ref: 668d03699c8fd729c728fc2e7a6b8e21e7a815d1
dir: /src/i_midipipe.c/
//
// Copyright(C) 2013 James Haley et al.
// Copyright(C) 2017 Alex Mayfield
//
// 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; either version 2
// of the License, or (at your option) any later version.
//
// 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.
//
// DESCRIPTION:
// Client Interface to RPC Midi Server
//
#if _WIN32
#include <stdlib.h>
#include <sys/stat.h>
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include "i_midipipe.h"
#include "config.h"
#include "i_sound.h"
#include "i_timer.h"
#include "m_misc.h"
#include "net_packet.h"
#if defined(_DEBUG)
#define DEBUGOUT(s) puts(s)
#else
#define DEBUGOUT(s)
#endif
//=============================================================================
//
// Public Data
//
// True if the midi proces was initialized at least once and has not been
// explicitly shut down. This remains true if the server is momentarily
// unreachable.
boolean midi_server_initialized;
// True if the current track is being handled via the MIDI server.
boolean midi_server_registered;
//=============================================================================
//
// Data
//
#define MIDIPIPE_MAX_WAIT 500 // Max amount of ms to wait for expected data.
static HANDLE midi_process_in_reader; // Input stream for midi process.
static HANDLE midi_process_in_writer;
static HANDLE midi_process_out_reader; // Output stream for midi process.
static HANDLE midi_process_out_writer;
//=============================================================================
//
// Private functions
//
//
// FreePipes
//
// Free all pipes in use by this module.
//
static void FreePipes()
{
if (midi_process_in_reader != NULL)
{
CloseHandle(midi_process_in_reader);
midi_process_in_reader = NULL;
}
if (midi_process_in_writer != NULL)
{
CloseHandle(midi_process_in_writer);
midi_process_in_writer = NULL;
}
if (midi_process_out_reader != NULL)
{
CloseHandle(midi_process_out_reader);
midi_process_in_reader = NULL;
}
if (midi_process_out_writer != NULL)
{
CloseHandle(midi_process_out_writer);
midi_process_out_writer = NULL;
}
}
//
// UsingNativeMidi
//
// Enumerate all music decoders and return true if NATIVEMIDI is one of them.
//
// If this is the case, using the MIDI server is probably necessary. If not,
// we're likely using Timidity and thus don't need to start the server.
//
static boolean UsingNativeMidi()
{
int decoders = Mix_GetNumMusicDecoders();
for (int i = 0;i < decoders;i++)
{
if (strcmp(Mix_GetMusicDecoder(i), "NATIVEMIDI") == 0)
{
return true;
}
}
return false;
}
//
// WritePipe
//
// Writes packet data to the subprocess' standard in.
//
static boolean WritePipe(net_packet_t *packet)
{
BOOL ok = WriteFile(midi_process_in_writer, packet->data, packet->len,
NULL, NULL);
if (!ok)
{
return false;
}
return true;
}
//
// ExpectPipe
//
// Expect the contents of a packet off of the subprocess' stdout. If the
// response is unexpected, or doesn't arrive within a specific amuont of time,
// assume the subprocess is in an unknown state.
//
static boolean ExpectPipe(net_packet_t *packet)
{
BOOL ok;
CHAR pipe_buffer[8192];
DWORD pipe_buffer_read = 0;
if (packet->len > sizeof(pipe_buffer))
{
// The size of the packet we're expecting is larger than our buffer
// size, so bail out now.
return false;
}
int start = I_GetTimeMS();
do
{
// Wait until we see exactly the amount of data we expect on the pipe.
ok = PeekNamedPipe(midi_process_out_reader, NULL, 0, NULL,
&pipe_buffer_read, NULL);
if (!ok)
{
goto fail;
}
else if (pipe_buffer_read < packet->len)
{
I_Sleep(1);
continue;
}
// Read precisely the number of bytes we're expecting, and no more.
ok = ReadFile(midi_process_out_reader, pipe_buffer, packet->len,
&pipe_buffer_read, NULL);
if (!ok || pipe_buffer_read != packet->len)
{
goto fail;
}
// Compare our data buffer to the packet.
if (memcmp(packet->data, pipe_buffer, packet->len) != 0)
{
goto fail;
}
return true;
// Continue looping as long as we don't exceed our maximum wait time.
} while (I_GetTimeMS() - start <= MIDIPIPE_MAX_WAIT);
fail:
// TODO: Deal with the wedged process?
return false;
}
//=============================================================================
//
// Protocol Commands
//
//
// I_MidiPipe_RegisterSong
//
// Tells the MIDI subprocess to load a specific filename for playing. This
// function blocks until there is an acknowledgement from the server.
//
boolean I_MidiPipe_RegisterSong(const char *filename)
{
boolean ok;
net_packet_t *packet;
packet = NET_NewPacket(64);
NET_WriteInt16(packet, NET_MIDIPIPE_PACKET_TYPE_REGISTER_SONG);
NET_WriteString(packet, filename);
ok = WritePipe(packet);
NET_FreePacket(packet);
if (!ok)
{
DEBUGOUT("I_MidiPipe_RegisterSong failed");
return false;
}
packet = NET_NewPacket(2);
NET_WriteInt16(packet, NET_MIDIPIPE_PACKET_TYPE_REGISTER_SONG_ACK);
ok = ExpectPipe(packet);
NET_FreePacket(packet);
if (!ok)
{
DEBUGOUT("I_MidiPipe_RegisterSong ack failed");
return false;
}
midi_server_registered = true;
DEBUGOUT("I_MidiPipe_RegisterSong succeeded");
return true;
}
//
// I_MidiPipe_SetVolume
//
// Tells the MIDI subprocess to set a specific volume for the song.
