add RefreshAll with workers

fetch/fetch.go

@@ -9,6 +9,7 @@ package fetch
 import (
 	"fmt"
 	"net/url"
+	"sync"
 
 	"golang.nytpu.com/comitium/core"
 )
@@ -42,3 +43,75 @@ func Page(data *core.FullData, remote *url.URL, title string) error {
 		return fmt.Errorf("Unsupported protocol '%s'", remote.Scheme)
 	}
 }
+
+type refreshJob struct {
+	typ string // "feed" or "page"
+	url url.URL
+}
+
+// RefreshAll will check all feeds and pages in a core.FullData for updates
+func RefreshAll(data *core.FullData, numWorkers int) error {
+	var wg sync.WaitGroup
+
+	data.RLock()
+	numJobs := len(data.Feeds) + len(data.Pages)
+	if numJobs == 0 {
+		data.RUnlock()
+		return nil
+	}
+
+	if numWorkers < 1 {
+		numWorkers = 1
+	}
+
+	jobs := make(chan refreshJob, numJobs)
+	returns := make(chan error, numJobs)
+
+	// start workers but jobs is blocking for right now
+	for w := 0; w < numWorkers; w++ {
+		wg.Add(1)
+		go refreshWorker(&wg, jobs, returns, data)
+	}
+
+	// get all keys in maps
+	feedKeys := make([]url.URL, 0, len(data.Feeds))
+	for k := range data.Feeds {
+		// we know that the keys are already validated uris, so no err
+		u, _ := url.ParseRequestURI(k)
+		feedKeys = append(feedKeys, *u)
+	}
+	pageKeys := make([]url.URL, 0, len(data.Pages))
+	for k := range data.Pages {
+		u, _ := url.ParseRequestURI(k)
+		pageKeys = append(pageKeys, *u)
+	}
+	data.RUnlock()
+
+	for _, v := range feedKeys {
+		jobs <- refreshJob{"feed", v}
+	}
+	for _, v := range pageKeys {
+		jobs <- refreshJob{"page", v}
+	}
+	close(jobs)
+
+	wg.Wait()
+
+	for i := 0; i < numJobs; i++ {
+		if err := <-returns; err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func refreshWorker(wg *sync.WaitGroup, jobs <-chan refreshJob, returns chan<- error, data *core.FullData) {
+	defer wg.Done()
+	for j := range jobs {
+		if j.typ == "feed" {
+			returns <- Feed(data, &j.url, "")
+		} else if j.typ == "page" {
+			returns <- Page(data, &j.url, "")
+		}
+	}
+}