les

package
v1.8.21 Latest Latest
Warning

This package is not in the latest version of its module.

 Go to latest Published: Jan 15, 2019 License: GPL-3.0 Imports: 50 Imported by: 4

Documentation

Overview

Package les implements the Light Ethereum Subprotocol.

Package light implements on-demand retrieval capable state and chain objects for the Ethereum Light Client.

Package les implements the Light Ethereum Subprotocol.

Package les implements the Light Ethereum Subprotocol.

Package les implements the Light Ethereum Subprotocol.

Package light implements on-demand retrieval capable state and chain objects for the Ethereum Light Client.

Package les implements the Light Ethereum Subprotocol.

Package les implements the Light Ethereum Subprotocol.

Package les implements the Light Ethereum Subprotocol.

Package light implements on-demand retrieval capable state and chain objects for the Ethereum Light Client.

Package les implements the Light Ethereum Subprotocol.

Package les implements the Light Ethereum Subprotocol.

Index

Constants

View Source 
const (
	MaxHeaderFetch           = 192 // Amount of block headers to be fetched per retrieval request
	MaxBodyFetch             = 32  // Amount of block bodies to be fetched per retrieval request
	MaxReceiptFetch          = 128 // Amount of transaction receipts to allow fetching per request
	MaxCodeFetch             = 64  // Amount of contract codes to allow fetching per request
	MaxProofsFetch           = 64  // Amount of merkle proofs to be fetched per retrieval request
	MaxHelperTrieProofsFetch = 64  // Amount of merkle proofs to be fetched per retrieval request
	MaxTxSend                = 64  // Amount of transactions to be send per request
	MaxTxStatus              = 256 // Amount of transactions to queried per request

)
View Source 
const (
	MsgBlockBodies = iota
	MsgCode
	MsgReceipts
	MsgProofsV1
	MsgProofsV2
	MsgHeaderProofs
	MsgHelperTrieProofs
)
View Source 
const (
	NetworkId          = 1
	ProtocolMaxMsgSize = 10 * 1024 * 1024 // Maximum cap on the size of a protocol message
)
View Source 
const (
	// Protocol messages belonging to LPV1
	StatusMsg          = 0x00
	AnnounceMsg        = 0x01
	GetBlockHeadersMsg = 0x02
	BlockHeadersMsg    = 0x03
	GetBlockBodiesMsg  = 0x04
	BlockBodiesMsg     = 0x05
	GetReceiptsMsg     = 0x06
	ReceiptsMsg        = 0x07
	GetProofsV1Msg     = 0x08
	ProofsV1Msg        = 0x09
	GetCodeMsg         = 0x0a
	CodeMsg            = 0x0b
	SendTxMsg          = 0x0c
	GetHeaderProofsMsg = 0x0d
	HeaderProofsMsg    = 0x0e
	// Protocol messages belonging to LPV2
	GetProofsV2Msg         = 0x0f
	ProofsV2Msg            = 0x10
	GetHelperTrieProofsMsg = 0x11
	HelperTrieProofsMsg    = 0x12
	SendTxV2Msg            = 0x13
	GetTxStatusMsg         = 0x14
	TxStatusMsg            = 0x15
)

les protocol message codes

View Source 
const (
	ErrMsgTooLarge = iota
	ErrDecode
	ErrInvalidMsgCode
	ErrProtocolVersionMismatch
	ErrNetworkIdMismatch
	ErrGenesisBlockMismatch
	ErrNoStatusMsg
	ErrExtraStatusMsg
	ErrSuspendedPeer
	ErrUselessPeer
	ErrRequestRejected
	ErrUnexpectedResponse
	ErrInvalidResponse
	ErrTooManyTimeouts
	ErrMissingKey
)

Variables

View Source 
var (
	ClientProtocolVersions    = []uint{lpv2, lpv1}
	ServerProtocolVersions    = []uint{lpv2, lpv1}
	AdvertiseProtocolVersions = []uint{lpv2} // clients are searching for the first advertised protocol in the list
)

Supported versions of the les protocol (first is primary)

View Source 
var ProtocolLengths = map[uint]uint64{/* contains filtered or unexported fields */}

Number of implemented message corresponding to different protocol versions.

Functions

This section is empty.

