[bugfix] wrap bun.Tx to add our own error processing (#2169)

* wrap bun.Tx to add our own error processing

Signed-off-by: kim <grufwub@gmail.com>

* add compile-time check for updateRowError() compatibility with sql.Row, fix wrapTx() not being used properly

Signed-off-by: kim <grufwub@gmail.com>

---------

Signed-off-by: kim <grufwub@gmail.com>

internal/db/bundb/account.go

@@ -298,7 +298,7 @@ func (a *accountDB) PutAccount(ctx context.Context, account *gtsmodel.Account) e
 		// It is safe to run this database transaction within cache.Store
 		// as the cache does not attempt a mutex lock until AFTER hook.
 		//
-		return a.db.RunInTx(ctx, func(tx bun.Tx) error {
+		return a.db.RunInTx(ctx, func(tx Tx) error {
 			// create links between this account and any emojis it uses
 			for _, i := range account.EmojiIDs {
 				if _, err := tx.NewInsert().Model(&gtsmodel.AccountToEmoji{
@@ -327,7 +327,7 @@ func (a *accountDB) UpdateAccount(ctx context.Context, account *gtsmodel.Account
 		// It is safe to run this database transaction within cache.Store
 		// as the cache does not attempt a mutex lock until AFTER hook.
 		//
-		return a.db.RunInTx(ctx, func(tx bun.Tx) error {
+		return a.db.RunInTx(ctx, func(tx Tx) error {
 			// create links between this account and any emojis it uses
 			// first clear out any old emoji links
 			if _, err := tx.
@@ -375,7 +375,7 @@ func (a *accountDB) DeleteAccount(ctx context.Context, id string) error {
 		return err
 	}
 
-	return a.db.RunInTx(ctx, func(tx bun.Tx) error {
+	return a.db.RunInTx(ctx, func(tx Tx) error {
 		// clear out any emoji links
 		if _, err := tx.
 			NewDelete().

internal/db/bundb/db.go

@@ -21,6 +21,7 @@ import (
 	"context"
 	"database/sql"
 	"time"
+	"unsafe"
 
 	"github.com/superseriousbusiness/gotosocial/internal/db"
 	"github.com/superseriousbusiness/gotosocial/internal/gtserror"
@@ -66,7 +67,7 @@ func WrapDB(db *bun.DB) *DB {
 	return &DB{
 		raw: rawdb{
 			errHook: errProc,
-			DB:      db.DB,
+			db:      db.DB,
 		},
 		bun: db,
 	}
@@ -87,18 +88,7 @@ func (db *DB) PingContext(ctx context.Context) error { return db.bun.PingContext
 // Close is a direct call-through to bun.DB.Close().
 func (db *DB) Close() error { return db.bun.Close() }
 
-// BeginTx wraps bun.DB.BeginTx() with retry-busy timeout.
+// ExecContext wraps bun.DB.ExecContext() with retry-busy timeout and our own error processing.
-func (db *DB) BeginTx(ctx context.Context, opts *sql.TxOptions) (tx bun.Tx, err error) {
-	bundb := db.bun // use *bun.DB interface to return bun.Tx type
-	err = retryOnBusy(ctx, func() error {
-		tx, err = bundb.BeginTx(ctx, opts)
-		err = db.raw.errHook(err)
-		return err
-	})
-	return
-}
-
-// ExecContext wraps bun.DB.ExecContext() with retry-busy timeout.
 func (db *DB) ExecContext(ctx context.Context, query string, args ...any) (result sql.Result, err error) {
 	bundb := db.bun // use underlying *bun.DB interface for their query formatting
 	err = retryOnBusy(ctx, func() error {
@@ -109,7 +99,7 @@ func (db *DB) ExecContext(ctx context.Context, query string, args ...any) (resul
 	return
 }
 
-// QueryContext wraps bun.DB.ExecContext() with retry-busy timeout.
+// QueryContext wraps bun.DB.ExecContext() with retry-busy timeout and our own error processing.
 func (db *DB) QueryContext(ctx context.Context, query string, args ...any) (rows *sql.Rows, err error) {
 	bundb := db.bun // use underlying *bun.DB interface for their query formatting
 	err = retryOnBusy(ctx, func() error {
@@ -120,19 +110,40 @@ func (db *DB) QueryContext(ctx context.Context, query string, args ...any) (rows
 	return
 }
 
