From 4c1616a746a648c816042f596eb199174a9858f1 Mon Sep 17 00:00:00 2001 From: Determinant Date: Fri, 9 Aug 2019 21:15:05 -0400 Subject: add necessary code base --- node/service.go | 131 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 131 insertions(+) create mode 100644 node/service.go (limited to 'node/service.go') diff --git a/node/service.go b/node/service.go new file mode 100644 index 0000000..fd03a57 --- /dev/null +++ b/node/service.go @@ -0,0 +1,131 @@ +// 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 . + +package node + +import ( + "path/filepath" + "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 + } + return rawdb.NewLevelDBDatabase(ctx.config.ResolvePath(name), cache, handles, namespace) +} + +// OpenDatabaseWithFreezer opens an existing database with the given name (or +// creates one if no previous can be found) from within the node's data directory, +// also attaching a chain freezer to it that moves ancient chain data from the +// database to immutable append-only files. If the node is an ephemeral one, a +// memory database is returned. +func (ctx *ServiceContext) OpenDatabaseWithFreezer(name string, cache int, handles int, freezer string, namespace string) (ethdb.Database, error) { + if ctx.config.DataDir == "" { + return rawdb.NewMemoryDatabase(), nil + } + root := ctx.config.ResolvePath(name) + + switch { + case freezer == "": + freezer = filepath.Join(root, "ancient") + case !filepath.IsAbs(freezer): + freezer = ctx.config.ResolvePath(freezer) + } + return rawdb.NewLevelDBDatabaseWithFreezer(root, cache, handles, freezer, namespace) +} + +// 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 +} + +// ExtRPCEnabled returns the indicator whether node enables the external +// RPC(http, ws or graphql). +func (ctx *ServiceContext) ExtRPCEnabled() bool { + return ctx.config.ExtRPCEnabled() +} + +func NewServiceContext(mux *event.TypeMux) ServiceContext { + return ServiceContext { + config: nil, + services: make(map[reflect.Type]Service), + EventMux: mux, + AccountManager: nil, + } +} + +// 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 +} -- cgit v1.2.3-70-g09d2