Types

type BlockChain 

type BlockChain interface {
	Config() *params.ChainConfig
	HasHeader(hash common.Hash, number uint64) bool
	GetHeader(hash common.Hash, number uint64) *types.Header
	GetHeaderByHash(hash common.Hash) *types.Header
	CurrentHeader() *types.Header
	GetTd(hash common.Hash, number uint64) *big.Int
	State() (*state.StateDB, error)
	InsertHeaderChain(chain []*types.Header, checkFreq int) (int, error)
	Rollback(chain []common.Hash)
	GetHeaderByNumber(number uint64) *types.Header
	GetAncestor(hash common.Hash, number, ancestor uint64, maxNonCanonical *uint64) (common.Hash, uint64)
	Genesis() *types.Block
	SubscribeChainHeadEvent(ch chan<- core.ChainHeadEvent) event.Subscription
}

type BlockRequest 

type BlockRequest light.BlockRequest

BlockRequest is the ODR request type for block bodies

func (*BlockRequest) CanSend added in v1.5.5 

func (r *BlockRequest) CanSend(peer *peer) bool

CanSend tells if a certain peer is suitable for serving the given request

func (*BlockRequest) GetCost 

func (r *BlockRequest) GetCost(peer *peer) uint64

GetCost returns the cost of the given ODR request according to the serving peer's cost table (implementation of LesOdrRequest)

func (*BlockRequest) Request 

func (r *BlockRequest) Request(reqID uint64, peer *peer) error

Request sends an ODR request to the LES network (implementation of LesOdrRequest)

func (*BlockRequest) Validate added in v1.6.0 

func (r *BlockRequest) Validate(db ethdb.Database, msg *Msg) error

Valid processes an ODR request reply message from the LES network returns true and stores results in memory if the message was a valid reply to the request (implementation of LesOdrRequest)

type BloomReq added in v1.7.3 

type BloomReq struct {
	BloomTrieNum, BitIdx, SectionIndex, FromLevel uint64
}

type BloomRequest added in v1.7.3 

type BloomRequest light.BloomRequest

ODR request type for requesting headers by Canonical Hash Trie, see LesOdrRequest interface

func (*BloomRequest) CanSend added in v1.7.3 

func (r *BloomRequest) CanSend(peer *peer) bool

CanSend tells if a certain peer is suitable for serving the given request

func (*BloomRequest) GetCost added in v1.7.3 

func (r *BloomRequest) GetCost(peer *peer) uint64

GetCost returns the cost of the given ODR request according to the serving peer's cost table (implementation of LesOdrRequest)

func (*BloomRequest) Request added in v1.7.3 

func (r *BloomRequest) Request(reqID uint64, peer *peer) error

Request sends an ODR request to the LES network (implementation of LesOdrRequest)

func (*BloomRequest) Validate added in v1.7.3 

func (r *BloomRequest) Validate(db ethdb.Database, msg *Msg) error

Valid processes an ODR request reply message from the LES network returns true and stores results in memory if the message was a valid reply to the request (implementation of LesOdrRequest)

type ChtReq 

type ChtReq struct {
	ChtNum, BlockNum uint64
	FromLevel        uint
}

legacy LES/1

type ChtRequest 

type ChtRequest light.ChtRequest

ODR request type for requesting headers by Canonical Hash Trie, see LesOdrRequest interface

func (*ChtRequest) CanSend added in v1.5.5 

func (r *ChtRequest) CanSend(peer *peer) bool

CanSend tells if a certain peer is suitable for serving the given request

func (*ChtRequest) GetCost 

func (r *ChtRequest) GetCost(peer *peer) uint64

GetCost returns the cost of the given ODR request according to the serving peer's cost table (implementation of LesOdrRequest)

func (*ChtRequest) Request 

func (r *ChtRequest) Request(reqID uint64, peer *peer) error

Request sends an ODR request to the LES network (implementation of LesOdrRequest)

func (*ChtRequest) Validate added in v1.6.0 

func (r *ChtRequest) Validate(db ethdb.Database, msg *Msg) error

Valid processes an ODR request reply message from the LES network returns true and stores results in memory if the message was a valid reply to the request (implementation of LesOdrRequest)

type ChtResp 

type ChtResp struct {
	Header *types.Header
	Proof  []rlp.RawValue
}

legacy LES/1

type CodeData 

type CodeData []struct {
	Value []byte
}

CodeData is the network response packet for a node data retrieval.