-// QueryRowContext wraps bun.DB.ExecContext() with retry-busy timeout.
+// QueryRowContext wraps bun.DB.ExecContext() with retry-busy timeout and our own error processing.
 func (db *DB) QueryRowContext(ctx context.Context, query string, args ...any) (row *sql.Row) {
 	bundb := db.bun // use underlying *bun.DB interface for their query formatting
 	_ = retryOnBusy(ctx, func() error {
 		row = bundb.QueryRowContext(ctx, query, args...)
-		err := db.raw.errHook(row.Err())
+		if err := db.raw.errHook(row.Err()); err != nil {
-		return err
+			updateRowError(row, err) // set new error
+		}
+		return row.Err()
 	})
 	return
 }
 
+// BeginTx wraps bun.DB.BeginTx() with retry-busy timeout and our own error processing.
+func (db *DB) BeginTx(ctx context.Context, opts *sql.TxOptions) (tx Tx, err error) {
+	var buntx bun.Tx // captured bun.Tx
+	bundb := db.bun  // use *bun.DB interface to return bun.Tx type
+
+	err = retryOnBusy(ctx, func() error {
+		buntx, err = bundb.BeginTx(ctx, opts)
+		err = db.raw.errHook(err)
+		return err
+	})
+
+	if err == nil {
+		// Wrap bun.Tx in our type.
+		tx = wrapTx(db, &buntx)
+	}
+
+	return
+}
+
 // RunInTx is functionally the same as bun.DB.RunInTx() but with retry-busy timeouts.
-func (db *DB) RunInTx(ctx context.Context, fn func(bun.Tx) error) error {
+func (db *DB) RunInTx(ctx context.Context, fn func(Tx) error) error {
 	// Attempt to start new transaction.
 	tx, err := db.BeginTx(ctx, nil)
 	if err != nil {
@@ -143,24 +154,18 @@ func (db *DB) RunInTx(ctx context.Context, fn func(bun.Tx) error) error {
 
 	defer func() {
 		if !done {
-			// Rollback (with retry-backoff).
+			// Rollback tx.
-			_ = retryOnBusy(ctx, func() error {
+			_ = tx.Rollback()
-				err := tx.Rollback()
-				return db.raw.errHook(err)
-			})
 		}
 	}()
 
 	// Perform supplied transaction
 	if err := fn(tx); err != nil {
-		return db.raw.errHook(err)
+		return err
 	}
 
-	// Commit (with retry-backoff).
+	// Commit tx.
-	err = retryOnBusy(ctx, func() error {
+	err = tx.Commit()
-		err := tx.Commit()
-		return db.raw.errHook(err)
-	})
 	done = true
 	return err
 }
@@ -275,39 +280,258 @@ type rawdb struct {
 
 	// embedded raw
 	// db interface
-	*sql.DB
+	db *sql.DB
 }
 
-// ExecContext wraps sql.DB.ExecContext() with retry-busy timeout.
+// ExecContext wraps sql.DB.ExecContext() with retry-busy timeout and our own error processing.
 func (db *rawdb) ExecContext(ctx context.Context, query string, args ...any) (result sql.Result, err error) {
 	err = retryOnBusy(ctx, func() error {
-		result, err = db.DB.ExecContext(ctx, query, args...)
+		result, err = db.db.ExecContext(ctx, query, args...)
 		err = db.errHook(err)
 		return err
 	})
 	return
 }
 
-// QueryContext wraps sql.DB.QueryContext() with retry-busy timeout.
+// QueryContext wraps sql.DB.QueryContext() with retry-busy timeout and our own error processing.
 func (db *rawdb) QueryContext(ctx context.Context, query string, args ...any) (rows *sql.Rows, err error) {
 	err = retryOnBusy(ctx, func() error {
-		rows, err = db.DB.QueryContext(ctx, query, args...)
+		rows, err = db.db.QueryContext(ctx, query, args...)
 		err = db.errHook(err)
 		return err
 	})
 	return
 }
 
-// QueryRowContext wraps sql.DB.QueryRowContext() with retry-busy timeout.
+// QueryRowContext wraps sql.DB.QueryRowContext() with retry-busy timeout and our own error processing.
 func (db *rawdb) QueryRowContext(ctx context.Context, query string, args ...any) (row *sql.Row) {
 	_ = retryOnBusy(ctx, func() error {
-		row = db.DB.QueryRowContext(ctx, query, args...)
+		row = db.db.QueryRowContext(ctx, query, args...)
 		err := db.errHook(row.Err())
 		return err
 	})
 	return
 }
 
