// Copyright 2015 The go-ethereum Authors

// (original work)

// Copyright 2024 The Erigon Authors

// (modifications)

// This file is part of Erigon.

//

// Erigon 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.

//

// Erigon 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 Erigon. If not, see <http://www.gnu.org/licenses/>.

package node

import (

"context"

"errors"

"fmt"

"path/filepath"

"reflect"

"slices"

"strings"

"sync"

"time"

"github.com/c2h5oh/datasize"

"github.com/gofrs/flock"

"golang.org/x/sync/semaphore"

"github.com/erigontech/erigon/cmd/utils"

"github.com/erigontech/erigon/common/dbg"

"github.com/erigontech/erigon/common/log/v3"

"github.com/erigontech/erigon/db/datadir"

"github.com/erigontech/erigon/db/kv"

"github.com/erigontech/erigon/db/kv/dbcfg"

"github.com/erigontech/erigon/db/kv/mdbx"

"github.com/erigontech/erigon/db/kv/memdb"

"github.com/erigontech/erigon/db/migrations"

"github.com/erigontech/erigon/db/rawdb"

"github.com/erigontech/erigon/db/version"

"github.com/erigontech/erigon/node/debug"

"github.com/erigontech/erigon/node/nodecfg"

)

// Node is a container on which services can be registered.

type Node struct {

config *nodecfg.Config

logger log.Logger

dirLock *flock.Flock // prevents concurrent use of instance directory

stop chan struct{} // Channel to wait for termination notifications

startStopLock sync.Mutex // Start/Stop are protected by an additional lock

state int // Tracks state of node lifecycle

lock sync.Mutex

lifecycles []Lifecycle // All registered backends, services, and auxiliary services that have a lifecycle

databases []kv.Closer

}

const (

initializingState = iota

runningState

closedState

)

// New creates a new P2P node, ready for protocol registration.

func New(ctx context.Context, conf *nodecfg.Config, logger log.Logger) (*Node, error) {

// Copy config and resolve the datadir so future changes to the current

// working directory don't affect the node.

confCopy := *conf

conf = &confCopy

// Ensure that the instance name doesn't cause weird conflicts with

// other files in the data directory.

if strings.ContainsAny(conf.Name, `/\`) {

return nil, errors.New(`Config.Name must not contain '/' or '\'`)

}

if strings.HasSuffix(conf.Name, ".ipc") {

return nil, errors.New(`Config.Name cannot end in ".ipc"`)

}

node := &Node{

config: conf,

logger: logger,

stop: make(chan struct{}),

databases: make([]kv.Closer, 0),

}

// Acquire the instance directory lock.

if err := node.openDataDir(ctx); err != nil {

return nil, err

}

return node, nil

}

// Start starts all registered lifecycles, RPC services and p2p networking.

// Node can only be started once.

func (n *Node) Start() error {

n.startStopLock.Lock()

defer n.startStopLock.Unlock()

n.lock.Lock()

switch n.state {

case runningState:

n.lock.Unlock()

return ErrNodeRunning

case closedState:

n.lock.Unlock()

return ErrNodeStopped

}

n.state = runningState

lifecycles := make([]Lifecycle, len(n.lifecycles))

copy(lifecycles, n.lifecycles)

n.lock.Unlock()

// Start all registered lifecycles.

// preallocation leads to bugs here

var started []Lifecycle //nolint:prealloc

var err error

for _, lifecycle := range lifecycles {

if err = lifecycle.Start(); err != nil {

break

}

started = append(started, lifecycle)

}

// Check if any lifecycle failed to start.

if err != nil {

stopErr := n.stopServices(started)

if stopErr != nil {

n.logger.Warn("Failed to doClose for this node", "err", stopErr)

} //nolint:errcheck

closeErr := n.doClose(nil)

if closeErr != nil {

n.logger.Warn("Failed to doClose for this node", "err", closeErr)

}

}

return err

}

// Close stops the Node and releases resources acquired in

// Node constructor New.