type CodeReq 

type CodeReq struct {
	BHash  common.Hash
	AccKey []byte
}

type CodeRequest 

type CodeRequest light.CodeRequest

ODR request type for node data (used for retrieving contract code), see LesOdrRequest interface

func (*CodeRequest) CanSend added in v1.5.5 

func (r *CodeRequest) CanSend(peer *peer) bool

CanSend tells if a certain peer is suitable for serving the given request

func (*CodeRequest) GetCost 

func (r *CodeRequest) GetCost(peer *peer) uint64

GetCost returns the cost of the given ODR request according to the serving peer's cost table (implementation of LesOdrRequest)

func (*CodeRequest) Request 

func (r *CodeRequest) Request(reqID uint64, peer *peer) error

Request sends an ODR request to the LES network (implementation of LesOdrRequest)

func (*CodeRequest) Validate added in v1.6.0 

func (r *CodeRequest) Validate(db ethdb.Database, msg *Msg) error

Valid processes an ODR request reply message from the LES network returns true and stores results in memory if the message was a valid reply to the request (implementation of LesOdrRequest)

type HelperTrieReq added in v1.7.3 

type HelperTrieReq struct {
	Type              uint
	TrieIdx           uint64
	Key               []byte
	FromLevel, AuxReq uint
}

type HelperTrieResps added in v1.7.3 

type HelperTrieResps struct {
	Proofs  light.NodeList
	AuxData [][]byte
}

type LesApiBackend 

type LesApiBackend struct {
	// contains filtered or unexported fields
}

func (*LesApiBackend) AccountManager 

func (b *LesApiBackend) AccountManager() *accounts.Manager

func (*LesApiBackend) BlockByNumber 

func (b *LesApiBackend) BlockByNumber(ctx context.Context, blockNr rpc.BlockNumber) (*types.Block, error)

func (*LesApiBackend) BloomStatus added in v1.7.0 

func (b *LesApiBackend) BloomStatus() (uint64, uint64)

func (*LesApiBackend) ChainConfig 

func (b *LesApiBackend) ChainConfig() *params.ChainConfig

func (*LesApiBackend) ChainDb 

func (b *LesApiBackend) ChainDb() ethdb.Database

func (*LesApiBackend) CurrentBlock 

func (b *LesApiBackend) CurrentBlock() *types.Block

func (*LesApiBackend) Downloader 

func (b *LesApiBackend) Downloader() *downloader.Downloader

func (*LesApiBackend) EventMux 

func (b *LesApiBackend) EventMux() *event.TypeMux

func (*LesApiBackend) GetBlock 

func (b *LesApiBackend) GetBlock(ctx context.Context, blockHash common.Hash) (*types.Block, error)

func (*LesApiBackend) GetEVM added in v1.6.0 

func (b *LesApiBackend) GetEVM(ctx context.Context, msg core.Message, state *state.StateDB, header *types.Header) (*vm.EVM, func() error, error)

func (*LesApiBackend) GetLogs added in v1.8.2 

func (b *LesApiBackend) GetLogs(ctx context.Context, hash common.Hash) ([][]*types.Log, error)

func (*LesApiBackend) GetPoolNonce 

func (b *LesApiBackend) GetPoolNonce(ctx context.Context, addr common.Address) (uint64, error)

func (*LesApiBackend) GetPoolTransaction 

func (b *LesApiBackend) GetPoolTransaction(txHash common.Hash) *types.Transaction

func (*LesApiBackend) GetPoolTransactions 

func (b *LesApiBackend) GetPoolTransactions() (types.Transactions, error)

func (*LesApiBackend) GetReceipts 

func (b *LesApiBackend) GetReceipts(ctx context.Context, hash common.Hash) (types.Receipts, error)

func (*LesApiBackend) GetTd 

func (b *LesApiBackend) GetTd(hash common.Hash) *big.Int

func (*LesApiBackend) HeaderByHash added in v1.8.13 

func (b *LesApiBackend) HeaderByHash(ctx context.Context, hash common.Hash) (*types.Header, error)

func (*LesApiBackend) HeaderByNumber 

func (b *LesApiBackend) HeaderByNumber(ctx context.Context, blockNr rpc.BlockNumber) (*types.Header, error)

