CCats/gui/src/climanager.cpp

#include <QDebug>
#include <QGuiApplication>

#include <chrono>
#include <csignal>
#include <cstdio>
#include <cstdlib>
#include <iostream>
#include <poll.h>
#include <string>
#include <sys/prctl.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <thread>
#include <unistd.h>

#include <iostream>
#include <json/json.h>

#include "../include/climanager.h"
#include "../include/jsonhandler.h"

using namespace std;

thread readPipeLoopThread;
thread notificationsLoopThread;
thread statusLoopThread;

namespace CliManager {

QMLHandler *qmlHandler;
bool programActive = true;
int inpipefd[2];
int outpipefd[2];

char buf[1025];
pid_t childpid;

} // namespace CliManager

void CliManager::writeToCli(QString command) {
	command += "\n";
	write(outpipefd[1], command.toUtf8().constData(), strlen(command.toUtf8().constData()));
}

void CliManager::onExit() {
	// stop threads
	CliManager::setProgramActive(false);
	readPipeLoopThread.join();
	notificationsLoopThread.join();
	statusLoopThread.join();

	writeToCli("exit");
}

void CliManager::setQmlHandler(QMLHandler *q) { qmlHandler = q; }

void CliManager::init() {
	pipe(inpipefd);
	pipe(outpipefd);

	childpid = fork();
	if (childpid == 0) {
		// Child
		dup2(outpipefd[0], STDIN_FILENO);
		dup2(inpipefd[1], STDOUT_FILENO);
		// dup2(inpipefd[1], STDERR_FILENO);

		// ask kernel to deliver SIGTERM in case the parent dies
		prctl(PR_SET_PDEATHSIG, SIGTERM);

		execl(Config::getValue("CLI-Path").c_str(), "ccats-cli", "--machine", (char *)NULL);

		exit(1);
	}

	close(outpipefd[0]);
	close(inpipefd[1]);

	// start threads
	readPipeLoopThread = thread(&CliManager::readPipeLoop);
	notificationsLoopThread = thread(&CliManager::notificationsLoop);
	statusLoopThread = thread(&CliManager::statusLoop);
}

std::vector<std::string> tokenizeByNewlines(std::string in) {
	vector<string> res;
	size_t index;
	for (index = in.find("\n"); index != std::string::npos; index = in.find("\n")) {
		if (index != 0)
			res.push_back(in.substr(0, index));
		in = in.substr(index + 1);
	}
	if (in.length() > 0)
		res.push_back(in);
	return res;
}

void CliManager::readPipeLoop() {
	unsigned int readOffset = 0;
	unsigned int pollCount = 0;
	struct pollfd inPipeStatus;
	inPipeStatus.fd = inpipefd[0];
	inPipeStatus.events = POLLIN;
	vector<string> inputs;
	string pipeInput;

	while (programActive) {
		inputs = vector<string>();
		poll(&inPipeStatus, 1, 100);

		if (inPipeStatus.revents & POLLIN) {
			readOffset += read(inpipefd[0], buf + readOffset, 1);
			pollCount = 0;

		} else {
			pollCount++;
		}

		if (pollCount > 4 && (readOffset || pipeInput.size())) {
			pipeInput.append(buf);
			inputs = tokenizeByNewlines(pipeInput);
			for (string s : inputs) {
				emit qmlHandler->log(QString::fromStdString(s));
				qInfo() << QString::fromStdString(s);
				// handleJSON(s);
				JsonHandler::parseJSON(s);
			}
			pipeInput = string();
			memset(buf, 0, 1025);
			pollCount = 0;
			readOffset = 0;
			if (waitpid(childpid, NULL, WNOHANG)) {
				// nonzero means error or childid has changed state
				// for us that means child has exited -> CLI is dead
				break;
			}
		}

		if (readOffset >= 1024) {
			pipeInput.append(buf);
			inputs = tokenizeByNewlines(pipeInput);
			for (unsigned i = 0; i < inputs.size() - 1; i++) { // process all lines except the last, potentially incomplete one
				// do not log these lines, Qt/Quick has no simple way of limiting the number of lines in the logging window so we might go OoM real quick
				//~ emit qmlHandler->log(QString::fromStdString(inputs[i]));
				qInfo() << QString::fromStdString(inputs[i]);
				// handleJSON(s);
				JsonHandler::parseJSON(inputs[i]);
			}
			if (pipeInput.back() == '\n') { // process last line if it was complete
				qInfo() << QString::fromStdString(inputs.back());
				// handleJSON(s);
				JsonHandler::parseJSON(inputs.back());
				pipeInput = string();
			} else {
				pipeInput = inputs[inputs.size() - 1]; // set last, potentially incomplete line, as current buffer
			}
			readOffset = 0;
			pollCount = 0;
			memset(buf, 0, 1025);
		}
	}
}

void CliManager::notificationsLoop() {
	while (programActive) {
		std::this_thread::sleep_for(std::chrono::milliseconds(3000));
		writeToCli("notifications");
		writeToCli("extendedlist");
	}
}

void CliManager::statusLoop() {
	while (programActive) {
		std::this_thread::sleep_for(std::chrono::seconds(1));
		writeToCli("status");
		writeToCli("extendedstatus");
	}
}

void CliManager::setProgramActive(bool active) { programActive = active; }