+// Tx wraps a bun transaction instance
+// to provide common per-dialect SQL error
+// conversions to common types, and retries
+// on busy commit/rollback (SQLite only).
+type Tx struct {
+	// our own wrapped Tx type
+	// kept separate to the *bun.Tx
+	// type to be passed into query
+	// builders as bun.IConn iface
+	// (this prevents double firing
+	// bun query hooks).
+	//
+	// also holds per-dialect
+	// error hook function.
+	raw rawtx
+
+	// bun Tx interface we use
+	// for dialects, and improved
+	// struct marshal/unmarshaling.
+	bun *bun.Tx
+}
+
+// wrapTx wraps a given bun.Tx in our own wrapping Tx type.
+func wrapTx(db *DB, tx *bun.Tx) Tx {
+	return Tx{
+		raw: rawtx{
+			errHook: db.raw.errHook,
+			tx:      tx.Tx,
+		},
+		bun: tx,
+	}
+}
+
+// ExecContext wraps bun.Tx.ExecContext() with our own error processing, WITHOUT retry-busy timeouts (as will be mid-transaction).
+func (tx Tx) ExecContext(ctx context.Context, query string, args ...interface{}) (sql.Result, error) {
+	buntx := tx.bun // use underlying *bun.Tx interface for their query formatting
+	res, err := buntx.ExecContext(ctx, query, args...)
+	err = tx.raw.errHook(err)
+	return res, err
+}
+
+// QueryContext wraps bun.Tx.QueryContext() with our own error processing, WITHOUT retry-busy timeouts (as will be mid-transaction).
+func (tx Tx) QueryContext(ctx context.Context, query string, args ...interface{}) (*sql.Rows, error) {
+	buntx := tx.bun // use underlying *bun.Tx interface for their query formatting
+	rows, err := buntx.QueryContext(ctx, query, args...)
+	err = tx.raw.errHook(err)
+	return rows, err
+}
+
+// QueryRowContext wraps bun.Tx.QueryRowContext() with our own error processing, WITHOUT retry-busy timeouts (as will be mid-transaction).
+func (tx Tx) QueryRowContext(ctx context.Context, query string, args ...interface{}) *sql.Row {
+	buntx := tx.bun // use underlying *bun.Tx interface for their query formatting
+	row := buntx.QueryRowContext(ctx, query, args...)
+	if err := tx.raw.errHook(row.Err()); err != nil {
+		updateRowError(row, err) // set new error
+	}
+	return row
+}
+
+// Commit wraps bun.Tx.Commit() with retry-busy timeout and our own error processing.
+func (tx Tx) Commit() (err error) {
+	buntx := tx.bun // use *bun.Tx interface
+	err = retryOnBusy(context.TODO(), func() error {
+		err = buntx.Commit()
+		err = tx.raw.errHook(err)
+		return err
+	})
+	return
+}
+
+// Rollback wraps bun.Tx.Rollback() with retry-busy timeout and our own error processing.
+func (tx Tx) Rollback() (err error) {
+	buntx := tx.bun // use *bun.Tx interface
+	err = retryOnBusy(context.TODO(), func() error {
+		err = buntx.Rollback()
+		err = tx.raw.errHook(err)
+		return err
+	})
+	return
+}
+
+// Dialect is a direct call-through to bun.DB.Dialect().
+func (tx Tx) Dialect() schema.Dialect {
+	return tx.bun.Dialect()
+}
+
+func (tx Tx) NewValues(model interface{}) *bun.ValuesQuery {
+	// note: passing in rawtx as conn iface so no double query-hook
+	// firing when passed through the bun.Tx.Query___() functions.
+	return tx.bun.NewValues(model).Conn(&tx.raw)
+}
+
+func (tx Tx) NewMerge() *bun.MergeQuery {
+	// note: passing in rawtx as conn iface so no double query-hook
+	// firing when passed through the bun.Tx.Query___() functions.
+	return tx.bun.NewMerge().Conn(&tx.raw)
+}
+
+func (tx Tx) NewSelect() *bun.SelectQuery {
+	// note: passing in rawtx as conn iface so no double query-hook
+	// firing when passed through the bun.Tx.Query___() functions.
+	return tx.bun.NewSelect().Conn(&tx.raw)
+}
+
+func (tx Tx) NewInsert() *bun.InsertQuery {
+	// note: passing in rawtx as conn iface so no double query-hook
+	// firing when passed through the bun.Tx.Query___() functions.
+	return tx.bun.NewInsert().Conn(&tx.raw)
+}
+
+func (tx Tx) NewUpdate() *bun.UpdateQuery {
+	// note: passing in rawtx as conn iface so no double query-hook
+	// firing when passed through the bun.Tx.Query___() functions.
+	return tx.bun.NewUpdate().Conn(&tx.raw)
+}
+