func (n *Node) Close() error {

n.startStopLock.Lock()

defer n.startStopLock.Unlock()

n.lock.Lock()

state := n.state

n.lock.Unlock()

switch state {

case initializingState:

// The node was never started.

return n.doClose(nil)

case runningState:

// The node was started, release resources acquired by Start().

var errs []error

if err := n.stopServices(n.lifecycles); err != nil {

errs = append(errs, err)

}

return n.doClose(errs)

case closedState:

return ErrNodeStopped

default:

panic(fmt.Sprintf("node is in unknown state %d", state))

}

}

// doClose releases resources acquired by New(), collecting errors.

func (n *Node) doClose(errs []error) error {

// Close databases. This needs the lock because it needs to

// synchronize with OpenDatabase*.

n.lock.Lock()

n.state = closedState

for _, closer := range n.databases {

closer.Close()

}

n.lock.Unlock()

// Release instance directory lock.

n.closeDataDir()

// Unblock n.Wait.

close(n.stop)

// Report any errors that might have occurred.

switch len(errs) {

case 0:

return nil

case 1:

return errs[0]

default:

return fmt.Errorf("%v", errs)

}

}

// containsLifecycle checks if 'lfs' contains 'l'.

func containsLifecycle(lfs []Lifecycle, l Lifecycle) bool {

return slices.Contains(lfs, l)

}

// stopServices terminates running services, RPC and p2p networking.

// It is the inverse of Start.

func (n *Node) stopServices(running []Lifecycle) error {

//n.stopRPC()

// Stop running lifecycles in reverse order.

failure := &StopError{Services: make(map[reflect.Type]error)}

for i := len(running) - 1; i >= 0; i-- {

if err := running[i].Stop(); err != nil {

failure.Services[reflect.TypeOf(running[i])] = err

}

}

if len(failure.Services) > 0 {

return failure

}

return nil

}

func (n *Node) openDataDir(ctx context.Context) error {

if n.config.Dirs.DataDir == "" {

return nil // ephemeral

}

instdir := n.config.Dirs.DataDir

for retry := 0; ; retry++ {

l, locked, err := datadir.TryFlock(n.config.Dirs)

if err != nil {

return err

}

if !locked {

if retry >= 10 {

return fmt.Errorf("%w: %s", datadir.ErrDataDirLocked, instdir)

}

log.Error(datadir.ErrDataDirLocked.Error() + ", retry in 2 sec")

select {

case <-ctx.Done():

return ctx.Err()

case <-time.After(2 * time.Second):

}

continue

}

n.dirLock = l

break

}

return nil

}

func (n *Node) closeDataDir() {

// Release instance directory lock.

if n.dirLock != nil {

if err := n.dirLock.Unlock(); err != nil {

n.logger.Error("Can't release datadir lock", "err", err)

}

n.dirLock = nil

}

}

// Wait blocks until the node is closed.

func (n *Node) Wait() {

<-n.stop

}

// RegisterLifecycle registers the given Lifecycle on the node.

func (n *Node) RegisterLifecycle(lifecycle Lifecycle) {

n.lock.Lock()

defer n.lock.Unlock()

if n.state != initializingState {

panic("can't register lifecycle on running/stopped node")

}

if containsLifecycle(n.lifecycles, lifecycle) {

panic(fmt.Sprintf("attempt to register lifecycle %T more than once", lifecycle))

}

n.lifecycles = append(n.lifecycles, lifecycle)

}

// Config returns the configuration of node.

func (n *Node) Config() *nodecfg.Config {

return n.config

}

// DataDir retrieves the current datadir used by the protocol stack.

func (n *Node) DataDir() string {

return n.config.Dirs.DataDir

}

func OpenDatabase(ctx context.Context, config *nodecfg.Config, label kv.Label, name string, readonly bool, logger log.Logger) (kv.RwDB, error) {

switch label {

case dbcfg.ChainDB:

name = "chaindata"

case dbcfg.TxPoolDB:

name = "txpool"

case dbcfg.PolygonBridgeDB:

name = "polygon-bridge"

case dbcfg.ConsensusDB:

if len(name) == 0 {

return nil, errors.New("expected a consensus name")

