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gotosocial/internal/db/bundb/conn.go

90 lines
2.4 KiB
Go

package bundb
import (
"context"
"database/sql"
"github.com/superseriousbusiness/gotosocial/internal/db"
"github.com/uptrace/bun"
"github.com/uptrace/bun/dialect"
)
// DBConn wrapps a bun.DB conn to provide SQL-type specific additional functionality
type DBConn struct {
// TODO: move *Config here, no need to be in each struct type
errProc func(error) db.Error // errProc is the SQL-type specific error processor
*bun.DB // DB is the underlying bun.DB connection
}
// WrapDBConn @TODO
func WrapDBConn(dbConn *bun.DB) *DBConn {
var errProc func(error) db.Error
switch dbConn.Dialect().Name() {
case dialect.PG:
errProc = processPostgresError
case dialect.SQLite:
errProc = processSQLiteError
default:
panic("unknown dialect name: " + dbConn.Dialect().Name().String())
}
return &DBConn{
errProc: errProc,
DB: dbConn,
}
}
// RunInTx wraps execution of the supplied transaction function.
func (conn *DBConn) RunInTx(ctx context.Context, fn func(bun.Tx) error) db.Error {
// Acquire a new transaction
tx, err := conn.BeginTx(ctx, nil)
if err != nil {
return conn.ProcessError(err)
}
// Perform supplied transaction
if err = fn(tx); err != nil {
tx.Rollback() //nolint
return conn.ProcessError(err)
}
// Finally, commit transaction
err = tx.Commit()
return conn.ProcessError(err)
}
// ProcessError processes an error to replace any known values with our own db.Error types,
// making it easier to catch specific situations (e.g. no rows, already exists, etc)
func (conn *DBConn) ProcessError(err error) db.Error {
switch {
case err == nil:
return nil
case err == sql.ErrNoRows:
return db.ErrNoEntries
default:
return conn.errProc(err)
}
}
// Exists checks the results of a SelectQuery for the existence of the data in question, masking ErrNoEntries errors
func (conn *DBConn) Exists(ctx context.Context, query *bun.SelectQuery) (bool, db.Error) {
exists, err := query.Exists(ctx)
// Process error as our own and check if it exists
switch err := conn.ProcessError(err); err {
case nil:
return exists, nil
case db.ErrNoEntries:
return false, nil
default:
return false, err
}
}
// NotExists is the functional opposite of conn.Exists()
func (conn *DBConn) NotExists(ctx context.Context, query *bun.SelectQuery) (bool, db.Error) {
// Simply inverse of conn.exists()
exists, err := conn.Exists(ctx, query)
return !exists, err
}