Bump version to v1.1.1

.gitignore

@@ -1,3 +1,6 @@
 /.idea/
 .DS_Store
-/od-database-crawler
+/od-database-crawler
+*.log
+/queue/
+/crawled/

README.md

@@ -5,3 +5,5 @@
  * Crawls HTTP open directories (standard Web Server Listings)
  * Gets name, path, size and modification time of all files
  * Lightweight and fast: __over 9000 requests per second__ on a standard laptop
+
+https://od-db.the-eye.eu/

config.go

@@ -1,9 +1,11 @@
 package main
 
 import (
+	"bufio"
 	"fmt"
 	"github.com/sirupsen/logrus"
 	"github.com/spf13/viper"
+	"io"
 	"os"
 	"strings"
 	"time"
@@ -17,12 +19,13 @@ var config struct {
 	ChunkSize  int64
 	Retries    int
 	Workers    int
-	Timeout    time.Duration
+	UserAgent  string
 	Tasks      int32
 	CrawlStats time.Duration
 	AllocStats time.Duration
 	Verbose    bool
 	PrintHTTP  bool
+	JobBufferSize int
 }
 
 const (
@@ -30,28 +33,44 @@ const (
 	ConfToken      = "server.token"
 	ConfServerTimeout = "server.timeout"
 	ConfRecheck    = "server.recheck"
+	ConfCooldown   = "server.cooldown"
 	ConfChunkSize  = "server.upload_chunk"
+	ConfUploadRetries = "server.upload_retries"
+	ConfUploadRetryInterval = "server.upload_retry_interval"
+
 	ConfTasks      = "crawl.tasks"
 	ConfRetries    = "crawl.retries"
 	ConfWorkers    = "crawl.connections"
+	ConfUserAgent  = "crawl.user-agent"
+	ConfDialTimeout = "crawl.dial_timeout"
 	ConfTimeout    = "crawl.timeout"
+	ConfJobBufferSize = "crawl.job_buffer"
+
 	ConfCrawlStats = "output.crawl_stats"
 	ConfAllocStats = "output.resource_stats"
 	ConfVerbose    = "output.verbose"
 	ConfPrintHTTP  = "output.http"
+	ConfLogFile    = "output.log"
 )
 
 func prepareConfig() {
 	viper.SetDefault(ConfRetries, 5)
 	viper.SetDefault(ConfWorkers, 2)
 	viper.SetDefault(ConfTasks, 3)
-	viper.SetDefault(ConfTimeout, 10 * time.Second)
+	viper.SetDefault(ConfUserAgent, "")
+	viper.SetDefault(ConfDialTimeout, 10 * time.Second)
+	viper.SetDefault(ConfTimeout, 60 * time.Second)
+	viper.SetDefault(ConfJobBufferSize, 5000)
 	viper.SetDefault(ConfCrawlStats, 3 * time.Second)
 	viper.SetDefault(ConfAllocStats, 0)
 	viper.SetDefault(ConfVerbose, false)
 	viper.SetDefault(ConfPrintHTTP, false)
+	viper.SetDefault(ConfLogFile, "")
 	viper.SetDefault(ConfRecheck, 3 * time.Second)
+	viper.SetDefault(ConfCooldown, 30 * time.Second)
 	viper.SetDefault(ConfChunkSize, "1 MB")
+	viper.SetDefault(ConfUploadRetries, 10)
+	viper.SetDefault(ConfUploadRetryInterval, 30 * time.Second)
 }
 
 func readConfig() {
@@ -98,7 +117,13 @@ func readConfig() {
 		configOOB(ConfTasks, int(config.Tasks))
 	}
 
-	config.Timeout = viper.GetDuration(ConfTimeout)
+	config.UserAgent = viper.GetString(ConfUserAgent)
+
+	setDialTimeout(viper.GetDuration(ConfDialTimeout))
+
+	setTimeout(viper.GetDuration(ConfTimeout))
+
+	config.JobBufferSize = viper.GetInt(ConfJobBufferSize)
 
 	config.CrawlStats = viper.GetDuration(ConfCrawlStats)
 
