refactor: Put paste model in separate file

assets/templates/html/index.html.tmpl

@@ -8,6 +8,9 @@ the command line.
 
 ## USAGE
 
+    # Upload a file
+    curl -F'file=@yourfile.png' <a href="{{Request.Host}}">{{Request.Host}}</a>
+
     # Shorten a URL
     curl -F'shorten=http://example.com/some/long/url' <a href="{{Request.Host}}">{{Request.Host}}</a>
 

assets/templates/txt/index.txt.tmpl

@@ -6,6 +6,9 @@ the command line.
 
 ## USAGE
 
+    # Upload a file
+    curl -F'file=@yourfile.png' {{Request.Host}}
+
     # Shorten a URL
     curl -F'shorten=http://example.com/some/long/url' {{Request.Host}}
 

handlers/handlers.go

@@ -1,15 +1,12 @@
 package handlers
 
 import (
-	"crypto/rand"
 	"crypto/subtle"
 	"encoding/base64"
-	"encoding/hex"
 	"fmt"
 	"log"
 	"net/http"
 	"net/url"
-	"strings"
 	"time"
 
 	"github.com/gorilla/mux"
@@ -17,31 +14,6 @@ import (
 	bolt "go.etcd.io/bbolt"
 
 	"gitea.hashru.nl/dsprenkels/rushlink/db"
-	"gitea.hashru.nl/dsprenkels/rushlink/gobmarsh"
-)
-
-type pasteType int
-type pasteState int
-
-type storedPaste struct {
-	Type        pasteType
-	State       pasteState
-	Content     []byte
-	Key         string
-	DeleteToken string
-	TimeCreated time.Time
-}
-
-const (
-	typeUndef    pasteType = 0
-	typePaste              = 1
-	typeRedirect           = 2
-)
-
-const (
-	stateUndef   pasteState = 0
-	statePresent            = 1
-	stateDeleted            = 2
 )
 
 type viewPaste uint
@@ -106,17 +78,17 @@ func viewPasteHandlerMeta(w http.ResponseWriter, r *http.Request) {
 func viewPasteHandlerInner(w http.ResponseWriter, r *http.Request, flags viewPaste) {
 	vars := mux.Vars(r)
 	key := vars["key"]
-	var storedPaste *storedPaste
+	var p *paste
 	if err := db.DB.View(func(tx *bolt.Tx) error {
 		var err error
-		storedPaste, err = getURL(tx, key)
+		p, err = getPaste(tx, key)
 		return err
 	}); err != nil {
 		log.Printf("error: %v\n", err)
 		renderInternalServerError(w, r, err)
 		return
 	}
-	if storedPaste == nil {
+	if p == nil {
 		renderError(w, r, http.StatusNotFound, "url key not found in the database")
 		return
 	}
@@ -130,7 +102,7 @@ func viewPasteHandlerInner(w http.ResponseWriter, r *http.Request, flags viewPas
 		if deleteToken == "" {
 			canDelete.String = "undefined"
 		} else {
-			if subtle.ConstantTimeCompare([]byte(deleteToken), []byte(storedPaste.DeleteToken)) == 1 {
+			if subtle.ConstantTimeCompare([]byte(deleteToken), []byte(p.DeleteToken)) == 1 {
 				canDelete.Bool = true
 				canDelete.String = "correct"
 			} else {
@@ -139,31 +111,31 @@ func viewPasteHandlerInner(w http.ResponseWriter, r *http.Request, flags viewPas
 		}
 
 		data := map[string]interface{}{
-			"Paste":     storedPaste,
+			"Paste":     p,
 			"CanDelete": canDelete,
 		}
 		render(w, r, "pasteMeta", data)
 		return
 	}
 
