/**
* Relational pipes
* Copyright © 2022 František Kučera (Frantovo.cz, GlobalCode.info)
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, version 3 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
#include <memory>
#include <string>
#include <vector>
#include <iostream>
#include <sstream>
#include <locale>
#include <codecvt>
#include <unistd.h>
#include <librdkafka/rdkafkacpp.h>
#include <relpipe/common/type/typedefs.h>
#include <relpipe/reader/TypeId.h>
#include <relpipe/reader/handlers/RelationalReaderStringHandler.h>
#include <relpipe/reader/handlers/AttributeMetadata.h>
#include "Configuration.h"
#include "Hex.h"
namespace relpipe {
namespace out {
namespace kafka {
static void check(RdKafka::Conf::ConfResult result, const std::string& errString) {
if (result != RdKafka::Conf::CONF_OK) {
throw std::logic_error("Unable to configure Kafka: " + errString);
}
}
static void check(RdKafka::ErrorCode result, const std::string& errString) {
if (result != RdKafka::ERR_NO_ERROR) {
throw std::logic_error("Kafka error: " + errString);
}
}
static void check(std::shared_ptr<RdKafka::Producer> kafkaProducer, const std::string& errString) {
if (kafkaProducer.get() == nullptr) {
throw std::logic_error("Unable to create Kafka producer: " + errString);
}
}
class KafkaHandler : public relpipe::reader::handlers::RelationalReaderStringHandler {
private:
std::wstring_convert<codecvt_utf8<wchar_t>> convertor; // TODO: support also other encodings.
Configuration configuration;
std::shared_ptr<RdKafka::Producer> kafkaProducer;
struct CurrentRelation {
relpipe::common::type::StringX name;
std::vector<relpipe::reader::handlers::AttributeMetadata> attributes;
relpipe::common::type::Integer attributeIndex = 0;
std::string currentValue;
} currentRelation;
void connect() {
if (!kafkaProducer) {
std::string errString;
std::shared_ptr<RdKafka::Conf> producerConf(RdKafka::Conf::create(RdKafka::Conf::ConfType::CONF_GLOBAL));
// TODO: configurable groupId, clientId and other parameters
std::string groupId = "relpipe-in-kafka-group-" + std::to_string(getpid());
std::string clientId = "relpipe-in-kafka-client-" + std::to_string(getpid());
check(producerConf->set("client.id", clientId, errString), errString);
check(producerConf->set("group.id", groupId, errString), errString);
check(producerConf->set("bootstrap.servers", "plaintext://127.0.0.1:9092", errString), errString); // "host1:9092,host2:9092" "192.168.1.56:9092"
//check(consumerConf->set("debug", "all", errString), errString);
kafkaProducer.reset(RdKafka::Producer::create(producerConf.get(), errString));
check(kafkaProducer, errString);
}
}
void sendMessage(const std::string& payload) {
std::string errString;
check(kafkaProducer->produce(
convertor.to_bytes(configuration.queue),
RdKafka::Topic::PARTITION_UA,
RdKafka::Producer::RK_MSG_COPY,
const_cast<char *> (payload.c_str()), payload.size(),
nullptr, 0,
0,
nullptr), errString);
}
public:
KafkaHandler(Configuration configuration) : configuration(configuration) {
}
void startRelation(relpipe::common::type::StringX name, std::vector<relpipe::reader::handlers::AttributeMetadata> attributes) override {
currentRelation = CurrentRelation{name, attributes};
connect();
}
void attribute(const relpipe::common::type::StringX& value) override {
auto attributeName = currentRelation.attributes[currentRelation.attributeIndex].getAttributeName();
if (attributeName == L"text") currentRelation.currentValue = convertor.to_bytes(value);
else if (attributeName == L"data") currentRelation.currentValue = Hex::fromHex(value).str();
currentRelation.attributeIndex++;
if (currentRelation.attributeIndex == currentRelation.attributes.size()) {
currentRelation.attributeIndex = 0;
sendMessage(currentRelation.currentValue);
}
}
void endOfPipe() {
std::string errString;
check(kafkaProducer->flush(60000), errString);
}
};
}
}
}