interfaces.go

// Copyright 2016 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 ethereum defines interfaces for interacting with Ethereum.
package ethereum

import (
	"context"
	"encoding/json"
	"errors"
	"math/big"

	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/common/hexutil"
	"github.com/ethereum/go-ethereum/core/types"
)

// NotFound is returned by API methods if the requested item does not exist.
var NotFound = errors.New("not found")

// Subscription represents an event subscription where events are
// delivered on a data channel.
type Subscription interface {
	// Unsubscribe cancels the sending of events to the data channel
	// and closes the error channel.
	Unsubscribe()
	// Err returns the subscription error channel. The error channel receives
	// a value if there is an issue with the subscription (e.g. the network connection
	// delivering the events has been closed). Only one value will ever be sent.
	// The error channel is closed by Unsubscribe.
	Err() <-chan error
}

// ChainReader provides access to the blockchain. The methods in this interface access raw
// data from either the canonical chain (when requesting by block number) or any
// blockchain fork that was previously downloaded and processed by the node. The block
// number argument can be nil to select the latest canonical block. Reading block headers
// should be preferred over full blocks whenever possible.
//
// The returned error is NotFound if the requested item does not exist.
type ChainReader interface {
	BlockByHash(ctx context.Context, hash common.Hash) (*types.Block, error)
	BlockByNumber(ctx context.Context, number *big.Int) (*types.Block, error)
	HeaderByHash(ctx context.Context, hash common.Hash) (*types.Header, error)
	HeaderByNumber(ctx context.Context, number *big.Int) (*types.Header, error)
	TransactionCount(ctx context.Context, blockHash common.Hash) (uint, error)
	TransactionInBlock(ctx context.Context, blockHash common.Hash, index uint) (*types.Transaction, error)

	// This method subscribes to notifications about changes of the head block of
	// the canonical chain.
	SubscribeNewHead(ctx context.Context, ch chan<- *types.Header) (Subscription, error)
}

// TransactionReceiptsQuery defines criteria for transaction receipts subscription.
// If TransactionHashes is empty, receipts for all transactions included in new blocks will be delivered.
// Otherwise, only receipts for the specified transactions will be delivered.
type TransactionReceiptsQuery struct {
	TransactionHashes []common.Hash
}

// TransactionReader provides access to past transactions and their receipts.
// Implementations may impose arbitrary restrictions on the transactions and receipts that
// can be retrieved. Historic transactions may not be available.
//
// Avoid relying on this interface if possible. Contract logs (through the LogFilterer
// interface) are more reliable and usually safer in the presence of chain
// reorganisations.
//
// The returned error is NotFound if the requested item does not exist.
type TransactionReader interface {
	// TransactionByHash checks the pool of pending transactions in addition to the
	// blockchain. The isPending return value indicates whether the transaction has been
	// mined yet. Note that the transaction may not be part of the canonical chain even if
	// it's not pending.
	TransactionByHash(ctx context.Context, txHash common.Hash) (tx *types.Transaction, isPending bool, err error)
	// TransactionReceipt returns the receipt of a mined transaction. Note that the
	// transaction may not be included in the current canonical chain even if a receipt
	// exists.
	TransactionReceipt(ctx context.Context, txHash common.Hash) (*types.Receipt, error)
	// SubscribeTransactionReceipts subscribes to notifications about transaction receipts.
	// The receipts are delivered in batches when transactions are included in blocks.
	// If q is nil or has empty TransactionHashes, all receipts from new blocks will be delivered.
	// Otherwise, only receipts for the specified transaction hashes will be delivered.
	SubscribeTransactionReceipts(ctx context.Context, q *TransactionReceiptsQuery, ch chan<- []*types.Receipt) (Subscription, error)
}

// ChainStateReader wraps access to the state trie of the canonical blockchain. Note that
// implementations of the interface may be unable to return state values for old blocks.
// In many cases, using CallContract can be preferable to reading raw contract storage.
type ChainStateReader interface {
	BalanceAt(ctx context.Context, account common.Address, blockNumber *big.Int) (*big.Int, error)
	StorageAt(ctx context.Context, account common.Address, key common.Hash, blockNumber *big.Int) ([]byte, error)
	CodeAt(ctx context.Context, account common.Address, blockNumber *big.Int) ([]byte, error)
	NonceAt(ctx context.Context, account common.Address, blockNumber *big.Int) (uint64, error)
}

