1
0
Fork 0
flightgear/src/Network/generic.cxx

299 lines
8.2 KiB
C++

// generic.cxx -- generic protocal class
//
// Written by Curtis Olson, started November 1999.
//
// Copyright (C) 1999 Curtis L. Olson - http://www.flightgear.org/~curt
//
// 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.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
//
// $Id$
#include <string.h> // strstr()
#include <stdlib.h> // strtod(), atoi()
#include <simgear/debug/logstream.hxx>
#include <simgear/io/iochannel.hxx>
#include <simgear/structure/exception.hxx>
#include <simgear/misc/sg_path.hxx>
#include <simgear/props/props.hxx>
#include <simgear/props/props_io.hxx>
#include <Main/globals.hxx>
#include <Main/fg_props.hxx>
#include "generic.hxx"
FGGeneric::FGGeneric(string& config) {
string file = config+".xml";
SGPath path( globals->get_fg_root() );
path.append("Protocol");
path.append(file.c_str());
SG_LOG(SG_GENERAL, SG_INFO, "Reading communication protocol from "
<< path.str());
SGPropertyNode root;
try {
readProperties(path.str(), &root);
} catch (const sg_exception &e) {
SG_LOG(SG_GENERAL, SG_ALERT,
"Unable to load the protocol configuration file");
return;
}
_out_message.clear();
SGPropertyNode *output = root.getNode("generic/output");
if (output)
read_config(output, _out_message);
_in_message.clear();
SGPropertyNode *input = root.getNode("generic/input");
if (input)
read_config(input, _in_message);
}
FGGeneric::~FGGeneric() {
_out_message.clear();
_in_message.clear();
}
// generate the message
bool FGGeneric::gen_message() {
string generic_sentence;
char tmp[255];
double val;
for (unsigned int i = 0; i < _out_message.size(); i++) {
if (i > 0)
generic_sentence += var_separator;
switch (_out_message[i].type) {
case FG_INT:
val = _out_message[i].offset +
_out_message[i].prop->getIntValue() * _out_message[i].factor;
snprintf(tmp, 255, _out_message[i].format.c_str(), (int)val);
break;
case FG_BOOL:
snprintf(tmp, 255, _out_message[i].format.c_str(),
_out_message[i].prop->getBoolValue());
break;
case FG_DOUBLE:
val = _out_message[i].offset +
_out_message[i].prop->getFloatValue() * _out_message[i].factor;
snprintf(tmp, 255, _out_message[i].format.c_str(), (float)val);
break;
default: // SG_STRING
snprintf(tmp, 255, _out_message[i].format.c_str(),
_out_message[i].prop->getStringValue());
}
generic_sentence += tmp;
}
/* After each lot of variables has been added, put the line separator
* char/string
*/
generic_sentence += line_separator;
length = generic_sentence.length();
strncpy( buf, generic_sentence.c_str(), length );
return true;
}
bool FGGeneric::parse_message() {
char *p2, *p1 = buf;
double val;
int i = -1;
while ((++i < _in_message.size()) &&
p1 && strcmp(p1, line_separator.c_str())) {
p2 = strstr(p1, var_separator.c_str());
if (p2) {
*p2 = 0;
p2 += var_separator.length();
}
switch (_in_message[i].type) {
case FG_INT:
val = _in_message[i].offset + atoi(p1) * _in_message[i].factor;
_in_message[i].prop->setIntValue((int)val);
break;
case FG_BOOL:
_in_message[i].prop->setBoolValue( atof(p1) != 0.0 );
break;
case FG_DOUBLE:
val = _in_message[i].offset + strtod(p1, 0) * _in_message[i].factor;
_in_message[i].prop->setFloatValue((float)val);
break;
default: // SG_STRING
_in_message[i].prop->setStringValue(p1);
}
p1 = p2;
}
return true;
}
// open hailing frequencies
bool FGGeneric::open() {
if ( is_enabled() ) {
SG_LOG( SG_IO, SG_ALERT, "This shouldn't happen, but the channel "
<< "is already in use, ignoring" );
return false;
}
SGIOChannel *io = get_io_channel();
if ( ! io->open( get_direction() ) ) {
SG_LOG( SG_IO, SG_ALERT, "Error opening channel communication layer." );
return false;
}
set_enabled( true );
return true;
}
// process work for this port
bool FGGeneric::process() {
SGIOChannel *io = get_io_channel();
if ( get_direction() == SG_IO_OUT ) {
gen_message();
if ( ! io->write( buf, length ) ) {
SG_LOG( SG_IO, SG_WARN, "Error writing data." );
return false;
}
} else if ( get_direction() == SG_IO_IN ) {
if ( (length = io->readline( buf, FG_MAX_MSG_SIZE )) > 0 ) {
parse_message();
} else {
SG_LOG( SG_IO, SG_ALERT, "Error reading data." );
return false;
}
}
return true;
}
// close the channel
bool FGGeneric::close() {
SGIOChannel *io = get_io_channel();
set_enabled( false );
if ( ! io->close() ) {
return false;
}
return true;
}
void
FGGeneric::read_config(SGPropertyNode *root, vector<_serial_prot> &msg)
{
/* These variables specified in the $FG_ROOT/data/Protocol/xxx.xml
* file for each format
*
* var_sep_string = the string/charachter to place between variables
* line_sep_string = the string/charachter to place at the end of each
* lot of variables
*/
var_sep_string = root->getStringValue("var_separator");
line_sep_string = root->getStringValue("line_separator");
if ( var_sep_string == "newline" )
var_separator = '\n';
else if ( var_sep_string == "tab" )
var_separator = '\t';
else if ( var_sep_string == "space" )
var_separator = ' ';
else if ( var_sep_string == "formfeed" )
var_separator = '\f';
else if ( var_sep_string == "carriagereturn" )
var_sep_string = '\r';
else if ( var_sep_string == "verticaltab" )
var_separator = '\v';
else
var_separator = var_sep_string;
if ( line_sep_string == "newline" )
line_separator = '\n';
else if ( line_sep_string == "tab" )
line_separator = '\t';
else if ( line_sep_string == "space" )
line_separator = ' ';
else if ( line_sep_string == "formfeed" )
line_separator = '\f';
else if ( line_sep_string == "carriagereturn" )
line_separator = '\r';
else if ( line_sep_string == "verticaltab" )
line_separator = '\v';
else
line_separator = line_sep_string;
vector<SGPropertyNode_ptr> chunks = root->getChildren("chunk");
for (unsigned int i = 0; i < chunks.size(); i++) {
_serial_prot chunk;
// chunk.name = chunks[i]->getStringValue("name");
chunk.format = chunks[i]->getStringValue("format", "%d");
chunk.offset = chunks[i]->getDoubleValue("offset");
chunk.factor = chunks[i]->getDoubleValue("factor", 1.0);
string node = chunks[i]->getStringValue("node");
chunk.prop = fgGetNode(node.c_str(), true);
string type = chunks[i]->getStringValue("type");
if (type == "bool")
chunk.type = FG_BOOL;
else if (type == "float")
chunk.type = FG_DOUBLE;
else if (type == "string")
chunk.type = FG_STRING;
else
chunk.type = FG_INT;
msg.push_back(chunk);
}
}