api/services/loaders/loaders.go

package loaders

import (
	"context"
	"git.aiterp.net/rpdata/api/models"
	"git.aiterp.net/rpdata/api/repositories"
	"time"
)

//go:generate go run github.com/vektah/dataloaden CharacterLoader string *git.aiterp.net/rpdata/api/models.Character

// CharacterLoaderFromRepository creates a new CharacterLoader
func CharacterLoaderFromRepository(repo repositories.CharacterRepository) *CharacterLoader {
	return &CharacterLoader{
		wait:     time.Millisecond * 1,
		maxBatch: 100,
		fetch: func(keys []string) ([]*models.Character, []error) {
			timeout, cancel := context.WithTimeout(context.Background(), time.Second*15)
			defer cancel()

			characters, err := repo.List(timeout, models.CharacterFilter{
				IDs: keys,
			})
			if err != nil {
				errs := make([]error, len(keys))
				for i := range errs {
					errs[i] = err
				}

				return nil, errs
			}

			charMap := make(map[string]*models.Character, len(keys))

			for _, character := range characters {
				charMap[character.ID] = character
			}

			results := make([]*models.Character, len(keys))
			errs := make([]error, len(keys))

			for i, key := range keys {
				if character, ok := charMap[key]; ok {
					results[i] = character
				} else {
					errs[i] = repositories.ErrNotFound
				}
			}

			return results, errs
		},
	}
}