Function ExReadDataDBFunc

src/vm/luavm/lmylib.cpp:1422–1453

*uint16_t ReadDataValueDB(const void* const key,const uint8_t keylen, void* const value,uint16_t const maxbuffer) * 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 ExReadDataDBFunc(lua_State *L) {
    vector<std::shared_ptr < vector<uint8_t> > > retdata;

    if (!GetDataString(L,retdata) ||retdata.size() != 1) {
        return RetFalse("ExReadDataDBFunc key err1");
    }

    string key((*retdata.at(0)).begin(), (*retdata.at(0)).end());

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

    CRegID scriptRegId = pVmRunEnv->GetContractRegID();

    string value;
    CContractDBCache* scriptDB = pVmRunEnv->GetScriptDB();
    int32_t len = 0;
    if (!scriptDB->GetContractData(scriptRegId, 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, "ReadData(), contract_regid=%s, key=%s, key_hex=%s, value=%s, value_hex=%s\n",
            scriptRegId.ToString(), key, HexStr(key), value, HexStr(value));
    #endif//TRACE_LUAVM_CONTRACT_DATA
    return len;
}

int32_t ExGetCurTxHash(lua_State *L) {