distribution/docs/storage/driver/factory/factory.go
Stephen J Day 6167220cdd Remove half-baked Storage Driver IPC support
This removes documentation and code related to IPC based storage driver
plugins. The existence of this functionality was an original feature goal but
is now not maintained and actively confusing incoming contributions. We will
likely explore some driver plugin mechanism in the future but we don't need
this laying around in the meantime.

Signed-off-by: Stephen J Day <stephen.day@docker.com>
2015-06-29 16:52:12 -07:00

56 lines
2.0 KiB
Go

package factory
import (
"fmt"
storagedriver "github.com/docker/distribution/registry/storage/driver"
)
// driverFactories stores an internal mapping between storage driver names and their respective
// factories
var driverFactories = make(map[string]StorageDriverFactory)
// StorageDriverFactory is a factory interface for creating storagedriver.StorageDriver interfaces
// Storage drivers should call Register() with a factory to make the driver available by name
type StorageDriverFactory interface {
// Create returns a new storagedriver.StorageDriver with the given parameters
// Parameters will vary by driver and may be ignored
// Each parameter key must only consist of lowercase letters and numbers
Create(parameters map[string]interface{}) (storagedriver.StorageDriver, error)
}
// Register makes a storage driver available by the provided name.
// If Register is called twice with the same name or if driver factory is nil, it panics.
func Register(name string, factory StorageDriverFactory) {
if factory == nil {
panic("Must not provide nil StorageDriverFactory")
}
_, registered := driverFactories[name]
if registered {
panic(fmt.Sprintf("StorageDriverFactory named %s already registered", name))
}
driverFactories[name] = factory
}
// Create a new storagedriver.StorageDriver with the given name and
// parameters. To use a driver, the StorageDriverFactory must first be
// registered with the given name. If no drivers are found, an
// InvalidStorageDriverError is returned
func Create(name string, parameters map[string]interface{}) (storagedriver.StorageDriver, error) {
driverFactory, ok := driverFactories[name]
if !ok {
return nil, InvalidStorageDriverError{name}
}
return driverFactory.Create(parameters)
}
// InvalidStorageDriverError records an attempt to construct an unregistered storage driver
type InvalidStorageDriverError struct {
Name string
}
func (err InvalidStorageDriverError) Error() string {
return fmt.Sprintf("StorageDriver not registered: %s", err.Name)
}