/
geziyor.go
310 lines (279 loc) · 7.64 KB
/
geziyor.go
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package geziyor
import (
"github.com/geziyor/geziyor/cache"
"github.com/geziyor/geziyor/client"
"github.com/geziyor/geziyor/metrics"
"github.com/geziyor/geziyor/middleware"
"io/ioutil"
"log"
"net/http/cookiejar"
"os"
"os/signal"
"runtime/debug"
"sync"
)
// Geziyor is our main scraper type
type Geziyor struct {
Opt *Options
Client *client.Client
Exports chan interface{}
metrics *metrics.Metrics
reqMiddlewares []middleware.RequestProcessor
resMiddlewares []middleware.ResponseProcessor
wgRequests sync.WaitGroup
wgExporters sync.WaitGroup
semGlobal chan struct{}
semHosts struct {
sync.RWMutex
hostSems map[string]chan struct{}
}
shutdown bool
}
// NewGeziyor creates new Geziyor with default values.
// If options provided, options
func NewGeziyor(opt *Options) *Geziyor {
// Default Options
if opt.UserAgent == "" {
opt.UserAgent = client.DefaultUserAgent
}
if opt.MaxBodySize == 0 {
opt.MaxBodySize = client.DefaultMaxBody
}
if opt.RetryTimes == 0 {
opt.RetryTimes = client.DefaultRetryTimes
}
if len(opt.RetryHTTPCodes) == 0 {
opt.RetryHTTPCodes = client.DefaultRetryHTTPCodes
}
geziyor := &Geziyor{
Opt: opt,
Exports: make(chan interface{}, 1),
reqMiddlewares: []middleware.RequestProcessor{
&middleware.AllowedDomains{AllowedDomains: opt.AllowedDomains},
&middleware.DuplicateRequests{RevisitEnabled: opt.URLRevisitEnabled},
&middleware.Headers{UserAgent: opt.UserAgent},
middleware.NewDelay(opt.RequestDelayRandomize, opt.RequestDelay),
},
resMiddlewares: []middleware.ResponseProcessor{
&middleware.ParseHTML{ParseHTMLDisabled: opt.ParseHTMLDisabled},
&middleware.LogStats{LogDisabled: opt.LogDisabled},
},
metrics: metrics.NewMetrics(opt.MetricsType),
}
// Client
geziyor.Client = client.NewClient(&client.Options{
MaxBodySize: opt.MaxBodySize,
CharsetDetectDisabled: opt.CharsetDetectDisabled,
RetryTimes: opt.RetryTimes,
RetryHTTPCodes: opt.RetryHTTPCodes,
RemoteAllocatorURL: opt.BrowserEndpoint,
})
if opt.Cache != nil {
geziyor.Client.Transport = &cache.Transport{
Policy: opt.CachePolicy,
Transport: geziyor.Client.Transport,
Cache: opt.Cache,
MarkCachedResponses: true,
}
}
if opt.Timeout != 0 {
geziyor.Client.Timeout = opt.Timeout
}
if !opt.CookiesDisabled {
geziyor.Client.Jar, _ = cookiejar.New(nil)
}
if opt.MaxRedirect != 0 {
geziyor.Client.CheckRedirect = client.NewRedirectionHandler(opt.MaxRedirect)
}
// Concurrency
if opt.ConcurrentRequests != 0 {
geziyor.semGlobal = make(chan struct{}, opt.ConcurrentRequests)
}
if opt.ConcurrentRequestsPerDomain != 0 {
geziyor.semHosts = struct {
sync.RWMutex
hostSems map[string]chan struct{}
}{hostSems: make(map[string]chan struct{})}
}
// Base Middlewares
metricsMiddleware := &middleware.Metrics{Metrics: geziyor.metrics}
geziyor.reqMiddlewares = append(geziyor.reqMiddlewares, metricsMiddleware)
geziyor.resMiddlewares = append(geziyor.resMiddlewares, metricsMiddleware)
robotsMiddleware := middleware.NewRobotsTxt(geziyor.Client, geziyor.metrics, opt.RobotsTxtDisabled)
geziyor.reqMiddlewares = append(geziyor.reqMiddlewares, robotsMiddleware)
// Custom Middlewares
geziyor.reqMiddlewares = append(geziyor.reqMiddlewares, opt.RequestMiddlewares...)
geziyor.resMiddlewares = append(geziyor.resMiddlewares, opt.ResponseMiddlewares...)