// SyncProgress gives progress indications when the node is synchronising with
// the Ethereum network.
type SyncProgress struct {
	StartingBlock uint64 // Block number where sync began
	CurrentBlock  uint64 // Current block number where sync is at
	HighestBlock  uint64 // Highest alleged block number in the chain

	// "fast sync" fields. These used to be sent by geth, but are no longer used
	// since version v1.10.
	PulledStates uint64 // Number of state trie entries already downloaded
	KnownStates  uint64 // Total number of state trie entries known about

	// "snap sync" fields.
	SyncedAccounts      uint64 // Number of accounts downloaded
	SyncedAccountBytes  uint64 // Number of account trie bytes persisted to disk
	SyncedBytecodes     uint64 // Number of bytecodes downloaded
	SyncedBytecodeBytes uint64 // Number of bytecode bytes downloaded
	SyncedStorage       uint64 // Number of storage slots downloaded
	SyncedStorageBytes  uint64 // Number of storage trie bytes persisted to disk

	HealedTrienodes     uint64 // Number of state trie nodes downloaded
	HealedTrienodeBytes uint64 // Number of state trie bytes persisted to disk
	HealedBytecodes     uint64 // Number of bytecodes downloaded
	HealedBytecodeBytes uint64 // Number of bytecodes persisted to disk

	HealingTrienodes uint64 // Number of state trie nodes pending
	HealingBytecode  uint64 // Number of bytecodes pending

	// "transaction indexing" fields
	TxIndexFinishedBlocks  uint64 // Number of blocks whose transactions are already indexed
	TxIndexRemainingBlocks uint64 // Number of blocks whose transactions are not indexed yet

	// "historical state indexing" fields
	StateIndexRemaining uint64 // Number of states remain unindexed
}

// Done returns the indicator if the initial sync is finished or not.
func (prog SyncProgress) Done() bool {
	if prog.CurrentBlock < prog.HighestBlock {
		return false
	}
	return prog.TxIndexRemainingBlocks == 0 && prog.StateIndexRemaining == 0
}

// ChainSyncReader wraps access to the node's current sync status. If there's no
// sync currently running, it returns nil.
type ChainSyncReader interface {
	SyncProgress(ctx context.Context) (*SyncProgress, error)
}

// CallMsg contains parameters for contract calls.
type CallMsg struct {
	From      common.Address  // the sender of the 'transaction'
	To        *common.Address // the destination contract (nil for contract creation)
	Gas       uint64          // if 0, the call executes with near-infinite gas
	GasPrice  *big.Int        // wei <-> gas exchange ratio
	GasFeeCap *big.Int        // EIP-1559 fee cap per gas.
	GasTipCap *big.Int        // EIP-1559 tip per gas.
	Value     *big.Int        // amount of wei sent along with the call
	Data      []byte          // input data, usually an ABI-encoded contract method invocation

	AccessList types.AccessList // EIP-2930 access list.

	// For BlobTxType
	BlobGasFeeCap *big.Int
	BlobHashes    []common.Hash

	// For SetCodeTxType
	AuthorizationList []types.SetCodeAuthorization
}

// A ContractCaller provides contract calls, essentially transactions that are executed by
// the EVM but not mined into the blockchain. ContractCall is a low-level method to
// execute such calls. For applications which are structured around specific contracts,
// the abigen tool provides a nicer, properly typed way to perform calls.
type ContractCaller interface {
	CallContract(ctx context.Context, call CallMsg, blockNumber *big.Int) ([]byte, error)
}

// FilterQuery contains options for contract log filtering.
type FilterQuery struct {
	BlockHash *common.Hash     // used by eth_getLogs, return logs only from block with this hash
	FromBlock *big.Int         // beginning of the queried range, nil means genesis block
	ToBlock   *big.Int         // end of the range, nil means latest block
	Addresses []common.Address // restricts matches to events created by specific contracts
	Pending   bool             // restricts matches to the current pending block

	// The Topic list restricts matches to particular event topics. Each event has a list
	// of topics. Topics matches a prefix of that list. An empty element slice matches any
	// topic. Non-empty elements represent an alternative that matches any of the
	// contained topics.
	//
	// Examples:
	// {} or nil          matches any topic list
	// {{A}}              matches topic A in first position
	// {{}, {B}}          matches any topic in first position AND B in second position
	// {{A}, {B}}         matches topic A in first position AND B in second position
	// {{A, B}, {C, D}}   matches topic (A OR B) in first position AND (C OR D) in second position
	Topics [][]common.Hash
}

