SYNOPSIS概要

Implements Ethereum's VM in Javascript.用Javascript实现以太坊虚拟机

Fork Support分支支持

Starting with the v2.5.0 release we now support both Byzantium and Constantinople fork rules - with Byzantium currently being the default (this will change in the future). See release notes for further details and have a look at the API docs on instructions how to instantiate the VM with the respective fork rules.

从v2.5.0版本发布开始，我们现在支持Byzantium和Constantinople两种分支规则-目前Byzantium是默认值（未来会改变）。看 release notes 了解更多版本细节并在说明中查看 API docs文档，了解要如何根据相应的版本初始化虚拟机

If you are still looking for a Spurious Dragon compatible version of this library install the latest of the 2.2.x series (see Changelog).

如果你仍在寻找这个库的Spurious Dragon兼容版本，可以安装最新的2.2.x系列

INSTALL

npm install ethereumjs-vm

USAGE

 
  var VM = require('ethereumjs-vm')

//create a new VM instance
var vm = new VM()
var code = '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'

vm.runCode({
  code: Buffer.from(code, 'hex'), // code needs to be a Buffer
  gasLimit: Buffer.from('ffffffff', 'hex')
}, function(err, results){
  console.log('returned: ' + results.return.toString('hex'));
}) 
 

Also more examples can be found here更多的例子可以在下面找到

BROWSER

To build for standalone use in the browser, install browserify and check run-transactions-simple example. This will give you a global variable EthVM to use. The generated file will be at ./examples/run-transactions-simple/build.js.

为了创建能够在浏览器中单独使用的情况，需要安装browserify模块，然后查看 run-transactions-simple example例子(可看本博客ethereumjs-vm/examples/run-transactions-simple)。这将提供全局变量EthVM 给你使用。生成的文件将在./examples/run-transactions-simple/build.js

API

VM

For documentation on VM instantiation, exposed API and emitted events see generated API docs.

有关VM实例化、公开API和发出事件的文档，可见生成的API docs (可看本博客ethereumjs/ethereumjs-vm-2-API文档)

StateManger状态管理

The API for the StateManager is currently in Beta, separate documentation can be found here.StateManager的API目前还是Beta版本，其单独的文档可见 here （可看本博客ethereumjs/ethereumjs-vm-3-StateManager）

The StateManager API has been largely reworked recently and the StateManager will be removed from the VM and provided as a separate package in a future v3.0.0 release, see release notes for the v2.5.0 VM release for further details.StateManager的API最近已经重新复用，并且StateManager将从VM中移除，在未来的v3.0.0版本中将作为单独的包来提供，更过未来的细节可见v2.5.0版本的VM发行release notes

Internal Structure内部结构

The VM processes state changes at many levels.

VM在许多级别上流程状态会变化

runBlockchain
- for every block, runBlock 就是对链上的没有区块都运行runBlock方法
runBlock
- for every tx, runTx 就是对区块中的所有交易都运行runTx方法
- pay miner and uncles 然后付款给矿工和叔块
runTx
- check sender balance 先查看发送者的余额
- check sender nonce 再检查发送者的nonce值
- runCall 运行runCall方法
- transfer gas charges 转移收取的gas费用
runCall
- checkpoint state 保存检查点状态
- transfer value 转移值
- load code 下载代码
- runCode 运行runCode方法
- materialize created contracts 实现创建的合约
- revert or commit checkpoint 恢复或提交检查点状态
runCode
- iterate over code 遍历代码
- run op codes 运行操作码
- track gas usage 追踪gas的使用
OpFns
- run individual op code 独自运行操作码
- modify stack 修改堆栈
- modify memory 修改内存
- calculate fee 计算开销

The opFns for CREATE, CALL, and CALLCODE call back up to runCall.

用于CREATE, CALL和CALLCODE调用的opFns将会回调到 runCall。

DEVELOPMENT开发

Developer documentation - currently mainly with information on testing and debugging - can be found here.

开发者文档-目前主要是测试和调试信息-可在here找到

Spurious Dragon

ethereumjs/ethereumjs-vm-1-简介