@@ -109,6 +134,17 @@ func readConfig() {
 		logrus.SetLevel(logrus.DebugLevel)
 	}
 
+	if filePath := viper.GetString(ConfLogFile); filePath != "" {
+		f, err := os.OpenFile(filePath, os.O_CREATE | os.O_WRONLY | os.O_APPEND, 0644)
+		bufWriter := bufio.NewWriter(f)
+		if err != nil { panic(err) }
+		exitHooks.Add(func() {
+			bufWriter.Flush()
+			f.Close()
+		})
+		logrus.SetOutput(io.MultiWriter(os.Stdout, bufWriter))
+	}
+
 	config.PrintHTTP = viper.GetBool(ConfPrintHTTP)
 }
 

config.yml

@@ -15,21 +15,35 @@ server:
   # between /task/get requests to the server.
   recheck: 1s
 
+  # Time to wait after receiving an error
+  # from the server. Doesn't apply to uploads.
+  cooldown: 30s
+
   # Upload chunk size
   # If the value is too high, the upload fails.
   upload_chunk: 1 MB
 
+  upload_retries: 10
+  upload_retry_interval: 30s
+
 # Log output settings
 output:
   # Crawl statistics
   crawl_stats: 1s
+
   # CPU/RAM/Job queue stats
   resource_stats: 10s
+
   # More output? (Every listed dir)
   verbose: false
+
   # Print HTTP errors (Super spammy)
   http: false
 
+  # Log file
+  # If empty, no log file is created.
+  log: crawler.log
+
 # Crawler settings
 crawl:
   # Number of sites that can be processed at once
@@ -39,11 +53,32 @@ crawl:
   # Please be careful with this setting!
   # The crawler fires fast and more than
   # ten connections can overwhelm a server.
-  connections: 10
+  connections: 4
 
   # How often to retry getting data
   # from the site before giving up
   retries: 5
 
+  # Time before discarding a failed connection attempt
+  dial_timeout: 10s
+
   # Time before discarding a network request
-  timeout: 10s
+  timeout: 30s
+
+  # Crawler User-Agent
+  # If empty, no User-Agent header is sent.
+  user-agent: "Mozilla/5.0 (X11; od-database-crawler) Gecko/20100101 Firefox/52.0"
+
+  # Job buffer size (per task)
+  # Higher values cause less disk writes
+  # but require more memory.
+  #
+  # The job queue contains all URLs
+  # that should be crawled next.
+  # As it grows very large over time,
+  # it's kept mainly on disk.
+  # This sets how many jobs are kept
+  # in memory.
+  # A negative value will cause all jobs
+  # to be stored in memory. (Don't do this)
+  job_buffer: 5000

crawl.go

@@ -8,6 +8,7 @@ import (
 	"github.com/valyala/fasthttp"
 	"golang.org/x/crypto/blake2b"
 	"golang.org/x/net/html"
+	"net"
 	"path"
 	"strconv"
 	"strings"
@@ -20,17 +21,31 @@ var client = fasthttp.Client {
 	},
 }
 
+func setDialTimeout(d time.Duration) {
+	client.Dial = func(addr string) (net.Conn, error) {
+		return fasthttp.DialTimeout(addr, d)
+	}
+}
+
+func setTimeout(d time.Duration) {
+	client.ReadTimeout = d
+	client.WriteTimeout = d / 2
+}
+
 func GetDir(j *Job, f *File) (links []fasturl.URL, err error) {
 	f.IsDir = true
 	f.Name = path.Base(j.Uri.Path)
 
 	req := fasthttp.AcquireRequest()
+	if config.UserAgent != "" {
+		req.Header.SetUserAgent(config.UserAgent)
+	}
 	req.SetRequestURI(j.UriStr)
 
 	res := fasthttp.AcquireResponse()
 	defer fasthttp.ReleaseResponse(res)
 
