From fb6b4f65ac4a5f26f43096da374340e514c838ad Mon Sep 17 00:00:00 2001
From: Jan-Lukas Else <mail@jlelse.de>
Date: Sun, 20 Sep 2020 22:04:42 +0200
Subject: [PATCH] Fix database lock when trying to write already existing
 redirect

---
 cache.go     | 4 ++--
 database.go  | 2 +-
 hugo.go      | 2 +-
 postsDb.go   | 9 +++++++++
 redirects.go | 7 +++++--
 5 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/cache.go b/cache.go
index 8ed6a1a..6f4db27 100644
--- a/cache.go
+++ b/cache.go
@@ -81,6 +81,7 @@ func getCache(context context.Context, path string) (creationTime int64, header
 func saveCache(path string, now time.Time, header map[string][]string, body []byte) {
 	headerBytes, _ := json.Marshal(header)
 	startWritingToDb()
+	defer finishWritingToDb()
 	tx, err := appDb.Begin()
 	if err != nil {
 		return
@@ -88,16 +89,15 @@ func saveCache(path string, now time.Time, header map[string][]string, body []by
 	_, _ = tx.Exec("delete from cache where time<?;", now.Unix()-appConfig.Cache.Expiration)
 	_, _ = tx.Exec("insert or replace into cache (path, time, header, body) values (?, ?, ?, ?);", path, now.Unix(), headerBytes, body)
 	_ = tx.Commit()
-	finishWritingToDb()
 }
 
 func purgeCache(path string) {
 	startWritingToDb()
+	defer finishWritingToDb()
 	tx, err := appDb.Begin()
 	if err != nil {
 		return
 	}
 	_, _ = tx.Exec("delete from cache where path=?", path)
 	_ = tx.Commit()
-	finishWritingToDb()
 }
diff --git a/database.go b/database.go
index a81b9c2..4e71adf 100644
--- a/database.go
+++ b/database.go
@@ -32,6 +32,6 @@ func closeDb() error {
 
 func vacuumDb() {
 	startWritingToDb()
+	defer finishWritingToDb()
 	_, _ = appDb.Exec("VACUUM;")
-	finishWritingToDb()
 }
diff --git a/hugo.go b/hugo.go
index ec600d4..f11b820 100644
--- a/hugo.go
+++ b/hugo.go
@@ -77,7 +77,7 @@ func parseHugoFile(fileContent string, path string) (*Post, error) {
 			splittedPostPath := strings.Split(post.Path, "/")
 			alias = strings.TrimSuffix(post.Path, splittedPostPath[len(splittedPostPath)-1]) + alias
 		}
-		_ = createRedirect(alias, post.Path)
+		_ = createOrReplaceRedirect(alias, post.Path)
 	}
 	// Return post
 	return post, nil
diff --git a/postsDb.go b/postsDb.go
index e77e5cd..dd13a27 100644
--- a/postsDb.go
+++ b/postsDb.go
@@ -44,16 +44,19 @@ func (p *Post) createOrReplace() error {
 	startWritingToDb()
 	tx, err := appDb.Begin()
 	if err != nil {
+		finishWritingToDb()
 		return err
 	}
 	_, err = tx.Exec("insert or replace into posts (path, content, published, updated) values (?, ?, ?, ?)", p.Path, p.Content, p.Published, p.Updated)
 	if err != nil {
 		_ = tx.Rollback()
+		finishWritingToDb()
 		return err
 	}
 	_, err = tx.Exec("delete from post_parameters where path=?", p.Path)
 	if err != nil {
 		_ = tx.Rollback()
+		finishWritingToDb()
 		return err
 	}
 	for param, value := range p.Parameters {
@@ -62,6 +65,7 @@ func (p *Post) createOrReplace() error {
 				_, err = tx.Exec("insert into post_parameters (path, parameter, value) values (?, ?, ?)", p.Path, param, value)
 				if err != nil {
 					_ = tx.Rollback()
+					finishWritingToDb()
 					return err
 				}
 			}
@@ -69,6 +73,7 @@ func (p *Post) createOrReplace() error {
 	}
 	err = tx.Commit()
 	if err != nil {
+		finishWritingToDb()
 		return err
 	}
 	finishWritingToDb()
@@ -84,20 +89,24 @@ func (p *Post) delete() error {
 	startWritingToDb()
 	tx, err := appDb.Begin()
 	if err != nil {
+		finishWritingToDb()
 		return err
 	}
 	_, err = tx.Exec("delete from posts where path=?", p.Path)
 	if err != nil {
 		_ = tx.Rollback()
+		finishWritingToDb()
 		return err
 	}
 	_, err = tx.Exec("delete from post_parameters where path=?", p.Path)
 	if err != nil {
 		_ = tx.Rollback()
+		finishWritingToDb()
 		return err
 	}
 	err = tx.Commit()
 	if err != nil {
+		finishWritingToDb()
 		return err
 	}
 	finishWritingToDb()
diff --git a/redirects.go b/redirects.go
index 9055f0a..35b4283 100644
--- a/redirects.go
+++ b/redirects.go
@@ -55,7 +55,7 @@ func allRedirectPaths() ([]string, error) {
 	return redirectPaths, nil
 }
 
-func createRedirect(from, to string) error {
+func createOrReplaceRedirect(from, to string) error {
 	if from == "" || to == "" {
 		return errors.New("empty path")
 	}
@@ -63,15 +63,18 @@ func createRedirect(from, to string) error {
 	startWritingToDb()
 	tx, err := appDb.Begin()
 	if err != nil {
+		finishWritingToDb()
 		return err
 	}
-	_, err = tx.Exec("insert into redirects (fromPath, toPath) values (?, ?)", from, to)
+	_, err = tx.Exec("insert or replace into redirects (fromPath, toPath) values (?, ?)", from, to)
 	if err != nil {
 		_ = tx.Rollback()
+		finishWritingToDb()
 		return err
 	}
 	err = tx.Commit()
 	if err != nil {
+		finishWritingToDb()
 		return err
 	}
 	finishWritingToDb()