1.2、基于Geth部署合约

智能合约，我理解它就是程序机器码，可以在区块链上执行的代码，好比 C语言的*.o 文件，Java的 *.class 文件。

1. 启动 私有链，我们的程序（合约）就跑在这条私有链上。

   $ geth --datadir data0 --networkid 1108 --nodiscover console

2. 查看挖矿账户

   > web3.eth.coinbase 
   "0x5400ca57071e4d804e1d5f7c14f63a70fa90d541"

3. 编写solidity代码

   pragma solidity ^0.4.0;
   
   contract HelloWorld { 
       
       function test(uint a) constant returns(uint d){
           
           return a * 8;
       } 
   }

4. 编译为字节码和abi

   在线编译 ，compile - Start To compile -> Details

   bytecode 只要 object 的值，abi 全部拷贝。

   注：Details -> web3Deploy有部署的示例，但我们自己手动来一遍。

   # bytecode
   6060604052341561000f57600080fd5b60b98061001d6000396000f300606060405260043610603f576000357c0100000000000000000000000000000000000000000000000000000000900463ffffffff16806329e99f07146044575b600080fd5b3415604e57600080fd5b606a600480360381019080803590602001909291905050506080565b6040518082815260200191505060405180910390f35b60006008820290509190505600a165627a7a7230582079ee88ca1fe7e781407b09bc2c5497dcabc538d6930265a54386d2b71b0cd7510029
   
   # abi
   [
   	{
   		"constant": true,
   		"inputs": [
   			{
   				"name": "a",
   				"type": "uint256"
   			}
   		],
   		"name": "test",
   		"outputs": [
   			{
   				"name": "d",
   				"type": "uint256"
   			}
   		],
   		"payable": false,
   		"stateMutability": "view",
   		"type": "function"
   	}
   ]
   # abi转义
   [{\"constant\":true,\"inputs\":[{\"name\":\"a\",\"type\":\"uint256\"}],\"name\":\"test\",\"outputs\":[{\"name\":\"d\",\"type\":\"uint256\"}],\"payable\":false,\"stateMutability\":\"view\",\"type\":\"function\"}]

5. 创建合约对象

   # 赋值为本地变量。
   # 因为是十六进制，加上 0x 赋值给 bytecode
   >
   > bytecode = '0x6060604052341561000f57600080fd5b60b98061001d6000396000f300606060405260043610603f576000357c0100000000000000000000000000000000000000000000000000000000900463ffffffff16806329e99f07146044575b600080fd5b3415604e57600080fd5b606a600480360381019080803590602001909291905050506080565b6040518082815260200191505060405180910390f35b60006008820290509190505600a165627a7a7230582079ee88ca1fe7e781407b09bc2c5497dcabc538d6930265a54386d2b71b0cd7510029'
   >
   # abi要解析为对象。
   > var abi = JSON.parse('[{\"constant\":true,\"inputs\":[{\"name\":\"a\",\"type\":\"uint256\"}],\"name\":\"test\",\"outputs\":[{\"name\":\"d\",\"type\":\"uint256\"}],\"payable\":false,\"stateMutability\":\"view\",\"type\":\"function\"}]')
   >
   > var helloWorldContract = web3.eth.contract(abi)
   undefined

6. 预估部署合约的手续费

   > eth.estimateGas({data: bytecode})
   102074
   # 查看余额，如果账户的余额不够，先挖矿。
   > account1 = web3.eth.coinbase
   > web3.eth.getBalance(account1)
   600000000000000000000

7. 部署

   # 解锁
   > personal.unlockAccount(account1, '123456') 
   true
   # 部署，gas 是手续费
   > var helloWorldContractInstance = helloWorldContract.new({data: bytecode ,gas: 2000000, from: account1})
   # 或者带上一个回调函数function，用于打印日志
   > var helloWorldContractInstance = helloWorldContract.new(
   	{
   	data: bytecode,
   	gas: 2000000,
   	from: account1
   	}, function (e, contract){
   		console.log(e, contract);
   		if (typeof contract.address !== 'undefined') {
   			 console.log('Contract mined! address: ' + contract.address + ' transactionHash: ' + contract.transactionHash);
   		}
   })
   
   # 从log看到，合约已经创建
   INFO [03-30|20:50:12] Submitted contract creation              fullhash=0x583c5c0e6f8c2225cd8411b1ba0a58304505aea929d6c9cd1c0773c952657416 contract=0x05E4898E94785523c6C5AcBa4324B529B5197Bcf
   null [object Object]
   undefined

8. 合约等待挖矿，开始挖矿

   合约需要有节点在挖矿才能部署成功，所以我们先启动挖矿。

   > miner.start()
   INFO [03-30|20:51:30] Updated mining threads                   threads=0
   INFO [03-30|20:51:30] Transaction pool price threshold updated price=18000000000
   null
   # 这里等待一会
   > INFO [03-30|20:51:30] Starting mining operation 
   INFO [03-30|20:51:30] Commit new mining work                   number=195 txs=1 uncles=0 elapsed=998.832µs
   INFO [03-30|20:51:46] Successfully sealed new block            number=195 hash=d60b89…65bffe
   INFO [03-30|20:51:46] 🔗 block reached canonical chain          number=190 hash=4159ba…196761
   INFO [03-30|20:51:46] 🔨 mined potential block                  number=195 hash=d60b89…65bffe
   INFO [03-30|20:51:46] Commit new mining work                   number=196 txs=0 uncles=0 elapsed=7.087ms
   null [object Object]
   Contract mined! address: 0x05e4898e94785523c6c5acba4324b529b5197bcf transactionHash: 0x583c5c0e6f8c2225cd8411b1ba0a58304505aea929d6c9cd1c0773c952657416
   INFO [03-30|20:51:55] Successfully sealed new block            number=196 hash=f6a947…15b0a4
   INFO [03-30|20:51:55] 🔗 block reached canonical chain          number=191 hash=c95b93…bdd2a6
   INFO [03-30|20:51:55] 🔨 mined potential block                  number=196 hash=f6a947…15b0a4
   INFO [03-30|20:51:55] Commit new mining work                   number=197 txs=0 uncles=0 elapsed=2.289ms
   # 只要挖矿成功了，就可以停止了
   > miner.stop()
   true

9. 检查部署结果和调用合约方法

   > helloWorldContractInstance.address
   "0x05e4898e94785523c6c5acba4324b529b5197bcf"
   > 
   > eth.getCode(helloWorldContractInstance.address)
   "0x606060405260043610603f576000357c0100000000000000000000000000000000000000000000000000000000900463ffffffff16806329e99f07146044575b600080fd5b3415604e57600080fd5b606a600480360381019080803590602001909291905050506080565b6040518082815260200191505060405180910390f35b60006008820290509190505600a165627a7a7230582079ee88ca1fe7e781407b09bc2c5497dcabc538d6930265a54386d2b71b0cd7510029"
   > 
   > 
   > helloWorldContractInstance.test(4)
   32

10. OK