librarian

README

Librarian

Generates in-memory, type-safe, thread-safe index of data stored from an arbitrary backend, keeping in memory only required meta-data (indexed fields).

Go generate capable. Go modules capable.

Install

go get -u -v github.com/reddec/librarian/cmd/...

Usage

librarian -out some/storage.go some/package/types.go

Configuration

For base type, exported field in struct use: index:"[NAME][,unique]":

• NAME - index name (also getter name). If not defined - field name prefixed by By will be used.
• unique - mark index as unique, by default index is not unique.

Example

For file

types.go

type User struct {
    Name string `index:",unique"`
    Role string `index:""`
    Year int
}

will generate (implementation omitted)

generated.go

// constructors

// NewUserStorage
// NewUserStorageJSON
// NewUserStorageFilesJSON

// storage
type UserStorage struct {}
func (*UserStorage) Synchronize(context.Context) error {}
func (*UserStorage) Add(ctx context.Context, user User) error {}
func (*UserStorage) ByName(ctx context.Context, name string) (User, error) {}
func (*UserStorage) ByRole(ctx context.Context, role string) ([]User, error) {}
func (*UserStorage) RemoveByName(ctx context.Context, name string) error {}
func (*UserStorage) RemoveByRole(ctx context.Context, role string) error {}
func (*UserStorage) UpdateByName(ctx context.Context, user User) error {}
func (*UserStorage) UpsertByName(ctx context.Context, user User) error {}

checkout examples

Basic usage in code:

func main() {
    directory := "."
    ctx := context.Background()
    store := NewUserStorageFilesJSON(directory)
    if err := store.Synchronize(ctx); err != nil { // synchronize internal state
        panic(err)
    }
    // store.ByName
    // store.Add
    // store.UpdateByName
    // ...
}

Documentation

Index

• type Storage
  • func Directory(dir string) Storage

Types

type Storage

type Storage interface {
	// Get data by ID.
	Get(ctx context.Context, id string) ([]byte, error)
	// Iterate over all items.
	Iterate(ctx context.Context, iterator func(id string, data []byte) error) error
	// Delete item by id.
	Delete(ctx context.Context, id string) error
	// Update or replace item by id.
	Update(ctx context.Context, id string, data []byte) error
	// Create record and issue id.
	Create(ctx context.Context, data []byte) (string, error)
}

Storage for indexed data.

func Directory

func Directory(dir string) Storage

Directory based storage, where ID is generated by UUIDv4 algorithm.