Implement retrieval of redirects

This commit is contained in:
Daan Sprenkels 2019-08-29 00:50:26 +02:00
parent 8322cbd0cf
commit 3c4d0ca60e
2 changed files with 56 additions and 4 deletions

View File

@ -15,6 +15,7 @@ import (
gobmarsh "gitea.hashru.nl/dsprenkels/rushlink/gobmarsh"
mux "github.com/gorilla/mux"
errors "github.com/pkg/errors"
bolt "go.etcd.io/bbolt"
@ -74,6 +75,38 @@ func indexPostHandler(w http.ResponseWriter, r *http.Request) {
shortenPostHandler(w, r)
}
func redirectHandler(w http.ResponseWriter, r *http.Request) {
vars := mux.Vars(r)
key := vars["key"]
var storedURL *StoredURL
if err := db.View(func(tx *bolt.Tx) error {
var err error
storedURL, err = getURL(tx, []byte(key))
return err
}); err != nil {
w.WriteHeader(http.StatusInternalServerError)
log.Printf("error: %v\n", err)
fmt.Fprintf(w, "internal server error: %v", err)
return
}
if storedURL == nil {
w.WriteHeader(http.StatusNotFound)
fmt.Fprintf(w, "url key not found in the database")
}
switch storedURL.State {
case Present:
w.Header().Set("Location", storedURL.RawURL)
w.WriteHeader(http.StatusTemporaryRedirect)
case Deleted:
w.WriteHeader(http.StatusGone)
fmt.Fprintf(w, "key has been deleted")
default:
w.WriteHeader(http.StatusInternalServerError)
log.Printf("error: invalid storedURL.State (%v) for key '%v'\n", storedURL.State, storedURL.Key)
fmt.Fprintf(w, "internal server error: invalid storedURL.State (%v)", storedURL.State)
}
}
func shortenPostHandler(w http.ResponseWriter, r *http.Request) {
rawurl := r.PostForm.Get("shorten")
userURL, err := url.ParseRequestURI(rawurl)
@ -100,12 +133,28 @@ func shortenPostHandler(w http.ResponseWriter, r *http.Request) {
return err
}); err != nil {
w.WriteHeader(http.StatusInternalServerError)
log.Printf("error: %v\n", err)
fmt.Fprintf(w, "internal server error: %v", err)
return
}
w.WriteHeader(http.StatusOK)
fmt.Fprintf(w, "new URL saved: %+v", storedURL)
fmt.Fprintf(w, "URL saved at /%v", string(storedURL.Key))
}
// Retrieve a URL from the database
func getURL(tx *bolt.Tx, key []byte) (*StoredURL, error) {
shortenBucket := tx.Bucket([]byte(BUCKET_SHORTEN))
if shortenBucket == nil {
return nil, fmt.Errorf("bucket %v does not exist", BUCKET_SHORTEN)
}
storedBytes := shortenBucket.Get(key)
if storedBytes == nil {
return nil, nil
}
storedURL := &StoredURL{}
err := gobmarsh.Unmarshal(storedBytes, storedURL)
return storedURL, err
}
// Add a new URL to the database
@ -145,7 +194,6 @@ func shortenURL(tx *bolt.Tx, userURL *url.URL) (*StoredURL, error) {
if err != nil {
return nil, errors.Wrap(err, "encoding for database failed")
}
log.Println(urlKey)
if err := shortenBucket.Put(urlKey, storedBytes); err != nil {
return nil, errors.Wrap(err, "database transaction failed")
}
@ -181,5 +229,8 @@ func generateURLKey(epoch int) ([]byte, error) {
urlKey[limb] &= ^(1 << uint(5-bit))
// Convert this ID to a canonical base64 notation
for i := range urlKey {
urlKey[i] = base64Alphabet[urlKey[i]]
}
return urlKey, nil
}

View File

@ -43,6 +43,7 @@ func main() {
router := mux.NewRouter()
router.HandleFunc("/", indexGetHandler).Methods("GET")
router.HandleFunc("/", indexPostHandler).Methods("POST")
router.HandleFunc("/{key:[A-Za-z0-9-_]{4,}}", redirectHandler).Methods("GET")
// Start the server
srv := &http.Server{