short URLs

Metadata.go

@@ -2,13 +2,21 @@ package contented
 
 import (
 	"encoding/json"
+	"errors"
 	"os"
 	"time"
 
 	"github.com/boltdb/bolt"
+	"github.com/speps/go-hashids"
+)
+
+const (
+	hashIdSalt      = "contented"
+	hashIdMinLength = 2
 )
 
 type Metadata struct {
+	FileHash   string
 	FileSize   int64
 	UploadTime time.Time
 	UploadIP   string
@@ -33,13 +41,35 @@ func (this *Server) Metadata(fileID string) (*Metadata, error) {
 	return &m, nil
 }
 
-func (this *Server) SetMetadata(fileID string, m Metadata) error {
-	jb, err := json.Marshal(m)
-	if err != nil {
-		return err
+func idToString(v uint64) string {
+	hd := hashids.NewData()
+	hd.Salt = hashIdSalt
+	hd.MinLength = hashIdMinLength
+	h, _ := hashids.NewWithData(hd)
+	s, _ := h.EncodeInt64([]int64{int64(v)})
+	return s
 }
 
-	return this.db.Update(func(tx *bolt.Tx) error {
-		return tx.Bucket(this.metadataBucket).Put([]byte(fileID), jb)
-	})
+func (this *Server) AddMetadata(m Metadata) (string, error) {
+	jb, err := json.Marshal(m)
+	if err != nil {
+		return "", err
+	}
+
+	var shortRef string = ""
+
+	err = this.db.Update(func(tx *bolt.Tx) error {
+		b := tx.Bucket(this.metadataBucket)
+		seq, _ := b.NextSequence() // cannot fail
+		shortRef = idToString(seq)
+		return tx.Bucket(this.metadataBucket).Put([]byte(shortRef), jb)
+	})
+	if err != nil {
+		return "", err
+	}
+	if shortRef == "" {
+		return "", errors.New("Invalid URL generated")
+	}
+
+	return shortRef, nil
 }

Server.go

@@ -5,7 +5,6 @@ import (
 	"log"
 	"net/http"
 	"os"
-	"path/filepath"
 	"strings"
 
 	"github.com/boltdb/bolt"
@@ -56,33 +55,6 @@ func NewServer(opts *ServerOptions) (*Server, error) {
 	return s, nil
 }
 
-func (this *Server) handleView(w http.ResponseWriter, r *http.Request, fileID string) error {
-	// Load file
-	f, err := os.Open(filepath.Join(this.opts.DataDirectory, fileID))
-	if err != nil {
-		return err
-	}
-
-	defer f.Close()
-
-	// Load metadata
-	m, err := this.Metadata(fileID)
-	if err != nil {
-		return err
-	}
-
-	// ServeContent only uses the filename to get the mime type, which we can
-	// set accurately (including blacklist)
-	w.Header().Set(`Content-Type`, m.MimeType)
-	if m.MimeType == `application/octet-stream` {
-		w.Header().Set(`Content-Disposition`, `attachment; filename="`+m.Filename+`"`)
-	}
-
-	http.ServeContent(w, r, "", m.UploadTime, f)
-
-	return nil
-}
-
 func (this *Server) handleInformation(w http.ResponseWriter, fileID string) {
 	m, err := this.Metadata(fileID)
 	if err != nil {

_dist/README.txt

@@ -15,6 +15,7 @@ You can use contented as a standalone upload server, or you can use the SDK to e
 - Hash verification (SHA512/256)
 - Detect duplicate upload content and reuse storage
 - Options to limit the upload filesize and the upload bandwidth
+- Short URLs (using [url=http://hashids.org]Hashids[/url] algorithm)
 
 =USAGE (SERVER)=
 
@@ -50,6 +51,5 @@ contented.init("#target", function(/* String[] */ items) {});
 
 - View upload history / view all uploads
 - Encrypted at rest (anti- provider snooping)
-- Shorter URLs
 - Deploy!
 - Display 'my uploads' (id + metadata history kept in localstorage)

download.go

@@ -0,0 +1,35 @@
+package contented
+
+import (
+	"net/http"
+	"os"
+	"path/filepath"
+)
+
+func (this *Server) handleView(w http.ResponseWriter, r *http.Request, fileID string) error {
+
+	// Load metadata
+	m, err := this.Metadata(fileID)
+	if err != nil {
+		return err
+	}
+
+	// Load file
+	f, err := os.Open(filepath.Join(this.opts.DataDirectory, m.FileHash))
+	if err != nil {
+		return err
+	}
+
+	defer f.Close()
+
+	// ServeContent only uses the filename to get the mime type, which we can
+	// set accurately (including blacklist)
+	w.Header().Set(`Content-Type`, m.MimeType)
+	if m.MimeType == `application/octet-stream` {
+		w.Header().Set(`Content-Disposition`, `attachment; filename="`+m.Filename+`"`)
+	}
+
+	http.ServeContent(w, r, "", m.UploadTime, f)
+
+	return nil
+}

upload.go

@@ -88,21 +88,25 @@ func (this *Server) handleUploadFile(src multipart.File, hdr *multipart.FileHead
 	}
 
 	// Save file to disk
-	fileID := hex.EncodeToString(hasher.Sum(nil))
-	dest, err := os.OpenFile(filepath.Join(this.opts.DataDirectory, fileID), os.O_CREATE|os.O_WRONLY, 0600)
-	if err != nil {
-		if os.IsExist(err) {
-			return fileID, nil // hash matches existing upload
-		}
-
+	fileHash := hex.EncodeToString(hasher.Sum(nil))
+	dest, err := os.OpenFile(filepath.Join(this.opts.DataDirectory, fileHash), os.O_CREATE|os.O_WRONLY, 0600)
+	shouldSave := true
+	if err != nil && os.IsExist(err) {
+		// hash matches existing upload
+		// That's fine - but still persist the metadata separately
+		shouldSave = false
+	} else if err != nil {
 		return "", err
 	}
+
+	if shouldSave {
 		defer dest.Close()
 
 		_, err = io.CopyN(dest, src, int64(srcLen))
 		if err != nil {
 			return "", err
 		}
+	}
 
 	// Determine mime type
 	ctype := hdr.Header.Get("Content-Type")
@@ -122,17 +126,19 @@ func (this *Server) handleUploadFile(src multipart.File, hdr *multipart.FileHead
 
 	// Persist metadata to DB
 	m := Metadata{
+		FileHash:   fileHash,
 		Filename:   hdr.Filename,
 		UploadTime: time.Now(),
 		UploadIP:   UploadIP,
 		FileSize:   srcLen,
 		MimeType:   ctype,
 	}
-	err = this.SetMetadata(fileID, m)
+
+	fileRef, err := this.AddMetadata(m)
 	if err != nil {
 		return "", err
 	}
 
 	// Done
-	return fileID, nil
+	return fileRef, nil
 }