ethereum

README

Huobi ECO Chain – Heco

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Introduction to the Huobi Open Platform

The Huobi Open Platform is a unified infrastructure platform based on the technical, traffic and ecological resources of the Huobi Group, and will be gradually open to the blockchain industry. It will make the construction of decentralized applications more efficient and cost-effective, and provide comprehensive empowerment in aspects of promotion, traffic, and resources. In December 2020, the first product of the Huobi Open Platform, the Huobi ECO Chain, also known as Heco, officially launched its "Tinder" phase. In addition, Huobi Open Platform will launch DEX and other blockchain infrastructures based on Layer 2. The Huobi Open Platform will provide global developers with series of diverse innovative facilities and services.

Introduction to Huobi ECO Chain

Huobi ECO Chain (Heco) is a decentralized, high-efficiency and energy-saving public chain, also the first product launched by the Huobi Open Platform. It is compatible with smart contracts and supports high-performance transactions. The endogenous token of Heco is HT and it adopts the HPoS consensus mechanism. Heco will continue to improve the efficiency of Ethereum by Layer2, which will supplement and empower the Ethereum ecosystem.

Declaration

To help developers’ evolvement at every stage

Vision

Technological innovation is the driving force behind the advancement of the blockchain industry, but many innovative projects have been misunderstood and ignored at their early stages. We have witnessed the growth process of great projects. Recalling that Ethereum and Polkadot were questioned as altcoins in the early days, they all went through difficult times. Therefore, Heco's mission is not only a public chain, but also to focus on the discovery and support of high-potential developers and innovative projects. Relying on the world's largest trading ecosystem, Heco is committed to becoming the birthplace of innovative technologies and innovative businesses, and building a complete ecological loop of technology development, application promotion, and trading.

Heco’s Performance

• TPS: 500+
• Average block interval: 3s

Consensus Mechanism

HPoS consensus mechanism: it has the characteristics of low transaction cost, low transaction delay, and high transaction concurrency.

The maximum number of validators supported is 21.

Economic Model

The endogenous token on the chain is HT; the transactions consume HT as gas fee.

Miners pledge HT to become validator nodes. The reward of nodes is gas fee, which is distributed according to the mortgage proportion.

Cross-Chain

Assets such as BTC, ETH and stable coins can be mapped to Heco by an asset bridge. The realization method is to lock a certain amount of tokens on the original chain then generate a corresponding number of tokens on Heco.

Heco encourages developers to provide more decentralized cross-chain solution.

Meta Transaction Function

The meta-transaction function is supported, which allows users to reduce gas fees step-wise, and Heco will cover the payment of the reduced part. The meta-transaction function allows to minimize the migration cost of DApp developers, as well as to effectively reduce the cost of DApp users.

Heco Technical Characteristics

• An open and decentralized network to maintain the security of the network and assets.
• Support the programmability of EVM, the compatibility of smart contracts to reduce development or migration costs.
• Meta-transaction function: gas fee reduction, effectively reducing the cost of developers and users on the chain.
• Support cross-chain asset transfer to optimize users’ experience.

Four Stages of Heco

Heco Technical Route
Stage	Features	Time	Sub Stage	Technical Points
Tinder	The initial version of Heco. The system is stable and easy to use. Developers can develop and promote Dapp at low cost. Users can participate in Dapp on Heco with a low threshold.	2020 Q4-2021 Q1	Public Beta	Higher transaction performance
				Lower transaction costs
				Meta transaction subsidy
			Node Election	More decentralized and safer
				Complete mainstream assets
				Basic tools in place
			Ecosystem Incubation	Technical service systemization
				Basic tool customization
				Convenient asset transfer
Spark	The protocol is further optimized. Heco will take the mission of connecting CeFi and DeFi, allowing more users to use DeFi applications at a low threshold.	2021 Q3	To be announced	Complete developer tools
				Complete developer forum, blog, and FAQ information
				Chain ecological infrastructure booms
				Innovative open ID
				Personalized portal accurately matches users and Dapps
Flame	Enable Layer2 technology. Expand performance while retaining the decentralized advantages of distributed protocols.	2022 Q2	To be announced	Application of Layer2
				Cross-chain interoperability protocol
				Cross-chain interoperability integration
Blaze	Landing of large-scale commercial applications. Support a variety of traditional businesses to run smoothly on the chain	2023 Q1	To be announced	Multiple virtual machine s supported
				Multiple zero-knowledge proofs and privacy protection capabilities
				Multiple signature schemes
				Storage compression and expansion solution
				Multi-dimensional sharding scheme

Current Stage of Heco

In December 2020, the Huobi ECO chain, Heco officially launched its "Tinder" phase, which will focus on improving the on-chain infrastructure, including but not limited to: Oracles, Voting tools, Anchor Coins, DEX, Lending, Fnancial Management, Insurance, Synthetic Assets, Cross-Chain Solutions, Data Analysis, Smart Contract Innovation, etc.

