/
worker.go
296 lines (257 loc) · 7.15 KB
/
worker.go
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package cocaine
import (
"flag"
"fmt"
"io/ioutil"
"os"
"runtime/debug"
"time"
uuid "github.com/satori/go.uuid"
"github.com/ugorji/go/codec"
)
var (
flagUUID string
flagEndpoint string
flagApp string
flagLocator string
)
func init() {
flagSet := flag.NewFlagSet("cocaine11", flag.ContinueOnError)
flagSet.SetOutput(ioutil.Discard)
flagSet.StringVar(&flagUUID, "uuid", "", "UUID")
flagSet.StringVar(&flagEndpoint, "endpoint", "", "Connection path")
flagSet.StringVar(&flagApp, "app", "standalone", "Connection path")
flagSet.StringVar(&flagLocator, "locator", "localhost:10053", "Connection path")
flagSet.Parse(os.Args[1:])
}
const (
HEARTBEAT_TIMEOUT = time.Second * 20
)
type Request struct {
from_worker chan []byte
to_handler chan []byte
quit chan bool
}
type EventHandler func(*Request, *Response)
func newRequest() *Request {
request := Request{make(chan []byte), make(chan []byte), make(chan bool)}
go func() {
var pending [][]byte
quit := false
for {
var out chan []byte
var first []byte
if len(pending) > 0 {
first = pending[0]
out = request.to_handler
} else {
if quit {
return
}
}
select {
case incoming := <-request.from_worker:
pending = append(pending, incoming)
case out <- first:
pending[0] = nil
pending = pending[1:]
case <-request.quit:
quit = true
}
}
}()
return &request
}
func (request *Request) push(data []byte) {
request.from_worker <- data
}
func (request *Request) close() {
request.quit <- true
}
func (request *Request) Read() chan []byte {
return request.to_handler
}
// Datastream from worker to a client.
type Response struct {
session int64
from_handler chan []byte
to_worker chan rawMessage
quit chan bool
}
func newResponse(session int64, to_worker chan rawMessage) *Response {
response := Response{session, make(chan []byte), to_worker, make(chan bool)}
go func() {
var pending [][]byte
quit := false
for {
var out chan rawMessage
var first rawMessage
if len(pending) > 0 {
first = pending[0]
out = to_worker
} else {
if quit {
return
}
}
select {
case incoming := <-response.from_handler:
pending = append(pending, incoming)
case out <- first:
pending[0] = nil
pending = pending[1:]
case quit = <-response.quit:
quit = true
}
}
}()
return &response
}
// Sends chunk of data to a client.
func (response *Response) Write(data interface{}) {
var res []byte
codec.NewEncoderBytes(&res, h).Encode(&data)
response.from_handler <- packMsg(&chunk{messageInfo{CHUNK, response.session}, res})
}
// Notify a client about finishing the datastream.
func (response *Response) Close() {
response.from_handler <- packMsg(&choke{messageInfo{CHOKE, response.session}})
response.quit <- true
}
// Send error to a client. Specify code and message, which describes this error.
func (response *Response) ErrorMsg(code int, msg string) {
response.from_handler <- packMsg(&errorMsg{messageInfo{ERROR, response.session}, code, msg})
}
type FallbackHandler func(string, *Request, *Response)
var defaultFallbackHandler = func(event string, req *Request, resp *Response) {
defer resp.Close()
resp.ErrorMsg(-100, fmt.Sprintf("There is no event handler for %s", event))
}
// Performs IO operations between application
// and cocaine-runtime, dispatches incoming messages from runtime.
type Worker struct {
unpacker *streamUnpacker
uuid uuid.UUID
logger *Logger
heartbeat_timer *time.Timer
disown_timer *time.Timer
sessions map[int64](*Request)
from_handlers chan rawMessage
socketIO
fallback FallbackHandler
disown_timeout time.Duration
}
// Creates new instance of Worker. Returns error on fail.
