storage/storage.go

package storage

import (
	"github.com/hashicorp/vault/api"
	"github.com/nats-io/nats.go"

	"code.uint32.ru/tiny/storage/internal/errinternal"
	"code.uint32.ru/tiny/storage/internal/filesystem"
	"code.uint32.ru/tiny/storage/internal/natsobj"
	"code.uint32.ru/tiny/storage/internal/vault"
)

var (
	// ErrInvalidKey is returned when key validation
	// for particular implementation of Storage fails.
	ErrInvalidKey = errinternal.ErrInvalidKey
	// ErrNotFound is returned when object is not found
	// in Storage.
	ErrNotFound = errinternal.ErrNotFound
)

var (
	_ Storage = (*natsobj.Storage)(nil)
	_ Storage = (*filesystem.Storage)(nil)
	_ Storage = (*vault.Storage)(nil)
)

// Storage is a very basic object store.
type Storage interface {
	// Save puts object with name 'key' into the store.
	// If a key already exists it gets overwritten.
	Save(key string, data []byte) error
	// Load returns contents of object named 'key' or
	// ErrNotFound.
	Load(key string) ([]byte, error)
	// Delete removes object named 'key' from the store.
	// If key does not exist Delete returns nil.
	Delete(key string) error
}

// NewNats wraps the provided ObjectStore with Storage interface.
func NewNats(store nats.ObjectStore) Storage {
	return natsobj.New(store)
}

// NewFS established a key/value within the directory 'path'
// and uses it as underlying physical store.
// Note that the implementation requires keys to be at least
// 3 characters long.
// Key "abcd" will be stored in /path/a/b/abcd.
func NewFS(path string) (Storage, error) {
	return filesystem.New(path)
}

// NewVault uses provided Vault client to store objects.
// All objects are stored as a single secret, a JSON object
// where key are keys and values are base64 encoded bytes of
// saved object.
// If secret specified by path does not exist it will be created
// on first call to Storage methods.
// Note that a secret in vault gets updated (a new version of secret is created)
// on every save/delete operation.
func NewVault(client *api.Client, path string) Storage {
	return vault.New(client, path)
}