-	err = client.DoTimeout(req, res, config.Timeout)
+	err = client.Do(req, res)
 	fasthttp.ReleaseRequest(req)
 
 	if err != nil {
@@ -47,6 +62,8 @@ func GetDir(j *Job, f *File) (links []fasturl.URL, err error) {
 
 	var linkHref string
 	for {
+		err = nil
+
 		tokenType := doc.Next()
 		if tokenType == html.ErrorToken {
 			break
@@ -77,16 +94,16 @@ func GetDir(j *Job, f *File) (links []fasturl.URL, err error) {
 				linkHref = ""
 
 				if strings.LastIndexByte(href, '?') != -1 {
-					goto nextToken
+					continue
 				}
 
 				switch href {
 				case "", " ", ".", "..", "/":
-					goto nextToken
+					continue
 				}
 
 				if strings.Contains(href, "../") {
-					goto nextToken
+					continue
 				}
 
 				var link fasturl.URL
@@ -105,8 +122,6 @@ func GetDir(j *Job, f *File) (links []fasturl.URL, err error) {
 				links = append(links, link)
 			}
 		}
-
-	nextToken:
 	}
 
 	return
@@ -120,13 +135,16 @@ func GetFile(u fasturl.URL, f *File) (err error) {
 
 	req := fasthttp.AcquireRequest()
 	req.Header.SetMethod("HEAD")
+	if config.UserAgent != "" {
+		req.Header.SetUserAgent(config.UserAgent)
+	}
 	req.SetRequestURI(u.String())
 
 	res := fasthttp.AcquireResponse()
 	res.SkipBody = true
 	defer fasthttp.ReleaseResponse(res)
 
-	err = client.DoTimeout(req, res, config.Timeout)
+	err = client.Do(req, res)
 	fasthttp.ReleaseRequest(req)
 
 	if err != nil {

main.go

@@ -3,25 +3,25 @@ package main
 import (
 	"context"
 	"github.com/sirupsen/logrus"
+	"github.com/spf13/viper"
 	"github.com/terorie/od-database-crawler/fasturl"
 	"github.com/urfave/cli"
-	"log"
-	"net/http"
-	_ "net/http/pprof"
 	"os"
 	"strings"
 	"sync/atomic"
 	"time"
 )
 
+var configFile string
+
 var app = cli.App {
 	Name:         "od-database-crawler",
 	Usage:        "OD-Database Go crawler",
-	Version:      "1.0",
+	Version:      "1.1.1",
 	BashComplete: cli.DefaultAppComplete,
 	Writer:       os.Stdout,
 	Action:       cmdBase,
-	Commands:     []cli.Command{
+	Commands:     []cli.Command {
 		{
 			Name:      "crawl",
 			Usage:     "Crawl a list of URLs",
@@ -29,28 +29,43 @@ var app = cli.App {
 			Action:    cmdCrawler,
 		},
 	},
+	Flags: []cli.Flag {
+		cli.StringFlag {
+			Name: "config",
+			EnvVar: "CONFIG",
+			Destination: &configFile,
+		},
+	},
+	Before: func(i *cli.Context) error {
+		if configFile != "" {
+			viper.SetConfigFile(configFile)
+		}
+		return nil
+	},
+	After: func(i *cli.Context) error {
+		exitHooks.Execute()
+		return nil
+	},
 }
 
+var exitHooks Hooks
+
 func init() {
 	prepareConfig()
 }
 
 func main() {
-	go func() {
-		log.Println(http.ListenAndServe("localhost:42069", nil))
-	}()
+	if err := os.MkdirAll("crawled", 0755);
+		err != nil { panic(err) }
 
-	err := os.MkdirAll("crawled", 0755)
-	if err != nil {
-		panic(err)
-	}
+	if err := os.MkdirAll("queue", 0755);
+		err != nil { panic(err) }
 
