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package main
import "os"
import "fmt"
import "log"
import "time"
import "sync"
import "strconv"
import "strings"
import "net/url"
import "github.com/PuerkitoBio/goquery"
type link struct {
u *url.URL
depth int
}
var mutex *sync.Mutex
var Prev map[string]bool
var tFile *os.File
var base string
func validLink(s string) bool {
return true
//return (strings.HasSuffix(s, ".html") || strings.HasSuffix(s, "/") || strings.HasSuffix(s, "\\"))
}
func addLinks(doc *goquery.Document, jobs chan link, current link, depth int, worker_id int) {
doc.Find("body a").Each(func(index int, item *goquery.Selection) {
link_s, _ := item.Attr("href")
d := depth + 1
u, err := url.Parse(link_s)
if err != nil {
panic(err)
}
if !u.IsAbs() {
u = current.u.ResolveReference(u)
}
if strings.Contains(u.String(), base) && validLink(u.String()) {
mutex.Lock()
if !Prev[u.String()] {
jobs <- link{u, d}
Prev[u.String()] = true
}
mutex.Unlock()
}
})
}
func consume(doc *goquery.Document, worker_id int) {
}
func worker(done chan bool, jobs chan link, depth int, id int) {
for {
select {
case j := <-jobs:
if j.depth < depth {
doc, err := goquery.NewDocument(j.u.String())
if err != nil {
log.Print("Error Reading Document: " + j.u.String() + err.Error())
break
}
fmt.Printf("worker %d Working on %s depth: %d...\n", id, j.u.String(), j.depth)
consume(doc, id)
addLinks(doc, jobs, j, j.depth, id)
}
case <-time.After(time.Second * 10):
fmt.Printf("Worker %d done\n", id)
done <- true
return
}
}
}
func init() {
mutex = &sync.Mutex{}
Prev = make(map[string]bool)
var err error
tFile, err = os.Create("./test.txt")
if err != nil {
panic(err)
}
}
func main() {
var d, w int
if len(os.Args) < 3 {
fmt.Printf("usage: crawler url depth [workers]\n")
panic("test")
}
base = strings.TrimPrefix(os.Args[1], "http://www.")
base = strings.TrimPrefix(base, "https://www.")
if base == os.Args[1] {
panic(base)
}
d, _ = strconv.Atoi(os.Args[2])
if len(os.Args) == 4 {
w, _ = strconv.Atoi(os.Args[3])
} else {
w = 4
}
jobs := make(chan link, 1024*1024)
done := make(chan bool)
u, err := url.Parse(os.Args[1])
if err != nil {
panic(err)
}
if !u.IsAbs() {
panic("Cannot start with relative url")
}
jobs <- link{u, 0}
//send first job
for i := 0; i < w; i++ {
go worker(done, jobs, d, i)
}
for i := 0; i < w; {
select {
case <-done:
fmt.Printf("%d done\n", i)
i++
case <-time.After(1 * time.Second):
if len(jobs) == (1024 * 1024) {
i = w
}
}
}
tFile.Close()
close(done)
fmt.Println(len(jobs))
close(jobs)
}
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