// Logging
if opt.LogDisabled {
log.SetOutput(ioutil.Discard)
} else {
log.SetOutput(os.Stdout)
}
return geziyor
}
// Start starts scraping
func (g *Geziyor) Start() {
log.Println("Scraping Started")
// Metrics
if g.Opt.MetricsType == metrics.Prometheus || g.Opt.MetricsType == metrics.ExpVar {
metricsServer := metrics.StartMetricsServer(g.Opt.MetricsType)
defer metricsServer.Close()
}
// Start Exporters
if len(g.Opt.Exporters) != 0 {
g.wgExporters.Add(len(g.Opt.Exporters))
for _, exp := range g.Opt.Exporters {
go func() {
defer g.wgExporters.Done()
exp.Export(g.Exports)
}()
}
} else {
g.wgExporters.Add(1)
go func() {
for range g.Exports {
}
g.wgExporters.Done()
}()
}
// Start Requests
if g.Opt.StartRequestsFunc != nil {
g.Opt.StartRequestsFunc(g)
} else {
for _, startURL := range g.Opt.StartURLs {
g.Get(startURL, g.Opt.ParseFunc)
}
}
// Wait for SIGINT (interrupt) signal.
shutdownChan := make(chan os.Signal, 1)
shutdownDoneChan := make(chan struct{})
signal.Notify(shutdownChan, os.Interrupt)
go func() {
for {
select {
case <-shutdownChan:
log.Println("Received SIGINT, shutting down gracefully. Send again to force")
g.shutdown = true
signal.Stop(shutdownChan)
case <-shutdownDoneChan:
return
}
}
}()
g.wgRequests.Wait()
close(g.Exports)
g.wgExporters.Wait()
shutdownDoneChan <- struct{}{}
log.Println("Scraping Finished")
}
// Get issues a GET to the specified URL.
func (g *Geziyor) Get(url string, callback func(g *Geziyor, r *client.Response)) {
req, err := client.NewRequest("GET", url, nil)
if err != nil {
log.Printf("Request creating error %v\n", err)
return
}
g.Do(req, callback)
}
// GetRendered issues GET request using headless browser
// Opens up a new Chrome instance, makes request, waits for rendering HTML DOM and closed.
// Rendered requests only supported for GET requests.
func (g *Geziyor) GetRendered(url string, callback func(g *Geziyor, r *client.Response)) {
req, err := client.NewRequest("GET", url, nil)
if err != nil {
log.Printf("Request creating error %v\n", err)
return
}
req.Rendered = true
g.Do(req, callback)
}
// Head issues a HEAD to the specified URL
func (g *Geziyor) Head(url string, callback func(g *Geziyor, r *client.Response)) {
req, err := client.NewRequest("HEAD", url, nil)
if err != nil {
log.Printf("Request creating error %v\n", err)
return
}
g.Do(req, callback)
}
// Do sends an HTTP request
func (g *Geziyor) Do(req *client.Request, callback func(g *Geziyor, r *client.Response)) {
if g.shutdown {
return
}
if req.Synchronized {
g.do(req, callback)
} else {
g.wgRequests.Add(1)
go g.do(req, callback)
}
}
// Do sends an HTTP request
func (g *Geziyor) do(req *client.Request, callback func(g *Geziyor, r *client.Response)) {
g.acquireSem(req)
defer g.releaseSem(req)
if !req.Synchronized {
defer g.wgRequests.Done()
}
defer g.recoverMe()
for _, middlewareFunc := range g.reqMiddlewares {
middlewareFunc.ProcessRequest(req)
if req.Cancelled {
return
}
}
res, err := g.Client.DoRequest(req)
if err != nil {
if g.Opt.ErrorFunc != nil {
g.Opt.ErrorFunc(g, req, err)
} else {
log.Println(err)
}
return
}
for _, middlewareFunc := range g.resMiddlewares {
middlewareFunc.ProcessResponse(res)
}
// Callbacks
if callback != nil {
callback(g, res)
} else {
if g.Opt.ParseFunc != nil {
g.Opt.ParseFunc(g, res)
}
}
}
func (g *Geziyor) acquireSem(req *client.Request) {
if g.Opt.ConcurrentRequests != 0 {
g.semGlobal <- struct{}{}
}
if g.Opt.ConcurrentRequestsPerDomain != 0 {
g.semHosts.RLock()
hostSem, exists := g.semHosts.hostSems[req.Host]
g.semHosts.RUnlock()
if !exists {
hostSem = make(chan struct{}, g.Opt.ConcurrentRequestsPerDomain)
g.semHosts.Lock()
g.semHosts.hostSems[req.Host] = hostSem
g.semHosts.Unlock()
}
hostSem <- struct{}{}
}
}
func (g *Geziyor) releaseSem(req *client.Request) {
if g.Opt.ConcurrentRequests != 0 {
<-g.semGlobal
}
if g.Opt.ConcurrentRequestsPerDomain != 0 {
<-g.semHosts.hostSems[req.Host]
}
}
// recoverMe prevents scraping being crashed.
// Logs error and stack trace
func (g *Geziyor) recoverMe() {
if r := recover(); r != nil {
log.Println(r, string(debug.Stack()))
g.metrics.PanicCounter.Add(1)
}
}