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