func MaterializeUnion(name string, field ...string) Reflex {
reflex, eye := plumb.NewEye(append(field, name)...)
go func() {
conj := New()
for {
dvalve, dvalue := eye.See()
if dvalve == name { // conjunction updated
y := make(chan struct{}) // block and
for _, f_ := range field { // send updated conjunction to all field valves
f := f_
go func() {
eye.Show(f, dvalue.(Circuit).At(f))
y <- struct{}{}
}()
}
for _ = range field {
<-y
}
} else { // field updated
conj.Abandon(dvalve).Grow(dvalve, dvalue)
if conj.Len() == len(field) {
eye.Show(name, conj)
}
}
}
}()
return reflex
}
func (Ticker) Materialize() be.Reflex {
reflex, eye := plumb.NewEye("Tick", "Duration")
go func() {
for {
valve, value := eye.See()
switch valve {
case "Duration":
dur := time.Duration(plumb.AsInt(value))
if dur <= 0 {
panic(4)
}
abr := make(chan struct{})
go func() {
start := time.Now()
tkr := time.NewTicker(dur)
defer tkr.Stop()
for {
select {
case <-abr:
return
case t := <-tkr.C:
eye.Show("Tick", int(t.Sub(start)))
}
}
}()
}
}
}()
return reflex
}
func MaterializeSubscription(kind string) be.Reflex {
reflex, eye := plumb.NewEye("Server", "_")
go func() {
var server string
for {
valve, value := eye.See()
?? // use containerlike spawn param with server and name!!
if valve != "Server" || server != "" {
continue
}
server = value.(string)
go func() {
id := ChooseID()
anchor := program.Client.Walk(
??
[]string{
server,
"escher",
program.Name,
"circuit." + kind,
id,
},
)
var ss client.Subscription
var err error
switch kind {
case "Joining":
ss, err = anchor.MakeOnJoin()
case "Leaving":
ss, err = anchor.MakeOnLeave()
default:
panic(2)
}
if err != nil {
panic("plugging")
}
defer anchor.Scrub()
for {
v, ok := ss.Consume()
if !ok {
panic("subscription should not be closing ever")
}
eye.Show("_", v)
}
}()
}
}()
return reflex
}
// Fix creates a gate that waits until all fix valves are set and
// then outputs a singular conjunction of all values.
func MaterializeFix(fwd string, fix ...string) be.Reflex {
reflex, eye := plumb.NewEye(append(fix, fwd)...)
go func() {
conj := New()
for {
dvalve, dvalue := eye.See()
if dvalve == fwd { // conjunction updated
continue // ignore upstream updates
} else { // field updated
conj.Abandon(dvalve).Grow(dvalve, dvalue)
if conj.Len() == len(fix) {
eye.Show(fwd, conj)
eye.Drain() // As soon as the conjunction is output, this gate is done.
}
}
}
}()
return reflex
}
func (Delay) Materialize() be.Reflex {
reflex, eye := plumb.NewEye("X", "Y", "Duration")
go func() {
ds := make(chan time.Duration, 2)
dur := ds
xy, yx := make(chan interface{}, 1), make(chan interface{}, 1)
go func() {
d := <-dur
for {
v := <-xy
time.Sleep(d)
eye.Show("Y", v)
}
}()
go func() {
d := <-dur
for {
v := <-yx
time.Sleep(d)
eye.Show("X", v)
}
}()
for {
valve, value := eye.See()
switch valve {
case "X":
xy <- value
case "Y":
yx <- value
case "Duration":
if ds == nil {
break
}
d := time.Duration(value.(int))
ds <- d
ds <- d
close(ds)
ds = nil
}
}
}()
return reflex
}
// File string
// Put {Key []byte, Value []byte}
// Query {Name interface{}, Start []byte, Limit []byte}
// Result {Name interface{}, Result Image}
func (File) Materialize() be.Reflex {
reflex, eye := plumb.NewEye("File", "Put", "Query", "Result")
go func() { // dispatch
var err error
var db *leveldb.DB
connected, put, query := make(chan struct{}), make(chan Image, 5), make(chan Image, 5)
go func() { // Put loop
<-connected // wait for db connection
for {
p := <-put
if err := db.Put(p[see.Name("Key")].([]byte), p[see.Name("Value")].([]byte), nil); err != nil {
panic(err)
}
}
}()
go func() { // Query loop
<-connected // wait for db connection
for {
q := <-query
iter := db.NewIterator(
&util.Range{
Start: q[see.Name("Start")].([]byte),
Limit: q[see.Name("Limit")].([]byte),
},
nil,
)
slice := Make()
if iter.First() {
for i := 0; ; i++ {
if err := iter.Error(); err != nil {
panic(err)
}
slice.Grow(
see.Number(i),
Image{
see.Name("Key"): iter.Key(),
see.Name("Value"): iter.Value(),
},
)
if !iter.Next() {
break
}
}
}
eye.Show("Result", Make().Grow(see.Name("Name"), q[see.Name("Name")]).Grow(see.Name("Slice"), slice))
}
}()
for {
valve, value := eye.See()
switch valve {
case "File":
if db, err = leveldb.OpenFile(value.(string), nil); err != nil {
panic(err)
}
close(connected)
case "Put":
put <- value.(Image)
case "Query":
query <- value.(Image)
}
}
}()
return reflex
}
