/
middleware_sync.go
285 lines (238 loc) · 6.52 KB
/
middleware_sync.go
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package goetty
import (
"net"
"sync"
"sync/atomic"
)
type syncClientMiddleware struct {
BaseMiddleware
bizDecoder Decoder
bizEncoder Encoder
writer func(IOSession, interface{}) error
cached *simpleQueue
localOffset, serverOffset uint64
syncing bool
maxReadTimeouts int
timeouts int
}
// NewSyncProtocolClientMiddleware return a middleware to process sync protocol
func NewSyncProtocolClientMiddleware(bizDecoder Decoder, bizEncoder Encoder, writer func(IOSession, interface{}) error, maxReadTimeouts int) Middleware {
return &syncClientMiddleware{
cached: newSimpleQueue(),
writer: writer,
bizDecoder: bizDecoder,
bizEncoder: bizEncoder,
maxReadTimeouts: maxReadTimeouts,
}
}
func (sm *syncClientMiddleware) PreWrite(msg interface{}, conn IOSession) (bool, interface{}, error) {
// The client side can only send notifySync,notifyRaw,notifyHB msg to the server,
// wrap the raw biz msg to notifyRaw
_, isSync := msg.(*notifySync)
if !isSync {
_, isSync = msg.(*notifyHB)
}
if !isSync {
m := acquireNotifyRaw()
err := sm.bizEncoder.Encode(msg, m.buf)
if err != nil {
return false, nil, err
}
return true, m, nil
}
return sm.BaseMiddleware.PreWrite(msg, conn)
}
func (sm *syncClientMiddleware) PreRead(conn IOSession) (bool, interface{}, error) {
// If there is any biz msg in the queue, returned it and cancel read option
if sm.cached.len() > 0 {
return false, sm.cached.pop(), nil
}
return true, nil, nil
}
func (sm *syncClientMiddleware) PostRead(msg interface{}, conn IOSession) (bool, interface{}, error) {
sm.timeouts = 0
// if read notify msg from server, sync msg with server,
// the client read option will block until sync complete and read the raw biz msg
if nt, ok := msg.(*notify); ok {
if nt.offset == 0 || nt.offset > sm.getLocalOffset() {
sm.resetServerOffset(nt.offset)
releaseNotify(nt)
err := sm.sync(conn)
if err != nil {
return false, nil, err
}
}
return false, nil, nil
} else if rsp, ok := msg.(*notifySyncRsp); ok {
sm.syncing = false
sm.resetLocalOffset(rsp.offset)
for i := byte(0); i < rsp.count; i++ {
c, rawMsg, err := sm.bizDecoder.Decode(rsp.buf)
if err != nil {
return false, nil, err
}
if !c {
panic("data cann't be enough")
}
sm.cached.push(rawMsg)
}
releaseNotifySyncRsp(rsp)
if sm.getLocalOffset() < sm.getServerOffset() {
err := sm.sync(conn)
if err != nil {
return false, nil, err
}
}
return false, nil, nil
}
return true, msg, nil
}
func (sm *syncClientMiddleware) Closed(conn IOSession) {
sm.cached = nil
sm.localOffset = 0
sm.serverOffset = 0
sm.syncing = false
sm.timeouts = 0
}
func (sm *syncClientMiddleware) Connected(conn IOSession) {
sm.cached = newSimpleQueue()
sm.localOffset = 0
sm.serverOffset = 0
sm.syncing = false
sm.timeouts = 0
}
func (sm *syncClientMiddleware) ReadError(err error, conn IOSession) error {
if netErr, ok := err.(*net.OpError); ok &&
netErr.Timeout() &&
sm.timeouts < sm.maxReadTimeouts {
sm.timeouts++
sm.syncing = false
return sm.writer(conn, ¬ifyHB{
offset: sm.getLocalOffset(),
})
}
return err
}