func (*LesApiBackend) ProtocolVersion 

func (b *LesApiBackend) ProtocolVersion() int

func (*LesApiBackend) RemoveTx 

func (b *LesApiBackend) RemoveTx(txHash common.Hash)

func (*LesApiBackend) SendTx 

func (b *LesApiBackend) SendTx(ctx context.Context, signedTx *types.Transaction) error

func (*LesApiBackend) ServiceFilter added in v1.7.0 

func (b *LesApiBackend) ServiceFilter(ctx context.Context, session *bloombits.MatcherSession)

func (*LesApiBackend) SetHead 

func (b *LesApiBackend) SetHead(number uint64)

func (*LesApiBackend) StateAndHeaderByNumber 

func (b *LesApiBackend) StateAndHeaderByNumber(ctx context.Context, blockNr rpc.BlockNumber) (*state.StateDB, *types.Header, error)

func (*LesApiBackend) Stats 

func (b *LesApiBackend) Stats() (pending int, queued int)

func (*LesApiBackend) SubscribeChainEvent added in v1.7.0 

func (b *LesApiBackend) SubscribeChainEvent(ch chan<- core.ChainEvent) event.Subscription

func (*LesApiBackend) SubscribeChainHeadEvent added in v1.7.0 

func (b *LesApiBackend) SubscribeChainHeadEvent(ch chan<- core.ChainHeadEvent) event.Subscription

func (*LesApiBackend) SubscribeChainSideEvent added in v1.7.0 

func (b *LesApiBackend) SubscribeChainSideEvent(ch chan<- core.ChainSideEvent) event.Subscription

func (*LesApiBackend) SubscribeLogsEvent added in v1.7.0 

func (b *LesApiBackend) SubscribeLogsEvent(ch chan<- []*types.Log) event.Subscription

func (*LesApiBackend) SubscribeNewTxsEvent added in v1.8.9 

func (b *LesApiBackend) SubscribeNewTxsEvent(ch chan<- core.NewTxsEvent) event.Subscription

func (*LesApiBackend) SubscribeRemovedLogsEvent added in v1.7.0 

func (b *LesApiBackend) SubscribeRemovedLogsEvent(ch chan<- core.RemovedLogsEvent) event.Subscription

func (*LesApiBackend) SuggestPrice 

func (b *LesApiBackend) SuggestPrice(ctx context.Context) (*big.Int, error)

func (*LesApiBackend) TxPoolContent 

func (b *LesApiBackend) TxPoolContent() (map[common.Address]types.Transactions, map[common.Address]types.Transactions)

type LesOdr 

type LesOdr struct {
	// contains filtered or unexported fields
}

LesOdr implements light.OdrBackend

func NewLesOdr 

func NewLesOdr(db ethdb.Database, config *light.IndexerConfig, retriever *retrieveManager) *LesOdr

func (*LesOdr) BloomIndexer added in v1.7.3 

func (odr *LesOdr) BloomIndexer() *core.ChainIndexer

BloomIndexer returns the bloombits chain indexer

func (*LesOdr) BloomTrieIndexer added in v1.7.3 

func (odr *LesOdr) BloomTrieIndexer() *core.ChainIndexer

BloomTrieIndexer returns the bloom trie chain indexer

func (*LesOdr) ChtIndexer added in v1.7.3 

func (odr *LesOdr) ChtIndexer() *core.ChainIndexer

ChtIndexer returns the CHT chain indexer

func (*LesOdr) Database 

func (odr *LesOdr) Database() ethdb.Database

Database returns the backing database

func (*LesOdr) IndexerConfig added in v1.8.15 

func (odr *LesOdr) IndexerConfig() *light.IndexerConfig

IndexerConfig returns the indexer config.

func (*LesOdr) Retrieve 

func (odr *LesOdr) Retrieve(ctx context.Context, req light.OdrRequest) (err error)

Retrieve tries to fetch an object from the LES network. If the network retrieval was successful, it stores the object in local db.

func (*LesOdr) SetIndexers added in v1.8.14 

func (odr *LesOdr) SetIndexers(chtIndexer, bloomTrieIndexer, bloomIndexer *core.ChainIndexer)

SetIndexers adds the necessary chain indexers to the ODR backend

func (*LesOdr) Stop 

func (odr *LesOdr) Stop()