+	readConfig()
 	app.Run(os.Args)
 }
 
 func cmdBase(_ *cli.Context) error {
-	readConfig()
-
 	// TODO Graceful shutdown
 	appCtx := context.Background()
 	forceCtx := context.Background()
@@ -69,7 +84,7 @@ func cmdBase(_ *cli.Context) error {
 			if err != nil {
 				logrus.WithError(err).
 					Error("Failed to get new task")
-				time.Sleep(30 * time.Second)
+				time.Sleep(viper.GetDuration(ConfCooldown))
 				continue
 			}
 			if t == nil {
@@ -96,7 +111,7 @@ func cmdBase(_ *cli.Context) error {
 			} else if err != nil {
 				logrus.WithError(err).
 					Error("Failed to get new task")
-				time.Sleep(30 * time.Second)
+				time.Sleep(viper.GetDuration(ConfCooldown))
 				continue
 			}
 			ScheduleTask(inRemotes, t, &baseUri)
@@ -107,8 +122,6 @@ func cmdBase(_ *cli.Context) error {
 }
 
 func cmdCrawler(clic *cli.Context) error {
-	readConfig()
-
 	if clic.NArg() != 1 {
 		cli.ShowCommandHelpAndExit(clic, "crawl", 1)
 	}

model.go

@@ -23,7 +23,6 @@ type TaskResult struct {
 }
 
 type Job struct {
-	OD        *OD
 	Uri       fasturl.URL
 	UriStr    string
 	Fails     int
@@ -57,3 +56,8 @@ func (o *OD) LoadOrStoreKey(k *redblackhash.Key) (exists bool) {
 	o.Scanned.Put(k)
 	return false
 }
+
+type errorString string
+func (e errorString) Error() string {
+	return string(e)
+}

queue.go

@@ -0,0 +1,129 @@
+package main
+
+import (
+	"github.com/beeker1121/goque"
+	"os"
+	"sync"
+	"sync/atomic"
+)
+
+type BufferedQueue struct {
+	dataDir string
+	q       *goque.Queue
+	buf     []Job
+	m       sync.Mutex
+}
+
+func OpenQueue(dataDir string) (bq *BufferedQueue, err error) {
+	bq = new(BufferedQueue)
+	if config.JobBufferSize < 0 {
+		return
+	}
+	bq.dataDir = dataDir
+	bq.q, err = goque.OpenQueue(dataDir)
+	if err != nil { return nil, err }
+	return
+}
+
+func (q *BufferedQueue) Enqueue(job *Job) error {
+	atomic.AddInt64(&totalQueued, 1)
+	if q.directEnqueue(job) {
+		return nil
+	}
+
+	var gob JobGob
+	gob.ToGob(job)
+	_, err := q.q.EnqueueObject(gob)
+	return err
+}
+
+func (q *BufferedQueue) Dequeue() (job Job, err error) {
+	if q.directDequeue(&job) {
+		atomic.AddInt64(&totalQueued, -1)
+		return job, nil
+	}
+
+	if config.JobBufferSize < 0 {
+		err = goque.ErrEmpty
+		return
+	}
+
+	var item *goque.Item
+	item, err = q.q.Dequeue()
+	if err != nil { return }
+
+	atomic.AddInt64(&totalQueued, -1)
+
+	var gob JobGob
+	err = item.ToObject(&gob)
+	if err != nil { return }
+	gob.FromGob(&job)
+
+	return
+}
+
+func (q *BufferedQueue) directEnqueue(job *Job) bool {
+	q.m.Lock()
+	defer q.m.Unlock()
+
+	bs := config.JobBufferSize
+	if len(q.buf) < bs || bs < 0 {
+		q.buf = append(q.buf, *job)
+		return true
+	} else {
+		return false
+	}
+}
+
+func (q *BufferedQueue) directDequeue(job *Job) bool {
+	q.m.Lock()
+	defer q.m.Unlock()
+
+	if len(q.buf) > 0 {
+		*job = q.buf[0]
+		q.buf = q.buf[1:]
+		return true
+	} else {
+		return false
+	}
+}
+
+// Always returns nil (But implements io.Closer)
+func (q *BufferedQueue) Close() error {
+	if config.JobBufferSize < 0 {
+		return nil
+	}
+
+	// Close ignoring errors
+	q.q.Close()
+
+	// Delete files
+	if err := os.RemoveAll(q.dataDir);
+		err != nil { panic(err) }
+
+	return nil
+}
+
+type JobGob struct {
+	Uri string
+	Fails int
+	LastError string
+}
+
+func (g *JobGob) ToGob(j *Job) {
+	g.Uri = j.UriStr
+	g.Fails = j.Fails
+	if j.LastError != nil {
+		g.LastError = j.LastError.Error()
+	}
+}
+
+func (g *JobGob) FromGob(j *Job) {
+	if err := j.Uri.Parse(g.Uri);
+		err != nil { panic(err) }
+	j.UriStr = g.Uri
+	j.Fails = g.Fails
+	if g.LastError != "" {
+		j.LastError = errorString(g.LastError)
+	}
+}

