add web3 useing

README.md

@@ -401,4 +401,95 @@ func TestCall(t *testing.T) {
 ```
 
 
+### web3使用说明
+
+可以使用 `web3.js` 很方便的在链上发布和使用 `wasm` 合约，我们提供了一个简单的封装用以演示 `hello-wasm` 的部署和调用合约中提供的三个方法
+
+可以将 [test-wasm-js](https://code.wuban.net.cn/cmpchain/ewasm-rust-demo/tree/master/test-wasm-js) 目录下的演示代码下载到本地，
+
+代码依赖 `nodejs` 环境以及 `npm` 工具，下载后 `npm install` 安装依赖并修改 `config.js` 填入正确的参数即可通过如下操作完成部署和使用合约
+
+#### config.js
+
+配置：
+
+* ethereumUri : 链的 rpc 接口地址
+* chainId : 可以通过 admin.nodeInfo 查看当前节点的 chainId,需要正确填写
+* gasLimit : 1800 万gas 
+* gasPrice : 18gwei 的 price
+* keyStore : 在keyStore 中管理的私钥文件内容，是一个 json 
+* password : 私钥文件的密码
+* wasm_path : 要发布的合约 filepath
+* methods : 合约提供的函数，类似 abi 的定义
+
+例如：
+
+```javascript
+const config = {
+    'ethereumUri': 'http://127.0.0.1:8545', 
+    'chainId': 738,
+    'gasLimit': 15000000,
+    'gasPrice': 18000000000,
+    'keyStore': '{"address":"286a713af771b89f7bd2bfb46832da710780552e","crypto":{"cipher":"aes-128-ctr","ciphertext":"c4b50bcc8127a99a9b7fa2484e3494032435f1f3bdc829b10a0b87bfe6cb6215","cipherparams":{"iv":"be2fa649e7cf0516db8f221371dbdb93"},"kdf":"scrypt","kdfparams":{"dklen":32,"n":262144,"p":1,"r":8,"salt":"3fde3e3d2d2e4576675868f443aca47a289ef913d46f973f405c79092d5b65dd"},"mac":"8e673dbf025e88115f2b913ec891a41e47b8dcdca572b3e3a96584bb1ca2cb78"},"id":"014df77c-b7fd-484e-8e1e-5d6a5a9fa902","version":3}',
+    'password': '123456',
+    'wasm_path': '/Users/wuxinyang/Desktop/MyGo/src/rust/hello-wasm/pkg/hello_wasm_bg.wasm',
+    'methods': {'put': 'put:{},{}', 'get': 'get:{}', 'GetCounter': 'GetCounter'}
+}
+module.exports = config
+```
+
+#### index.js 
+
+测试程序的入口，正确填写配置后使用 `npm test` 会默认执行这个脚本
+
+```javascript
+
+function test_put(...params) {
+    let put_method = config.methods['put']
+    put_method = format(put_method, params[0], params[1])
+    let data = web3.utils.toHex(put_method)
+    contract.runWriteMethod(data)
+}
+
+function test_get(key) {
+    let get_method = config.methods['get']
+    get_method = format(get_method, key)
+    let data = web3.utils.toHex(get_method)
+    contract.runReadMethod(data).then(value => {
+        console.log(`value==>${web3.utils.hexToString(value)}`)
+        test_GetCounter()
+    })
+}
+
+function test_GetCounter() {
+    let getcounter_method = config.methods['GetCounter']
+    let data = web3.utils.toHex(getcounter_method)
+    contract.runReadMethod(data).then(counter => {
+        console.log(`counter==>${web3.utils.hexToNumber(counter)}`)
+    })
+}
+
+//部署并调用合约3个方法
+//此测试方法每次调用时都会重新部署一次 hello-wasm 合约，
+function test() {
+    // 2:合约部署成功后触发该事件，通过 put(key,val) 函数插入状态
+    contract.once('contract_address', contract_address => {
+        console.log(`contract_address==>${contract_address}`)
+        contract.contract_address = contract_address
+        test_put('foo', 'bar')
+    })
+
+    // 3:put成功后触发该事件，通过 get(key) 函数获取刚刚插入的状态
+    // 同时通过合约的 GetCounter 函数获取合约状态变更次数
+    contract.once('runWriteMethod_success', ()=>{
+        test_get('foo')
+    })
+    // 1:部署合约
+    contract.pub()
+}
+
+//脚本入口函数
+test()
+```
+
 

test-wasm-js/Contract.js

+const fs = require('fs')
+const Web3 = require('web3')
+const co = require('co')
+const thunk = require('thunkify')
+const Tx = require('ethereumjs-tx')
+const EventEmitter = require('events').EventEmitter
+const config = require('./config.js')
+
+class Contract extends EventEmitter {
+    constructor() {
+        super()
+        this.web3 = new Web3(new Web3.providers.HttpProvider(config.ethereumUri))
+        this.getTransactionCount = thunk(this.web3.eth.getTransactionCount)
+    }
+
+    pub() {
+        let _this = this
+        let rs = fs.createReadStream(config.wasm_path)
+        rs.on('data', function (data) {
+            data = data.toString('hex')
+            _this._sendTransaction('0x' + data)
+        })
+    }
+
+    runReadMethod(data) {
+        let _this = this
+        return this.web3.eth.call({
+            to: _this.contract_address,
+            data: data
+        })
+    }
+
+    runWriteMethod(data) {
+        this._sendTransaction(data)
+    }
+
+    _sendTransaction(data) {
+        let decryptObj = this.web3.eth.accounts.decrypt(config.keyStore, config.password)
+        let address = decryptObj.address
+        let privateKey = decryptObj.privateKey
