基于solidity的共享物品管理系统合约调试过程

这份合约包括创建物品、租用物品、支付押金租金返还押金等功能。这个需求其实很简单，很适合学习和参考。合约并非原创，感谢我的师兄对本合约的帮助！如果有语法还不清楚的朋友请参看solidity官方文档。

代码更新于2018.5.8 14：52分

pragma solidity ^0.4.4;

contract myShare {
struct Renter{
address addr;//renter's address
uint since;//from which time?
}

struct Object{
address creator;//the owner of obj
string name;// name of obj
uint priceDaily;//price of each day
uint deposit;//deposits of the obj
Renter renter;//who rent the obj
bool rented;//if rented?
string detail;//another infomation
}

struct Namekey{
uint[] keys;//storage the name's keys
}

uint[] private ids; //to return the ids of obj
uint public numObjects;
mapping(uint => Object) private objects;
mapping(string => Namekey) private nameToKeys;
address public owner;
event NewObject(uint objID,address creator);

modifier objectInRange(uint objID) {//modify function
if (objID >= numObjects)
throw;
_;
}

modifier onlyOwner(){
if(msg.sender != owner){
throw;
}
_;
}

function myShare() {
owner = msg.sender;
}

function objectIsRented(uint objID) objectInRange(objID) returns (bool){
return objects[objID].rented;
}

function createObj(string name,uint priceDaily,uint deposit,string detail){
Object newObject = objects[numObjects];
nameToKeys[name].keys.push(numObjects);//add the key to the name's key

newObject.creator = msg.sender;
newObject.name = name;
newObject.priceDaily = priceDaily;
newObject.rented = false;
newObject.deposit = deposit;
newObject.detail = detail;

NewObject(numObjects,msg.sender);
ids.push(numObjects);
numObjects++;
}

function rentObj(uint objID) payable objectInRange(objID) returns(bool){
if(objectIsRented(objID) || msg.value < objects[objID].deposit || msg.sender == objects[objID].creator){
throw;
}
objects[objID].renter = Renter({addr:msg.sender, since:now}); //record the info of the renter
uint rest = msg.value - objects[objID].deposit;
if(!objects[objID].renter.addr.send(rest)){ // return the rest balance
throw;
}
objects[objID].rented = true;
return true;
}

function returnObj(uint objID) payable objectInRange(objID) returns (bool){
if(!objects[objID].rented){
throw;
}
//if(objects[objID].renter.addr != msg.sender){
// throw;
//}
uint duration = (now - objects[objID].renter.since) / (24*60*60*1.0);
if(duration == 0){
duration = 1;
}
uint charge = duration * objects[objID].priceDaily;
if(!objects[objID].creator.send(charge)){ //return the charge to creator
throw;
}
if(!objects[objID].renter.addr.send(objects[objID].deposit - charge)){ //return the rest deposit to renter
throw;
}
delete objects[objID].renter;
objects[objID].rented = false;
return true;
}

function getBalance(address addr) returns (uint){

return addr.balance;

}

function findNames(string name) constant returns(uint[]){
return nameToKeys[name].keys;
}

function getNumObjects() constant returns(uint){
return numObjects;
}

function getObjectIds() constant returns(uint[]){
return ids;
}

function getObjectName(uint objID) objectInRange(objID) returns(string objName){
var obj = objects[objID];
objName = obj.name;
}

function getObjectCreator(uint objID) constant objectInRange(objID) returns(address){
return objects[objID].creator;
}

function getObjectPriceDaily(uint objID) constant objectInRange(objID) returns(uint){
return objects[objID].priceDaily;
}

function getObjectDeposit(uint objID) constant objectInRange(objID) returns(uint){
return objects[objID].deposit;
}

function getObjectRenterAddress(uint objID) constant objectInRange(objID) returns(address){
return objects[objID].renter.addr;
}

function getObjectRenterSince(uint objID) constant objectInRange(objID) returns(uint){
return objects[objID].renter.since;
}

function getObjectDetail(uint objID) constant objectInRange(objID) returns(string){
return objects[objID].detail;
}

function remove() onlyOwner {
selfdestruct(owner);
}

}

这份合约运行在Remix IDE上（一个在线的Solidity编译器很适合新手入门，直接百度进入）。如何编译运行参照点击打开链接

（下面这段解释我这个实验是怎么设计的。以及为什么这样设计）

我发现了一个很棘手的问题，创建合约和执行合约中的某个函数都要消耗gas，（什么是gas请参看点击打开链接），会给我的实验带来麻烦，我设计的验证方案是，账户1创建一个物品，账户2来租用，然后归还，跟踪整个过程中以太币的去向。但是比如账户2归还的时候一定会消耗gas，也就会消耗余额同时押金返还会增加余额，尽管日志中有gas消耗具体数值，但是实在不会计算。而账户1在创建物品后，不再需要调用任何函数，所以只能判断账户1的余额具体变化。应该有一个账户3，专门用来创建合约和调用函数的。简单来说就是为了跟踪余额，尽量排除gas带来的影响！但是到最后我设计的方案还是无法具体检测用户2的余额变化，因为消耗gas。如果有更好的实验方案请提出来谢谢！

一、创建合约

基于solidity的共享物品管理系统合约调试过程