func (this *InterpretedExecutor) processItem(q network.Query, item *dparval.Value) bool {
projection := item.GetAttachment("projection")
switch projection := projection.(type) {
case *dparval.Value:
result := projection.Value()
q.Response().SendResult(result)
}
return true
}
func Dispatch(q network.Query, comp compiler.Compiler, exec executor.Executor,
timeout *time.Duration) {
request := q.Request()
response := q.Response()
switch request := request.(type) {
case network.StringQueryRequest:
plan, err := comp.Compile(request.QueryString)
if err != nil {
response.SendError(err)
return
}
exec.Execute(plan, q, timeout)
}
}
func (this *InterpretedExecutor) Execute(optimalPlan *plan.Plan, q network.Query, timeout *time.Duration) {
stopChannel := make(misc.StopChannel)
if timeout.Nanoseconds() < 0 {
this.executeInternal(optimalPlan, q, stopChannel)
} else {
c := make(chan error, 1)
go func() {
this.executeInternal(optimalPlan, q, stopChannel)
c <- nil
}()
select {
case <-c:
return
case <-time.After(*timeout):
clog.To(executor.CHANNEL, "simple executor timeout trigger")
close(stopChannel)
clog.To(executor.CHANNEL, "stop channel closed")
}
<-c
q.Response().SendError(query.NewTimeoutError(timeout))
}
}
func (this *InterpretedExecutor) executeInternal(optimalPlan *plan.Plan, q network.Query, timeoutStopChannel misc.StopChannel) {
clog.To(executor.CHANNEL, "simple executor started")
// first make the plan excutable
executablePipeline, berr := this.xpipelinebuilder.Build(optimalPlan, q)
if berr != nil {
q.Response().SendError(query.NewError(berr, ""))
return
}
root := executablePipeline.Root
// create a stop channel
stopChannel := make(misc.StopChannel)
// set it on the query object, so HTTP layer can
// stop us if the client goes away
q.SetStopChannel(stopChannel)
go root.Run(stopChannel)
// now execute it
var item *dparval.Value
var obj interface{}
sourceItemChannel, supportChannel := root.GetChannels()
ok := true
for ok {
select {
case item, ok = <-sourceItemChannel:
if ok {
ok = this.processItem(q, item)
clog.To(executor.CHANNEL, "simple executor sent client item: %v", item)
}
case obj, ok = <-supportChannel:
if ok {
switch obj := obj.(type) {
case query.Error:
q.Response().SendError(obj)
clog.To(executor.CHANNEL, "simple executor sent client error: %v", obj)
if obj.IsFatal() {
return
}
}
}
case _, ok = <-timeoutStopChannel:
clog.To(executor.CHANNEL, "simple execution aborted, timeout")
return
}
}
q.Response().NoMoreResults()
clog.To(executor.CHANNEL, "simple executor finished")
}