Files
outbox/outbox.go
Dmitry Fedotov 73f9ba3c59 init
2025-05-03 20:27:04 +03:00

104 lines
2.2 KiB
Go

package outbox
import (
"context"
"database/sql"
"encoding/json"
"errors"
"time"
)
var (
ErrMarshal = errors.New("error marshaling value")
ErrInsert = errors.New("error inserting value")
ErrSelectPending = errors.New("error selecting pending objects")
ErrUpdate = errors.New("error updating object")
ErrCleanup = errors.New("error deleting processed items")
)
type Box[T any] interface {
Save(ctx context.Context, id string, v *T) error
MarkProcessed(ctx context.Context, id string) error
GetPending(ctx context.Context, n int) ([]*T, error)
}
func OpenOrCreate[T any](ctx context.Context, db *sql.DB) (*Outbox[T], error) {
if err := initDB(ctx, db); err != nil {
return nil, err
}
return &Outbox[T]{
db: db,
}, nil
}
type Outbox[T any] struct {
db *sql.DB
}
func (o *Outbox[T]) Save(ctx context.Context, id string, v *T) error {
now := time.Now()
b, err := json.Marshal(v)
if err != nil {
return errors.Join(ErrMarshal, err)
}
stmt := "INSERT INTO outbox (id, created_at, is_processed, payload) VALUES ($1, $2, $3, $4)"
if _, err := o.db.ExecContext(ctx, stmt, id, now, false, b); err != nil {
return errors.Join(ErrInsert, err)
}
return nil
}
func (o *Outbox[T]) MarkProcessed(ctx context.Context, id string) error {
stmt := "UPDATE outbox SET is_processed = true WHERE id = $1"
if _, err := o.db.ExecContext(ctx, stmt, id); err != nil {
return errors.Join(ErrUpdate, err)
}
return nil
}
func (o *Outbox[T]) GetPending(ctx context.Context, n int) ([]*T, error) {
stmt := "SELECT payload FROM outbox WHERE is_processed = false order by created_at desc limit $1"
rows, err := o.db.QueryContext(ctx, stmt, n)
if err != nil {
return nil, errors.Join(ErrSelectPending, err)
}
defer rows.Close()
out := make([]*T, 0)
for rows.Next() {
b := []byte{}
if err := rows.Scan(&b); err != nil {
return nil, err
}
v := new(T)
if err := json.Unmarshal(b, v); err != nil {
return nil, err
}
out = append(out, v)
}
return out, nil
}
func (o *Outbox[T]) Cleanup(ctx context.Context) error {
stmt := "DELETE FROM outbox WHERE is_processed = true"
if _, err := o.db.ExecContext(ctx, stmt); err != nil {
return errors.Join(ErrCleanup, err)
}
return nil
}