This operate is to fetch some xml content material and reserve it. One difficulty i encounterd is that learn how to ship case s.updates ← pending[0]: (pending Merchandise) one by one. the code presently has an error of accessing index out of sure.
right here’s the hyperlink to the total code : Higher Go Playground
func(s *sub) loop(){
var pending []Merchandise // appended by fetch; consumed by ship
var subsequent time.Time
var err error
var seen = make(map[string]bool) // set of merchandise.GUIDS
for{
// var updates chan Merchandise
var fetchDone chan fetchResult// if non-nil, fetch is working
var fetchDelay time.Length // initally 0
if now := time.Now(); subsequent.After(now) {
fetchDelay = subsequent.Sub(now)
}
var startFetch <-chan time.Time
if fetchDone == nil && len(pending) < maxPending {
startFetch = time.After(fetchDelay)
}
choose{
case errc := <-s.closing:
errc <- err
shut(s.updates)// tells receiver we're accomplished
return
case <-startFetch:
fmt.Println("begin fetch")
var fetched []Merchandise
fetchDone = make(chan fetchResult, 1)
go func(){
fetched, subsequent, err = s.fetcher.Fetch()
fetchDone <- fetchResult{fetched, subsequent, err}
}()
case s.updates <- pending[0]:
fmt.Println("add pending")
if len(pending) > 0 {
pending = pending[1:]
}
case consequence := <-fetchDone:
fmt.Println("fetch accomplished")
fetchDone = nil
if consequence.err != nil {
subsequent = time.Now().Add(10 * time.Second)
break
}
for _, merchandise := vary consequence.fetched {
if !seen[item.Channel.Link] {
pending = append(pending, merchandise)
seen[item.Channel.Title] = true
}
}
}
}
}
Certain, I’d be glad to assist enhance your Go concurrency code. Might you please present the code you’re working with? Then, I can provide strategies for optimization or any enhancements primarily based in your particular necessities.
Howdy there,
The code within the hyperlink Higher Go Playground
The code is about fetching .xml knowledge on the internet, and retailer it, I wished to fetch 10 gadgets at a time. and retailer it one by one by passing to a channel named updates.
Thanks