// LogFilterer provides access to contract log events using a one-off query or continuous
// event subscription.
//
// Logs received through a streaming query subscription may have Removed set to true,
// indicating that the log was reverted due to a chain reorganisation.
type LogFilterer interface {
	FilterLogs(ctx context.Context, q FilterQuery) ([]types.Log, error)
	SubscribeFilterLogs(ctx context.Context, q FilterQuery, ch chan<- types.Log) (Subscription, error)
}

// TransactionSender wraps transaction sending. The SendTransaction method injects a
// signed transaction into the pending transaction pool for execution. If the transaction
// was a contract creation, the TransactionReceipt method can be used to retrieve the
// contract address after the transaction has been mined.
//
// The transaction must be signed and have a valid nonce to be included. Consumers of the
// API can use package accounts to maintain local private keys and need can retrieve the
// next available nonce using PendingNonceAt.
type TransactionSender interface {
	SendTransaction(ctx context.Context, tx *types.Transaction) error
}

// GasPricer wraps the gas price oracle, which monitors the blockchain to determine the
// optimal gas price given current fee market conditions.
type GasPricer interface {
	SuggestGasPrice(ctx context.Context) (*big.Int, error)
}

// GasPricer1559 provides access to the EIP-1559 gas price oracle.
type GasPricer1559 interface {
	SuggestGasTipCap(ctx context.Context) (*big.Int, error)
}

// FeeHistoryReader provides access to the fee history oracle.
type FeeHistoryReader interface {
	FeeHistory(ctx context.Context, blockCount uint64, lastBlock *big.Int, rewardPercentiles []float64) (*FeeHistory, error)
}

// FeeHistory provides recent fee market data that consumers can use to determine
// a reasonable maxPriorityFeePerGas value.
type FeeHistory struct {
	OldestBlock  *big.Int     // block corresponding to first response value
	Reward       [][]*big.Int // list every txs priority fee per block
	BaseFee      []*big.Int   // list of each block's base fee
	GasUsedRatio []float64    // ratio of gas used out of the total available limit
}

// A PendingStateReader provides access to the pending state, which is the result of all
// known executable transactions which have not yet been included in the blockchain. It is
// commonly used to display the result of ’unconfirmed’ actions (e.g. wallet value
// transfers) initiated by the user. The PendingNonceAt operation is a good way to
// retrieve the next available transaction nonce for a specific account.
type PendingStateReader interface {
	PendingBalanceAt(ctx context.Context, account common.Address) (*big.Int, error)
	PendingStorageAt(ctx context.Context, account common.Address, key common.Hash) ([]byte, error)
	PendingCodeAt(ctx context.Context, account common.Address) ([]byte, error)
	PendingNonceAt(ctx context.Context, account common.Address) (uint64, error)
	PendingTransactionCount(ctx context.Context) (uint, error)
}

// PendingContractCaller can be used to perform calls against the pending state.
type PendingContractCaller interface {
	PendingCallContract(ctx context.Context, call CallMsg) ([]byte, error)
}

// GasEstimator wraps EstimateGas, which tries to estimate the gas needed to execute a
// specific transaction based on the pending state. There is no guarantee that this is the
// true gas limit requirement as other transactions may be added or removed by miners, but
// it should provide a basis for setting a reasonable default.
type GasEstimator interface {
	EstimateGas(ctx context.Context, call CallMsg) (uint64, error)
}

// A PendingStateEventer provides access to real time notifications about changes to the
// pending state.
type PendingStateEventer interface {
	SubscribePendingTransactions(ctx context.Context, ch chan<- *types.Transaction) (Subscription, error)
}

// StateSyncFilter state sync filter
type StateSyncFilter struct {
	ID       uint64
	Contract common.Address
}

// interface for whitelist service
type ChainValidator interface {
	IsValidPeer(fetchHeadersByNumber func(number uint64, amount int, skip int, reverse bool) ([]*types.Header, []common.Hash, error)) (bool, error)
	IsValidChain(currentHeader *types.Header, chain []*types.Header) (bool, error)
	GetWhitelistedCheckpoint() (bool, uint64, common.Hash)
	GetWhitelistedMilestone() (bool, uint64, common.Hash)
	ProcessCheckpoint(endBlockNum uint64, endBlockHash common.Hash)
	ProcessMilestone(endBlockNum uint64, endBlockHash common.Hash)
	ProcessFutureMilestone(num uint64, hash common.Hash)
	PurgeWhitelistedCheckpoint()
	PurgeWhitelistedMilestone()
	PurgeMilestonesAfter(block uint64)