release.sh

@@ -18,3 +18,8 @@ name=${appname}-${tag}-mac
 GOOS="darwin" GOARCH="amd64" go build -ldflags="-s -w" -o $name
 gzip -f $name
 echo $name
+
+name=${appname}-${tag}-freebsd
+GOOS="freebsd" GOARCH="amd64" go build -ldflags="-s -w" -o $name
+gzip -f $name
+echo $name

scheduler.go

@@ -16,7 +16,7 @@ import (
 var activeTasksLock sync.Mutex
 var activeTasks = make(map[uint64]bool)
 var numActiveTasks int32
-var totalBuffered int64
+var totalQueued int64
 
 func Schedule(c context.Context, remotes <-chan *OD) {
 	go Stats(c)
@@ -28,8 +28,21 @@ func Schedule(c context.Context, remotes <-chan *OD) {
 		// Collect results
 		results := make(chan File)
 
+		remote.WCtx.OD = remote
+
+		// Get queue path
+		queuePath := path.Join("queue", fmt.Sprintf("%d", remote.Task.WebsiteId))
+
+		// Delete existing queue
+		if err := os.RemoveAll(queuePath);
+			err != nil { panic(err) }
+
+		// Start new queue
+		var err error
+		remote.WCtx.Queue, err = OpenQueue(queuePath)
+		if err != nil { panic(err) }
+
 		// Spawn workers
-		remote.WCtx.in, remote.WCtx.out = makeJobBuffer(c)
 		for i := 0; i < config.Workers; i++ {
 			go remote.WCtx.Worker(results)
 		}
@@ -37,7 +50,6 @@ func Schedule(c context.Context, remotes <-chan *OD) {
 		// Enqueue initial job
 		atomic.AddInt32(&numActiveTasks, 1)
 		remote.WCtx.queueJob(Job{
-			OD:     remote,
 			Uri:    remote.BaseUri,
 			UriStr: remote.BaseUri.String(),
 			Fails:  0,
@@ -148,7 +160,11 @@ func (o *OD) handleCollect(results chan File, f *os.File, collectErrC chan error
 
 	// Wait for all jobs on remote to finish
 	o.Wait.Wait()
-	close(o.WCtx.in)
+
+	// Close queue
+	if err := o.WCtx.Queue.Close(); err != nil {
+		panic(err)
+	}
 	atomic.AddInt32(&numActiveTasks, -1)
 
 	// Log finish
@@ -198,51 +214,3 @@ func (t *Task) collect(results chan File, f *os.File) error {
 
 	return nil
 }
-
-func makeJobBuffer(c context.Context) (chan<- Job, <-chan Job) {
-	in  := make(chan Job)
-	out := make(chan Job)
-	go bufferJobs(c, in, out)
-	return in, out
-}
-
-func bufferJobs(c context.Context, in chan Job, out chan Job) {
-	defer close(out)
-	var inQueue []Job
-	outCh := func() chan Job {
-		if len(inQueue) == 0 {
-			return nil
-		}
-		return out
-	}
-	for len(inQueue) > 0 || in != nil {
-		if len(inQueue) == 0 {
-			select {
-			case v, ok := <-in:
-				if !ok {
-					in = nil
-				} else {
-					atomic.AddInt64(&totalBuffered, 1)
-					inQueue = append(inQueue, v)
-				}
-			case <-c.Done():
-				return
-			}
-		} else {
-			select {
-			case v, ok := <-in:
-				if !ok {
-					in = nil
-				} else {
-					atomic.AddInt64(&totalBuffered, 1)
-					inQueue = append(inQueue, v)
-				}
-			case outCh() <- inQueue[0]:
-				atomic.AddInt64(&totalBuffered, -1)
-				inQueue = inQueue[1:]
-			case <-c.Done():
-				return
-			}
-		}
-	}
-}

