main.cpp File Reference

Main entry point and implementation of the playd class. More...

#include <algorithm>
#include <cstdint>
#include <iostream>
#include <tuple>
#include "io.hpp"
#include "response.hpp"
#include "player.hpp"
#include "messages.h"

Include dependency graph for main.cpp:

Go to the source code of this file.

Functions
std::vector< std::string >	MakeArgVector (int argc, char *argv[])
	Creates a vector of strings from a C-style argument vector. More...
int	GetDeviceID (const std::vector< std::string > &args)
	Tries to get the output device ID from program arguments. More...
void	ExitWithUsage (const std::string &progname)
	Reports usage information and exits. More...
std::pair< std::string, std::string >	GetHostAndPort (const std::vector< std::string > &args)
	Gets the host and port from the program arguments. More...
void	ExitWithNetError (const std::string &host, const std::string &port, const std::string &msg)
	Exits with an error message for a network error. More...
void	ExitWithError (const std::string &msg)
	Exits with an error message for an unhandled exception. More...
int	main (int argc, char *argv[])
	The main entry point. More...

Detailed Description

Main entry point and implementation of the playd class.

See also

main.cpp

Definition in file main.cpp.

Function Documentation

ExitWithError()

void ExitWithError

(

const std::string &

msg

)

Exits with an error message for an unhandled exception.

Parameters

msg	The exception's error message.

Definition at line 138 of file main.cpp.

Referenced by main().

{
    std::cerr << "Unhandled exception in main loop: " << msg << std::endl;
    exit(EXIT_FAILURE);
}

ExitWithNetError()

void ExitWithNetError	(	const std::string &	host,
		const std::string &	port,
		const std::string &	msg
	)

Exits with an error message for a network error.

Parameters

host	The IP host to which playd tried to bind.
port	The TCP port to which playd tried to bind.
msg	The exception's error message.

Definition at line 126 of file main.cpp.

Referenced by main().

{
    std::cerr << "Network error: " << msg << "\n";
    std::cerr << "Is " << host << ":" << port << " available?\n";
    exit(EXIT_FAILURE);
}

ExitWithUsage()

void ExitWithUsage

(

const std::string &

progname

)

Reports usage information and exits.

Parameters

progname

The name of the program as executed.

Definition at line 88 of file main.cpp.

References SdlAudioSink::GetDevicesInfo().

Referenced by main().

{
    std::cerr << "usage: " << progname << " ID [HOST] [PORT]\n";
    std::cerr << "where ID is one of the following numbers:\n";

    // Show the user the valid device IDs they can use.
    auto device_list = SdlAudioSink::GetDevicesInfo();
    for (const auto &device : device_list) {
        std::cerr << "\t" << device.first << ": " << device.second
                  << "\n";
    }

    std::cerr << "default HOST: " << DEFAULT_HOST << "\n";
    std::cerr << "default PORT: " << DEFAULT_PORT << "\n";

    exit(EXIT_FAILURE);
}

GetDeviceID()

int GetDeviceID

(

const std::vector< std::string > &

args

)

Tries to get the output device ID from program arguments.

Parameters

args	The program argument vector.

Returns

The device ID, -1 if invalid selection (or none).

Definition at line 64 of file main.cpp.

References SdlAudioSink::IsOutputDevice().

Referenced by main().

{
    // Did the user provide an ID at all?
    if (args.size() < 2) return -1;

    // Only accept valid numbers (stoi will throw for invalid ones).
    int id;
    try {
        id = std::stoi(args.at(1));
    } catch (...) {
        // Only std::{invalid_argument,out_of_range} are thrown here.
        return -1;
    }

    // Only allow valid, outputtable devices; reject input-only devices.
    if (!SdlAudioSink::IsOutputDevice(id)) return -1;

    return id;
}

GetHostAndPort()

std::pair<std::string, std::string> GetHostAndPort

(

const std::vector< std::string > &

args

)

Gets the host and port from the program arguments.

The default arguments are used if the host and/or port are not supplied.

Parameters

args	The program argument vector.

Returns

A pair of strings representing the hostname and port.

Definition at line 112 of file main.cpp.

Referenced by main().

{
    auto size = args.size();
    return std::make_pair(size > 2 ? args.at(2) : DEFAULT_HOST,
                          size > 3 ? args.at(3) : DEFAULT_PORT);
}

main()

int main	(	int	argc,
		char *	argv[]
	)

The main entry point.

Parameters

argc	Program argument count.
argv	Program argument vector.

Returns

The exit code (zero for success; non-zero otherwise).

Definition at line 150 of file main.cpp.

References SdlAudioSink::CleanupLibrary(), ExitWithError(), ExitWithNetError(), ExitWithUsage(), GetDeviceID(), GetHostAndPort(), SdlAudioSink::InitLibrary(), MakeArgVector(), Error::Message(), and IoCore::Run().

{
#ifndef _MSC_VER
    // If we don't ignore SIGPIPE, certain classes of connection droppage
    // will crash our program with it.
    // TODO(CaptainHayashi): a more rigorous ifndef here.
    signal(SIGPIPE, SIG_IGN);
#endif

    // SDL requires some cleanup and teardown.
    // This call needs to happen before GetDeviceID, otherwise no device
    // IDs will be recognised.  (This is why it's here, and not in
    // SetupAudioSystem.)
    SdlAudioSink::InitLibrary();
    atexit(SdlAudioSink::CleanupLibrary);

#ifdef WITH_MP3
    // mpg123 insists on us running its init and exit functions, too.
    mpg123_init();
    atexit(mpg123_exit);
#endif // WITH_MP3

    auto args = MakeArgVector(argc, argv);

    auto device_id = GetDeviceID(args);
    if (device_id < 0) ExitWithUsage(args.at(0));

    Player player(device_id,
                  &std::make_unique<SdlAudioSink, const AudioSource &, int>,
                  SOURCES);

    // Set up the IO now (to avoid a circular dependency).
    // Make sure the player broadcasts its responses back to the IoCore.
    IoCore io(player);
    player.SetIo(io);

    // Now, actually run the IO loop.
    std::string host;
    std::string port;
    std::tie(host, port) = GetHostAndPort(args);
    try {
        io.Run(host, port);
    } catch (NetError &e) {
        ExitWithNetError(host, port, e.Message());
    } catch (Error &e) {
        ExitWithError(e.Message());
    }

    return EXIT_SUCCESS;
}

MakeArgVector()

std::vector<std::string> MakeArgVector	(	int	argc,
		char *	argv[]
	)

Creates a vector of strings from a C-style argument vector.

Parameters

argc	Program argument count.
argv	Program argument vector.

Returns

The argument vector, as a C++ string vector.

Definition at line 52 of file main.cpp.

Referenced by main().

{
    std::vector<std::string> args;
    for (int i = 0; i < argc; i++) args.emplace_back(argv[i]);
    return args;
}