Support Plan of Heco

Financial Support

• Heco will set up a special fund to invest, support and incentivize high-potential developers.
• Heco will launch a variety of developer activities and competitions to discover and fund potential developers.
• In order to reduce the cost of users on Heco Dapp, the Heco meta transaction function will reduce the gas fee of users holding HT in a step-wise manner.

Traffic Support

Huobi Global will strongly support the development of Heco ecosystem:

• Provide traffic entrance for high-quality Dapp on Heco.
• After running successfully on Heco, high-quality projects can submit token listing application to Huobi Global, and can be listed on Huobi Global if they meet the listing standards.

Resource Support

• Projects or developers that have received investment and support from Heco have not only the opportunity to get official news report, but also can apply for marketing service packages and promote their projects globally.
• High-quality projects can participate in Heco global roadshows for free.
• Huobi Group will open up ecological resources to high-potential developers, matching the win-win cooperation between developers and our ecological partners.

Interact with Us on Social Media

• Facebook：Huobi Eco Chain
• Twitter：Huobi_EcoChain
• Telegram： HuobiEcoChain
• Weibo：火币生态链Heco
• Wechat Offical Account：Huobi Eco Heco

Risk Warning

• All users and developers can participate in the current test environment and subsequent stages of Heco for free, and there is no charging scenario.
• All users must distinguish the test environment from the Mainnet. The assets generated in the test environment have no value. Be aware of counterfeit currency fraud.
• Heco announces authorization, promotion and other collaborations only through the official social media platform. Developers and users should check carefully to avoid losses.
• Do not misread the official website (hecochain.com), and be cautious with private key phishing.

Documentation

Overview

Package ethereum defines interfaces for interacting with Ethereum.

Index

• Variables
• type CallMsg
• type ChainReader
• type ChainStateReader
• type ChainSyncReader
• type ContractCaller
• type FilterQuery
• type GasEstimator
• type GasPricer
• type LogFilterer
• type PendingContractCaller
• type PendingStateEventer
• type PendingStateReader
• type Subscription
• type SyncProgress
• type TransactionReader
• type TransactionSender

Variables

var NotFound = errors.New("not found")

NotFound is returned by API methods if the requested item does not exist.

Types

type CallMsg

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
	Value    *big.Int        // amount of wei sent along with the call
	Data     []byte          // input data, usually an ABI-encoded contract method invocation
}

CallMsg contains parameters for contract calls.

type ChainReader

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)
}

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 ChainStateReader

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)
}

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 ChainSyncReader

type ChainSyncReader interface {
	SyncProgress(ctx context.Context) (*SyncProgress, error)
}

ChainSyncReader wraps access to the node's current sync status. If there's no sync currently running, it returns nil.

type ContractCaller

type ContractCaller interface {
	CallContract(ctx context.Context, call CallMsg, blockNumber *big.Int) ([]byte, error)
}

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 FilterQuery

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

	// 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
}

FilterQuery contains options for contract log filtering.

type GasEstimator

type GasEstimator interface {
	EstimateGas(ctx context.Context, call CallMsg) (uint64, 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 GasPricer

type GasPricer interface {
	SuggestGasPrice(ctx context.Context) (*big.Int, error)
}

GasPricer wraps the gas price oracle, which monitors the blockchain to determine the optimal gas price given current fee market conditions.

type LogFilterer

type LogFilterer interface {
	FilterLogs(ctx context.Context, q FilterQuery) ([]types.Log, error)
	SubscribeFilterLogs(ctx context.Context, q FilterQuery, ch chan<- types.Log) (Subscription, error)
}

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 PendingContractCaller

type PendingContractCaller interface {
	PendingCallContract(ctx context.Context, call CallMsg) ([]byte, error)
}

PendingContractCaller can be used to perform calls against the pending state.

type PendingStateEventer

type PendingStateEventer interface {
	SubscribePendingTransactions(ctx context.Context, ch chan<- *types.Transaction) (Subscription, error)
}

A PendingStateEventer provides access to real time notifications about changes to the pending state.

type PendingStateReader

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)
}

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 Subscription

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
}

Subscription represents an event subscription where events are delivered on a data channel.

type SyncProgress

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
	PulledStates  uint64 // Number of state trie entries already downloaded
	KnownStates   uint64 // Total number of state trie entries known about
}

SyncProgress gives progress indications when the node is synchronising with the Ethereum network.

type TransactionReader

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)
}

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 TransactionSender

type TransactionSender interface {
	SendTransaction(ctx context.Context, tx *types.Transaction) 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.