Masahiko AMANO a2823337b6 docs(project): add reference Python/Flask implementation
Previous version of Tanabata used as visual and functional reference
for the new Go + SvelteKit rewrite.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-04-03 18:36:05 +03:00

93 lines
2.1 KiB
Go

package postgres
import (
"context"
"errors"
"fmt"
"net/http"
"time"
"github.com/jackc/pgx/v5"
"github.com/jackc/pgx/v5/pgconn"
"github.com/jackc/pgx/v5/pgxpool"
)
type Storage struct {
db *pgxpool.Pool
}
var connPool *pgxpool.Pool
// Initialize new database storage
func New(dbURL string) (*Storage, error) {
ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
defer cancel()
config, err := pgxpool.ParseConfig(dbURL)
if err != nil {
return nil, fmt.Errorf("failed to parse DB URL: %w", err)
}
config.MaxConns = 10
config.MinConns = 2
config.HealthCheckPeriod = time.Minute
db, err := pgxpool.NewWithConfig(ctx, config)
if err != nil {
return nil, fmt.Errorf("failed to connect to database: %w", err)
}
err = db.Ping(ctx)
if err != nil {
return nil, fmt.Errorf("database ping failed: %w", err)
}
return &Storage{db: db}, nil
}
// Close database storage
func (s *Storage) Close() {
s.db.Close()
}
// Run handler inside transaction
func (s *Storage) transaction(ctx context.Context, handler func(context.Context, pgx.Tx) (statusCode int, err error)) (statusCode int, err error) {
tx, err := connPool.Begin(ctx)
if err != nil {
statusCode = http.StatusInternalServerError
return
}
statusCode, err = handler(ctx, tx)
if err != nil {
tx.Rollback(ctx)
return
}
err = tx.Commit(ctx)
if err != nil {
statusCode = http.StatusInternalServerError
}
return
}
// Handle database error
func (s *Storage) handleDBError(errIn error) (statusCode int, err error) {
if errIn == nil {
statusCode = http.StatusOK
return
}
if errors.Is(errIn, pgx.ErrNoRows) {
err = fmt.Errorf("not found")
statusCode = http.StatusNotFound
return
}
var pgErr *pgconn.PgError
if errors.As(errIn, &pgErr) {
switch pgErr.Code {
case "22P02", "22007": // Invalid data format
err = fmt.Errorf("%s", pgErr.Message)
statusCode = http.StatusBadRequest
return
case "23505": // Unique constraint violation
err = fmt.Errorf("already exists")
statusCode = http.StatusConflict
return
}
}
return http.StatusInternalServerError, errIn
}