-	switch storedPaste.State {
+	switch p.State {
 	case statePresent:
 		if flags&viewNoRedirect == 0 {
-			rawurl := string(storedPaste.Content)
+			rawurl := string(p.Content)
 			urlParse, err := url.Parse(rawurl)
 			if err != nil {
-				log.Printf("error: invalid URL ('%v') in database for key '%v': %v\n", rawurl, storedPaste.Key, err)
+				log.Printf("error: invalid URL ('%v') in database for key '%v': %v\n", rawurl, p.Key, err)
 				renderInternalServerError(w, r, "invalid url in database")
 				return
 			}
 			http.Redirect(w, r, urlParse.String(), http.StatusSeeOther)
 		}
-		w.Write(storedPaste.Content)
+		w.Write(p.Content)
 	case stateDeleted:
 		renderError(w, r, http.StatusGone, "paste has been deleted")
 	default:
-		log.Printf("error: invalid storedPaste.State (%v) for key '%v'\n", storedPaste.State, storedPaste.Key)
+		log.Printf("error: invalid paste.State (%v) for key '%v'\n", p.State, p.Key)
-		msg := fmt.Sprintf("internal server error: invalid storedPaste.State (%v\n)", storedPaste.State)
+		msg := fmt.Sprintf("internal server error: invalid paste.State (%v\n)", p.State)
 		renderInternalServerError(w, r, msg)
 	}
 }
@@ -210,18 +182,18 @@ func newRedirectPasteHandler(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	var storedPaste *storedPaste
+	var paste *paste
 	if err := db.DB.Update(func(tx *bolt.Tx) error {
 		// Generate a new delete token for this paste
 		var err error
-		storedPaste, err = shortenURL(tx, userURL)
+		paste, err = shortenURL(tx, userURL)
 		return err
 	}); err != nil {
 		log.Printf("error: %v\n", err)
 		renderInternalServerError(w, r, err)
 		return
 	}
-	data := map[string]interface{}{"Paste": storedPaste}
+	data := map[string]interface{}{"Paste": paste}
 	render(w, r, "newRedirectPasteSuccess", data)
 }
 
@@ -238,18 +210,13 @@ func deletePasteHandler(w http.ResponseWriter, r *http.Request) {
 
 	var errorCode int
 	if err := db.DB.Update(func(tx *bolt.Tx) error {
-		paste, err := getURL(tx, key)
+		p, err := getPaste(tx, key)
 		if err != nil {
 			errorCode = http.StatusNotFound
 			return err
 		}
-		if subtle.ConstantTimeCompare([]byte(deleteToken), []byte(paste.DeleteToken)) == 1 {
+		if subtle.ConstantTimeCompare([]byte(deleteToken), []byte(p.DeleteToken)) == 1 {
-			// Replace the old paste with a new empty paste
+			p.delete(tx)
-			return savePaste(tx, key, storedPaste{
-				Key:         paste.Key,
-				State:       stateDeleted,
-				DeleteToken: paste.DeleteToken,
-			})
 		}
 		errorCode = http.StatusForbidden
 		return errors.New("invalid delete token")
@@ -260,58 +227,13 @@ func deletePasteHandler(w http.ResponseWriter, r *http.Request) {
 	}
 }
 
-// Retrieve a URL from the database
-func getURL(tx *bolt.Tx, key string) (*storedPaste, error) {
-	pastesBucket := tx.Bucket([]byte(db.BUCKET_PASTES))
-	if pastesBucket == nil {
-		return nil, errors.Errorf("bucket %v does not exist", db.BUCKET_PASTES)
-	}
-	storedBytes := pastesBucket.Get([]byte(key))
-	if storedBytes == nil {
-		return nil, nil
-	}
-	storedPaste := &storedPaste{}
-	err := gobmarsh.Unmarshal(storedBytes, storedPaste)
-	return storedPaste, err
-}
-
 // Add a new URL to the database
 //
 // Returns the new ID if the url was successfully shortened
-func shortenURL(tx *bolt.Tx, userURL *url.URL) (*storedPaste, error) {
+func shortenURL(tx *bolt.Tx, userURL *url.URL) (*paste, error) {
-	pastesBucket := tx.Bucket([]byte(db.BUCKET_PASTES))
+	pasteKey, err := generatePasteKey(tx)
-	if pastesBucket == nil {
-		return nil, errors.Errorf("bucket %v does not exist", db.BUCKET_PASTES)
-	}
-
-	// Generate a key until it is not in the database, this occurs in O(log N),
-	// where N is the amount of keys stored in the url-shorten database.
-	epoch := 0
-	var urlKey string
-	for {
-		var err error
-		urlKey, err = generateURLKey(epoch)
 	if err != nil {
-			return nil, errors.Wrap(err, "url-key generation failed")
+		return nil, errors.Wrap(err, "generating paste key")
-		}
-
-		found := pastesBucket.Get([]byte(urlKey))
-		if found == nil {
-			break
-		}
-
-		isReserved := false
-		for _, reservedKey := range ReservedPasteKeys {
-			if strings.HasPrefix(urlKey, reservedKey) {
-				isReserved = true
-				break
-			}
-		}
-		if !isReserved {
-			break
-		}
-
-		epoch++
 	}
 