+func (tx Tx) NewDelete() *bun.DeleteQuery {
+	// note: passing in rawtx as conn iface so no double query-hook
+	// firing when passed through the bun.Tx.Query___() functions.
+	return tx.bun.NewDelete().Conn(&tx.raw)
+}
+
+func (tx Tx) NewRaw(query string, args ...interface{}) *bun.RawQuery {
+	// note: passing in rawtx as conn iface so no double query-hook
+	// firing when passed through the bun.Tx.Query___() functions.
+	return tx.bun.NewRaw(query, args...).Conn(&tx.raw)
+}
+
+func (tx Tx) NewCreateTable() *bun.CreateTableQuery {
+	// note: passing in rawtx as conn iface so no double query-hook
+	// firing when passed through the bun.Tx.Query___() functions.
+	return tx.bun.NewCreateTable().Conn(&tx.raw)
+}
+
+func (tx Tx) NewDropTable() *bun.DropTableQuery {
+	// note: passing in rawtx as conn iface so no double query-hook
+	// firing when passed through the bun.Tx.Query___() functions.
+	return tx.bun.NewDropTable().Conn(&tx.raw)
+}
+
+func (tx Tx) NewCreateIndex() *bun.CreateIndexQuery {
+	// note: passing in rawtx as conn iface so no double query-hook
+	// firing when passed through the bun.Tx.Query___() functions.
+	return tx.bun.NewCreateIndex().Conn(&tx.raw)
+}
+
+func (tx Tx) NewDropIndex() *bun.DropIndexQuery {
+	// note: passing in rawtx as conn iface so no double query-hook
+	// firing when passed through the bun.Tx.Query___() functions.
+	return tx.bun.NewDropIndex().Conn(&tx.raw)
+}
+
+func (tx Tx) NewTruncateTable() *bun.TruncateTableQuery {
+	// note: passing in rawtx as conn iface so no double query-hook
+	// firing when passed through the bun.Tx.Query___() functions.
+	return tx.bun.NewTruncateTable().Conn(&tx.raw)
+}
+
+func (tx Tx) NewAddColumn() *bun.AddColumnQuery {
+	// note: passing in rawtx as conn iface so no double query-hook
+	// firing when passed through the bun.Tx.Query___() functions.
+	return tx.bun.NewAddColumn().Conn(&tx.raw)
+}
+
+func (tx Tx) NewDropColumn() *bun.DropColumnQuery {
+	// note: passing in rawtx as conn iface so no double query-hook
+	// firing when passed through the bun.Tx.Query___() functions.
+	return tx.bun.NewDropColumn().Conn(&tx.raw)
+}
+
+type rawtx struct {
+	// dialect specific error
+	// processing function hook.
+	errHook func(error) error
+
+	// embedded raw
+	// tx interface
+	tx *sql.Tx
+}
+
+// ExecContext wraps sql.Tx.ExecContext() with our own error processing, WITHOUT retry-busy timeouts (as will be mid-transaction).
+func (tx *rawtx) ExecContext(ctx context.Context, query string, args ...interface{}) (sql.Result, error) {
+	res, err := tx.tx.ExecContext(ctx, query, args...)
+	err = tx.errHook(err)
+	return res, err
+}
+
+// QueryContext wraps sql.Tx.QueryContext() with our own error processing, WITHOUT retry-busy timeouts (as will be mid-transaction).
+func (tx *rawtx) QueryContext(ctx context.Context, query string, args ...interface{}) (*sql.Rows, error) {
+	rows, err := tx.tx.QueryContext(ctx, query, args...)
+	err = tx.errHook(err)
+	return rows, err
+}
+
+// QueryRowContext wraps sql.Tx.QueryRowContext() with our own error processing, WITHOUT retry-busy timeouts (as will be mid-transaction).
+func (tx *rawtx) QueryRowContext(ctx context.Context, query string, args ...interface{}) *sql.Row {
+	row := tx.tx.QueryRowContext(ctx, query, args...)
+	if err := tx.errHook(row.Err()); err != nil {
+		updateRowError(row, err) // set new error
+	}
+	return row
+}
+
+// updateRowError updates an sql.Row's internal error field using the unsafe package.
+func updateRowError(sqlrow *sql.Row, err error) {
+	type row struct {
+		err  error
+		rows *sql.Rows
+	}
+
+	// compile-time check to ensure sql.Row not changed.
+	if unsafe.Sizeof(row{}) != unsafe.Sizeof(sql.Row{}) {
+		panic("sql.Row has changed definition")
+	}
+
+	// this code is awful and i must be shamed for this.
+	(*row)(unsafe.Pointer(sqlrow)).err = err
+}
+
 // retryOnBusy will retry given function on returned 'errBusy'.
 func retryOnBusy(ctx context.Context, fn func() error) error {
 	var backoff time.Duration