}

default:

name = "test"

}

var db kv.RwDB

if config.Dirs.DataDir == "" {

db = memdb.New(nil, "", label)

return db, nil

}

dbPath := filepath.Join(config.Dirs.DataDir, name)

logger.Info("Opening Database", "label", name, "path", dbPath)

openFunc := func(exclusive bool) (kv.RwDB, error) {

roTxLimit := int64(32)

if config.Http.DBReadConcurrency > 0 {

roTxLimit = int64(config.Http.DBReadConcurrency)

}

roTxsLimiter := semaphore.NewWeighted(roTxLimit) // 1 less than max to allow unlocking to happen

opts := mdbx.New(label, logger).

Path(dbPath).

GrowthStep(16 * datasize.MB).

DBVerbosity(config.DatabaseVerbosity).RoTxsLimiter(roTxsLimiter).

WriteMap(config.MdbxWriteMap).

Readonly(readonly).

Exclusive(exclusive)

switch label {

case dbcfg.ChainDB:

if config.MdbxPageSize.Bytes() > 0 {

opts = opts.PageSize(config.MdbxPageSize)

}

if config.MdbxDBSizeLimit > 0 {

opts = opts.MapSize(config.MdbxDBSizeLimit)

}

if config.MdbxGrowthStep > 0 {

opts = opts.GrowthStep(config.MdbxGrowthStep)

}

opts = opts.DirtySpace(uint64(1024 * datasize.MB))

case dbcfg.ConsensusDB:

if config.MdbxPageSize.Bytes() > 0 {

opts = opts.PageSize(config.MdbxPageSize)

}

// Don't adjust up the consensus DB - this will lead to resource exhaustion lor large map sizes

if config.MdbxDBSizeLimit > 0 && config.MdbxDBSizeLimit < mdbx.DefaultMapSize {

opts = opts.MapSize(config.MdbxDBSizeLimit)

}

// Don't adjust up the consensus DB - to align with db size limit above

if config.MdbxGrowthStep > 0 && config.MdbxGrowthStep < mdbx.DefaultGrowthStep {

opts = opts.GrowthStep(config.MdbxGrowthStep)

}

default:

}

return opts.Open(ctx)

}

var err error

db, err = openFunc(false)

if err != nil {

return nil, err

}

if label == dbcfg.ChainDB {

migrationsDB, err := migrations.OpenMigrationsDB(config.Dirs.Migrations, logger)

if err != nil {

return nil, fmt.Errorf("open migrations db: %w", err)

}

defer migrationsDB.Close()

migrator := migrations.NewMigrator(label)

if err := migrator.VerifyVersion(db, dbPath); err != nil {

return nil, err

}

has, err := migrator.HasPendingMigrations(migrationsDB)

if err != nil {

return nil, err

}

if has && !dbg.OnlyCreateDB {

logger.Info("Re-Opening DB in exclusive mode to apply migrations")

db.Close()

db, err = openFunc(true)

if err != nil {

return nil, err

}

if err = migrator.Apply(db, migrationsDB, config.Dirs.DataDir, dbPath, logger); err != nil {

return nil, err

}

db.Close()

db, err = openFunc(false)

if err != nil {

return nil, err

}

}

if err := db.Update(context.Background(), func(tx kv.RwTx) (err error) {

return rawdb.SetErigonVersion(tx, version.VersionKeyCreated)

}); err != nil {

return nil, err

}

}

return db, nil

}

// ResolvePath returns the absolute path of a resource in the instance directory.

func (n *Node) ResolvePath(x string) string {

return n.config.ResolvePath(x)

}

func StartNode(stack *Node) {

if err := stack.Start(); err != nil {

utils.Fatalf("Error starting protocol stack: %v", err)

}

go debug.ListenSignals(func() { stack.Close() }, stack.logger)

}