From e8b1808eaf87a49e4c34ebbfb66854baa627418c Mon Sep 17 00:00:00 2001
From: Tucker Evans <tuckerevans24@gmail.com>
Date: Mon, 18 Feb 2019 07:35:54 -0500
Subject: Moves assignments to given course folder.

---
 CSC2636/webCrawler2/crawler.go | 164 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 164 insertions(+)
 create mode 100644 CSC2636/webCrawler2/crawler.go

(limited to 'CSC2636/webCrawler2/crawler.go')

diff --git a/CSC2636/webCrawler2/crawler.go b/CSC2636/webCrawler2/crawler.go
new file mode 100644
index 0000000..5c4dba6
--- /dev/null
+++ b/CSC2636/webCrawler2/crawler.go
@@ -0,0 +1,164 @@
+package main
+
+import "crypto/md5"
+import "fmt"
+import "github.com/PuerkitoBio/goquery"
+import "log"
+import "net/url"
+import "os"
+import "strconv"
+import "strings"
+import "sync"
+import "sync/atomic"
+import "time"
+
+type link struct {
+	u     *url.URL
+	depth int
+}
+
+var mutex *sync.Mutex
+var Prev map[string]bool
+var base string
+var links_visited uint64 = 0
+
+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, url link, worker_id int) {
+	f, _ := os.Create(fmt.Sprintf("./pages/%x", md5.Sum([]byte(url.u.String()))))
+	s, _ := doc.Html()
+	f.Write([]byte(s))
+}
+
+func worker(done chan bool, jobs chan link, depth int, id int, total uint64) {
+	for {
+		x := atomic.LoadUint64(&links_visited)
+		if x >= total {
+			done <- true
+			return
+		}
+
+		atomic.AddUint64(&links_visited, 1)
+		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...\n", id, j.u.String())
+
+				consume(doc, j, 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
+
+	fi, err := os.Lstat("./pages");
+	if err != nil {
+		fmt.Printf("INIT ERROR: %s\n", err);
+	}
+	
+	if (fi == nil) {
+		os.Mkdir("./pages", 0755);
+	} else if (fi.Mode().IsRegular()) {
+		panic("pages is not a valid directory\n")
+	}
+
+}
+
+func main() {
+	var d, w, b int
+	var t uint64
+
+	if len(os.Args) < 5 {
+		fmt.Printf("usage: crawler url depth max_links 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])
+	b, _ = (strconv.Atoi(os.Args[3]))
+	t = uint64(b)
+	b, _ = (strconv.Atoi(os.Args[3]))
+	t = uint64(b)
+	w, _ = strconv.Atoi(os.Args[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, t)
+	}
+
+	for i := 0; i < w; {
+		select {
+		case <-done:
+			i++
+		case <-time.After(1 * time.Second):
+			if len(jobs) == (1024 * 1024) {
+				i = w
+			}
+		}
+	}
+
+	close(done)
+	close(jobs)
+}
-- 
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