server.go

@@ -5,12 +5,14 @@ import (
 	"encoding/json"
 	"fmt"
 	"github.com/sirupsen/logrus"
+	"github.com/spf13/viper"
 	"io"
 	"mime/multipart"
 	"net/http"
 	"net/url"
 	"os"
 	"strconv"
+	"time"
 )
 
 var serverClient = http.Client {
@@ -101,25 +103,37 @@ func uploadChunks(websiteId uint64, f *os.File) error {
 
 		multi.Close()
 
-		req, err := http.NewRequest(
-			http.MethodPost,
-			config.ServerUrl + "/task/upload",
-			&b)
-		req.Header.Set("content-type", multi.FormDataContentType())
-		if err != nil { return err }
+		for retries := 0; retries < viper.GetInt(ConfUploadRetries); retries++ {
+			if retries > 0 {
+				// Error occurred, retry upload
+				time.Sleep(viper.GetDuration(ConfUploadRetryInterval))
+			}
 
-		res, err := serverClient.Do(req)
-		if err != nil { return err }
-		res.Body.Close()
+			req, err := http.NewRequest(
+				http.MethodPost,
+				config.ServerUrl + "/task/upload",
+				&b)
+			req.Header.Set("content-type", multi.FormDataContentType())
+			if err != nil { continue }
 
-		if res.StatusCode != http.StatusOK {
-			return fmt.Errorf("failed to upload list part %d: %s",
-				iter, res.Status)
+			res, err := serverClient.Do(req)
+			if err != nil { continue }
+			res.Body.Close()
+
+			if res.StatusCode != http.StatusOK {
+				logrus.WithField("status", res.Status).
+					WithField("part", iter).
+					Errorf("Upload failed")
+				continue
+			}
+
+			// Upload successful
+			break
 		}
 
 		logrus.WithField("id", websiteId).
 			WithField("part", iter).
-			Infof("Uploading files chunk")
+			Infof("Uploaded files chunk")
 	}
 	return nil
 }

stats.go

@@ -57,7 +57,7 @@ func Stats(c context.Context) {
 			runtime.ReadMemStats(&mem)
 
 			logrus.WithFields(logrus.Fields{
-				"queue_count": atomic.LoadInt64(&totalBuffered),
+				"queue_count": atomic.LoadInt64(&totalQueued),
 				"heap": FormatByteCount(mem.Alloc),
 				"objects": mem.HeapObjects,
 				"num_gc": mem.NumGC,

util.go

@@ -1,6 +1,9 @@
 package main
 
-import "fmt"
+import (
+	"fmt"
+	"sync"
+)
 
 // https://programming.guide/go/formatting-byte-size-to-human-readable-format.html
 func FormatByteCount(b uint64) string {
@@ -16,3 +19,20 @@ func FormatByteCount(b uint64) string {
 		return fmt.Sprintf("%.1f %ciB", float64(b)/float64(div), "KMGTPE"[exp])
 	}
 }
+
+type Hooks struct {
+	m sync.Mutex
+	l []func()
+}
+
+func (h *Hooks) Add(hook func()) {
+	h.m.Lock()
+	h.l = append(h.l, hook)
+	h.m.Unlock()
+}
+
+func (h *Hooks) Execute() {
+	for _, hook := range h.l {
+		hook()
+	}
+}

worker.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"github.com/beeker1121/goque"
 	"github.com/sirupsen/logrus"
 	"github.com/valyala/fasthttp"
 	"math"
@@ -14,24 +15,38 @@ import (
 var globalWait sync.WaitGroup
 
 type WorkerContext struct {
-	in chan<- Job
-	out <-chan Job
+	OD *OD
+	Queue *BufferedQueue
 	lastRateLimit time.Time
 	numRateLimits int
 }
 
