58 lines
2.0 KiB
Go
58 lines
2.0 KiB
Go
|
// Package postgres provides a pgx-backed PostgreSQL client with lifecycle management,
|
||
|
|
// health checks, and unit-of-work transaction support for Einherjar applications.
|
||
|
|
//
|
||
|
|
// # Overview
|
||
|
|
//
|
||
|
|
// [New] returns a [Component] that manages a [pgxpool.Pool] connection pool,
|
||
|
|
// satisfies the [lifecycle.Component] lifecycle hooks (OnInit, OnStart, OnStop),
|
||
|
|
// and implements [observability.Checkable] with critical priority.
|
||
|
|
//
|
||
|
|
// [NewUnitOfWork] wraps multiple repository operations in a single transaction
|
||
|
|
// via context injection — no transaction object is passed between functions.
|
||
|
|
//
|
||
|
|
// # Lifecycle Registration
|
||
|
|
//
|
||
|
|
// db := postgres.New(logger, cfg)
|
||
|
|
// launcher.Register(db)
|
||
|
|
// health.Register(db)
|
||
|
|
//
|
||
|
|
// # Querying
|
||
|
|
//
|
||
|
|
// Repository code receives a [Provider] or [Executor] and calls [Provider.GetExecutor]
|
||
|
|
// to obtain the active transaction (if inside a [UnitOfWork]) or the pool:
|
||
|
|
//
|
||
|
|
// exec := db.GetExecutor(ctx)
|
||
|
|
// row := exec.QueryRow(ctx, "SELECT id FROM users WHERE email = $1", email)
|
||
|
|
// if err := row.Scan(&id); err != nil {
|
||
|
|
// return db.HandleError(err) // maps pgx.ErrNoRows → ErrNotFound, etc.
|
||
|
|
// }
|
||
|
|
//
|
||
|
|
// # Unit of Work
|
||
|
|
//
|
||
|
|
// [NewUnitOfWork] wraps operations in a single transaction. The transaction is
|
||
|
|
// injected into the context; [Provider.GetExecutor] returns it automatically.
|
||
|
|
//
|
||
|
|
// uow := postgres.NewUnitOfWork(logger, db)
|
||
|
|
// err := uow.Do(ctx, func(ctx context.Context) error {
|
||
|
|
// exec := db.GetExecutor(ctx) // returns active Tx
|
||
|
|
// _, err := exec.Exec(ctx, "INSERT INTO orders ...")
|
||
|
|
// return err
|
||
|
|
// })
|
||
|
|
//
|
||
|
|
// # Error Handling
|
||
|
|
//
|
||
|
|
// [HandleError] translates pgx and PostgreSQL error codes into typed
|
||
|
|
// [xerrors] values. Call it at every point where a pgx error is first observed:
|
||
|
|
//
|
||
|
|
// if err := row.Scan(&out); err != nil {
|
||
|
|
// return db.HandleError(err)
|
||
|
|
// }
|
||
|
|
//
|
||
|
|
// Mapped codes:
|
||
|
|
// - UniqueViolation → ErrAlreadyExists
|
||
|
|
// - ForeignKeyViolation → ErrInvalidInput
|
||
|
|
// - CheckViolation → ErrInvalidInput
|
||
|
|
// - pgx.ErrNoRows → ErrNotFound
|
||
|
|
// - all others → ErrInternal
|
||
|
|
package postgres
|