+        privateKey = Buffer.from(privateKey.substring(2), 'hex')
+        let _this = this
+        co(function* () {
+            let nonce = yield _this.getTransactionCount(address, 'pending')
+            let rawTransaction = {
+                "from": address,
+                "to": _this.contract_address ? _this.contract_address : '',
+                "nonce": "0x" + nonce.toString(16),
+                "gasPrice": _this.web3.utils.toHex(config.gasPrice),
+                "gasLimit": _this.web3.utils.toHex(config.gasLimit),
+                "data": data,
+                "chainId": _this.web3.utils.toHex(config.chainId)
+            }
+            let tx = new Tx(rawTransaction)
+            tx.sign(privateKey)
+            let serializedTx = tx.serialize()
+            let sign = '0x' + serializedTx.toString('hex')
+            try {
+                let date = new Date();
+                let transaction = _this.web3.eth.sendSignedTransaction(sign)
+                transaction.on('transactionHash', hash => {
+                    console.log(`[${date.toLocaleString()}] hash ${hash}`);
+                });
+                transaction.on('receipt', receipt => {
+                    if (receipt.contractAddress) {
+                        _this.emit('contract_address', receipt.contractAddress)
+                    } else {
+                        _this.emit('runWriteMethod_success')
+                    }
+                });
+            } catch (error) {
+                console.log('sendSignedTransaction err:', error);
+            }
+        })
+    }
+}
+
+module.exports = new Contract()

test-wasm-js/config.js

+const config = {
+		'ethereumUri': 'http://127.0.0.1:8545',
+		'chainId': 738,
+		'gasLimit': 15000000,
+		'gasPrice': 18000000000,
+		'keyStore': '{"address":"286a713af771b89f7bd2bfb46832da710780552e","crypto":{"cipher":"aes-128-ctr","ciphertext":"c4b50bcc8127a99a9b7fa2484e3494032435f1f3bdc829b10a0b87bfe6cb6215","cipherparams":{"iv":"be2fa649e7cf0516db8f221371dbdb93"},"kdf":"scrypt","kdfparams":{"dklen":32,"n":262144,"p":1,"r":8,"salt":"3fde3e3d2d2e4576675868f443aca47a289ef913d46f973f405c79092d5b65dd"},"mac":"8e673dbf025e88115f2b913ec891a41e47b8dcdca572b3e3a96584bb1ca2cb78"},"id":"014df77c-b7fd-484e-8e1e-5d6a5a9fa902","version":3}',
+		'password': '123456',
+		'wasm_path': '/app/rusthome/hello-wasm/pkg/hello_wasm_bg.wasm',
+		'methods': {'put': 'put:{},{}', 'get': 'get:{}', 'GetCounter': 'GetCounter'}
+}
+
+module.exports = config

test-wasm-js/index.js

+const contract = require('./Contract')
+const format = require('string-format')
+const Web3 = require('web3')
+const web3 = new Web3()
+const config = require('./config')
+
+function test_put(...params) {
+    let put_method = config.methods['put']
+    put_method = format(put_method, params[0], params[1])
+    let data = web3.utils.toHex(put_method)
+    contract.runWriteMethod(data)
+}
+
+function test_get(key) {
+    let get_method = config.methods['get']
+    get_method = format(get_method, key)
+    let data = web3.utils.toHex(get_method)
+    contract.runReadMethod(data).then(value => {
+        console.log(`value==>${web3.utils.hexToString(value)}`)
+        test_GetCounter()
+    })
+}
+
+function test_GetCounter() {
+    let getcounter_method = config.methods['GetCounter']
+    let data = web3.utils.toHex(getcounter_method)
+    contract.runReadMethod(data).then(counter => {
+        console.log(`counter==>${web3.utils.hexToNumber(counter)}`)
+    })
+}
+
+function test() {
+    contract.once('contract_address', contract_address => {
+        console.log(`contract_address==>${contract_address}`)
+        contract.contract_address = contract_address
+        test_put('foo', 'bar')
+    })
+    contract.once('runWriteMethod_success', ()=>{
+        test_get('foo')
+    })
+    contract.pub()
+}
+
+test()

test-wasm-js/package.json

+{
+  "name": "wasm_contract_test",
+  "version": "1.0.0",
+  "description": "wasm contract publish and run with MetaVM",
+  "main": "index.js",
+  "scripts": {
+    "test": "node index.js"
+  },
+  "keywords": [
+    "wasm",
+    "contract",
+    "pdx"
+  ],
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "co": "^4.6.0",
+    "ethereumjs-tx": "1.3.7",
+    "string-format": "^2.0.0",
+    "thunkify": "^2.1.2",
+    "web3": "1.0.0-beta.34"
+  }
+}