doc/codewalk: update urlpoll to use time.Duration.
R=adg
CC=golang-dev
https://golang.org/cl/5545061
diff --git a/doc/codewalk/urlpoll.go b/doc/codewalk/urlpoll.go
index 1439e34..e716c7e 100644
--- a/doc/codewalk/urlpoll.go
+++ b/doc/codewalk/urlpoll.go
@@ -11,11 +11,10 @@
)
const (
- numPollers = 2 // number of Poller goroutines to launch
- second = 1e9 // one second is 1e9 nanoseconds
- pollInterval = 60 * second // how often to poll each URL
- statusInterval = 10 * second // how often to log status to stdout
- errTimeout = 10 * second // back-off timeout on error
+ numPollers = 2 // number of Poller goroutines to launch
+ pollInterval = 60 * time.Second // how often to poll each URL
+ statusInterval = 10 * time.Second // how often to log status to stdout
+ errTimeout = 10 * time.Second // back-off timeout on error
)
var urls = []string{
@@ -33,7 +32,7 @@
// StateMonitor maintains a map that stores the state of the URLs being
// polled, and prints the current state every updateInterval nanoseconds.
// It returns a chan State to which resource state should be sent.
-func StateMonitor(updateInterval int64) chan<- State {
+func StateMonitor(updateInterval time.Duration) chan<- State {
updates := make(chan State)
urlStatus := make(map[string]string)
ticker := time.NewTicker(updateInterval)
@@ -61,7 +60,7 @@
// Resource represents an HTTP URL to be polled by this program.
type Resource struct {
url string
- errCount int64
+ errCount int
}
// Poll executes an HTTP HEAD request for url
@@ -79,8 +78,8 @@
// Sleep sleeps for an appropriate interval (dependant on error state)
// before sending the Resource to done.
-func (r *Resource) Sleep(done chan *Resource) {
- time.Sleep(pollInterval + errTimeout*r.errCount)
+func (r *Resource) Sleep(done chan<- *Resource) {
+ time.Sleep(pollInterval + errTimeout*time.Duration(r.errCount))
done <- r
}
@@ -93,18 +92,18 @@
}
func main() {
- // create our input and output channels
+ // Create our input and output channels.
pending, complete := make(chan *Resource), make(chan *Resource)
- // launch the StateMonitor
+ // Launch the StateMonitor.
status := StateMonitor(statusInterval)
- // launch some Poller goroutines
+ // Launch some Poller goroutines.
for i := 0; i < numPollers; i++ {
go Poller(pending, complete, status)
}
- // send some Resources to the pending queue
+ // Send some Resources to the pending queue.
go func() {
for _, url := range urls {
pending <- &Resource{url: url}
