GoBlog/shortPath.go

76 lines
1.5 KiB
Go

package main
import (
"database/sql"
"errors"
"fmt"
"net/http"
"strconv"
"github.com/go-chi/chi/v5"
)
func (db *database) shortenPath(p string) (string, error) {
if p == "" {
return "", errors.New("empty path")
}
idi, err, _ := db.sp.Do(p, func() (interface{}, error) {
id := db.getShortPathID(p)
if id == -1 {
_, err := db.exec("insert or ignore into shortpath (path) values (@path)", sql.Named("path", p))
if err != nil {
return nil, err
}
id = db.getShortPathID(p)
}
return id, nil
})
if err != nil {
return "", err
}
id := idi.(int)
if id == -1 {
return "", errors.New("failed to retrieve short path for " + p)
}
return fmt.Sprintf("/s/%x", id), nil
}
func (db *database) getShortPathID(p string) (id int) {
if p == "" {
return -1
}
if idi, ok := db.spc.Load(p); ok {
return idi.(int)
}
row, err := db.queryRow("select id from shortpath where path = @path", sql.Named("path", p))
if err != nil {
return -1
}
err = row.Scan(&id)
if err != nil {
return -1
}
db.spc.Store(p, id)
return id
}
func (a *goBlog) redirectToLongPath(rw http.ResponseWriter, r *http.Request) {
id, err := strconv.ParseInt(chi.URLParam(r, "id"), 16, 64)
if err != nil {
a.serve404(rw, r)
return
}
row, err := a.db.queryRow("select path from shortpath where id = @id", sql.Named("id", id))
if err != nil {
a.serve404(rw, r)
return
}
var path string
err = row.Scan(&path)
if err != nil {
a.serve404(rw, r)
return
}
http.Redirect(rw, r, path, http.StatusMovedPermanently)
}