115 lines
3.1 KiB
Go
115 lines
3.1 KiB
Go
package backend
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import (
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"fmt"
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"log"
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)
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func (db *DB) WriteArticleAuthors(articleID int64, authorIDs []int64) error {
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query := "INSERT INTO articles_authors (article_id, author_id) VALUES (?, ?)"
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for i := 0; i < TxMaxRetries; i++ {
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err := func() error {
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tx, err := db.Begin()
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if err != nil {
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return fmt.Errorf("error starting transaction: %v", err)
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}
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for _, authorID := range authorIDs {
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if _, err := tx.Exec(query, articleID, authorID); err != nil {
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if rollbackErr := tx.Rollback(); rollbackErr != nil {
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log.Fatalf("transaction error: %v, rollback error: %v", err, rollbackErr)
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}
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return fmt.Errorf("error inserting into articles_authors: %v", err)
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}
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}
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if err = tx.Commit(); err != nil {
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return fmt.Errorf("error committing transaction: %v", err)
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}
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return nil
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}()
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if err == nil {
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return nil
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}
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log.Println(err)
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wait(i)
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}
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return fmt.Errorf("error: %v unsuccessful retries for DB operation, aborting", TxMaxRetries)
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}
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func (db *DB) GetArticleAuthors(c *Config, articleID int64) ([]*User, error) {
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query := `
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SELECT u.id
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FROM articles a
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INNER JOIN articles_authors aa ON a.id = aa.article_id
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INNER JOIN users u ON aa.author_id = u.id
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WHERE a.id = ?
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`
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rows, err := db.Query(query, articleID)
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if err != nil {
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return nil, fmt.Errorf("error querying articles_authors: %v", err)
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}
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authors := make([]*User, 0)
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for rows.Next() {
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var authorID int64
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if err = rows.Scan(&authorID); err != nil {
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return nil, fmt.Errorf("error scanning rows: %v", err)
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}
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author, err := db.GetUser(c, authorID)
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if err != nil {
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return nil, fmt.Errorf("error getting user info for article author: %v", err)
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}
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authors = append(authors, author)
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}
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return authors, nil
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}
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func (db *DB) UpdateArticleAuthors(articleID int64, authorIDs []int64) error {
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deleteQuery := "DELETE FROM articles_authors WHERE article_id = ?"
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insertQuery := "INSERT INTO articles_authors (article_id, author_id) VALUES (?, ?)"
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for i := 0; i < TxMaxRetries; i++ {
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err := func() error {
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tx, err := db.Begin()
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if err != nil {
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return fmt.Errorf("error starting transaction: %v", err)
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}
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if _, err := tx.Exec(deleteQuery, articleID); err != nil {
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if rollbackErr := tx.Rollback(); rollbackErr != nil {
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log.Fatalf("transaction error: %v, rollback error: %v", err, rollbackErr)
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}
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return fmt.Errorf("error deleting entries from articles_authors before inserting new ones: %v", err)
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}
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for _, authorID := range authorIDs {
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if _, err := tx.Exec(insertQuery, articleID, authorID); err != nil {
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if rollbackErr := tx.Rollback(); rollbackErr != nil {
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log.Fatalf("transaction error: %v, rollback error: %v", err, rollbackErr)
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}
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return fmt.Errorf("error inserting new entries into articles_authors: %v", err)
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}
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}
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if err = tx.Commit(); err != nil {
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return fmt.Errorf("error committing transaction: %v", err)
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}
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return nil
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}()
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if err == nil {
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return nil
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}
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log.Println(err)
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wait(i)
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}
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return fmt.Errorf("error: %v unsuccessful retries for DB operation, aborting", TxMaxRetries)
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}
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