//
void I_MidiPipe_SetVolume(int vol)
{
boolean ok;
net_packet_t *packet;
packet = NET_NewPacket(6);
NET_WriteInt16(packet, NET_MIDIPIPE_PACKET_TYPE_SET_VOLUME);
NET_WriteInt32(packet, vol);
ok = WritePipe(packet);
NET_FreePacket(packet);
if (!ok)
{
DEBUGOUT("I_MidiPipe_SetVolume failed");
return;
}
DEBUGOUT("I_MidiPipe_SetVolume succeeded");
}
//
// I_MidiPipe_PlaySong
//
// Tells the MIDI subprocess to play the currently loaded song.
//
void I_MidiPipe_PlaySong(int loops)
{
boolean ok;
net_packet_t *packet;
packet = NET_NewPacket(6);
NET_WriteInt16(packet, NET_MIDIPIPE_PACKET_TYPE_PLAY_SONG);
NET_WriteInt32(packet, loops);
ok = WritePipe(packet);
NET_FreePacket(packet);
if (!ok)
{
DEBUGOUT("I_MidiPipe_PlaySong failed");
return;
}
DEBUGOUT("I_MidiPipe_PlaySong succeeded");
}
//
// I_MidiPipe_StopSong
//
// Tells the MIDI subprocess to stop playing the currently loaded song.
//
void I_MidiPipe_StopSong()
{
boolean ok;
net_packet_t *packet;
packet = NET_NewPacket(2);
NET_WriteInt16(packet, NET_MIDIPIPE_PACKET_TYPE_STOP_SONG);
ok = WritePipe(packet);
NET_FreePacket(packet);
midi_server_registered = false;
if (!ok)
{
DEBUGOUT("I_MidiPipe_StopSong failed");
return;
}
DEBUGOUT("I_MidiPipe_StopSong succeeded");
}
//
// I_MidiPipe_ShutdownServer
//
// Tells the MIDI subprocess to shutdown.
//
void I_MidiPipe_ShutdownServer()
{
boolean ok;
net_packet_t *packet;
packet = NET_NewPacket(2);
NET_WriteInt16(packet, NET_MIDIPIPE_PACKET_TYPE_SHUTDOWN);
ok = WritePipe(packet);
NET_FreePacket(packet);
FreePipes();
midi_server_initialized = false;
if (!ok)
{
DEBUGOUT("I_MidiPipe_ShutdownServer failed");
return;
}
DEBUGOUT("I_MidiPipe_ShutdownServer succeeded");
}
//=============================================================================
//
// Public Interface
//
//
// I_MidiPipeInitServer
//
// Start up the MIDI server.
//
boolean I_MidiPipe_InitServer()
{
struct stat sbuf;
char filename[MAX_PATH + 1];
char *module = NULL;
char *cmdline = NULL;
if (!UsingNativeMidi() || strlen(snd_musiccmd) > 0)
{
// If we're not using native MIDI, or if we're playing music through
// an exteranl program, we don't need to start the server.
return false;
}
memset(filename, 0, sizeof(filename));
size_t filename_len = GetModuleFileName(NULL, filename, MAX_PATH);
// Remove filespec
// TODO: Move this to m_misc?
char *fp = &filename[filename_len];
while (filename <= fp && *fp != DIR_SEPARATOR)
{
fp--;
}
*(fp + 1) = '\0';
module = M_StringJoin(filename, PROGRAM_PREFIX "midiproc.exe", NULL);
cmdline = M_StringJoin(module, " \"" PACKAGE_STRING "\"", NULL);
// Look for executable file
if(stat(module, &sbuf))
{
DEBUGOUT("Could not find midiproc");
return false;
}
// Set up pipes
SECURITY_ATTRIBUTES sec_attrs;
memset(&sec_attrs, 0, sizeof(SECURITY_ATTRIBUTES));
sec_attrs.nLength = sizeof(SECURITY_ATTRIBUTES);
sec_attrs.bInheritHandle = TRUE;
sec_attrs.lpSecurityDescriptor = NULL;
if (!CreatePipe(&midi_process_in_reader, &midi_process_in_writer, &sec_attrs, 0))
{
DEBUGOUT("Could not initialize midiproc stdin");
return false;
}
if (!SetHandleInformation(midi_process_in_writer, HANDLE_FLAG_INHERIT, 0))
{
DEBUGOUT("Could not disinherit midiproc stdin");
return false;
}
if (!CreatePipe(&midi_process_out_reader, &midi_process_out_writer, &sec_attrs, 0))
{
DEBUGOUT("Could not initialize midiproc stdout/stderr");
return false;
}
if (!SetHandleInformation(midi_process_out_reader, HANDLE_FLAG_INHERIT, 0))
{
DEBUGOUT("Could not disinherit midiproc stdin");
return false;
}
// Launch the subprocess
PROCESS_INFORMATION proc_info;
memset(&proc_info, 0, sizeof(proc_info));
STARTUPINFO startup_info;
memset(&startup_info, 0, sizeof(startup_info));
startup_info.cb = sizeof(startup_info);
startup_info.hStdInput = midi_process_in_reader;
startup_info.hStdOutput = midi_process_out_writer;
startup_info.dwFlags = STARTF_USESTDHANDLES;
BOOL ok = CreateProcess(TEXT(module), TEXT(cmdline), NULL, NULL, TRUE,
CREATE_NEW_CONSOLE, NULL, NULL, &startup_info, &proc_info);
if (!ok)
{
goto fail;
}
// Since the server has these handles, we don't need them anymore.
CloseHandle(midi_process_in_reader);
midi_process_in_reader = NULL;
CloseHandle(midi_process_out_writer);
midi_process_out_writer = NULL;
midi_server_initialized = true;
return true;
fail:
FreePipes();
free(cmdline);
free(module);
return false;
}
#endif