ringbuffer.cpp

// -lstdc++ -std=c++17 -lpthread
// https://forums.mageia.org/en/viewtopic.php?f=5&t=13294

#include <iostream>
#include <iterator>
#include <list>
#include <sstream>

// https://github.com/yhirose/cpp-httplib
#include "httplib.h"

/* max 100 thousand lines */
#define MAX_LINES 100000
#define HOST "127.0.0.1"
#define PORT 12345

using namespace std;
using namespace httplib;

int main()
{
	list<string> lst;
	Server srv;
	mutex mut;

	srv.Get("/", [&lst, &mut](const Request& req, Response& res) {
		// copy strings into another area
		mut.lock();
		list<string> lstCopy(lst);
		mut.unlock();
		stringstream ss;
		auto row = lstCopy.begin();
		while(row != lstCopy.end())
		{
			ss << *row << endl;
			row = next(row, 1);
		}
		// Send strings to client
		res.set_content(ss.str(), "text/plain");
	});

	thread tsrv([&srv](){ srv.listen(HOST, PORT); });

	while(true)
	{
		string line;
		getline(cin, line);
		mut.lock();
		lst.push_back(line);
		while(lst.size() > MAX_LINES) {
			lst.pop_front();
		}
		mut.unlock();
	}

	return 0;
}