示例三:数字货币发行与管理

简介

该智能合约实现一个简单的商业应用案例,即数字货币的发行与转账。在这之中一共分为三种角色:中央银行,商业银行,企业。其中中央银行可以发行一定数量的货币,企业之间可以进行相互的转账。主要实现如下的功能:

  • 初始化中央银行及其发行的货币数量

  • 新增商业银行,同时央行并向其发行一定数量的货币

  • 新增企业

  • 商业银行向企业转给一定数量的数字货币

  • 企业之间进行相互的转账

  • 查询企业、银行、交易信息

主要函数

  • init:初始化中央银行,并发行一定数量的货币;

  • invoke:调用合约内部的函数;

  • query:查询相关的信息;

  • createBank:新增商业银行,同时央行向其发行一定数量的货币;

  • createCompany:新增企业;

  • issueCoin:央行再次发行一定数量的货币(归于交易);

  • issueCoinToBank:央行向商业银行转一定数量的数字货币(归于交易);

  • issueCoinToCp:商业银行向企业转一定数量的数字货币(归于交易行为);

  • transfer:企业之间进行相互转账(归于交易行为);

  • getCompanys:获取所有的公司信息,如果企业个数大于10,先访问前10个;

  • getBanks:获取所有的商业银行信息,如果商业银行个数大于10,先访问前 10 个

  • getTransactions:获取所有的交易记录 如果交易个数大于10,先访问前 10 个;

  • getCompanyById:获取某家公司信息;

  • getBankById:获取某家银行信息;

  • getTransactionBy:获取某笔交易记录;

  • writeCenterBank:修改央行信息;

  • writeBank:修改商业银行信息;

  • writeCompany:修改企业信息;

  • writeTransaction:写入交易信息。

数据结构设计

  • centerBank 中央银行

    • Name:名称

    • TotalNumber:发行货币总数额

    • RestNumber:账户余额

    • ID:ID固定为 0

  • bank 商业银行

    • Name:名称

    • TotalNumber:收到货币总数额

    • RestNumber:账户余额

    • ID:银行 ID

  • company 企业

    • Name:名称

    • Number:账户余额

    • ID:企业 ID

  • transaction 交易内容

    • FromType:发送方角色 //centerBank:0,Bank:1,Company:2

    • FromID:发送方 ID

    • ToType:接收方角色 //Bank:1,Company:2

    • ToID:接收方 ID

    • Time:交易时间

    • Number:交易数额

    • ID:交易 ID

接口设计

init

request 参数:

args[0] 银行名称
args[1] 初始化发布金额

response 参数:

{"Name":"XXX","TotalNumber":"0","RestNumber":"0","ID":"XX"}

createBank

request 参数:

args[0] 银行名称

response 参数:

{"Name":"XXX","TotalNumber":"0","RestNumber":"0","ID":"XX"}

createCompany

request 参数:

args[0] 公司名称

response 参数:

{"Name":"XXX","Number":"0","ID":"XX"}

issueCoin

request 参数:

args[0] 再次发行货币数额

response 参数:

{"FromType":"0","FromID":"0","ToType":"0","ToID":"0","Time":"XX","Number":"XX","ID":"XX"}

issueCoinToBank

request 参数:

args[0] 商业银行ID
args[1] 转账数额

response 参数:

{"FromType":"0","FromID":"0","ToType":"1","ToID":"XX","Time":"XX","Number":"XX","ID":"XX"}

issueCoinToCp

request 参数:

args[0] 商业银行ID
args[1] 企业ID
args[2] 转账数额

response 参数:

{"FromType":"1","FromID":"XX","ToType":"2","ToID":"XX","Time":"XX","Number":"XX","ID":"XX"}

transfer

request 参数:

args[0] 转账用户ID
args[1] 被转账用户ID
args[2] 转账余额

response 参数:

{"FromType":"2","FromID":"XX","ToType":"2","ToID":"XX","Time":"XX","Number":"XX","ID":"XX"}

getBanks

response 参数

[{"Name":"XXX","Number":"XX","ID":"XX"},{"Name":"XXX","Number":"XX","ID":"XX"},...]

getCompanys

response 参数

[{"Name":"XXX","TotalNumber":"XX","RestNumber":"XX","ID":"XX"},{"Name":"XXX","TotalNumber":"XX","RestNumber":"XX","ID":"XX"},...]

getTransactions

response 参数

[{"FromType":"XX","FromID":"XX","ToType":"XX","ToID":"XX","Time":"XX","Number":"XX","ID":"XX"},{"FromType":"XX","FromID":"XX","ToType":"XX","ToID":"XX","Time":"XX","Number":"XX","ID":"XX"},...]

getCenterBank

response 参数

[{"Name":"XX","TotalNumber":"XX","RestNumber":"XX","ID":"XX"}]

getBankById

request 参数

args[0] 商业银行ID

response 参数

[{"Name":"XX","TotalNumber":"XX","RestNumber":"XX","ID":"XX"}]

getCompanyById

request 参数

args[0] 企业ID

response 参数

[{"Name":"XXX","Number":"XX","ID":"XX"}]

getTransactionById

request 参数

args[0] 交易ID

response 参数

{"FromType":"XX","FromID":"XX","ToType":"XX","ToID":"XX","Time":"XX","Number":"XX","ID":"XX"}

writeCenterBank

request 参数

CenterBank

response 参数

err nil 为成功

writeBank

request 参数

Bank

response 参数

err nil 为成功

writeCompany

request 参数

Company

response 参数

err nil 为成功

writeTransaction

request 参数

Transaction

response 参数

``` err nil 为成功 ···

其它

查询时为了兼顾读速率,将一些信息备份存放在非区块链数据库上也是一个较好的选择。