	LockMutex(endBlockNum uint64) bool
	UnlockMutex(doLock bool, milestoneId string, endBlockNum uint64, endBlockHash common.Hash)
	UnlockSprint(endBlockNum uint64)
	RemoveMilestoneID(milestoneId string)
	GetMilestoneIDsList() []string
}

// BlockNumberReader provides access to the current block number.
type BlockNumberReader interface {
	BlockNumber(ctx context.Context) (uint64, error)
}

// ChainIDReader provides access to the chain ID.
type ChainIDReader interface {
	ChainID(ctx context.Context) (*big.Int, error)
}

// OverrideAccount specifies the state of an account to be overridden.
type OverrideAccount struct {
	// Nonce sets nonce of the account. Note: the nonce override will only
	// be applied when it is set to a non-zero value.
	Nonce uint64

	// Code sets the contract code. The override will be applied
	// when the code is non-nil, i.e. setting empty code is possible
	// using an empty slice.
	Code []byte

	// Balance sets the account balance.
	Balance *big.Int

	// State sets the complete storage. The override will be applied
	// when the given map is non-nil. Using an empty map wipes the
	// entire contract storage during the call.
	State map[common.Hash]common.Hash

	// StateDiff allows overriding individual storage slots.
	StateDiff map[common.Hash]common.Hash
}

func (a OverrideAccount) MarshalJSON() ([]byte, error) {
	type acc struct {
		Nonce     hexutil.Uint64              `json:"nonce,omitempty"`
		Code      string                      `json:"code,omitempty"`
		Balance   *hexutil.Big                `json:"balance,omitempty"`
		State     interface{}                 `json:"state,omitempty"`
		StateDiff map[common.Hash]common.Hash `json:"stateDiff,omitempty"`
	}

	output := acc{
		Nonce:     hexutil.Uint64(a.Nonce),
		Balance:   (*hexutil.Big)(a.Balance),
		StateDiff: a.StateDiff,
	}
	if a.Code != nil {
		output.Code = hexutil.Encode(a.Code)
	}
	if a.State != nil {
		output.State = a.State
	}
	return json.Marshal(output)
}

// BlockOverrides specifies the set of header fields to override.
type BlockOverrides struct {
	// Number overrides the block number.
	Number *big.Int
	// Difficulty overrides the block difficulty.
	Difficulty *big.Int
	// Time overrides the block timestamp. Time is applied only when
	// it is non-zero.
	Time uint64
	// GasLimit overrides the block gas limit. GasLimit is applied only when
	// it is non-zero.
	GasLimit uint64
	// Coinbase overrides the block coinbase. Coinbase is applied only when
	// it is different from the zero address.
	Coinbase common.Address
	// Random overrides the block extra data which feeds into the RANDOM opcode.
	// Random is applied only when it is a non-zero hash.
	Random common.Hash
	// BaseFee overrides the block base fee.
	BaseFee *big.Int
}

func (o BlockOverrides) MarshalJSON() ([]byte, error) {
	type override struct {
		Number     *hexutil.Big    `json:"number,omitempty"`
		Difficulty *hexutil.Big    `json:"difficulty,omitempty"`
		Time       hexutil.Uint64  `json:"time,omitempty"`
		GasLimit   hexutil.Uint64  `json:"gasLimit,omitempty"`
		Coinbase   *common.Address `json:"feeRecipient,omitempty"`
		Random     *common.Hash    `json:"prevRandao,omitempty"`
		BaseFee    *hexutil.Big    `json:"baseFeePerGas,omitempty"`
	}

	output := override{
		Number:     (*hexutil.Big)(o.Number),
		Difficulty: (*hexutil.Big)(o.Difficulty),
		Time:       hexutil.Uint64(o.Time),
		GasLimit:   hexutil.Uint64(o.GasLimit),
		BaseFee:    (*hexutil.Big)(o.BaseFee),
	}
	if o.Coinbase != (common.Address{}) {
		output.Coinbase = &o.Coinbase
	}
	if o.Random != (common.Hash{}) {
		output.Random = &o.Random
	}
	return json.Marshal(output)
}