100 lines
3.9 KiB
Go
100 lines
3.9 KiB
Go
// Copyright 2015 The go-ethereum Authors
|
|
// This file is part of the go-ethereum library.
|
|
//
|
|
// The go-ethereum library is free software: you can redistribute it and/or modify
|
|
// it under the terms of the GNU Lesser General Public License as published by
|
|
// the Free Software Foundation, either version 3 of the License, or
|
|
// (at your option) any later version.
|
|
//
|
|
// The go-ethereum library is distributed in the hope that it will be useful,
|
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
// GNU Lesser General Public License for more details.
|
|
//
|
|
// You should have received a copy of the GNU Lesser General Public License
|
|
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
package node
|
|
|
|
import (
|
|
"reflect"
|
|
|
|
"github.com/ethereum/go-ethereum/accounts"
|
|
"github.com/ethereum/go-ethereum/core/rawdb"
|
|
"github.com/ethereum/go-ethereum/ethdb"
|
|
"github.com/ethereum/go-ethereum/event"
|
|
"github.com/ethereum/go-ethereum/p2p"
|
|
"github.com/ethereum/go-ethereum/rpc"
|
|
)
|
|
|
|
// ServiceContext is a collection of service independent options inherited from
|
|
// the protocol stack, that is passed to all constructors to be optionally used;
|
|
// as well as utility methods to operate on the service environment.
|
|
type ServiceContext struct {
|
|
config *Config
|
|
services map[reflect.Type]Service // Index of the already constructed services
|
|
EventMux *event.TypeMux // Event multiplexer used for decoupled notifications
|
|
AccountManager *accounts.Manager // Account manager created by the node.
|
|
}
|
|
|
|
// OpenDatabase opens an existing database with the given name (or creates one
|
|
// if no previous can be found) from within the node's data directory. If the
|
|
// node is an ephemeral one, a memory database is returned.
|
|
func (ctx *ServiceContext) OpenDatabase(name string, cache int, handles int, namespace string) (ethdb.Database, error) {
|
|
if ctx.config.DataDir == "" {
|
|
return rawdb.NewMemoryDatabase(), nil
|
|
}
|
|
db, err := rawdb.NewLevelDBDatabase(ctx.config.ResolvePath(name), cache, handles, namespace)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
return db, nil
|
|
}
|
|
|
|
// ResolvePath resolves a user path into the data directory if that was relative
|
|
// and if the user actually uses persistent storage. It will return an empty string
|
|
// for emphemeral storage and the user's own input for absolute paths.
|
|
func (ctx *ServiceContext) ResolvePath(path string) string {
|
|
return ctx.config.ResolvePath(path)
|
|
}
|
|
|
|
// Service retrieves a currently running service registered of a specific type.
|
|
func (ctx *ServiceContext) Service(service interface{}) error {
|
|
element := reflect.ValueOf(service).Elem()
|
|
if running, ok := ctx.services[element.Type()]; ok {
|
|
element.Set(reflect.ValueOf(running))
|
|
return nil
|
|
}
|
|
return ErrServiceUnknown
|
|
}
|
|
|
|
// ServiceConstructor is the function signature of the constructors needed to be
|
|
// registered for service instantiation.
|
|
type ServiceConstructor func(ctx *ServiceContext) (Service, error)
|
|
|
|
// Service is an individual protocol that can be registered into a node.
|
|
//
|
|
// Notes:
|
|
//
|
|
// • Service life-cycle management is delegated to the node. The service is allowed to
|
|
// initialize itself upon creation, but no goroutines should be spun up outside of the
|
|
// Start method.
|
|
//
|
|
// • Restart logic is not required as the node will create a fresh instance
|
|
// every time a service is started.
|
|
type Service interface {
|
|
// Protocols retrieves the P2P protocols the service wishes to start.
|
|
Protocols() []p2p.Protocol
|
|
|
|
// APIs retrieves the list of RPC descriptors the service provides
|
|
APIs() []rpc.API
|
|
|
|
// Start is called after all services have been constructed and the networking
|
|
// layer was also initialized to spawn any goroutines required by the service.
|
|
Start(server *p2p.Server) error
|
|
|
|
// Stop terminates all goroutines belonging to the service, blocking until they
|
|
// are all terminated.
|
|
Stop() error
|
|
}
|