 	// Also generate a deleteToken
@@ -321,78 +243,18 @@ func shortenURL(tx *bolt.Tx, userURL *url.URL) (*storedPaste, error) {
 	}
 
 	// Store the new key
-	storedPaste := storedPaste{
+	p := paste{
 		Type:        typeRedirect,
 		State:       statePresent,
 		Content:     []byte(userURL.String()),
-		Key:         urlKey,
+		Key:         pasteKey,
 		DeleteToken: deleteToken,
 		TimeCreated: time.Now().UTC(),
 	}
-	if err := savePaste(tx, urlKey, storedPaste); err != nil {
+	if err := p.save(tx); err != nil {
 		return nil, err
 	}
-	return &storedPaste, nil
+	return &p, nil
-}
-
-func savePaste(tx *bolt.Tx, key string, paste storedPaste) error {
-	bucket := tx.Bucket([]byte(db.BUCKET_PASTES))
-	if bucket == nil {
-		return errors.Errorf("bucket %v does not exist", db.BUCKET_PASTES)
-	}
-
-	buf, err := gobmarsh.Marshal(paste)
-	if err != nil {
-		return errors.Wrap(err, "encoding for database failed")
-	}
-	if err := bucket.Put([]byte(key), buf); err != nil {
-		return errors.Wrap(err, "database transaction failed")
-	}
-	return nil
-}
-
-func generateURLKey(epoch int) (string, error) {
-	urlKey := make([]byte, 4+epoch)
-	_, err := rand.Read(urlKey)
-	if err != nil {
-		return "", err
-	}
-	// Put all the values in the range 0..64 for easier base64-encoding
-	for i := 0; i < len(urlKey); i++ {
-		urlKey[i] &= 0x3F
-	}
-	// Implement truncate-resistance by forcing the prefix to
-	//     0b111110xxxxxxxxxx
-	//       ^----- {epoch} ones followed by a single 0
-	//
-	// Example when epoch is 1: prefix is 0b10.
-	i := 0
-	for i < epoch {
-		// Set this bit to 1
-		limb := i / 6
-		bit := i % 6
-		urlKey[limb] |= 1 << uint(5-bit)
-		i++
-	}
-	// Finally set the next bit to 0
-	limb := i / 6
-	bit := i % 6
-	urlKey[limb] &= ^(1 << uint(5-bit))
-
-	// Convert this ID to a canonical base64 notation
-	for i := range urlKey {
-		urlKey[i] = base64Alphabet[urlKey[i]]
-	}
-	return string(urlKey), nil
-}
-
-func generateDeleteToken() (string, error) {
-	var deleteToken [16]byte
-	_, err := rand.Read(deleteToken[:])
-	if err != nil {
-		return "", err
-	}
-	return hex.EncodeToString(deleteToken[:]), nil
 }
 
