// Decode a job from byte slice
func decodeJob(data []byte) (job *Job, err error) {
if len(data) < 12 {
return nil, common.Errorf("Invalid data: %V", data)
}
datatype := common.BytesToUint32([4]byte{data[4], data[5], data[6], data[7]})
l := common.BytesToUint32([4]byte{data[8], data[9], data[10], data[11]})
if len(data[12:]) != int(l) {
return nil, common.Errorf("Invalid data: %V", data)
}
data = data[12:]
var handle string
switch datatype {
case common.WORK_DATA, common.WORK_WARNING, common.WORK_STATUS,
common.WORK_COMPLETE, common.WORK_FAIL, common.WORK_EXCEPTION:
i := bytes.IndexByte(data, '\x00')
if i != -1 {
handle = string(data[:i])
data = data[i+1:]
}
}
return &Job{magicCode: common.RES,
DataType: datatype,
Data: data,
Handle: handle}, nil
}
// Decode job from byte slice
func decodeJob(data []byte) (job *Job, err error) {
if len(data) < 12 {
return nil, common.Errorf("Invalid data: %V", data)
}
datatype := common.BytesToUint32([4]byte{data[4], data[5], data[6], data[7]})
l := common.BytesToUint32([4]byte{data[8], data[9], data[10], data[11]})
if len(data[12:]) != int(l) {
return nil, common.Errorf("Invalid data: %V", data)
}
data = data[12:]
job = &Job{magicCode: common.RES, DataType: datatype, c: make(chan bool)}
switch datatype {
case common.JOB_ASSIGN:
s := bytes.SplitN(data, []byte{'\x00'}, 3)
if len(s) == 3 {
job.Handle = string(s[0])
job.Fn = string(s[1])
data = s[2]
}
case common.JOB_ASSIGN_UNIQ:
s := bytes.SplitN(data, []byte{'\x00'}, 4)
if len(s) == 4 {
job.Handle = string(s[0])
job.Fn = string(s[1])
job.UniqueId = string(s[2])
data = s[3]
}
}
job.Data = data
return
}
// inputing loop
func (a *agent) inLoop() {
defer func() {
if r := recover(); r != nil {
a.worker.err(common.Errorf("Exiting: %s", r))
}
close(a.in)
close(a.out)
a.worker.removeAgent(a)
}()
for a.worker.running {
a.WriteJob(newJob(common.REQ, common.PRE_SLEEP, nil))
RESTART:
// got noop msg and in queue is zero, grab job
rel, err := a.read()
if err != nil {
if err == common.ErrConnection {
for a.worker.running {
// if we lose connection, try to reconnect once a second forever
if a.conn, err = net.Dial(common.NETWORK, a.addr); err != nil {
a.worker.err(common.Errorf("Reconnection attempt failed. Waiting to retry..."))
<-time.After(time.Second)
continue
}
goto RESTART
}
a.worker.err(err)
break
}
a.worker.err(err)
continue
}
job, err := decodeJob(rel)
if err != nil {
a.worker.err(err)
continue
}
switch job.DataType {
case common.NOOP:
a.WriteJob(newJob(common.REQ, common.GRAB_JOB_UNIQ, nil))
case common.ERROR, common.ECHO_RES, common.JOB_ASSIGN_UNIQ, common.JOB_ASSIGN:
if a.worker.running {
if a.worker.limit != nil {
a.worker.limit <- true
}
job.agent = a
a.worker.in <- job
}
}
}
}
// Remove a function.
// Tell job servers 'I can not do this now' at the same time.
func (worker *Worker) RemoveFunc(funcname string) (err error) {
if _, ok := worker.funcs[funcname]; !ok {
return common.Errorf("The function does not exist: %s", funcname)
}
delete(worker.funcs, funcname)
if worker.running {
worker.removeFunc(funcname)
}
return
}
// Add a function.
// Plz added job servers first, then functions.
// The API will tell every connected job server that 'I can do this'
func (worker *Worker) AddFunc(funcname string,
f JobFunc, timeout uint32) (err error) {
if _, ok := worker.funcs[funcname]; ok {
return common.Errorf("The function already exists: %s", funcname)
}
worker.funcs[funcname] = &jobFunc{f: f, timeout: timeout}
if worker.running {
worker.addFunc(funcname, timeout)
}
return
}
// status handler
func (client *Client) handleStatus(job *Job) {
data := bytes.SplitN(job.Data, []byte{'\x00'}, 5)
if len(data) != 5 {
client.err(common.Errorf("Invalid data: %V", job.Data))
return
}
status := &Status{}
status.Handle = string(data[0])
status.Known = (data[1][0] == '1')
status.Running = (data[2][0] == '1')
var err error
status.Numerator, err = strconv.ParseUint(string(data[3]), 10, 0)
if err != nil {
client.err(common.Errorf("Invalid Integer: %s", data[3]))
return
}
status.Denominator, err = strconv.ParseUint(string(data[4]), 10, 0)
if err != nil {
client.err(common.Errorf("Invalid Integer: %s", data[4]))
return
}
client.status <- status
}
// Extract the job's result.
func (job *Job) Result() (data []byte, err error) {
switch job.DataType {
case common.WORK_FAIL:
job.Handle = string(job.Data)
return nil, common.ErrWorkFail
case common.WORK_EXCEPTION:
err = common.ErrWorkException
fallthrough
case common.WORK_COMPLETE:
s := bytes.SplitN(job.Data, []byte{'\x00'}, 2)
if len(s) != 2 {
return nil, common.Errorf("Invalid data: %V", job.Data)
}
job.Handle = string(s[0])
data = s[1]
default:
err = common.ErrDataType
}
return
}
// Execute the job. And send back the result.
func (worker *Worker) exec(job *Job) (err error) {
defer func() {
if r := recover(); r != nil {
if e, ok := r.(error); ok {
err = e
} else {
err = common.ErrUnknown
}
}
}()
f, ok := worker.funcs[job.Fn]
if !ok {
return common.Errorf("The function does not exist: %s", job.Fn)
}
var r *result
if f.timeout == 0 {
d, e := f.f(job)
r = &result{data: d, err: e}
} else {
r = execTimeout(f.f, job, time.Duration(f.timeout)*time.Second)
}
var datatype uint32
if r.err == nil {
datatype = common.WORK_COMPLETE
} else {
if r.data == nil {
datatype = common.WORK_FAIL
} else {
datatype = common.WORK_EXCEPTION
}
err = r.err
}
job.magicCode = common.REQ
job.DataType = datatype
job.Data = r.data
if worker.running {
job.agent.WriteJob(job)
}
return
}