Stop cancels all pending retrievals

type LesOdrRequest 

type LesOdrRequest interface {
	GetCost(*peer) uint64
	CanSend(*peer) bool
	Request(uint64, *peer) error
	Validate(ethdb.Database, *Msg) error
}

func LesRequest 

func LesRequest(req light.OdrRequest) LesOdrRequest

type LesServer 

type LesServer struct {
	// contains filtered or unexported fields
}

func NewLesServer 

func NewLesServer(eth *eth.Ethereum, config *eth.Config) (*LesServer, error)

func (*LesServer) Protocols 

func (s *LesServer) Protocols() []p2p.Protocol

func (*LesServer) SetBloomBitsIndexer added in v1.7.3 

func (s *LesServer) SetBloomBitsIndexer(bloomIndexer *core.ChainIndexer)

func (*LesServer) Start 

func (s *LesServer) Start(srvr *p2p.Server)

Start starts the LES server

func (*LesServer) Stop 

func (s *LesServer) Stop()

Stop stops the LES service

type LesTxRelay 

type LesTxRelay struct {
	// contains filtered or unexported fields
}

func NewLesTxRelay 

func NewLesTxRelay(ps *peerSet, reqDist *requestDistributor) *LesTxRelay

func (*LesTxRelay) Discard 

func (self *LesTxRelay) Discard(hashes []common.Hash)

func (*LesTxRelay) NewHead 

func (self *LesTxRelay) NewHead(head common.Hash, mined []common.Hash, rollback []common.Hash)

func (*LesTxRelay) Send 

func (self *LesTxRelay) Send(txs types.Transactions)

type LightDummyAPI 

type LightDummyAPI struct{}

func (*LightDummyAPI) Coinbase 

func (s *LightDummyAPI) Coinbase() (common.Address, error)

Coinbase is the address that mining rewards will be send to (alias for Etherbase)

func (*LightDummyAPI) Etherbase 

func (s *LightDummyAPI) Etherbase() (common.Address, error)

Etherbase is the address that mining rewards will be send to

func (*LightDummyAPI) Hashrate 

func (s *LightDummyAPI) Hashrate() hexutil.Uint

Hashrate returns the POW hashrate

func (*LightDummyAPI) Mining 

func (s *LightDummyAPI) Mining() bool

Mining returns an indication if this node is currently mining.

type LightEthereum 

type LightEthereum struct {
	ApiBackend *LesApiBackend
	// contains filtered or unexported fields
}

func New 

func New(ctx *node.ServiceContext, config *eth.Config) (*LightEthereum, error)

func (*LightEthereum) APIs 

func (s *LightEthereum) APIs() []rpc.API

APIs returns the collection of RPC services the ethereum package offers. NOTE, some of these services probably need to be moved to somewhere else.

func (*LightEthereum) BlockChain 

func (s *LightEthereum) BlockChain() *light.LightChain

func (*LightEthereum) Downloader 

func (s *LightEthereum) Downloader() *downloader.Downloader

func (*LightEthereum) Engine added in v1.6.0 

func (s *LightEthereum) Engine() consensus.Engine

func (*LightEthereum) EventMux added in v1.5.4 

func (s *LightEthereum) EventMux() *event.TypeMux

func (*LightEthereum) LesVersion 

func (s *LightEthereum) LesVersion() int

func (*LightEthereum) Protocols 

func (s *LightEthereum) Protocols() []p2p.Protocol

Protocols implements node.Service, returning all the currently configured network protocols to start.

func (*LightEthereum) ResetWithGenesisBlock 

func (s *LightEthereum) ResetWithGenesisBlock(gb *types.Block)

func (*LightEthereum) Start 

func (s *LightEthereum) Start(srvr *p2p.Server) error

Start implements node.Service, starting all internal goroutines needed by the Ethereum protocol implementation.

func (*LightEthereum) Stop 

func (s *LightEthereum) Stop() error

Stop implements node.Service, terminating all internal goroutines used by the Ethereum protocol.

