Function ExGetContractDataFunc

src/vm/luavm/lmylib.cpp:1640–1670

*bool GetContractData(const void* const scriptID,void* const pkey,short len,void* const pValue,short maxlen) * 中间层传了两个个参数 * 1.脚本的id号 * 2.数据库的key值 */

 * 2.数据库的key值
 */
int32_t ExGetContractDataFunc(lua_State *L) {
    vector<std::shared_ptr<vector<uint8_t>>> retdata;

    if (!GetDataTableGetContractData(L, retdata) || retdata.size() != 2 || retdata.at(0).get()->size() != 6)
        return RetFalse("ExGetContractDataFunc tep1 err1");

    CLuaVMRunEnv *pVmRunEnv = GetVmRunEnv(L);
    if (nullptr == pVmRunEnv)
        return RetFalse("pVmRunEnv is nullptr");

    CContractDBCache *scriptDB = pVmRunEnv->GetScriptDB();
    CRegID contractRegId(*retdata.at(0));
    string key((*retdata.at(1)).begin(), (*retdata.at(1)).end());
    string value;

    int32_t len = 0;
    if (contractRegId.IsEmpty() || !scriptDB->GetContractData(contractRegId, key, value)) {
        len = 0;
        lua_BurnStoreUnchanged(L, key.size(), 0, BURN_VER_R2);
    } else {
        lua_BurnStoreGet(L, key.size(), value.size(), BURN_VER_R2);
        len = RetRstToLua(L, vector<uint8_t>(value.begin(), value.end()));
    }
    #ifdef TRACE_LUAVM_CONTRACT_DATA
        LogPrint(BCLog::LUAVM, "GetContractData(), contract_regid=%s, key=%s, key_hex=%s, value=%s, value_hex=%s\n",
            contractRegId.ToString(), key, HexStr(key), value, HexStr(value));
    #endif//TRACE_LUAVM_CONTRACT_DATA
    /*
     * 每个函数里的Lua栈是私有的,当把返回值压入Lua栈以后，该栈会自动被清空*/
    return len;
}

/**
 * 取目的账户ID