-func (w WorkerContext) Worker(results chan<- File) {
-	for job := range w.out {
-		w.step(results, job)
+func (w *WorkerContext) Worker(results chan<- File) {
+	for {
+		job, err := w.Queue.Dequeue()
+		switch err {
+		case goque.ErrEmpty:
+			time.Sleep(500 * time.Millisecond)
+			continue
+
+		case goque.ErrDBClosed:
+			return
+
+		case nil:
+			w.step(results, job)
+
+		default:
+			panic(err)
+		}
 	}
 }
 
-func (w WorkerContext) step(results chan<- File, job Job) {
+func (w *WorkerContext) step(results chan<- File, job Job) {
 	defer w.finishJob(&job)
 
 	var f File
 
-	newJobs, err := DoJob(&job, &f)
+	newJobs, err := w.DoJob(&job, &f)
 	atomic.AddUint64(&totalStarted, 1)
 	if err == ErrKnown {
 		return
@@ -42,15 +57,11 @@ func (w WorkerContext) step(results chan<- File, job Job) {
 
 		if httpErr, ok := err.(*HttpError); ok {
 			switch httpErr.code {
-			case
-				fasthttp.StatusMovedPermanently,
-				fasthttp.StatusFound,
-				fasthttp.StatusUnauthorized,
-				fasthttp.StatusForbidden,
-				fasthttp.StatusNotFound:
-				return
 			case fasthttp.StatusTooManyRequests:
 				err = ErrRateLimit
+			default:
+				// Don't retry HTTP error codes
+				return
 			}
 		}
 
@@ -79,7 +90,7 @@ func (w WorkerContext) step(results chan<- File, job Job) {
 	}
 }
 
-func DoJob(job *Job, f *File) (newJobs []Job, err error) {
+func (w *WorkerContext) DoJob(job *Job, f *File) (newJobs []Job, err error) {
 	if len(job.Uri.Path) == 0 { return }
 	if job.Uri.Path[len(job.Uri.Path)-1] == '/' {
 		// Load directory
@@ -97,7 +108,7 @@ func DoJob(job *Job, f *File) (newJobs []Job, err error) {
 		hash := f.HashDir(links)
 
 		// Skip symlinked dirs
-		if job.OD.LoadOrStoreKey(&hash) {
+		if w.OD.LoadOrStoreKey(&hash) {
 			return nil, ErrKnown
 		}
 
@@ -118,7 +129,6 @@ func DoJob(job *Job, f *File) (newJobs []Job, err error) {
 			lastLink = uriStr
 
 			newJobs = append(newJobs, Job{
-				OD:     job.OD,
 				Uri:    link,
 				UriStr: uriStr,
 				Fails:  0,
@@ -143,13 +153,13 @@ func DoJob(job *Job, f *File) (newJobs []Job, err error) {
 			}
 			return nil, err
 		}
-		atomic.AddUint64(&job.OD.Result.FileCount, 1)
+		atomic.AddUint64(&w.OD.Result.FileCount, 1)
 	}
 	return
 }
 
-func (w WorkerContext) queueJob(job Job) {
-	job.OD.Wait.Add(1)
+func (w *WorkerContext) queueJob(job Job) {
+	w.OD.Wait.Add(1)
 
 	if w.numRateLimits > 0 {
 		if time.Since(w.lastRateLimit) > 5 * time.Second {
@@ -160,11 +170,13 @@ func (w WorkerContext) queueJob(job Job) {
 		}
 	}
 
-	w.in <- job
+	if err := w.Queue.Enqueue(&job); err != nil {
+		panic(err)
+	}
 }
 
-func (w WorkerContext) finishJob(job *Job) {
-	job.OD.Wait.Done()
+func (w *WorkerContext) finishJob(job *Job) {
+	w.OD.Wait.Done()
 }
 
 func isErrSilent(err error) bool {