Repository: bitcoin/bitcoin
File: src/httprpc.cpp (C++)

Code before:
                        }
                    }
                }
            }

            // Execute each request
            reply = UniValue{UniValue::VARR};
            bool all_notifications = true;
            for (unsigned int reqIdx = 0; reqIdx < valRequest.size(); reqIdx++) {
                // Batches never throw HTTP errors, they are always just included
                // in "HTTP OK" responses. Notifications never get any response.
                UniValue response;
                try {
                    jreq.parse(valRequest[reqIdx]);
                    response = JSONRPCExec(jreq);
                } catch (const UniValue& objError) {
                    response = JSONRPCReplyObj(NullUniValue, objError, jreq.id, jreq.m_json_version);
                } catch (const std::exception& e) {
                    response = JSONRPCReplyObj(NullUniValue, JSONRPCError(RPC_PARSE_ERROR, e.what()), jreq.id, jreq.m_json_version);
                }
                if (!jreq.IsNotification()) {
                    reply.push_back(std::move(response));
                    all_notifications = false;
                }
            }
            // All-notification batch expects no response
            if (all_notifications && valRequest.size() > 0) {
                req->WriteReply(HTTP_NO_CONTENT);
                return true;
            }
        }
        else
            throw JSONRPCError(RPC_PARSE_ERROR, "Top-level object parse error");

        req->WriteHeader("Content-Type", "application/json");
        req->WriteReply(HTTP_OK, reply.write() + "\n");
    } catch (const UniValue& objError) {
        JSONErrorReply(req, objError, jreq);
        return false;
    } catch (const std::exception& e) {
        JSONErrorReply(req, JSONRPCError(RPC_PARSE_ERROR, e.what()), jreq);
        return false;
    }
    return true;
}

static bool InitRPCAuthentication()
{
    if (gArgs.GetArg("-rpcpassword", "") == "")
    {
        LogPrintf("Using random cookie authentication.\n");

Review comment (suggestion):
In commit "rpc: JSON-RPC 2.0 should not respond to "notifications"" (d62dcf81e152d03aa3cf02d0eb0e7e9c44807464)

I think this needs some explanation about how valRequest.size() check is here for backward compatibility since it is surprising and violates the 2.0 spec.

Code after:
                        // Parse method
                        std::string strMethod = request.find_value("method").get_str();
                        if (!g_rpc_whitelist[jreq.authUser].count(strMethod)) {
                            LogPrintf("RPC User %s not allowed to call method %s\n", jreq.authUser, strMethod);
                            req->WriteReply(HTTP_FORBIDDEN);
                            return false;
                        }
                    }
                }
            }

            // Execute each request
            reply = UniValue::VARR;
            for (size_t i{0}; i < valRequest.size(); ++i) {
                // Batches never throw HTTP errors, they are always just included
                // in "HTTP OK" responses. Notifications never get any response.
                UniValue response;
                try {
                    jreq.parse(valRequest[i]);
                    response = JSONRPCExec(jreq, /*catch_errors=*/true);
                } catch (UniValue& e) {
                    response = JSONRPCReplyObj(NullUniValue, std::move(e), jreq.id, jreq.m_json_version);
                } catch (const std::exception& e) {
                    response = JSONRPCReplyObj(NullUniValue, JSONRPCError(RPC_PARSE_ERROR, e.what()), jreq.id, jreq.m_json_version);
                }
                if (!jreq.IsNotification()) {
                    reply.push_back(std::move(response));
                }
            }
            // Return no response for an all-notification batch, but only if the
            // batch request is non-empty. Technically according to the JSON-RPC
            // 2.0 spec, an empty batch request should also return no response,
            // However, if the batch request is empty, it means the request did
            // not contain any JSON-RPC version numbers, so returning an empty
            // response could break backwards compatibility with old RPC clients
            // relying on previous behavior. Return an empty array instead of an
            // empty response in this case to favor being backwards compatible
            // over complying with the JSON-RPC 2.0 spec in this case.
            if (reply.size() == 0 && valRequest.size() > 0) {
                req->WriteReply(HTTP_NO_CONTENT);
                return true;
            }
        }
        else
            throw JSONRPCError(RPC_PARSE_ERROR, "Top-level object parse error");

        req->WriteHeader("Content-Type", "application/json");
        req->WriteReply(HTTP_OK, reply.write() + "\n");
    } catch (UniValue& e) {
        JSONErrorReply(req, std::move(e), jreq);
        return false;