func (sm *syncClientMiddleware) getLocalOffset() uint64 {
return atomic.LoadUint64(&sm.localOffset)
}
func (sm *syncClientMiddleware) getServerOffset() uint64 {
return sm.serverOffset
}
func (sm *syncClientMiddleware) resetLocalOffset(offset uint64) {
atomic.StoreUint64(&sm.localOffset, offset)
}
func (sm *syncClientMiddleware) resetServerOffset(offset uint64) {
sm.serverOffset = offset
}
func (sm *syncClientMiddleware) sync(conn IOSession) error {
if !sm.syncing {
req := acquireNotifySync()
req.offset = sm.getLocalOffset()
err := sm.writer(conn, req)
if err != nil {
return err
}
sm.syncing = true
}
return nil
}
type syncServerMiddleware struct {
sync.RWMutex
BaseMiddleware
bizDecoder Decoder
bizEncoder Encoder
writer func(IOSession, interface{}) error
offsetQueueMap map[interface{}]*OffsetQueue
}
// NewSyncProtocolServerMiddleware return a middleware to process sync protocol
func NewSyncProtocolServerMiddleware(bizDecoder Decoder, bizEncoder Encoder, writer func(IOSession, interface{}) error) Middleware {
return &syncServerMiddleware{
bizDecoder: bizDecoder,
bizEncoder: bizEncoder,
writer: writer,
offsetQueueMap: make(map[interface{}]*OffsetQueue),
}
}
func (sm *syncServerMiddleware) Connected(conn IOSession) {
sm.Lock()
sm.offsetQueueMap[conn.ID()] = newOffsetQueue()
sm.Unlock()
}
func (sm *syncServerMiddleware) Closed(conn IOSession) {
sm.Lock()
delete(sm.offsetQueueMap, conn.ID())
sm.Unlock()
}
func (sm *syncServerMiddleware) PreWrite(msg interface{}, conn IOSession) (bool, interface{}, error) {
if _, ok := msg.(*notify); ok {
return sm.BaseMiddleware.PreWrite(msg, conn)
} else if _, ok := msg.(*notifySyncRsp); ok {
return sm.BaseMiddleware.PreWrite(msg, conn)
}
// add biz msg to the offset queue, and send notify msg to client
sm.RLock()
q := sm.offsetQueueMap[conn.ID()]
sm.RUnlock()
if q == nil {
panic("offset queue cann't be nil")
}
m := acquireNotify()
m.offset = q.Add(msg)
return true, m, nil
}
func (sm *syncServerMiddleware) PostRead(msg interface{}, conn IOSession) (bool, interface{}, error) {
if m, ok := msg.(*notifySync); ok {
sm.RLock()
q := sm.offsetQueueMap[conn.ID()]
sm.RUnlock()
if q == nil {
panic("offset queue cann't be nil")
}
// send biz msgs to client
items, maxOffset := q.Get(m.offset)
releaseNotifySync(m)
rsp := acquireNotifySyncRsp()
rsp.offset = maxOffset
rsp.count = byte(len(items))
for _, item := range items {
err := sm.bizEncoder.Encode(item, rsp.buf)
if err != nil {
return false, nil, err
}
}
err := sm.writer(conn, rsp)
if err != nil {
return false, nil, err
}
return false, nil, nil
} else if m, ok := msg.(*notifyRaw); ok {
c, biz, err := sm.bizDecoder.Decode(m.buf)
releaseNotifyRaw(m)
if err != nil {
return false, nil, err
}
if !c {
panic("bug, cann't missing data")
}
return true, biz, nil
} else if m, ok := msg.(*notifyHB); ok {
sm.RLock()
q := sm.offsetQueueMap[conn.ID()]
sm.RUnlock()
if q == nil {
panic("offset queue cann't be nil")
}
max := q.GetMaxOffset()
if m.offset < max {
nt := acquireNotify()
nt.offset = q.GetMaxOffset()
err := sm.writer(conn, nt)
if err != nil {
return false, nil, err
}
}
return false, nil, nil
}
return true, msg, nil
}