mirror of https://github.com/jlelse/GoBlog
56 lines
1.4 KiB
Go
56 lines
1.4 KiB
Go
package main
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import (
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"context"
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"database/sql"
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"errors"
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"net/http"
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)
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var errRedirectNotFound = errors.New("redirect not found")
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func serveRedirect(w http.ResponseWriter, r *http.Request) {
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redirect, err := getRedirect(r.Context(), slashTrimmedPath(r))
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if err == errRedirectNotFound {
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serve404(w, r)
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return
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} else if err != nil {
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http.Error(w, err.Error(), http.StatusInternalServerError)
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return
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}
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// Send redirect
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w.Header().Set("Location", redirect)
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render(w, templateRedirect, struct {
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Permalink string
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}{
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Permalink: redirect,
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})
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w.WriteHeader(http.StatusFound)
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}
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func getRedirect(context context.Context, fromPath string) (string, error) {
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var toPath string
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row := appDb.QueryRowContext(context, "with recursive f (i, fp, tp) as (select 1, fromPath, toPath from redirects where fromPath = ? union all select f.i + 1, r.fromPath, r.toPath from redirects as r join f on f.tp = r.fromPath) select tp from f order by i desc limit 1", fromPath)
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err := row.Scan(&toPath)
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if err == sql.ErrNoRows {
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return "", errRedirectNotFound
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} else if err != nil {
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return "", err
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}
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return toPath, nil
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}
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func allRedirectPaths() ([]string, error) {
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var redirectPaths []string
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rows, err := appDb.Query("select fromPath from redirects")
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if err != nil {
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return nil, err
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}
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for rows.Next() {
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var path string
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_ = rows.Scan(&path)
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redirectPaths = append(redirectPaths, path)
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}
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return redirectPaths, nil
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}
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