 func getDeleteTokenFromRequest(r *http.Request) string {

handlers/paste.go

@@ -0,0 +1,159 @@
+package handlers
+
+import (
+	"crypto/rand"
+	"encoding/hex"
+	"strings"
+	"time"
+
+	"gitea.hashru.nl/dsprenkels/rushlink/db"
+	"gitea.hashru.nl/dsprenkels/rushlink/gobmarsh"
+	"github.com/pkg/errors"
+	bolt "go.etcd.io/bbolt"
+)
+
+type pasteType int
+type pasteState int
+
+type paste struct {
+	Type        pasteType
+	State       pasteState
+	Content     []byte
+	Key         string
+	DeleteToken string
+	TimeCreated time.Time
+}
+
+const (
+	typeUndef    pasteType = 0
+	typePaste              = 1
+	typeRedirect           = 2
+)
+
+const (
+	stateUndef   pasteState = 0
+	statePresent            = 1
+	stateDeleted            = 2
+)
+
+// Retrieve a paste from the database
+func getPaste(tx *bolt.Tx, key string) (*paste, error) {
+	pastesBucket := tx.Bucket([]byte(db.BUCKET_PASTES))
+	if pastesBucket == nil {
+		return nil, errors.Errorf("bucket %v does not exist", db.BUCKET_PASTES)
+	}
+	storedBytes := pastesBucket.Get([]byte(key))
+	if storedBytes == nil {
+		return nil, nil
+	}
+	p := &paste{}
+	err := gobmarsh.Unmarshal(storedBytes, p)
+	return p, err
+}
+
+func (p *paste) save(tx *bolt.Tx) error {
+	bucket := tx.Bucket([]byte(db.BUCKET_PASTES))
+	if bucket == nil {
+		return errors.Errorf("bucket %v does not exist", db.BUCKET_PASTES)
+	}
+
+	buf, err := gobmarsh.Marshal(p)
+	if err != nil {
+		return errors.Wrap(err, "encoding for database failed")
+	}
+	if err := bucket.Put([]byte(p.Key), buf); err != nil {
+		return errors.Wrap(err, "database transaction failed")
+	}
+	return nil
+}
+
+func (p paste) delete(tx *bolt.Tx) error {
+	// Replace the old paste with a new empty paste
+	return (&paste{
+		Key:         p.Key,
+		State:       stateDeleted,
+		DeleteToken: p.DeleteToken,
+	}).save(tx)
+}
+
+// Generate a key until it is not in the database, this occurs in O(log N),
+// where N is the amount of keys stored in the url-shorten database.
+func generatePasteKey(tx *bolt.Tx) (string, error) {
+	pastesBucket := tx.Bucket([]byte(db.BUCKET_PASTES))
+	if pastesBucket == nil {
+		return "", errors.Errorf("bucket %v does not exist", db.BUCKET_PASTES)
+	}
+
+	epoch := 0
+	var key string
+	for {
+		var err error
+		key, err = generatePasteKeyInner(epoch)
+		if err != nil {
+			return "", errors.Wrap(err, "url-key generation failed")
+		}
+
+		found := pastesBucket.Get([]byte(key))
+		if found == nil {
+			break
+		}
+
+		isReserved := false
+		for _, reservedKey := range ReservedPasteKeys {
+			if strings.HasPrefix(key, reservedKey) {
+				isReserved = true
+				break
+			}
+		}
+		if !isReserved {
+			break
+		}
+
+		epoch++
+	}
+	return key, nil
+}
+
+func generatePasteKeyInner(epoch int) (string, error) {
+	urlKey := make([]byte, 4+epoch)
+	_, err := rand.Read(urlKey)
+	if err != nil {
+		return "", err
+	}
+	// Put all the values in the range 0..64 for easier base64-encoding
+	for i := 0; i < len(urlKey); i++ {
+		urlKey[i] &= 0x3F
+	}
+	// Implement truncate-resistance by forcing the prefix to
+	//     0b111110xxxxxxxxxx
+	//       ^----- {epoch} ones followed by a single 0
+	//
+	// Example when epoch is 1: prefix is 0b10.
+	i := 0
+	for i < epoch {
+		// Set this bit to 1
+		limb := i / 6
+		bit := i % 6
+		urlKey[limb] |= 1 << uint(5-bit)
+		i++
+	}
+	// Finally set the next bit to 0
+	limb := i / 6
+	bit := i % 6
+	urlKey[limb] &= ^(1 << uint(5-bit))
+
+	// Convert this ID to a canonical base64 notation
+	for i := range urlKey {
+		urlKey[i] = base64Alphabet[urlKey[i]]
+	}
+	return string(urlKey), nil
+}
+
+func generateDeleteToken() (string, error) {
+	var deleteToken [16]byte
+	_, err := rand.Read(deleteToken[:])
+	if err != nil {
+		return "", err
+	}
+	return hex.EncodeToString(deleteToken[:]), nil
+}