hubble

README

Hubble Network

VNT Chain的公链——Hubble Network是下一代商业级智能价值传递的基础设施，致力于解决当前公链高能耗、低效率，难以支撑大规模商业应用的问题。它借鉴了以太坊架构，融合DPOS与BFT技术以获取更高的性能和安全性，服务于规模化商业应用，实现价值的无摩擦转移。基于VNT Chain的公有链，用户可建立和发布下一代分布式智能应用，如游戏、金融资产交易、知识产权交易、电子签约、社交等。

特点

1. 采用Vortex双层共识设计，可迅速验证交易及产生区块，高效节约。
2. Vortex具有快速终局性，避免分叉。
3. Vortex可容错1/3的见证人节点。
4. 采用基于WASM的智能合约执行引擎——WAVM，支持多开发语言，降低开发者门槛。
5. WAVM指令精简，可提高交易执行效率。
6. WAVM基于沙箱运行，内存方面具有良好的安全性。
7. WAVM是平台无关的，可运行在各种架构的CPU平台上，且性能等同于原生应用，具有良好的可移植性。
8. WAVM采用模块化设计，可以针对特定功能实现模块化库的开发，提高代码利用率。
9. 采用基于libp2p的P2P网络对已存在节点更加偏好，可以有效抵御恶意新节点的洪泛攻击。
10. P2P网络具有灵活简单特性，可从任意节点发起查找，且查找算法对数收敛，能快速定位内容。
11. P2P子协议框架具有稳定拓展特性，可以在其上任意扩展子协议处理，而底层框架无需做任何改动。

从源码安装Gvnt

安装gvnt需要Go编译器（版本大于1.9）和C编译器。

首先，克隆仓库go-vnt到路径$GOPATH/src/github.com/vntchain，并进入项目目录:

mkdir -p $GOPATH/src/github.com/vntchain
cd $GOPATH/src/github.com/vntchain
git clone https://github.com/vntchain/go-vnt
cd go-vnt

然后，使用下面命令编译gvnt:

make gvnt

或者使用下面命令编译gvnt和所有工具:

make all

经过以上可以在$GOPATH/src/github.com/vntchain/go-vnt/build/bin/目录调用gvnt，为方便使用可以将gvnt安装到$GOPATH/bin:

go install -v ./cmd/gvnt

运行Gvnt

当前VNT的公链测试网络还未启动，你可以在本地搭建一个小型测试网，资料请参考：如何搭建VNT网络。

资源

1. VNT Chain官网
2. VNT Chain开发者文档
3. VNT Chain白皮书

贡献源码

欢迎PR，感谢您为go-vnt做的任何一点改进。您可以fork项目到个人仓库后、修复问题进行提交，然后向go-vnt仓库发起PR。

贡献代码请遵循以下规则，方便go-vnt核心开发人员对代码进行Review。

1. 所有代码经gofmt进行格式化。
2. PR请遵循以下规则：
   1. 标题格式：[fixed/style/test] #Issue PR标题，fixed/style/test代表了修复/调整格式/修改测试，#Issue为本PR相关的Issue编号，PR标题为一句简洁话，描述本次PR的目的。
   2. PR内容：描述本次PR具体的内容，希望能尽可能详细，这样能让Review本PR的开发人员了解你的意图。

许可证

所有go-vnt仓库生成的二进制程序都采用GNU General Public License v3.0许可证, 具体请查看COPYING。

Documentation

Overview

Package hubble defines interfaces for interacting with VNT Hubble.

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 VM but not produced 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 {
	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, B in second position
	// {{A}, {B}}         matches topic A in first position, B in second position
	// {{A, B}}, {C, D}}  matches topic (A OR B) in first position, (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 producers, 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 VNT 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
	// produced 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 produced 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 produced.

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.