fly/flightgear
1
0
Fork 0
Code Activity
flightgear/src/Network/generic.cxx
mfranz 306b818490 generic/output: 
- support optional <preamble> and <postamble> which are written right
  after opening and before closing respectively. This can be used for a header
  line or an XML header.
- unescape <preamble>, <postamble>, <format>, <line_separator>, <var_separator>
  so that \t, \n, \r, \f, \v, \xnn, \nnn can be used directly (\a and \b are
  ignored; use \\ for the backslash) The long names ("carriagereturn") are still
  supported for <var_separator>, but one can just use \r, or \r\n too.
- don't abort when a chunk doesn't have a <node>. This is useful for adding
  constant chunks which consist only of a <format>, such as XML tags.
2007-07-29 13:58:58 +00:00

387 lines
12 KiB
C++
Raw Blame History

// 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
//
// $Id$
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#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/misc/stdint.hxx>
#include <simgear/props/props.hxx>
#include <simgear/props/props_io.hxx>
#include <Main/globals.hxx>
#include <Main/fg_props.hxx>
#include <Main/util.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;
}
SGPropertyNode *output = root.getNode("generic/output");
if (output)
read_config(output, _out_message);
SGPropertyNode *input = root.getNode("generic/input");
if (input)
read_config(input, _in_message);
}
FGGeneric::~FGGeneric() {
}
// generate the message
bool FGGeneric::gen_message() {
string generic_sentence;
char tmp[255];
length = 0;
double val;
for (unsigned int i = 0; i < _out_message.size(); i++) {
if (i > 0 && !binary_mode)
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;
if (binary_mode) {
*((int32_t*)&buf[length]) = (int32_t)val;
length += sizeof(int32_t);
} else {
snprintf(tmp, 255, _out_message[i].format.c_str(), (int)val);
}
break;
case FG_BOOL:
if (binary_mode) {
*((int8_t*)&buf[length])
= _out_message[i].prop->getBoolValue() ? true : false;
length += sizeof(int8_t);
} else {
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;
if (binary_mode) {
*((double*)&buf[length]) = val;
length += sizeof(double);
} else {
snprintf(tmp, 255, _out_message[i].format.c_str(), (float)val);
}
break;
default: // SG_STRING
if (binary_mode) {
const char *strdata = _out_message[i].prop->getStringValue();
int strlength = strlen(strdata);
/* Format for strings is
* [length as int, 4 bytes][ASCII data, length bytes]
*/
*((int32_t*)&buf[length]) = strlength;
length += sizeof(int32_t);
strncpy(&buf[length], strdata, strlength);
length += strlength;
/* FIXME padding for alignment? Something like:
* length += (strlength % 4 > 0 ? sizeof(int32_t) - strlength % 4 : 0;
*/
} else {
snprintf(tmp, 255, _out_message[i].format.c_str(),
_out_message[i].prop->getStringValue());
}
}
if (!binary_mode) {
generic_sentence += tmp;
}
}
if (!binary_mode) {
/* 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 );
} else {
// add the footer to the packet ("line")
switch (binary_footer_type) {
case FOOTER_LENGTH:
binary_footer_value = length;
break;
case FOOTER_MAGIC:
break;
}
if (binary_footer_type != FOOTER_NONE) {
*((int32_t*)&buf[length]) = binary_footer_value;
length += sizeof(int32_t);
}
}
return true;
}
bool FGGeneric::parse_message() {
char *p2, *p1 = buf;
double val;
int i = -1;
if (binary_mode)
SG_LOG( SG_IO, SG_ALERT,
"generic protocol: binary mode input is not yet implemented.");
while ((++i < (int)_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 );
if ( get_direction() == SG_IO_OUT && ! preamble.empty() ) {
if ( ! io->write( preamble.c_str(), preamble.size() ) ) {
SG_LOG( SG_IO, SG_WARN, "Error writing preamble." );
return false;
}
}
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();
if ( get_direction() == SG_IO_OUT && ! postamble.empty() ) {
if ( ! io->write( postamble.c_str(), postamble.size() ) ) {
SG_LOG( SG_IO, SG_ALERT, "Error writing postamble." );
return false;
}
}
set_enabled( false );
if ( ! io->close() ) {
return false;
}
return true;
}
void
FGGeneric::read_config(SGPropertyNode *root, vector<_serial_prot> &msg)
{
binary_mode = root->getBoolValue("binary_mode");
if (!binary_mode) {
/* 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
*/
preamble = fgUnescape(root->getStringValue("preamble"));
postamble = fgUnescape(root->getStringValue("postamble"));
var_sep_string = fgUnescape(root->getStringValue("var_separator"));
line_sep_string = fgUnescape(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;
} else {
binary_footer_type = FOOTER_NONE; // default choice
if ( root->hasValue("binary_footer") ) {
string footer_type = root->getStringValue("binary_footer");
if ( footer_type == "length" )
binary_footer_type = FOOTER_LENGTH;
else if ( footer_type.substr(0, 5) == "magic" ) {
binary_footer_type = FOOTER_MAGIC;
binary_footer_value = strtol(footer_type.substr(6,
footer_type.length() - 6).c_str(), (char**)0, 0);
} else if ( footer_type != "none" )
SG_LOG(SG_IO, SG_ALERT,
"generic protocol: Undefined generic binary protocol"
"footer, using no footer.");
}
}
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 = fgUnescape(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", "/null");
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);
}
}
View git blame Copy permalink