func (*LightEthereum) TxPool 

func (s *LightEthereum) TxPool() *light.TxPool

type Msg 

type Msg struct {
	MsgType int
	ReqID   uint64
	Obj     interface{}
}

Msg encodes a LES message that delivers reply data for a request

type NodeInfo added in v1.8.0 

type NodeInfo struct {
	Network    uint64                   `json:"network"`    // Ethereum network ID (1=Frontier, 2=Morden, Ropsten=3, Rinkeby=4)
	Difficulty *big.Int                 `json:"difficulty"` // Total difficulty of the host's blockchain
	Genesis    common.Hash              `json:"genesis"`    // SHA3 hash of the host's genesis block
	Config     *params.ChainConfig      `json:"config"`     // Chain configuration for the fork rules
	Head       common.Hash              `json:"head"`       // SHA3 hash of the host's best owned block
	CHT        params.TrustedCheckpoint `json:"cht"`        // Trused CHT checkpoint for fast catchup
}

NodeInfo represents a short summary of the Ethereum sub-protocol metadata known about the host peer.

type ProofReq 

type ProofReq struct {
	BHash       common.Hash
	AccKey, Key []byte
	FromLevel   uint
}

type ProtocolManager 

type ProtocolManager struct {
	// contains filtered or unexported fields
}

func NewProtocolManager 

func NewProtocolManager(chainConfig *params.ChainConfig, indexerConfig *light.IndexerConfig, lightSync bool, networkId uint64, mux *event.TypeMux, engine consensus.Engine, peers *peerSet, blockchain BlockChain, txpool txPool, chainDb ethdb.Database, odr *LesOdr, txrelay *LesTxRelay, serverPool *serverPool, quitSync chan struct{}, wg *sync.WaitGroup) (*ProtocolManager, error)

NewProtocolManager returns a new ethereum sub protocol manager. The Ethereum sub protocol manages peers capable with the ethereum network.

func (*ProtocolManager) Start 

func (pm *ProtocolManager) Start(maxPeers int)

func (*ProtocolManager) Stop 

func (pm *ProtocolManager) Stop()

type ReceiptsRequest 

type ReceiptsRequest light.ReceiptsRequest

ReceiptsRequest is the ODR request type for block receipts by block hash

func (*ReceiptsRequest) CanSend added in v1.5.5 

func (r *ReceiptsRequest) CanSend(peer *peer) bool

CanSend tells if a certain peer is suitable for serving the given request

func (*ReceiptsRequest) GetCost 

func (r *ReceiptsRequest) GetCost(peer *peer) uint64

GetCost returns the cost of the given ODR request according to the serving peer's cost table (implementation of LesOdrRequest)

func (*ReceiptsRequest) Request 

func (r *ReceiptsRequest) Request(reqID uint64, peer *peer) error

Request sends an ODR request to the LES network (implementation of LesOdrRequest)

func (*ReceiptsRequest) Validate added in v1.6.0 

func (r *ReceiptsRequest) Validate(db ethdb.Database, msg *Msg) error

Valid processes an ODR request reply message from the LES network returns true and stores results in memory if the message was a valid reply to the request (implementation of LesOdrRequest)

type RequestCostList 

type RequestCostList []struct {
	MsgCode, BaseCost, ReqCost uint64
}

type TrieRequest 

type TrieRequest light.TrieRequest

ODR request type for state/storage trie entries, see LesOdrRequest interface

func (*TrieRequest) CanSend added in v1.5.5 

func (r *TrieRequest) CanSend(peer *peer) bool

CanSend tells if a certain peer is suitable for serving the given request

func (*TrieRequest) GetCost 

func (r *TrieRequest) GetCost(peer *peer) uint64

GetCost returns the cost of the given ODR request according to the serving peer's cost table (implementation of LesOdrRequest)

func (*TrieRequest) Request 

func (r *TrieRequest) Request(reqID uint64, peer *peer) error

Request sends an ODR request to the LES network (implementation of LesOdrRequest)

func (*TrieRequest) Validate added in v1.6.0 

func (r *TrieRequest) Validate(db ethdb.Database, msg *Msg) error

Valid processes an ODR request reply message from the LES network returns true and stores results in memory if the message was a valid reply to the request (implementation of LesOdrRequest)

Source Files

View all Source files

Directories

Path Synopsis
Package flowcontrol implements a client side flow control mechanism Package flowcontrol implements a client side flow control mechanism
 Package flowcontrol implements a client side flow control mechanism Package flowcontrol implements a client side flow control mechanism

Jump to

Keyboard shortcuts

? : This menu
/ : Search site
f or F : Jump to
y or Y : Canonical URL
go.dev uses cookies from Google to deliver and enhance the quality of its services and to analyze traffic. Learn more.