func NewWorkerWithLocalLogger(localLogger LocalLogger) (worker *Worker, err error) {
sock, err := newAsyncRWSocket("unix", flagEndpoint, time.Second*5, localLogger)
if err != nil {
return
}
logger, err := NewLogger()
if err != nil {
return
}
workerID, _ := uuid.FromString(flagUUID)
disown_timeout := 5 * time.Second
w := Worker{
unpacker: newStreamUnpacker(),
uuid: workerID,
logger: logger,
heartbeat_timer: time.NewTimer(HEARTBEAT_TIMEOUT),
disown_timer: time.NewTimer(disown_timeout),
sessions: make(map[int64](*Request)),
from_handlers: make(chan rawMessage),
socketIO: sock,
fallback: defaultFallbackHandler,
disown_timeout: disown_timeout,
}
w.disown_timer.Stop()
w.handshake()
w.heartbeat()
worker = &w
return
}
func NewWorker() (worker *Worker, err error) {
return NewWorkerWithLocalLogger(&LocalLoggerImpl{})
}
func (worker *Worker) SetFallbackHandler(fallback FallbackHandler) {
worker.fallback = fallback
}
// Initializes worker in runtime as starting. Launchs an eventloop.
func (worker *Worker) Loop(bind map[string]EventHandler) {
for {
select {
case answer := <-worker.Read():
msgs := worker.unpacker.Feed(answer, worker.logger)
for _, rawmsg := range msgs {
switch msg := rawmsg.(type) {
case *chunk:
worker.logger.Debug("Receive chunk")
worker.sessions[msg.getSessionID()].push(msg.Data)
case *choke:
worker.logger.Debug("Receive choke")
worker.sessions[msg.getSessionID()].close()
delete(worker.sessions, msg.getSessionID())
case *invoke:
worker.logger.Debug(fmt.Sprintf("Receive invoke %s %d", msg.Event, msg.getSessionID()))
cur_session := msg.getSessionID()
req := newRequest()
resp := newResponse(cur_session, worker.from_handlers)
worker.sessions[cur_session] = req
if callback, ok := bind[msg.Event]; ok {
go func() {
defer func() {
if r := recover(); r != nil {
errMsg := fmt.Sprintf("Error in event: '%s', exception: %s", msg.Event, r)
worker.logger.Err(fmt.Sprintf("%s \n Stacktrace: \n %s",
errMsg, string(debug.Stack())))
resp.ErrorMsg(1, errMsg)
resp.Close()
}
}()
callback(req, resp)
}()
} else {
go func() {
defer func() {
if r := recover(); r != nil {
resp.Close()
}
}()
worker.fallback(msg.Event, req, resp)
}()
}
case *heartbeat:
worker.logger.Debug("Receive heartbeat. Stop disown_timer")
worker.disown_timer.Stop()
case *terminateStruct:
worker.logger.Info("Receive terminate")
os.Exit(0)
default:
worker.logger.Warn("Unknown message")
}
}
case <-worker.heartbeat_timer.C:
worker.logger.Debug("Send heartbeat")
worker.heartbeat()
case <-worker.disown_timer.C:
worker.logger.Info("Disowned")
os.Exit(0)
case outcoming := <-worker.from_handlers:
worker.Write() <- outcoming
}
}
}
func (worker *Worker) heartbeat() {
heartbeat := heartbeat{messageInfo{HEARTBEAT, 0}}
worker.Write() <- packMsg(&heartbeat)
worker.disown_timer.Reset(worker.disown_timeout)
worker.heartbeat_timer.Reset(HEARTBEAT_TIMEOUT)
}
func (worker *Worker) handshake() {
handshake := handshakeStruct{messageInfo{HANDSHAKE, 0}, worker.uuid}
worker.Write() <- packMsg(&handshake)
}
func (worker *Worker) SetDisownTimeout(timeout time.Duration) {
worker.disown_timeout = timeout
}