piotrkowalczuk/mnemosyne

package storage

import (
    "errors"
    "time"

    "context"

    "github.com/piotrkowalczuk/mnemosyne/mnemosynerpc"
    "github.com/prometheus/client_golang/prometheus"
)

const (
    // DefaultTTL is session time to live default value.
    DefaultTTL = 24 * time.Minute
    // DefaultTTC is time to clear default value.
    DefaultTTC = 1 * time.Minute
)

var (
    ErrSessionNotFound    = errors.New("storage: session not found")
    ErrMissingAccessToken = errors.New("storage: missing access token")
    ErrMissingSubjectID   = errors.New("storage: missing subject accessToken")
    ErrMissingSession     = errors.New("storage: missing session")
)

const (
    // EngineInMemory is not implemented yet.
    EngineInMemory = "in_memory"
    // EnginePostgres keeps session within postgres database.
    EnginePostgres = "postgres"
    // EngineRedis is not implemented yet.
    EngineRedis = "redis"
)

// Storage combines API that needs to be implemented by any storage to be replaceable.
type Storage interface {
    Setup() error
    TearDown() error
    Start(context.Context, string, string, string, string, map[string]string) (*mnemosynerpc.Session, error)
    Abandon(context.Context, string) (bool, error)
    Get(context.Context, string) (*mnemosynerpc.Session, error)
    List(context.Context, int64, int64, *time.Time, *time.Time) ([]*mnemosynerpc.Session, error)
    Exists(context.Context, string) (bool, error)
    Delete(context.Context, string, string, string, *time.Time, *time.Time) (int64, error)
    SetValue(context.Context, string, string, string) (map[string]string, error)
}

// InstrumentedStorage combines Storage and prometheus Collector interface.
type InstrumentedStorage interface {
    Storage
    prometheus.Collector
}

func Init(s Storage, isTest bool) (Storage, error) {
    if isTest {
        if err := s.TearDown(); err != nil {
            return nil, err
        }
    }
    if err := s.Setup(); err != nil {
        return nil, err
    }

    return s, nil
}