internal/db/bundb/emoji.go

@@ -105,7 +105,7 @@ func (e *emojiDB) DeleteEmojiByID(ctx context.Context, id string) error {
 		return err
 	}
 
-	return e.db.RunInTx(ctx, func(tx bun.Tx) error {
+	return e.db.RunInTx(ctx, func(tx Tx) error {
 		// Delete relational links between this emoji
 		// and any statuses using it, returning the
 		// status IDs so we can later update them.

internal/db/bundb/list.go

@@ -206,7 +206,7 @@ func (l *listDB) DeleteListByID(ctx context.Context, id string) error {
 		}
 	}()
 
-	return l.db.RunInTx(ctx, func(tx bun.Tx) error {
+	return l.db.RunInTx(ctx, func(tx Tx) error {
 		// Delete all entries attached to list.
 		if _, err := tx.NewDelete().
 			Table("list_entries").
@@ -423,7 +423,7 @@ func (l *listDB) PutListEntries(ctx context.Context, entries []*gtsmodel.ListEnt
 	}()
 
 	// Finally, insert each list entry into the database.
-	return l.db.RunInTx(ctx, func(tx bun.Tx) error {
+	return l.db.RunInTx(ctx, func(tx Tx) error {
 		for _, entry := range entries {
 			entry := entry // rescope
 			if err := l.state.Caches.GTS.ListEntry().Store(entry, func() error {

internal/db/bundb/marker.go

@@ -87,7 +87,7 @@ func (m *markerDB) UpdateMarker(ctx context.Context, marker *gtsmodel.Marker) er
 		// Optimistic concurrency control: start a transaction, try to update a row with a previously retrieved version.
 		// If the update in the transaction fails to actually change anything, another update happened concurrently, and
 		// this update should be retried by the caller, which in this case involves sending HTTP 409 to the API client.
-		return m.db.RunInTx(ctx, func(tx bun.Tx) error {
+		return m.db.RunInTx(ctx, func(tx Tx) error {
 			result, err := tx.NewUpdate().
 				Model(marker).
 				WherePK().

internal/db/bundb/media.go

@@ -122,7 +122,7 @@ func (m *mediaDB) DeleteAttachment(ctx context.Context, id string) error {
 	defer m.state.Caches.GTS.Media().Invalidate("ID", id)
 
 	// Delete media attachment in new transaction.
-	err = m.db.RunInTx(ctx, func(tx bun.Tx) error {
+	err = m.db.RunInTx(ctx, func(tx Tx) error {
 		if media.AccountID != "" {
 			var account gtsmodel.Account
 

internal/db/bundb/status.go

@@ -276,7 +276,7 @@ func (s *statusDB) PutStatus(ctx context.Context, status *gtsmodel.Status) error
 		// It is safe to run this database transaction within cache.Store
 		// as the cache does not attempt a mutex lock until AFTER hook.
 		//
-		return s.db.RunInTx(ctx, func(tx bun.Tx) error {
+		return s.db.RunInTx(ctx, func(tx Tx) error {
 			// create links between this status and any emojis it uses
 			for _, i := range status.EmojiIDs {
 				if _, err := tx.
@@ -342,7 +342,7 @@ func (s *statusDB) UpdateStatus(ctx context.Context, status *gtsmodel.Status, co
 		// It is safe to run this database transaction within cache.Store
 		// as the cache does not attempt a mutex lock until AFTER hook.
 		//
-		return s.db.RunInTx(ctx, func(tx bun.Tx) error {
+		return s.db.RunInTx(ctx, func(tx Tx) error {
 			// create links between this status and any emojis it uses
 			for _, i := range status.EmojiIDs {
 				if _, err := tx.
@@ -420,7 +420,7 @@ func (s *statusDB) DeleteStatusByID(ctx context.Context, id string) error {
 	// On return ensure status invalidated from cache.
 	defer s.state.Caches.GTS.Status().Invalidate("ID", id)
 
-	return s.db.RunInTx(ctx, func(tx bun.Tx) error {
+	return s.db.RunInTx(ctx, func(tx Tx) error {
 		// delete links between this status and any emojis it uses
 		if _, err := tx.
 			NewDelete().