Function ExDeleteDataDBFunc

src/vm/luavm/lmylib.cpp:1381–1415

*bool DeleteDataDB(const void* const key,const uint8_t keylen) * 这个函数式从中间层传了一个参数过来: * 1.第一个是 key值 */

 * 1.第一个是 key值
 */
int32_t ExDeleteDataDBFunc(lua_State *L) {
    vector<std::shared_ptr < vector<uint8_t> > > retdata;

    if (!GetDataString(L, retdata) || retdata.size() != 1) {
        LogPrint(BCLog::LUAVM, "ExDeleteDataDBFunc key err1");
        return RetFalse(string(__FUNCTION__) + "para  err !");
    }
    string key = string((*retdata.at(0)).begin(), (*retdata.at(0)).end());

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

    CRegID contractRegId       = pVmRunEnv->GetContractRegID();
    CContractDBCache *scriptDB = pVmRunEnv->GetScriptDB();

    bool flag = true;
    string oldValue;
    // TODO: get old data when set data ??
    scriptDB->GetContractData(contractRegId, key, oldValue);

    if (!scriptDB->EraseContractData(contractRegId, key)) {
        LogPrint(BCLog::LUAVM, "ExDeleteDataDBFunc EraseContractData railed, key:%s!\n", HexStr(*retdata.at(0)));
        lua_BurnStoreUnchanged(L, key.size(), oldValue.size(), BURN_VER_R2);
        flag = false;
    } else {
        lua_BurnStoreSet(L, key.size(), oldValue.size(), 0, BURN_VER_R2);
    }
    #ifdef TRACE_LUAVM_CONTRACT_DATA
    LogPrint(BCLog::LUAVM, "DeleteData(), contract_regid=%s, key=%s, key_hex=%s, old_value=%s, old_value_hex=%s\n",
        contractRegId.ToString(), key, HexStr(key), oldValue, HexStr(oldValue));
    #endif//TRACE_LUAVM_CONTRACT_DATA
    return RetRstBooleanToLua(L, flag);
}

/**
 *uint16_t ReadDataValueDB(const void* const key,const uint8_t keylen, void* const value,uint16_t const maxbuffer)