C++ UniValue::empty方法代码示例

    bool LoadCheckpoints(const std::string& strNetwork)
    {
        UniValue v;
        if (strNetwork == "main")
            v = read_json(GetMainCheckpoints());
        else if (strNetwork == "test")
            v = read_json(GetTestCheckpoints());
        else if (strNetwork == "regtest")
            v = read_json(GetRegTestCheckpoints());
        else
            return false;

        if (v.empty())
            return false;

        for (unsigned int idx = 0; idx < v.size(); idx++) {
            const UniValue &val = v[idx];
            const UniValue &o = val.get_obj();

            const UniValue &vHeight = find_value(o, "height");
            if (!vHeight.isNum())
                return false;

            int nHeight = vHeight.get_int();
            if (nHeight < 0)
                return false;

            Checkpoint checkpoint;
            for (auto denom : libzerocoin::zerocoinDenomList) {
                const UniValue& vDenomValue = find_value(o, std::to_string(denom));
                if (!vDenomValue.isStr()) {
                    return false;
                }
                CBigNum bn = 0;
                bn.SetHex(vDenomValue.get_str());
                checkpoint.insert(std::make_pair(denom, bn));
            }

            mapCheckpoints.insert(make_pair(nHeight, checkpoint));
        }
        return true;
    }

static UniValue CallRPC(BaseRequestHandler *rh, const std::string& strMethod, const std::vector<std::string>& args)
{
    std::string host;
    // In preference order, we choose the following for the port:
    //     1. -rpcport
    //     2. port in -rpcconnect (ie following : in ipv4 or ]: in ipv6)
    //     3. default port for chain
    int port = BaseParams().RPCPort();
    SplitHostPort(gArgs.GetArg("-rpcconnect", DEFAULT_RPCCONNECT), port, host);
    port = gArgs.GetArg("-rpcport", port);

    // Obtain event base
    raii_event_base base = obtain_event_base();

    // Synchronously look up hostname
    raii_evhttp_connection evcon = obtain_evhttp_connection_base(base.get(), host, port);
    evhttp_connection_set_timeout(evcon.get(), gArgs.GetArg("-rpcclienttimeout", DEFAULT_HTTP_CLIENT_TIMEOUT));

    HTTPReply response;
    raii_evhttp_request req = obtain_evhttp_request(http_request_done, (void*)&response);
    if (req == nullptr)
        throw std::runtime_error("create http request failed");
#if LIBEVENT_VERSION_NUMBER >= 0x02010300
    evhttp_request_set_error_cb(req.get(), http_error_cb);
#endif

    // Get credentials
    std::string strRPCUserColonPass;
    bool failedToGetAuthCookie = false;
    if (gArgs.GetArg("-rpcpassword", "") == "") {
        // Try fall back to cookie-based authentication if no password is provided
        if (!GetAuthCookie(&strRPCUserColonPass)) {
            failedToGetAuthCookie = true;
        }
    } else {
        strRPCUserColonPass = gArgs.GetArg("-rpcuser", "") + ":" + gArgs.GetArg("-rpcpassword", "");
    }

    struct evkeyvalq* output_headers = evhttp_request_get_output_headers(req.get());
    assert(output_headers);
    evhttp_add_header(output_headers, "Host", host.c_str());
    evhttp_add_header(output_headers, "Connection", "close");
    evhttp_add_header(output_headers, "Authorization", (std::string("Basic ") + EncodeBase64(strRPCUserColonPass)).c_str());

    // Attach request data
    std::string strRequest = rh->PrepareRequest(strMethod, args).write() + "\n";
    struct evbuffer* output_buffer = evhttp_request_get_output_buffer(req.get());
    assert(output_buffer);
    evbuffer_add(output_buffer, strRequest.data(), strRequest.size());

    // check if we should use a special wallet endpoint
    std::string endpoint = "/";
    if (!gArgs.GetArgs("-rpcwallet").empty()) {
        std::string walletName = gArgs.GetArg("-rpcwallet", "");
        char *encodedURI = evhttp_uriencode(walletName.c_str(), walletName.size(), false);
        if (encodedURI) {
            endpoint = "/wallet/"+ std::string(encodedURI);
            free(encodedURI);
        }
        else {
            throw CConnectionFailed("uri-encode failed");
        }
    }
    int r = evhttp_make_request(evcon.get(), req.get(), EVHTTP_REQ_POST, endpoint.c_str());
    req.release(); // ownership moved to evcon in above call
    if (r != 0) {
        throw CConnectionFailed("send http request failed");
    }

    event_base_dispatch(base.get());

    if (response.status == 0) {
        std::string responseErrorMessage;
        if (response.error != -1) {
            responseErrorMessage = strprintf(" (error code %d - \"%s\")", response.error, http_errorstring(response.error));
        }
        throw CConnectionFailed(strprintf("Could not connect to the server %s:%d%s\n\nMake sure the bitcoind server is running and that you are connecting to the correct RPC port.", host, port, responseErrorMessage));
    } else if (response.status == HTTP_UNAUTHORIZED) {
        if (failedToGetAuthCookie) {
            throw std::runtime_error(strprintf(
                "Could not locate RPC credentials. No authentication cookie could be found, and RPC password is not set.  See -rpcpassword and -stdinrpcpass.  Configuration file: (%s)",
                GetConfigFile(gArgs.GetArg("-conf", BITCOIN_CONF_FILENAME)).string().c_str()));
        } else {
            throw std::runtime_error("Authorization failed: Incorrect rpcuser or rpcpassword");
        }
    } else if (response.status >= 400 && response.status != HTTP_BAD_REQUEST && response.status != HTTP_NOT_FOUND && response.status != HTTP_INTERNAL_SERVER_ERROR)
        throw std::runtime_error(strprintf("server returned HTTP error %d", response.status));
    else if (response.body.empty())
        throw std::runtime_error("no response from server");

    // Parse reply
    UniValue valReply(UniValue::VSTR);
    if (!valReply.read(response.body))
        throw std::runtime_error("couldn't parse reply from server");
    const UniValue reply = rh->ProcessReply(valReply);
    if (reply.empty())
        throw std::runtime_error("expected reply to have result, error and id properties");

    return reply;
}