Handle rollbackError with log.Fatalf()

cmd/data/articles.go

@@ -140,11 +140,15 @@ func LoadArticleList(filename string) (*ArticleList, error) {
 		return nil, fmt.Errorf("error opening key file: %v", err)
 	}
 
-	articleList := NewArticleList()
+	articleList := initArticleList()
 	if err = gob.NewDecoder(file).Decode(&articleList.articles); err != nil {
 		return nil, fmt.Errorf("error decoding key: %v", err)
 	}
 
+	articleList.wg.Add(1)
+	go articleList.start()
+	articleList.wg.Wait()
+
 	return articleList, nil
 }
 
@@ -189,10 +193,14 @@ func LoadTagList(filename string) (*TagList, error) {
 	}
 	defer file.Close()
 
-	tagList := NewTagList()
+	tagList := initTagList()
 	if err = gob.NewDecoder(file).Decode(&tagList.tags); err != nil {
 		return nil, fmt.Errorf("error decoding key: %v", err)
 	}
 
+	tagList.wg.Add(1)
+	go tagList.start()
+	tagList.wg.Wait()
+
 	return tagList, nil
 }

cmd/data/db.go

@@ -3,6 +3,7 @@ package data
 import (
 	"database/sql"
 	"fmt"
+	"log"
 
 	"github.com/go-sql-driver/mysql"
 	"golang.org/x/crypto/bcrypt"
@@ -89,24 +90,56 @@ func (db *DB) CheckPassword(id int64, pass string) error {
 }
 
 func (db *DB) ChangePassword(id int64, oldPass, newPass string) error {
-	if err := db.CheckPassword(id, oldPass); err != nil {
-		return fmt.Errorf("error checking password: %v", err)
+	tx, err := db.Begin()
+	if err != nil {
+		return fmt.Errorf("error starting transaction: %v", err)
+	}
+
+	var queriedPass string
+	getQuery := `
+    SELECT password
+    FROM users
+    WHERE id = ?
+    `
+	row := tx.QueryRow(getQuery, id)
+	if err := row.Scan(&queriedPass); err != nil {
+		if rollbackErr := tx.Rollback(); rollbackErr != nil {
+			log.Fatalf("error: transaction error: %v, rollback error: %v", err, rollbackErr)
+		}
+		return fmt.Errorf("error reading password from DB: %v", err)
+	}
+
+	if err := bcrypt.CompareHashAndPassword([]byte(queriedPass), []byte(oldPass)); err != nil {
+		if rollbackErr := tx.Rollback(); rollbackErr != nil {
+			log.Fatalf("error: transaction error: %v, rollback error: %v", err, rollbackErr)
+		}
+		return fmt.Errorf("incorrect password: %v", err)
 	}
 
 	newHashedPass, err := bcrypt.GenerateFromPassword([]byte(newPass), bcrypt.DefaultCost)
 	if err != nil {
+		if rollbackErr := tx.Rollback(); rollbackErr != nil {
+			log.Fatalf("error: transaction error: %v, rollback error: %v", err, rollbackErr)
+		}
 		return fmt.Errorf("error creating password hash: %v", err)
 	}
 
-	query := `
+	setQuery := `
     UPDATE users
     SET password = ?
     WHERE id = ?
     `
-	if _, err = db.Exec(query, string(newHashedPass), id); err != nil {
+	if _, err = tx.Exec(setQuery, string(newHashedPass), id); err != nil {
+		if rollbackErr := tx.Rollback(); rollbackErr != nil {
+			log.Fatalf("error: transaction error: %v, rollback error: %v", err, rollbackErr)
+		}
 		return fmt.Errorf("error updating password in DB: %v", err)
 	}
 
+	if err = tx.Commit(); err != nil {
+		return fmt.Errorf("error committing transaction: %v", err)
+	}
+
 	return nil
 }
 

cmd/data/rss.go

@@ -70,17 +70,17 @@ func LoadChannel(filename string) (*Channel, error) {
 	}
 	defer file.Close()
 
-	channel := initChannel()
-	channel.wg.Add(1)
-	go channel.start()
-	channel.wg.Wait()
-
 	tmpChannel := new(rss.Channel)
 	if err = gob.NewDecoder(file).Decode(tmpChannel); err != nil {
 		return nil, fmt.Errorf("error decoding channel from file %v: %v", filename, err)
 	}
 
+	channel := initChannel()
+	channel.wg.Add(1)
+	go channel.start()
+	channel.wg.Wait()
 	channel.Set(*tmpChannel)
+
 	return channel, nil
 }