream has ended
event = makeUprEvent(pkt, stream, bytes)
logging.Infof("Stream Ended for vb %d", vb)
feed.negotiator.deleteStreamFromMap(vb, appOpaque)
feed.cleanUpVbStream(vb)
case gomemcached.UPR_SNAPSHOT:
if stream == nil {
logging.Infof("Stream not found for vb %d: %#v", vb, pkt)
break loop
}
// snapshot marker
event = makeUprEvent(pkt, stream, bytes)
uprStats.TotalSnapShot++
case gomemcached.UPR_FLUSH:
if stream == nil {
logging.Infof("Stream not found for vb %d: %#v", vb, pkt)
break loop
}
// special processing for flush ?
event = makeUprEvent(pkt, stream, bytes)
case gomemcached.UPR_CLOSESTREAM:
if stream == nil {
logging.Infof("Stream not found for vb %d: %#v", vb, pkt)
break loop
}
event = makeUprEvent(pkt, stream, bytes)
event.Opcode = gomemcached.UPR_STREAMEND // opcode re-write !!
logging.Infof("Stream Closed for vb %d StreamEnd simulated", vb)
feed.negotiator.deleteStreamFromMap(vb, appOpaque)
feed.cleanUpVbStream(vb)
case gomemcached.UPR_ADDSTREAM:
logging.Infof("Opcode %v not implemented", pkt.Opcode)
case gomemcached.UPR_CONTROL, gomemcached.UPR_BUFFERACK:
if res.Status != gomemcached.SUCCESS {
logging.Infof("Opcode %v received status %d", pkt.Opcode.String(), res.Status)
}
case gomemcached.UPR_NOOP:
// send a NOOP back
noop := &gomemcached.MCResponse{
Opcode: gomemcached.UPR_NOOP,
Opaque: pkt.Opaque,
}
if err := feed.conn.TransmitResponse(noop); err != nil {
logging.Warnf("failed to transmit command %s. Error %s", noop.Opcode.String(), err.Error())
}
default:
logging.Infof("Recived an unknown response for vbucket %d", vb)
}
}
if event != nil {
select {
case ch <- event:
case <-feed.closer:
logging.Infof("Feed has been closed. Skip sending events. Exiting.")
break loop
}
feed.muVbstreams.RLock()
l := len(feed.vbstreams)
feed.muVbstreams.RUnlock()
if event.Opcode == gomemcached.UPR_CLOSESTREAM && l == 0 {
logging.Infof("No more streams")
}
}
if !feed.ackByClient {
// if client does not ack, do the ack check now
feed.sendBufferAckIfNeeded(event)
}
}
}
// make sure that feed is closed before we signal transmitCl and exit runFeed
feed.Close()
close(feed.transmitCl)
logging.Infof("runFeed exiting")
}
// Client, after completing processing of an UprEvent, need to call this API to notify UprFeed,
// so that UprFeed can update its ack bytes stats and send ack to DCP if needed
// Client needs to set ackByClient flag to true in NewUprFeedWithConfig() call as a prerequisite for this call to work
// This API is not thread safe. Caller should NOT have more than one go rountine calling this API
func (feed *UprFeed) ClientAck(event *UprEvent) error {
if !feed.ackByClient {
return errors.New("Upr feed does not have ackByclient flag set")
}
feed.sendBufferAckIfNeeded(event)
return nil
}
// increment ack bytes if the event needs to be acked to DCP
// send buffer ack if enough ack bytes have been accumulated
func (feed *UprFeed) sendBufferAckIfNeeded(event *UprEvent) {
if event == nil || event.AckSize == 0 {
// this indicates that there is no need to ack to DCP
return
}
totalBytes := feed.toAckBytes + event.AckSize
if totalBytes > feed.maxAckBytes {
feed.toAckBytes = 0
feed.sendBufferAck(totalBytes)
} else {
feed.toAckBytes = totalBytes
}
}
// send buffer ack to dcp
func (feed *UprFeed) sendBufferAck(sendSize uint32) {
bufferAck := &gomemcached.MCRequest{
Opcode: gomemcached.UPR_BUFFERACK,
}
bufferAck.Extras = make([]byte, 4)
binary.BigEndian.PutUint32(bufferAck.Extras[:4], uint32(sendSize))
feed.writeToTransmitCh(bufferAck)
feed.stats.TotalBufferAckSent++
}
func (feed *UprFeed) GetUprStats() *UprStats {
return &feed.stats
}
func composeOpaque(vbno, opaqueMSB uint16) uint32 {
return (uint32(opaqueMSB) << 16) | uint32(vbno)
}
func getUprOpenCtrlOpaque() uint32 {
return atomic.AddUint32(&opaqueOpenCtrlWell, 1)
}
func appOpaque(opq32 uint32) uint16 {
return uint16((opq32 & 0xFFFF0000) >> 16)
}
func vbOpaque(opq32 uint32) uint16 {
return uint16(opq32 & 0xFFFF)
}
// Close this UprFeed.
func (feed *UprFeed) Close() {
feed.muClosed.Lock()
defer feed.muClosed.Unlock()
if !feed.closed {
close(feed.closer)
feed.closed = true
feed.negotiator.initialize()
}
}
// check if the UprFeed has been closed
func (feed *UprFeed) Closed() bool {
feed.muClosed.RLock()
defer feed.muClosed.RUnlock()
return feed.closed
}