geziyor/geziyor.go

153 lines
2.7 KiB
Go

package geziyor
import (
"bytes"
"fmt"
"github.com/PuerkitoBio/goquery"
"github.com/fpfeng/httpcache"
"io/ioutil"
"log"
"net/http"
"net/url"
"os"
"sync"
"time"
)
// Geziyor is our main scraper type
type Geziyor struct {
client *http.Client
wg sync.WaitGroup
opt Options
visitedURLS []string
}
func init() {
log.SetOutput(os.Stdout)
}
// NewGeziyor creates new Geziyor with default values.
// If options provided, options
func NewGeziyor(opt Options) *Geziyor {
geziyor := &Geziyor{
client: &http.Client{
Timeout: time.Second * 60,
},
opt: opt,
}
if opt.Cache != nil {
geziyor.client.Transport = httpcache.NewTransport(opt.Cache)
}
return geziyor
}
// Start starts scraping
func (g *Geziyor) Start() {
for _, startURL := range g.opt.StartURLs {
go g.Get(startURL)
}
time.Sleep(time.Millisecond)
g.wg.Wait()
}
// Get issues a GET to the specified URL.
func (g *Geziyor) Get(url string) {
req, err := http.NewRequest("GET", url, nil)
if err != nil {
log.Printf("Request creating error %v\n", err)
return
}
g.Do(req)
}
// Head issues a HEAD to the specified URL
func (g *Geziyor) Head(url string) {
req, err := http.NewRequest("HEAD", url, nil)
if err != nil {
log.Printf("Request creating error %v\n", err)
return
}
g.Do(req)
}
// Do sends an HTTP request
func (g *Geziyor) Do(req *http.Request) {
g.wg.Add(1)
defer g.wg.Done()
if !checkURL(req.URL, g) {
return
}
// Log
log.Println("Fetching: ", req.URL.String())
// Do request
resp, err := g.client.Do(req)
if resp != nil {
defer resp.Body.Close()
}
if err != nil {
return
}
// Read body
body, err := ioutil.ReadAll(resp.Body)
if err != nil {
fmt.Fprintf(os.Stderr, "reading body error: %v\n", err)
return
}
// Create Document
doc, _ := goquery.NewDocumentFromReader(bytes.NewReader(body))
// Create response
response := Response{
Response: resp,
Body: body,
Doc: doc,
Geziyor: g,
Exports: make(chan map[string]interface{}, 1),
}
// Export Function
go Export(&response)
// ParseFunc response
g.opt.ParseFunc(&response)
time.Sleep(time.Millisecond)
}
func checkURL(parsedURL *url.URL, g *Geziyor) bool {
rawURL := parsedURL.String()
// Check for allowed domains
if len(g.opt.AllowedDomains) != 0 && !contains(g.opt.AllowedDomains, parsedURL.Host) {
log.Printf("Domain not allowed: %s\n", parsedURL.Host)
return false
}
// Check for duplicate requests
if contains(g.visitedURLS, rawURL) {
log.Printf("URL already visited %s\n", rawURL)
return false
}
g.visitedURLS = append(g.visitedURLS, rawURL)
return true
}
// contains checks whether []string contains string
func contains(s []string, e string) bool {
for _, a := range s {
if a == e {
return true
}
}
return false
}