distribution/storagedriver/ipc/ipc.go
Olivier Gambier da205085f3 Merge pull request #686 from BrianBland/storagedriver-versioning
Adds versioning for out-of-process storage driver
2014-11-07 14:55:13 -08:00

99 lines
2.5 KiB
Go

package ipc
import (
"fmt"
"io"
"reflect"
"github.com/docker/docker-registry/storagedriver"
"github.com/docker/libchan"
)
// IPCStorageDriver is the interface which IPC storage drivers must implement. As external storage
// drivers may be defined to use a different version of the storagedriver.StorageDriver interface,
// we use an additional version check to determine compatiblity.
type IPCStorageDriver interface {
// Version returns the storagedriver.StorageDriver interface version which this storage driver
// implements, which is used to determine driver compatibility
Version() (storagedriver.Version, error)
}
// IncompatibleVersionError is returned when a storage driver is using an incompatible version of
// the storagedriver.StorageDriver api
type IncompatibleVersionError struct {
version storagedriver.Version
}
func (e IncompatibleVersionError) Error() string {
return fmt.Sprintf("Incompatible storage driver version: %s", e.version)
}
// Request defines a remote method call request
// A return value struct is to be sent over the ResponseChannel
type Request struct {
Type string
Parameters map[string]interface{}
ResponseChannel libchan.Sender
}
type responseError struct {
Type string
Message string
}
// ResponseError wraps an error in a serializable struct containing the error's type and message
func ResponseError(err error) *responseError {
if err == nil {
return nil
}
return &responseError{
Type: reflect.TypeOf(err).String(),
Message: err.Error(),
}
}
func (err *responseError) Error() string {
return fmt.Sprintf("%s: %s", err.Type, err.Message)
}
// IPC method call response object definitions
// VersionResponse is a response for a Version request
type VersionResponse struct {
Version storagedriver.Version
Error *responseError
}
// ReadStreamResponse is a response for a ReadStream request
type ReadStreamResponse struct {
Reader io.ReadCloser
Error *responseError
}
// WriteStreamResponse is a response for a WriteStream request
type WriteStreamResponse struct {
Error *responseError
}
// CurrentSizeResponse is a response for a CurrentSize request
type CurrentSizeResponse struct {
Position uint64
Error *responseError
}
// ListResponse is a response for a List request
type ListResponse struct {
Keys []string
Error *responseError
}
// MoveResponse is a response for a Move request
type MoveResponse struct {
Error *responseError
}
// DeleteResponse is a response for a Delete request
type DeleteResponse struct {
Error *responseError
}