herald.go/server/notifier.go
Jonathan Moody 8fb3db8136
Add subscribe/unsubscribe RPCs. Add session, sessionManager, and serve JSON RPC (without HTTP). (#66)
* Move and rename BlockchainCodec, BlockchainCodecRequest.
These are not specifically "blockchain", rather they are
specific to how gorilla/rpc works.

* Move claimtrie-related service/handlers to jsonrpc_claimtrie.go.

* Pull out decode logic into named func newBlockHeaderElectrum().

* Rename BlockchainService -> BlockchainBlockService.

* Drop http.Request arg from handlers, and use RegisterTCPService().

* Implement GetStatus() to pull data from HashXStatus table.

* Make the service objects independent, so we don't have inheritance.

* Add core session/subscription logic (session.go).
Implement subsribe/unsubscribe handlers.

* Support both pure JSON and JSON-over-HTTP services.
Forward NotifierChan messages to sessionManager.

* Only assign default port (50001) if neither --json-rpc-port nor
--json-rpc-http-port are specified.

* Handle failures with goto instead of break. Update error logging.

* Add --max-sessions, --session-timeout args. Enforce max sessions.

* Changes to make session.go testable. Conn created with Pipe()
used in testing has no unique Addr.

* Add tests for headers, headers.subscribe, address.subscribe.

* HashXStatus, HashXMempoolStatus not populated by default. Fix GetStatus().

* Use time.Ticker object to drive management activity.
2022-10-04 17:05:06 +03:00

102 lines
2.2 KiB
Go

package server
import (
"encoding/binary"
"net"
"github.com/lbryio/herald.go/internal"
"github.com/sirupsen/logrus"
)
const NotifierResponseLength = 40
// AddHeightSub adds a new height subscriber
func (s *Server) AddHeightSub(addr net.Addr, conn net.Conn) {
s.HeightSubsMut.Lock()
defer s.HeightSubsMut.Unlock()
s.HeightSubs[addr] = conn
}
// DoNotify sends a notification to all height subscribers
func (s *Server) DoNotify(heightHash *internal.HeightHash) error {
buff := make([]byte, NotifierResponseLength)
toDelete := make([]net.Addr, 0)
s.HeightSubsMut.RLock()
for addr, conn := range s.HeightSubs {
// struct.pack(b'>Q32s', height, block_hash)
binary.BigEndian.PutUint64(buff, heightHash.Height)
copy(buff[8:], heightHash.BlockHash[:32])
logrus.Tracef("notifying %s", addr)
n, err := conn.Write(buff)
if err != nil {
logrus.Warn(err)
toDelete = append(toDelete, addr)
}
if n != NotifierResponseLength {
logrus.Warn("not all bytes written")
}
}
s.HeightSubsMut.RUnlock()
if len(toDelete) > 0 {
s.HeightSubsMut.Lock()
for _, v := range toDelete {
delete(s.HeightSubs, v)
}
s.HeightSubsMut.Unlock()
}
return nil
}
// RunNotifier Runs the notfying action forever
func (s *Server) RunNotifier() error {
for notification := range s.NotifierChan {
switch notification.(type) {
case internal.HeightHash:
heightHash, _ := notification.(internal.HeightHash)
s.DoNotify(&heightHash)
}
s.sessionManager.doNotify(notification)
}
return nil
}
// NotifierServer implements the TCP protocol for height/blockheader notifications
func (s *Server) NotifierServer() error {
address := ":" + s.Args.NotifierPort
addr, err := net.ResolveTCPAddr("tcp", address)
if err != nil {
return err
}
listen, err := net.ListenTCP("tcp", addr)
if err != nil {
return err
}
defer listen.Close()
for {
logrus.Info("Waiting for connection")
conn, err := listen.Accept()
if err != nil {
logrus.Warn(err)
continue
}
addr := conn.RemoteAddr()
logrus.Println(addr)
// _, err = conn.Write([]byte(addr.String()))
// if err != nil {
// logrus.Warn(err)
// continue
// }
go s.AddHeightSub(addr, conn)
}
}